C peptide and insulin in diabetes mellitus: treatment and analyzes

With an increase in blood glucose, the pancreas activates proinsulin molecules, which contributes to their breakdown into insulin and the amino acid residue, which is the C-peptide.

Thus, a chain of peptides appears when insulin is produced in the body. And the higher the content of C-peptides in the blood, the more active insulin in the body.

The peptide received the name “C” because its chain is a formation in the form of this letter. Initially, the insulin chain looks like a spiral.

In diabetes mellitus or liver diseases, an analysis is made for C-peptides, because when the pancreas forms, insulin passes through the liver, and there it partially settles, getting into the blood in the wrong amount. Therefore, it is impossible to determine the exact amount of insulin produced.

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In the process of insulin synthesis, the pancreas produces its original base - preproinsulin. It consists of 110 amino acids linked into an A peptide, an L peptide, a B peptide and a C peptide.

A small portion of the L-peptide is separated from preproinsulin and proinsulin is formed, which is activated by enzymes. After this process, the C-peptide remains cut off, and chains A and B are linked together by a disulfide bridge.

It is these chains with their bridges that are the hormone insulin.

Both insulin and C-peptide are released into the blood in equal proportions, which means that by the level of the latter one can also judge the level of insulin in the blood. In addition, the C-peptide reflects the rate of insulin production.

The level of insulin and C-peptide in the blood is always different. This fact is explained by the fact that insulin “lives” in the blood for only 4 minutes, and the C-peptide for about 20 minutes. That is why the concentration of C-peptide is 5 times higher than the level of insulin.

The connecting peptide (C-peptide) is part of the peptide chain of proinsulin, upon cleavage of which insulin is formed. Insulin and C-peptide are the end products of the transformation of proinsulin in β-cells of pancreatic islets (pancreas) as a result of exposure to endoleptidase. In this case, insulin and C-peptide are released into the bloodstream in equimolar amounts.

The half-life in plasma of the C-peptide is longer than that of insulin: in the C-peptide - 20 minutes, in insulin - 4 minutes. It is because of this that the C-peptide is present in the blood about 5 times as much as insulin, and therefore the C-peptide / insulin ratio is 5: 1.

This suggests the conclusion that the C-peptide is a more stable marker compared to insulin. From the circulation system, insulin is removed by the liver, and the C-peptide by the kidneys.

Detection of the concentration of C-peptide in the blood makes it possible to characterize the residual synthetic function of β-cells (after stimulation with glucagon or tolbutamide), in particular in patients treated with heterogeneous insulin.

In practical medicine, the detection of C-peptide is used to determine the causative factor of hypoglycemia. For example, in patients with insulinoma, a significant increase in the concentration of C-peptide in the blood is detected.

To confirm the diagnosis, a test of suppression of the genesis of C-peptide is carried out. In the morning, blood is taken from the patient to detect the C-peptide, after which insulin is infused intravenously for one hour at a rate of 0.1 U / kg and the blood is taken again for analysis.

If the level of C-peptide after insulin infusion drops by less than 50%, one can definitely determine the presence of an insulin-secreting tumor in the patient. Analysis of the C-peptide allows you to evaluate the secretion of insulin against the background of the use of exogenous insulin, in the presence of autoantibodies to insulin.

The C-peptide, in contrast to insulin, does not form a cross-link with insulin antibodies (AT), which makes it possible to determine the level of endogenous insulin in patients with diabetes by its level. Knowing that insulin medications do not contain a C-peptide, by its level in blood serum it is possible to evaluate the function of pancreatic β-cells in patients with diabetes who are on insulin treatment.

Blood test for C-peptides in diabetes

Different variants of C-peptide assays play an important role in the diagnosis of serious and serious diseases. The mechanisms for their conduct and proper preparation are also important for obtaining correct and objective results, with the help of which adequate therapy can be prescribed.

C-peptide: what is it?

To determine the level of glucose in the blood of a patient, venous blood is used. The fence occurs before and after, i.e. after 2 hours, when a person received a glucose load. However, it is also important to distinguish between insulin-dependent and non-insulin-dependent diabetes, and for these purposes studies are carried out on C-peptides.

The C-peptide itself is not very biologically active, its norm is low, but its indicator is the rate of insulin production. Indeed, with various jumps in glucose, the process of proinsulin breakdown into insulin and the same C-peptide occurs. The process of synthesis of this substance occurs in pancreatic cells.

Indications for the appointment of a blood test for C-peptide

The C-peptide, in contrast to insulin, does not form a cross-link with insulin antibodies (AT), which makes it possible to determine the level of endogenous insulin in patients with diabetes by its level. Knowing that insulin medications do not contain a C-peptide, the function of pancreatic β-cells in patients with diabetes mellitus can be evaluated by its level in blood serum. being treated with insulin.

C-peptide means “connecting peptide”, translated from English. This is an indicator of the secretion of your own insulin. It shows the level of pancreatic beta cells.

Beta cells produce insulin in the pancreas, where it is stored as proinsulin in the form of molecules. In these molecules, as an amino acid residue, a fragment is located that is called a C-peptide.

With an increase in glucose, proinsulin molecules break down into peptide and insulin. Such a combination ejected in the blood always correlates with each other. Thus, the norm is 5: 1.

It is the analysis of C-peptide that allows us to understand that the secretion (production) of insulin is reduced, and also to determine the possibility of the appearance of insulinoma, that is, a pancreatic tumor.

An increased level of a substance is observed with:

  • insulin-dependent diabetes mellitus,
  • renal failure
  • the use of hormonal drugs,
  • insulinoma
  • beta cell hypertrophy.

A reduced level of c-peptide is characteristic for:

  1. insulin-dependent diabetes mellitus in hypoglycemic conditions,
  2. stressful conditions.

What is research necessary for?

Such an analysis is prescribed in cases:

  • suspected diabetes of various types,
  • suspected pancreatic cancer,
  • determining the presence / absence of various liver lesions,
  • suspected polycystic ovary in women,
  • analysis of the presence / absence of preserved intact parts of the pancreas after operations,
  • analysis of the state of the body in young people who have problems with the norm of weight.

Laboratory studies specifically on the C-peptide have important bases:

  • firstly, such an analysis allows you to objectively assess the level of insulin in the blood, even when autoimmune antibodies are present in the body, which happens with type I diabetes,
  • secondly, the half-life of this substance is longer than that of insulin, which is why such indicators will be more persistent,
  • thirdly, this analysis helps to determine the insulin formation even in the presence of synthetic hormone.

This analysis is carried out after agreement with the endocrinologist if there is a suspicion of the presence of metabolic diseases. As a rule, blood sampling is carried out on an empty stomach. It is best if a person did not eat any food for 6-8 hours before analysis. Many experts recommend it in the morning, after the person woke up.

After piercing a vein, the required amount of blood is collected in a special bowl. In the case of hematomas after the technical part of the analysis, warming compresses are prescribed.

Blood is passed through a centrifuge so that the serum separates, and then it is frozen. After this, the study process begins with the use of special reagents.

Analysis Features

C-peptide analysis is the determination of the quantitative degree of the protein part of proinsulin in blood serum using the immunochemiluminescent method.

Test material: serum (tested on an empty stomach in the morning (between 10-12 hours)). Before starting the examination, the patient, if possible, is recommended to drink 200-300 ml of water. It is checked 2 times a month. Normal values: in men and women: from 5.74 to 60.3 nmol / l (in serum). Reference Values:

  • serum or plasma: 1.1-4.4 ng / ml (average 1.96 ng / ml), 0.37-1.47 nmol / L (average 0.65 nmol / L),
  • in urine after 24 hours: 17.2-181 mg / 24 h (average, 54.8 mcg / 24 hours), 5.74-60.3 nmol / 24 h (average 18.3 nmol / 24 h) .

Insulin and C-peptide are members of a large family of regulatory proteins. C-peptide is important in the formation of a 2-chain insulin structure; therefore, it is an indicator of the insulin's own production in pancreatic β-cells.

It is a binding protein in a proinsulin molecule, from which it is cleaved when proinsulin is converted to insulin. Specifically binds to the membranes of various cells, induces gene expression and affects the signaling cascade of growth factors.

In the formation of insulin resistance, an important role is played by genetic factors and environmental factors, in particular, overweight and obesity. The body seeks to overcome this tissue insensitivity by increasing insulin production by pancreatic β-cells (compensatory hyperinsulinemia - C-peptide is increased).

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Compensatory hyperinsulinemia initially overcomes the effect of tissue insensitivity to insulin and maintains normal blood sugar levels. When pancreatic β-cells cannot produce an increased amount of long-term insulin, they undergo progressive destruction.

The insulin level in blood plasma begins to decline, which leads to an increased level of glucose in the blood (hyperglycemia) and the clinical manifestation (manifestation) of type 2 diabetes mellitus.

C-peptide is investigated in several cases. The main ones are represented, in particular, by the following:

  • newly diagnosed type 1 diabetes mellitus,
  • if there is a suspicion of a decrease in insulin production by pancreatic cells in type 2 diabetics, for whom a decision is made on treatment with insulin,
  • in people with suspected diabetes mellitus type LADA (autoimmune diabetes in adulthood),
  • to determine the cause of hyperglycemia,
  • to determine acute or recurring hypoglycemia.

Reduced values ​​may indicate type 1 or 2 diabetes mellitus, LADA diabetes, or suppression of insulin production through the use of exogenous insulin. Low levels can be observed in the case of starvation, non-physiological hypoglycemia, Addison's disease, hypoinsulinism and after radical pancreatectomy.

Higher levels of C-peptide can occur at low potassium levels in the blood during pregnancy and in case of obesity.

The insulin gene is located on the short arm of the 11th chromosome. In β-cells of the pancreatic islets of Langerhans, this gene serves as a matrix for the synthesis of insulin protein.

The first step in insulin biosynthesis is the formation of preproinsulin, which, under the influence of a specific prosthesis, turns into proinsulin. It consists of the peptide chain A (residues of 21 amino acids) and B (30 amino acid residues) of future insulin.

Both chains are connected by a bridge called a C-peptide consisting of 35 amino acid residues. Proinsulin is cleaved by proteases into C-peptide and insulin.

In the cleavage phase, the C-peptide loses 4 amino acids and is secreted into the circulation as a single chain consisting of 31 amino acids.

The structure of the C-peptide was discovered in 1967, and until the new millennium, it was considered only a marker of insulin secretion. At present, its endogenous activity is known when it binds to the membranes of various cells, induces gene expression and affects the production of growth factors.

In addition, in many tissues, it activates Na / K-dependent ATPase (an enzyme of the cell membrane) and, by an unexplained mechanism, regulates anomalies in cell metabolism (metabolism) caused by hyperglycemia.

The effects of the C-peptide can be summarized in the following paragraphs:

  • has significant direct and indirect effects that affect the degree and rate of development of vascular and nerve changes in tissues,
  • higher levels prevent endothelial dysfunction, reduce the leakage of albumin through the vascular wall and have an analgesic effect,
  • it is indicated that the C-peptide, on the one hand, is a marker of harmful hyperinsulinemia, and on the other is a protective factor of blood vessels and nerves from the negative effects of hyperinsulinemia and hyperglycemia.

Analysis methods: screening is carried out by the RIA (or ELISA) method, there are 3 main options for determining:

  1. On an empty stomach and after stimulation of glucagon: the basal value is investigated and 6 minutes after stimulation of glucagon (1 mg intravenously). The physiological value of the C-peptide is greater than 600 pmol / L, and after stimulation it increases at least 2 times. In diabetes mellitus, the C-peptide decreases significantly below the lower limit and does not respond to stimulation.
  2. Fasting and after a certain breakfast: the study is performed on an empty stomach and 60 minutes after a standard breakfast, which is as follows: 100 g of bread, 125 g of low-fat cottage cheese, 1 egg, you can drink hot tea.
  3. In the framework of PTTG: sampling is performed on an empty stomach, and then after an oral glucose load (75 g), usually after 60 and 120 minutes, within the experiment, there may even be 30, 45, 90 and 180 minutes.

The following factors may influence the definition of indicators:

  • significant hyperglycemia,
  • renal failure with reduced creatinine clearance,
  • hemolysis (hemoglobin

Features

It often happens that on an empty stomach the level of C-peptide is normal or shows the lower limit of the norm. This makes it difficult to make a final diagnosis. To clarify stimulated test.

For its use, glucagon injections are used, or before a test, a person should have a light bite. It should be remembered that glucagon is contraindicated for people suffering from high blood pressure.

If the study is carried out on an empty stomach, then the subject is allowed to drink only a little water.

The use of any medications is unacceptable, since they can directly or indirectly affect the results of the study.

If it is impossible to refuse to use this or that drug for objective reasons, then this should be reflected in a special accompanying form.

As a rule, the minimum time for preparation of the analysis is about 3 hours.The prepared material is suitable for research for 3 months, provided that the storage is about -20 ° C.

Analysis and interpretation of the results

Normal is the content of C-peptide in the body in an amount of 0.78 to 1.89 ng / ml. SI system operates with indicators 0.26-0.63 mmol / L.

At elevated level C-peptides are often referred to:

  • Type II diabetes
  • insulinoma
  • Itsenko-Cushing's disease,
  • kidney failure
  • the presence of cirrhosis or hepatitis of various forms,
  • polycystic ovary,
  • obesity (specific type).

Frequent and excessive use of estrogens or other hormonal drugs can also cause an increase in the level of C-peptide.

Low level note in case of:

  • diabetes (type I),
  • artificial hypoglycemia,
  • pancreatic resection operations.

It should also be noted that at a reduced level, the risks of developing various complications significantly increase, among which:

  • serious vision problems
  • various lesions of the skin,
  • serious problems in the work of the digestive tract and, as a rule, the kidneys, liver,
  • damage to the vessels and nerves of the legs, which can lead to gangrenous processes and amputation.

For objective results proving the presence / absence of insulinoma, as well as its difference from false hypoglycemia, the C-peptide indices are correlated with their relations to the insulin level indices. A ratio of one or less indicates that internal insulin is produced excessively. If the indicators exceed unity, then this is a factor of input and exposure to external insulin.

It should be remembered that insulin and C-peptide values ​​can change if a person is diagnosed with concomitant kidney or liver diseases.

General recommendations for preparing for the analysis

Features of preparation for the delivery of this analysis, as well as the feasibility of its implementation in each case, is determined only by the attending physician. There are general recommendations for its implementation:

  • before carrying out the patient should refrain from eating any food for 8 hours,
  • it is best to drink only non-carbonated water, without sugar or other impurities,
  • alcohol or drugs containing it are strictly forbidden
  • try not to use any medications other than vital ones (when taking this, inform the specialist),
  • refrain from any physical exertion, try to avoid possible traumatic factors,
  • try to refrain from smoking at least 3 hours before the scheduled analysis.

The results of modern research

Modern science does not stand still, and the results of recent studies suggest that C-peptides are not only a by-product of insulin production. That is, this substance is not biologically useless and plays a role, especially in people suffering from various types of diabetes.

Some scientists are talking about the fact that the single administration of insulin and peptide in type II diabetes significantly reduces the risks of possible complications, including:

  • renal dysfunctions
  • damage to nerves and / or vessels of the limbs.

A relatively small amount of peptide in the patient’s blood can reduce the risks of dependence on constant doses of insulin.

Who knows, perhaps in the foreseeable future there will be special peptide drugs that help fight and defeat diabetes.

To date, all the possible risks and side effects of such therapy have not yet been taken into account, but various academic studies are continuing successfully.

An excellent way out is a low-carb diet, in which the consumption rate does not exceed 2.5 bread units. Such a constant diet helps to reduce dependence on the regular use of sugar-lowering medications, as well as insulin.

In addition, one should not forget about general hygiene measures, which include regular walks in the fresh air, unconditional rejection of all bad habits, stress avoidance, regular visits to sanatoriums specializing in the treatment and prevention of endocrine diseases.

C-peptides in diabetes

With any type of diabetes mellitus, monitoring of his condition is extremely important for the patient.

This is primarily the monitoring of plasma glucose levels. This procedure can be practiced with the help of individual diagnostic devices - glucometers.

But no less important is the analysis of C-peptide - an indicator of insulin production in the body and carbohydrate metabolism.

Such an analysis is done only in the laboratory: the procedure should be carried out regularly for patients with diabetes of both types.

What is a C-peptide

Medical science gives the following definition:

C-peptide is a stable fragment of a substance synthesized in the human body - proinsulin.

C-peptide and insulin are separated during the formation of the latter: thus, the level of C-peptide indirectly indicates the level of insulin.

How is C-peptide synthesized in the body? Proinsulin, which is produced in the pancreas (more precisely, in the β-cells of pancreatic islets), is a large polypeptide chain containing 84 amino acid residues. In this form, the substance is deprived of hormonal activity.

The transformation of inactive proinsulin to insulin occurs as a result of the movement of proinsulin from the ribosomes inside the cells to the secretory granules by the method of partial decomposition of the molecule. At the same time, 33 amino acid residues, known as the connecting peptide or C-peptide, are cleaved from one end of the chain.

In the blood, therefore, there is a pronounced correlation between the amount of C-peptide and insulin.

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Why do I need a C-peptide test?

For a clear understanding of the topic, you need to understand why in the laboratory tests are performed on the C-peptide, and not on the actual insulin.

Medicinal insulin preparations do not contain a C-peptide, therefore, the determination of this compound in blood serum allows us to evaluate the function of pancreatic beta cells in patients undergoing treatment.

The level of the basal C-peptide, and in particular the concentration of this substance after glucose loading, makes it possible to determine the presence of sensitivity (or resistance) of the patient to insulin.

Thus, the phases of remission or exacerbation are established and therapeutic measures are adjusted.

With exacerbation of diabetes mellitus (especially type I), the content of C-peptide in the blood is low: this is direct evidence of a deficiency of endogenous (internal) insulin. The study of the concentration of the connecting peptide allows the assessment of insulin secretion in various clinical situations.

The ratio of insulin and C-peptide may vary if the patient has concomitant liver and kidney diseases.

Insulin is metabolized primarily in the liver parenchyma, and the C-peptide is excreted through the kidneys. Thus, indicators of the amount of C-peptide and insulin may be important for the correct interpretation of data in diseases of the liver and kidneys.

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How is the analysis of C-peptide

A blood test for C-peptide is usually carried out on an empty stomach, unless there is special instructions from an endocrinologist (this specialist should be consulted if you suspect a metabolic disease). The period of fasting before giving blood is 6-8 hours: the best time for giving blood is the morning after waking up.

The blood sampling itself does not differ from the usual one: a vein is punctured, blood is collected in an empty tube (sometimes a gel tube is used). If hematomas form after venipuncture, the doctor prescribes a warming compress. The taken blood is run through a centrifuge, separating the serum, and frozen, and then examined in the laboratory under a microscope using reagents.

An ideal option for diagnosis is to conduct 2 tests:

  • fasting analysis
  • stimulated.

When analyzing an empty stomach, you are allowed to drink water, but you should refrain from taking any medications that may affect the correctness of the analysis result. If medications cannot be canceled for medical reasons, this fact must be indicated on the referral form.

The minimum analysis readiness time is 3 hours. Archive whey stored at -20 ° C can be used for 3 months.

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What are the indicators of the analysis for C-peptides

Fluctuations in the level of C-peptide in serum correspond to the dynamics of the amount of insulin in the blood. The fasting peptide content ranges from 0.78 to 1.89 ng / ml (in the SI system, 0.26-0.63 mmol / l).

For the diagnosis of insulinoma and its differentiation from false (factual) hypoglycemia, the ratio of the level of C-peptide to the level of insulin is determined.

If the ratio is equal to one or less than this value, this indicates an increased formation of internal insulin. If the indicators are greater than 1, this is evidence of the introduction of external insulin.

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C peptide functions

Readers may have a logical question: why do we need C-peptides in the body?

Until recently, it was believed that this part of the amino acid chain is biologically inactive and is a by-product of the formation of insulin.

But recent studies by endocrinologists and diabetologists have led to the conclusion that the substance is not at all useless and plays a role in the body, especially for patients with diabetes.

It is possible that in the near future diabetics will be given C-peptide preparations together with insulin, but so far the possible risks and side effects of such therapy have not been determined clinically. Extensive research on this topic is yet to come.

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C-peptide: determination, interpretation of the analysis (norm)

C-peptide means “connecting peptide”, translated from English. This is an indicator of the secretion of your own insulin. It shows the level of pancreatic beta cells.

Beta cells produce insulin in the pancreas, where it is stored as proinsulin in the form of molecules. In these molecules, as an amino acid residue, a fragment is located that is called a C-peptide.

With an increase in glucose, proinsulin molecules break down into peptide and insulin. Such a combination ejected in the blood always correlates with each other. Thus, the norm is 5: 1.

It is the analysis of C-peptide that allows us to understand that the secretion (production) of insulin is reduced, and also to determine the possibility of the appearance of insulinoma, that is, a pancreatic tumor.

An increased level of a substance is observed with:

  • insulin-dependent diabetes mellitus,
  • renal failure
  • the use of hormonal drugs,
  • insulinoma
  • beta cell hypertrophy.

A reduced level of c-peptide is characteristic for:

  1. insulin-dependent diabetes mellitus in hypoglycemic conditions,
  2. stressful conditions.

The norm of the C-peptide and interpretation

The norm of the C-peptide is the same in women and men. The norm does not depend on the age of patients and is 0.9 - 7.1ng / ml. Norms for children in each case are determined by the doctor.

As a rule, the dynamics of the C-peptide in the blood corresponds to the dynamics of the concentration of insulin. The norm of the fasting C-peptide is 0.78 -1.89 ng / ml (SI: 0.26-0.63 mmol / L).

For children, the rules for blood sampling do not change. However, this substance in a child during analysis on an empty stomach may be slightly lower than the lower limit of the norm, since the C-peptide leaves beta cells in the blood only after eating.

To distinguish between insulin and actual hypoglycemia, it is necessary to determine the ratio of insulin content to C-peptide content.

If the ratio is 1 or less, then this indicates an increased secretion of endogenous insulin. If ratio 1 is exceeded, it can be argued that insulin is administered externally.

C-peptide can be increased with:

  • hypertrophy of cells of islets of Langerhans. Areas of Langerhans are called areas of the pancreas in which insulin is synthesized,
  • obesity
  • insulinoma
  • type 2 diabetes
  • pancreatic cancer
  • long QT interval syndrome,
  • the use of sulfonylureas.

C-peptide is reduced when:

  • alcohol hypoglycemia,
  • type 1 diabetes.

The substance in serum may decrease for two reasons:

  1. Diabetes,
  2. The use of thiazolidinediones, for example troglitazone or rosiglitazone.

Due to insulin therapy, a decrease in the level of C-peptide may be noted. This indicates a healthy reaction of the pancreas to the appearance of "artificial" insulin in the body.

However, very often it happens that the level in the blood of the peptide on an empty stomach is normal or is almost normal. This means that the norm cannot say what type of diabetes a person has.

Based on this, it is recommended to conduct a special stimulated test so that the norm for a given person becomes known. This study can be performed using:

  1. Glucagon injections (an insulin antagonist), it is strictly contraindicated for people with hypertension or pheochromocytoma,
  2. Glucose tolerance test.

It is best to pass two indicators: an analysis on an empty stomach, and a stimulated test. Now different laboratories use different sets of definitions of substances, and the norm is somewhat different.

Having received the result of the analysis, the patient can independently compare it with reference values.

Peptide and diabetes

Modern medicine believes that controlling the level of C-peptide better reflects the amount of insulin than measuring the insulin itself.

The second advantage can be called the fact that with the help of research it is easy to distinguish between endogenous (internal) insulin and exogenous insulin. Unlike insulin, the C-peptide does not respond to antibodies to insulin, and is not destroyed by these antibodies.

Since insulin medicines do not contain this substance, its concentration in the patient’s blood makes it possible to evaluate the performance of beta cells. Recall: pancreatic beta cells produce endogenous insulin.

In a person with diabetes, the basal level of the C-peptide, and especially its concentration after glucose loading, makes it possible to understand whether there is resistance and sensitivity to insulin.

In addition, the phases of remission are determined, which allows you to correctly correct treatment measures. If diabetes is exacerbated, then the level of the substance is not increased, but lowered. This means that endogenous insulin is not enough.

Taking into account all these factors, we can say that the analysis allows us to evaluate the secretion of insulin in various cases.

Determining the level of C-peptide also provides opportunities for interpreting fluctuations in insulin concentration during its retention in the liver.

People with diabetes who have antibodies to insulin can sometimes experience a falsely elevated level of C-peptide due to antibodies that cross-interact with proinsulin. Patients with insulinoma have an increased level of C-peptide.

It is important to know that special attention needs to be paid to changing the concentration of a substance in people after operating on insulinomas. A high C-peptide indicates either a recurring tumor or metastases.

Research is needed for:

  1. Distinctive diagnostic measures of forms of diabetes,
  2. The choice of types of medical therapy,
  3. Choosing the type of medicine and dosage,
  4. Determination of beta cell deficiency
  5. Diagnosis of hypoglycemic state,
  6. Assessment of insulin production,
  7. Determination of insulin resistance,
  8. An element of state control after the elimination of the pancreas.

Modern medicine

For a long time, modern medicine has stated that the substance itself does not carry any functions and only its norm is important. Of course, it is split off from the proinsulin molecule and opens the way to the further path of insulin, but that is probably all.

What is the very meaning of the C-peptide? After many years of research and hundreds of scientific papers, it became known that if insulin is administered to patients with diabetes along with the C-peptide, then there is a significant reduction in the risk of such dangerous complications of diabetes, such as:

  • nephropathy
  • neuropathy
  • diabetic angiopathy.

About this at present, scientists say with full confidence. Nevertheless, it has not yet been able to reliably determine the protective mechanisms of this substance itself.

Please note: recently, statements by paramedical figures that they cure diabetes mellitus due to the introduction of just one miracle injection have become more frequent. Such a “treatment” is usually very expensive.

In no case should you agree to such dubious treatment. The rate of the substance, interpretation and further treatment strategy should be under the full supervision of a qualified physician.

Of course, there is a huge difference between clinical research and practice. Therefore, with regard to the C-peptide, there is still debate in medical circles. There is insufficient information on the side effects and risks of the C-peptide.

The norm of C-peptide in the body

Diagnosing diabetes mellitus requires several studies. The patient is prescribed a blood and urine test for sugar, a stress test with glucose.

In diabetes mellitus, the determination of the C-peptide in the blood is mandatory.

The result of this analysis will show whether hyperglycemia is a consequence of absolute or relative insulin deficiency. What threatens a decrease or increase in the C-peptide, we will analyze below.

There is an analysis that can evaluate the work of the islets of Langerhans in the pancreas and reveal the amount of secretion of hypoglycemic hormone in the body. This indicator is called the connecting peptide or C-peptide (C-peptide).

The pancreas is a kind of storehouse of protein hormone. It is stored there in the form of proinsulin. When a person rises sugar, proinsulin breaks down into a peptide and insulin.

In a healthy person, their ratio should always be 5: 1. Determination of the C-peptide reveals a decrease or increase in insulin production. In the first case, the doctor can diagnose diabetes, and in the second case, insulin.

Under what conditions and diseases is an analysis prescribed?

Diseases in which an analysis is prescribed:

  • type 1 and type 2 diabetes
  • various liver diseases
  • polycystic ovary,
  • pancreatic tumors,
  • pancreas surgery
  • Cushing's syndrome
  • monitoring hormone treatment for type 2 diabetes.

Insulin is important to humans. This is the main hormone involved in carbohydrate metabolism and energy production. An analysis that determines the level of insulin in the blood is not always accurate.

The reasons are as follows:

  1. Initially, insulin is formed in the pancreas. When a person rises sugar, the hormone enters the liver first. There, some of it settles, while the other part performs its function and reduces sugar. Therefore, when determining the level of insulin, this level will always be less than the pancreas synthesized.
  2. Since the main release of insulin occurs after consuming carbohydrates, its level rises after eating.
  3. Incorrect data is obtained if the patient has diabetes mellitus and is treated with recombinant insulin.

In turn, the C-peptide does not settle anywhere and enters the bloodstream immediately, so this study will show real numbers and the exact amount of the hormone secreted by the pancreas. In addition, the compound is not associated with glucose-containing products, that is, its level does not increase after eating.

How is the analysis carried out?

Dinner 8 hours before taking blood should be light, not contain fatty foods.

Research algorithm:

  1. The patient comes on an empty stomach to the blood collection room.
  2. A nurse takes venous blood from him.
  3. Blood is placed in a special tube. Sometimes it contains a special gel so that the blood does not clot.
  4. Then the tube is placed in a centrifuge. This is necessary in order to separate the plasma.
  5. Then the blood is placed in the freezer and cooled to -20 degrees.
  6. After that, the proportions of the peptide to insulin in the blood are determined.

If the patient is suspected of diabetes, he is prescribed a stress test. It consists in the introduction of intravenous glucagon or ingestion of glucose. Then there is a measurement of blood sugar.

What affects the result?

The study shows the pancreas, so the main rule is to maintain a diet.

The main recommendations for patients donating blood to the C-peptide:

  • 8 hours fast before blood donation,
  • you can drink non-carbonated water,
  • you can’t take alcohol a few days before the study,
  • reduce physical and emotional stress,
  • do not smoke 3 hours before the study.

The norm for men and women is the same and ranges from 0.9 to 7, 1 μg / L. Results are independent of age and gender. It should be remembered that in different laboratories the results of the norm may differ, therefore, reference values ​​should be taken into account. These values ​​are average for this laboratory and are established after the examination of healthy people.

Video lecture on the causes of diabetes:

When is the level below normal?

If the peptide level is low, and sugar, on the contrary, is high, this is a sign of diabetes. If the patient is young and not obese, he is most likely diagnosed with type 1 diabetes.

Older patients with a tendency to obesity will be given type 2 diabetes and a decompensated course. In this case, the patient must be shown insulin injections.

In addition, the patient needs additional examination.

  • fundus examination
  • determining the state of vessels and nerves of the lower extremities,
  • determination of liver and kidney functions.

These organs are "targets" and suffer primarily with a high level of glucose in the blood. If after examination the patient has problems with these organs, then he needs an urgent restoration of the normal glucose level and additional treatment of the affected organs.

Peptide reduction also occurs:

  • after surgical removal of a part of the pancreas,
  • artificial hypoglycemia, that is, a decrease in blood sugar that was triggered by insulin injections.

In what cases is the level above the norm?

The results of one analysis will not be enough, so the patient is assigned at least one more analysis to determine the level of sugar in the blood.

If the C-peptide is elevated and there is no sugar, then the patient is diagnosed with insulin resistance or prediabetes.

In this case, the patient does not need insulin injections yet, but he urgently needs to change his lifestyle. Refuse bad habits, start playing sports and eat right.

Elevated levels of C-peptide and glucose indicate the presence of type 2 diabetes. Depending on the severity of the disease, tablets or insulin injections may be prescribed to the person. The hormone is prescribed only prolonged action, 1 - 2 times a day. If all the requirements are observed, the patient can avoid injections and stay only on tablets.

In addition, an increase in the C-peptide is possible with:

  • insulinoma - a pancreatic tumor that synthesizes a large amount of insulin,
  • insulin resistance - a condition in which human tissues lose their sensitivity to insulin,
  • polycystic ovary - a female disease accompanied by hormonal disorders,
  • chronic renal failure - possibly a hidden complication of diabetes.

The determination of the C-peptide in the blood is an important analysis in the diagnosis of diabetes mellitus and some other pathologies. Timely diagnosis and treatment of the disease started will help to maintain health and prolong life.

Recommended Other Related Articles

Normal content

The norm of peptides ranges from 0.26 to 0.63 mol / L, although other units of measurement are used in the analysis. The concentration of the substance in nanograms per milliliter of blood is calculated, in this case the norm is 0.9-7.1 ng / ml. Such a significant gap in the scale of the norm indicator is due to the fact that people have different indicators:

  • body weight
  • age
  • chronic diseases
  • various infections (ARVI, Influenza),
  • hormone levels.

Low level

Low in comparison with the normal level of C-peptide is observed when:

  • Type 1 diabetes
  • Artificial hypoglycemia,
  • Radical pancreatic removal surgery.

C peptide functions

Readers may have a logical question: why do we need C-peptides in the body?

Until recently, it was believed that this part of the amino acid chain is biologically inactive and is a by-product of the formation of insulin.

But recent studies by endocrinologists and diabetologists have led to the conclusion that the substance is not at all useless and plays a role in the body, especially for patients with diabetes.

It is possible that in the near future diabetics will be given C-peptide preparations together with insulin, but so far the possible risks and side effects of such therapy have not been determined clinically. Extensive research on this topic is yet to come.

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C-peptide: determination, interpretation of the analysis (norm)

C-peptide means “connecting peptide”, translated from English. This is an indicator of the secretion of your own insulin. It shows the level of pancreatic beta cells.

Beta cells produce insulin in the pancreas, where it is stored as proinsulin in the form of molecules. In these molecules, as an amino acid residue, a fragment is located that is called a C-peptide.

With an increase in glucose, proinsulin molecules break down into peptide and insulin. Such a combination ejected in the blood always correlates with each other. Thus, the norm is 5: 1.

It is the analysis of C-peptide that allows us to understand that the secretion (production) of insulin is reduced, and also to determine the possibility of the appearance of insulinoma, that is, a pancreatic tumor.

An increased level of a substance is observed with:

  • insulin-dependent diabetes mellitus,
  • renal failure
  • the use of hormonal drugs,
  • insulinoma
  • beta cell hypertrophy.

A reduced level of c-peptide is characteristic for:

  1. insulin-dependent diabetes mellitus in hypoglycemic conditions,
  2. stressful conditions.

Analysis Features

C-peptide analysis is the determination of the quantitative degree of the protein part of proinsulin in blood serum using the immunochemiluminescent method.

First, a passive precursor of insulin, proinsulin, is synthesized in beta cells of the pancreas, it is activated only when the blood sugar level rises by cleaving the protein component, the C-peptide, from it.

Molecules of insulin and C-peptide enter the bloodstream and circulate there.

  1. To indirectly determine the amount of insulin with inactivating antibodies, which change indicators, making them smaller. It is also used for severe violations of the liver.
  2. To determine the type of diabetes mellitus and the features of pancreatic beta cells for choosing a treatment strategy.
  3. To identify tumor metastases of the pancreas after its surgical removal.

A blood test is prescribed for the following diseases:

  • Type 1 diabetes, in which the protein level is lowered.
  • Type 2 diabetes mellitus, in which indicators are higher than normal.
  • Diabetes mellitus is insulin-resistant, due to the production of antibodies to insulin receptors, while the C-peptide index is lowered.
  • The state of postoperative elimination of pancreatic cancer.
  • Infertility and its cause - polycystic ovary.
  • Gestational diabetes mellitus (potential risk to the child is specified).
  • A variety of disorders in the deformation of the pancreas.
  • Somatotropinoma, where the C-peptide is elevated.
  • Cushing's Syndrome.

In addition, the determination of a substance in human blood will reveal the cause of the hypoglycemic state in diabetes. This indicator increases with insulinoma, the use of synthetic sugar-lowering drugs.

A study is prescribed if a person complains:

  1. for constant thirst
  2. increased urine output,
  3. weight gain.

If you already have a diagnosis of diabetes, then the substance is determined to evaluate the quality of treatment. Improper treatment leads to a chronic form, most often, in this case, people complain of blurred vision and decreased sensitivity of the legs.

In addition, signs of malfunctioning of the kidneys and arterial hypertension may be observed.

For analysis, venous blood is taken into a plastic box. Within eight hours before the analysis, the patient can not eat, but you can drink water.

It is advisable not to smoke and not to undergo heavy physical and emotional stress three hours before the procedure. Correction of insulin therapy by an endocrinologist is sometimes required. The result of the analysis can be known after 3 hours.

The norm of the C-peptide and interpretation

The norm of the C-peptide is the same in women and men. The norm does not depend on the age of patients and is 0.9 - 7.1ng / ml. Norms for children in each case are determined by the doctor.

As a rule, the dynamics of the C-peptide in the blood corresponds to the dynamics of the concentration of insulin. The norm of the fasting C-peptide is 0.78 -1.89 ng / ml (SI: 0.26-0.63 mmol / L).

For children, the rules for blood sampling do not change. However, this substance in a child during analysis on an empty stomach may be slightly lower than the lower limit of the norm, since the C-peptide leaves beta cells in the blood only after eating.

To distinguish between insulin and actual hypoglycemia, it is necessary to determine the ratio of insulin content to C-peptide content.

If the ratio is 1 or less, then this indicates an increased secretion of endogenous insulin. If ratio 1 is exceeded, it can be argued that insulin is administered externally.

C-peptide can be increased with:

  • hypertrophy of cells of islets of Langerhans. Areas of Langerhans are called areas of the pancreas in which insulin is synthesized,
  • obesity
  • insulinoma
  • type 2 diabetes
  • pancreatic cancer
  • long QT interval syndrome,
  • the use of sulfonylureas.

C-peptide is reduced when:

  • alcohol hypoglycemia,
  • type 1 diabetes.

The substance in serum may decrease for two reasons:

  1. Diabetes,
  2. The use of thiazolidinediones, for example troglitazone or rosiglitazone.

Due to insulin therapy, a decrease in the level of C-peptide may be noted. This indicates a healthy reaction of the pancreas to the appearance of "artificial" insulin in the body.

However, very often it happens that the level in the blood of the peptide on an empty stomach is normal or is almost normal. This means that the norm cannot say what type of diabetes a person has.

Based on this, it is recommended to conduct a special stimulated test so that the norm for a given person becomes known. This study can be performed using:

  1. Glucagon injections (an insulin antagonist), it is strictly contraindicated for people with hypertension or pheochromocytoma,
  2. Glucose tolerance test.

It is best to pass two indicators: an analysis on an empty stomach, and a stimulated test. Now different laboratories use different sets of definitions of substances, and the norm is somewhat different.

Having received the result of the analysis, the patient can independently compare it with reference values.

Peptide and diabetes

Modern medicine believes that controlling the level of C-peptide better reflects the amount of insulin than measuring the insulin itself.

The second advantage can be called the fact that with the help of research it is easy to distinguish between endogenous (internal) insulin and exogenous insulin. Unlike insulin, the C-peptide does not respond to antibodies to insulin, and is not destroyed by these antibodies.

Since insulin medicines do not contain this substance, its concentration in the patient’s blood makes it possible to evaluate the performance of beta cells. Recall: pancreatic beta cells produce endogenous insulin.

In a person with diabetes, the basal level of the C-peptide, and especially its concentration after glucose loading, makes it possible to understand whether there is resistance and sensitivity to insulin.

In addition, the phases of remission are determined, which allows you to correctly correct treatment measures. If diabetes is exacerbated, then the level of the substance is not increased, but lowered. This means that endogenous insulin is not enough.

Taking into account all these factors, we can say that the analysis allows us to evaluate the secretion of insulin in various cases.

Determining the level of C-peptide also provides opportunities for interpreting fluctuations in insulin concentration during its retention in the liver.

People with diabetes who have antibodies to insulin can sometimes experience a falsely elevated level of C-peptide due to antibodies that cross-interact with proinsulin. Patients with insulinoma have an increased level of C-peptide.

It is important to know that special attention needs to be paid to changing the concentration of a substance in people after operating on insulinomas. A high C-peptide indicates either a recurring tumor or metastases.

Research is needed for:

  1. Distinctive diagnostic measures of forms of diabetes,
  2. The choice of types of medical therapy,
  3. Choosing the type of medicine and dosage,
  4. Determination of beta cell deficiency
  5. Diagnosis of hypoglycemic state,
  6. Assessment of insulin production,
  7. Determination of insulin resistance,
  8. An element of state control after the elimination of the pancreas.

Modern medicine

For a long time, modern medicine has stated that the substance itself does not carry any functions and only its norm is important. Of course, it is split off from the proinsulin molecule and opens the way to the further path of insulin, but that is probably all.

What is the very meaning of the C-peptide? After many years of research and hundreds of scientific papers, it became known that if insulin is administered to patients with diabetes along with the C-peptide, then there is a significant reduction in the risk of such dangerous complications of diabetes, such as:

  • nephropathy
  • neuropathy
  • diabetic angiopathy.

About this at present, scientists say with full confidence. Nevertheless, it has not yet been able to reliably determine the protective mechanisms of this substance itself.

Please note: recently, statements by paramedical figures that they cure diabetes mellitus due to the introduction of just one miracle injection have become more frequent. Such a “treatment” is usually very expensive.

In no case should you agree to such dubious treatment. The rate of the substance, interpretation and further treatment strategy should be under the full supervision of a qualified physician.

Of course, there is a huge difference between clinical research and practice. Therefore, with regard to the C-peptide, there is still debate in medical circles. There is insufficient information on the side effects and risks of the C-peptide.

The norm of C-peptide in the body

Diagnosing diabetes mellitus requires several studies. The patient is prescribed a blood and urine test for sugar, a stress test with glucose.

In diabetes mellitus, the determination of the C-peptide in the blood is mandatory.

The result of this analysis will show whether hyperglycemia is a consequence of absolute or relative insulin deficiency. What threatens a decrease or increase in the C-peptide, we will analyze below.

There is an analysis that can evaluate the work of the islets of Langerhans in the pancreas and reveal the amount of secretion of hypoglycemic hormone in the body. This indicator is called the connecting peptide or C-peptide (C-peptide).

The pancreas is a kind of storehouse of protein hormone. It is stored there in the form of proinsulin. When a person rises sugar, proinsulin breaks down into a peptide and insulin.

In a healthy person, their ratio should always be 5: 1. Determination of the C-peptide reveals a decrease or increase in insulin production. In the first case, the doctor can diagnose diabetes, and in the second case, insulin.

Under what conditions and diseases is an analysis prescribed?

Diseases in which an analysis is prescribed:

  • type 1 and type 2 diabetes
  • various liver diseases
  • polycystic ovary,
  • pancreatic tumors,
  • pancreas surgery
  • Cushing's syndrome
  • monitoring hormone treatment for type 2 diabetes.

Insulin is important to humans. This is the main hormone involved in carbohydrate metabolism and energy production. An analysis that determines the level of insulin in the blood is not always accurate.

The reasons are as follows:

  1. Initially, insulin is formed in the pancreas. When a person rises sugar, the hormone enters the liver first. There, some of it settles, while the other part performs its function and reduces sugar. Therefore, when determining the level of insulin, this level will always be less than the pancreas synthesized.
  2. Since the main release of insulin occurs after consuming carbohydrates, its level rises after eating.
  3. Incorrect data is obtained if the patient has diabetes mellitus and is treated with recombinant insulin.

In turn, the C-peptide does not settle anywhere and enters the bloodstream immediately, so this study will show real numbers and the exact amount of the hormone secreted by the pancreas. In addition, the compound is not associated with glucose-containing products, that is, its level does not increase after eating.

How is the analysis carried out?

Dinner 8 hours before taking blood should be light, not contain fatty foods.

Research algorithm:

  1. The patient comes on an empty stomach to the blood collection room.
  2. A nurse takes venous blood from him.
  3. Blood is placed in a special tube. Sometimes it contains a special gel so that the blood does not clot.
  4. Then the tube is placed in a centrifuge. This is necessary in order to separate the plasma.
  5. Then the blood is placed in the freezer and cooled to -20 degrees.
  6. After that, the proportions of the peptide to insulin in the blood are determined.

If the patient is suspected of diabetes, he is prescribed a stress test. It consists in the introduction of intravenous glucagon or ingestion of glucose. Then there is a measurement of blood sugar.

What affects the result?

The study shows the pancreas, so the main rule is to maintain a diet.

The main recommendations for patients donating blood to the C-peptide:

  • 8 hours fast before blood donation,
  • you can drink non-carbonated water,
  • you can’t take alcohol a few days before the study,
  • reduce physical and emotional stress,
  • do not smoke 3 hours before the study.

The norm for men and women is the same and ranges from 0.9 to 7, 1 μg / L. Results are independent of age and gender. It should be remembered that in different laboratories the results of the norm may differ, therefore, reference values ​​should be taken into account. These values ​​are average for this laboratory and are established after the examination of healthy people.

Video lecture on the causes of diabetes:

When is the level below normal?

If the peptide level is low, and sugar, on the contrary, is high, this is a sign of diabetes. If the patient is young and not obese, he is most likely diagnosed with type 1 diabetes.

Older patients with a tendency to obesity will be given type 2 diabetes and a decompensated course. In this case, the patient must be shown insulin injections.

In addition, the patient needs additional examination.

  • fundus examination
  • determining the state of vessels and nerves of the lower extremities,
  • determination of liver and kidney functions.

These organs are "targets" and suffer primarily with a high level of glucose in the blood. If after examination the patient has problems with these organs, then he needs an urgent restoration of the normal glucose level and additional treatment of the affected organs.

Peptide reduction also occurs:

  • after surgical removal of a part of the pancreas,
  • artificial hypoglycemia, that is, a decrease in blood sugar that was triggered by insulin injections.

In what cases is the level above the norm?

The results of one analysis will not be enough, so the patient is assigned at least one more analysis to determine the level of sugar in the blood.

If the C-peptide is elevated and there is no sugar, then the patient is diagnosed with insulin resistance or prediabetes.

In this case, the patient does not need insulin injections yet, but he urgently needs to change his lifestyle. Refuse bad habits, start playing sports and eat right.

Elevated levels of C-peptide and glucose indicate the presence of type 2 diabetes. Depending on the severity of the disease, tablets or insulin injections may be prescribed to the person. The hormone is prescribed only prolonged action, 1 - 2 times a day. If all the requirements are observed, the patient can avoid injections and stay only on tablets.

In addition, an increase in the C-peptide is possible with:

  • insulinoma - a pancreatic tumor that synthesizes a large amount of insulin,
  • insulin resistance - a condition in which human tissues lose their sensitivity to insulin,
  • polycystic ovary - a female disease accompanied by hormonal disorders,
  • chronic renal failure - possibly a hidden complication of diabetes.

The determination of the C-peptide in the blood is an important analysis in the diagnosis of diabetes mellitus and some other pathologies. Timely diagnosis and treatment of the disease started will help to maintain health and prolong life.

Recommended Other Related Articles

C-peptides in diabetes mellitus: type 1, type 2, sugar level (what to do if elevated) analysis, norm, treatment

C-peptides are substances that are produced by the beta cells of the pancreas and indicate the amount of insulin in the body. Analysis for C-peptides is prescribed for diabetes mellitus for a more accurate diagnosis of the form (type 1 or type 2) of the disease and the accompanying complications of diabetes mellitus.

What are C-peptides

With an increase in blood glucose, the pancreas activates proinsulin molecules, which contributes to their breakdown into insulin and the amino acid residue, which is the C-peptide.

Thus, a chain of peptides appears when insulin is produced in the body. And the higher the content of C-peptides in the blood, the more active insulin in the body.

The peptide received the name “C” because its chain is a formation in the form of this letter. Initially, the insulin chain looks like a spiral.

In diabetes mellitus or liver diseases, an analysis is made for C-peptides, because when the pancreas forms, insulin passes through the liver, and there it partially settles, getting into the blood in the wrong amount. Therefore, it is impossible to determine the exact amount of insulin produced.

How is the analysis

Peculiarities of C-peptide analysis for the patient differ little from the usual biochemical blood test.

Blood is taken from a vein to test for peptides, and since food directly affects insulin production, blood is given on an empty stomach. Meal should be 6-8 hours before analysis.

Forbidden before research:

  • drink alcohol
  • to smoke
  • take hormonal drugs (if they are not vital for health),
  • eat chocolate or other types of sweets.

Sometimes an analysis on an empty stomach does not give accurate data, so the doctor prescribes stimulating measures for more accurate research results. Such measures include:

  • regular breakfast containing light carbohydrates (white bread, roll, pie), which increases the production of insulin and, accordingly, C-peptides,
  • glucagon injection is an insulin antagonist (the procedure is contraindicated for people with hypertension), it increases the level of glucose in the blood.

The patient receives the results no earlier than 3 hours after taking the blood. This period may increase, since the analysis of C-peptide is not done in all clinical laboratories and may need to be transported to a more qualified research center. The standard waiting time is 1-3 days from the date of analysis.

On the day of analysis, you should refrain from using all types of medications. If the refusal entails a threat to life or health, it is necessary to consult the doctor who prescribed these medications.

Normal content

The norm of peptides ranges from 0.26 to 0.63 mol / L, although other units of measurement are used in the analysis. The concentration of the substance in nanograms per milliliter of blood is calculated, in this case the norm is 0.9-7.1 ng / ml. Such a significant gap in the scale of the norm indicator is due to the fact that people have different indicators:

  • body weight
  • age
  • chronic diseases
  • various infections (ARVI, Influenza),
  • hormone levels.

Elevated level

The level is increased if the indicator is more than 0.63 mol / l (more than 7.1 ng / ml). An increased level of peptides is observed with:

  • type 1 and type 2 diabetes
  • adrenal dysfunction,
  • violation of the endocrine system,
  • overweight (obesity),
  • hormonal imbalance (in women in connection with the use of contraceptives),
  • surge of hormones (inherent in the male sex during puberty),
  • insulinoma (malignant formation),
  • pancreatic disease
  • cirrhosis of the liver.

Low level

The level of C-peptides is reduced if the indicator is less than 0.26 mol / l (less than 0.9 ng / ml).

A lower peptide content indicates complications of type 1 diabetes mellitus such as:

  • diabetic retinopathy (damage to the vessels of the eye retina),
  • impaired function of the nerve endings and blood vessels of the legs (risk of developing gangrene and amputation of the lower extremities),
  • pathology of the kidneys and liver (nephropathy, hepatitis),
  • diabetic dermopathy (red spot or papules with a diameter of 3-7 cm on the legs).

The role of peptides in diabetes

Studies by endocrinologists of C-peptides indicate the benefits of the amino acid chain, which improves the condition of diabetics. With the parallel administration of C-peptides and insulin to patients with diabetes mellitus, positive changes are observed, such as:

  • a decrease in the frequency of nephrosis diseases (kidney damage with pathological changes in the renal tubules),
  • reduced risk of neuropathy (non-inflammatory nerve damage),
  • overall well-being,
  • decrease in the frequency of attacks.

Therefore, peptides perform functions directly related to the regulation of insulin in the body, their normalization will help improve the patient's condition.

The need for screening for C-peptides is necessary for:

  1. Definitions of the form of diabetes.
  2. The correct choice of drugs and method of therapy.
  3. Finding out beta cell deficiencies.
  4. Monitoring the patient's condition after removal of the pancreas.

A competent analysis of C-peptides can give more information than other studies of the body on the content of insulin.

C peptide: analysis, norms, decoding

C (C) peptide, if you translate the name from English, means a connecting peptide. It shows the level of secretion and is an indicator of the functioning of pancreatic cells. The above cells are necessary to create insulin.

Peptide Substance and Diabetes

Modern medical experts believe that the analysis of the peptide answers the question about the content of insulin more accurately than the analysis for insulin. This can be called one of the main advantages of this analysis.

The second advantage is that such an analysis makes it easy to identify differences between exogenous insulin and endogenous. This is explained by the fact that the C - peptide has no reaction to insulin antibodies and cannot be destroyed by them.

Since medications do not have a peptide substance in their composition, the analysis will provide information on the functioning of beta cells in the human body. Do not forget that it is beta cells that are responsible for the production of endogenous insulin.

If a person suffers from diabetes, a C - peptide test will provide information on the sensitivity and resistance of the body to insulin.

Also, based on the analysis, it is possible to determine the phases of remission, this information will allow you to draw up an effective course of treatment. With exacerbation of diabetes mellitus, the level of concentration of the peptide in the blood vessels will be below normal. Thus, it can be concluded that endogenous insulin in the body is not enough.

If you take into account all of the above factors, you can assess the level of insulin secretion in various situations. If the patient has antibodies to insulin, in some cases the level of C - peptide may be supposedly increased. This is explained by the interaction of cells with proinsulin.

It is very important to pay attention to the concentration of C - peptide in the blood vessels after the operation of insulinoma. In this case, the increased content of the peptide substance indicates a relapse of the tumor of a malignant nature or a metastasis process. Do not forget that the level of C - peptide may differ from the norm in case of disorders in the pancreas or kidneys.

Why are studies on the C - peptide necessary?

The analysis will determine the type of diabetes.

The analysis will help determine the course of treatment.

Decide on the dosage and type of medication.

The analysis will provide information on the content of beta cells in the pancreas,

Information about the degree of synthesis of insulin appears.

You can control the C peptide after removal of the pancreas.

Why is C peptide needed?

For a rather long period, medical experts argued that the body does not use a peptide substance in any way and doctors only need a peptide to diagnose complications of diabetes mellitus.

Recently, however, medical experts have found that injecting a peptide with insulin significantly reduces the risk of diabetes complications, namely, neuropathy, angiopathy and nephropathy.

Active debate is still ongoing regarding this issue. This is explained by the fact that evidence of the effect of the peptide substance on the causes of complications has not been established. Currently, this is still a phenomenon.

If you have been diagnosed with diabetes, you should not agree to an instant cure with a single injection, which is offered by people who are not qualified medical specialists. The entire treatment process should be monitored by the attending physician.

You may also find useful articles on this topic:

What is a C peptide?

The amount of C-peptide partially released into the blood with insulin can be measured using special diagnostic measures. Compared to the direct determination of insulin, this study has the advantage of significantly greater biochemical stability. The concentration of the C-peptide correlates directly with the level of insulin.

In addition to its diagnostic value, the C-peptide also has its own effects in cell metabolism in accordance with recent results. It binds to receptors associated with the G-protein on the cell membrane of various cells (neurons or endothelial cells) and thereby activates intracellular signaling pathways. In clinical studies with animals suffering from type 1 diabetes, administration of the C-peptide improved renal function and symptoms of diabetic neuropathy.

C-peptide blood test: why is it needed?

The C-peptide is used to detect diabetes mellitus and insulin-producing pancreatic tumors. C-peptides help determine the cause of hypoglycemia.

Many people ask: what does this analysis show? C-peptide and insulin are peptide chains formed by the activation and division of proinsulin (an inactive precursor of insulin). When the body needs insulin, it is released into the bloodstream to facilitate the transfer of glucose (as a raw material for energy) to the body's cells, while equimolar amounts of the C-peptide are released at the same time.

A C-peptide blood test can be used to evaluate the release of endogenous insulin (the insulin produced by B cells in the body). Typically, a blood sample is obtained from the brachial vein. If 24-hour monitoring is required, urine should be collected within 24 hours.

Peptides and diabetes treatment

GLP-1 is a hormone that is produced in special cells of the intestinal mucosa. The hormone is released after eating - especially after taking glucose. It acts on islet cells of the pancreas and has a double effect:

  • Increases insulin secretion from pancreatic B cells,
  • It reduces the rate of glucagon synthesis, which is produced in pancreatic cells and is an insulin antagonist.

It has been shown that glucose-dependent insulinotropic polypeptide (HIP) does not have a stimulating effect on the release of insulin with elevated blood sugar. GLP-1 is less effective in diabetics than in healthy people. However, GLP-1 itself turned out to be too unstable when used as a medicine due to degradation of dipeptidyl peptidase 4 by enzymes and, therefore, is too short in its effect.

Exenatide has also been shown to reduce body weight. In addition, it was found that long-term treatment with incretin mimetics and IDDP-4 can protect beta cells from damage. The effect of both classes of drugs also depends on the level of glucose in the blood. When using the drug, hypoglycemia is very rare.

As a result of the drug, more insulin is released, and it can remain active longer. The natural peptide is cleaved for 1 to 2 minutes with the enzyme dipeptidyl peptidase-4. Therefore, GLP-1 can act for a very short period of time. To prolong the action of GLP-1, drugs have been developed that inhibit the degradation enzyme DPP-4. These drugs include sitagliptin and vildagliptin, also called DPP-4 inhibitors.

Drugs can be used only if the patient synthesizes a sufficient amount of endogenous insulin. The effect depends on the meal. For this reason, inhibitors do not usually cause hypoglycemia. The risk of hypoglycemia is very low compared to other antidiabetic agents.

Drugs in this group are well tolerated and have few side effects. They lead to slower emptying of the stomach and a decrease in appetite. Thus, they do not lead to weight gain. The risk of hypoglycemia is relatively low. Some patients had runny nose, throat, head and body pains, and diarrhea. Long-term tolerance studies have not yet been published.

The main peptide drugs that are used for diabetes:

  • Liraglutide: In July 2009, the drug was approved for the treatment of obesity and diabetes. The duration of action is up to 24 hours,
  • Exenatide: the synthesis of the polypeptide was carried out according to the model of exendin-4 contained in the saliva of an Arizona toothfish. In April 2005, the United States approved a decision to use the drug in combination with metformin or glitazones. The drug is used in the form of weekly injections.
  • Albiglutide: has been on the market in Russia since October 2014. It is approved for diabetes monotherapy,
  • Dulaglutide: sold on the Russian pharmaceutical market since February 2015. The dosage is also a weekly injection,
  • Taspoglutide: an analogue of GLP-1 was developed at the end of 2009. In September 2010, Roche announced that all studies with the drug were discontinued. This was partially due to a serious allergic reaction and frequent adverse reactions in the gastrointestinal tract, mainly nausea and vomiting.

The cost of drugs varies widely: from 5,000 to 32,000 Russian rubles.

Advice! Drugs to lower blood sugar should be taken strictly according to a doctor’s prescription. If symptoms of hypoglycemia (low sugar) periodically appear, it is recommended that you inform your doctor. The child is not recommended to give the above drugs, since clinical studies in children have not been conducted.

Peptides play an important role in the regulation of glycemia. In clinical practice, they are used as medicines and biomarkers of various diseases. It is recommended that you take the drugs only under the supervision of a doctor, and if unclear as well as dangerous symptoms occur, you should contact a qualified specialist to prevent possible complications.

Watch the video: Dr. Sarah Hallberg Live on Ketogenic Diets and Diabetes (April 2020).