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C-Peptide Test

C-Peptide Test

also known as: Connecting Peptide , Insulin C-Peptide , Proinsulin C-Peptide

C-peptide is a product which is formed when the hormone insulin is produced and released into the body. A C-peptide is a type of blood test which is carried out to find out the quantity of insulin, your body is producing. This test helps in diagnosing the type of diabetes, the patient is suffering from or whether he is insulin resistant. The test measures the level of this peptide in the blood. Insulin helps the body to use and control the amount of sugar in the blood. Insulin allows glucose to enter into the body cells, where it is used for generating energy. The level of C-peptide in the blood can show how much insulin is being made by the pancreas. C-peptide does not affect the blood sugar level in the body. A person whose pancreas does not make any insulin (type 1 diabetes) has a low level of insulin and C-peptide. A person with type 2 diabetes can have a normal or high level of C-peptide.

Patient may be asked to do fasting for both food and water for 8 hours before having this blood test. Insulin and oral medicines used to treat type 2 diabetes can change the test results. You may be asked to stop medication before this test.

Helps in differentiating between type 1 diabetes and type 2 diabetes. Find the cause of low blood sugar (hypoglycemia). Check to see whether a tumor of the pancreas (insulinoma) was completely removed.

The insulin C-peptide test requires a blood sample to be collected by the doctor. The blood is drawn from a vein, either from the arm or on the back of the hand. The procedure is quiet painful, but on the temporary basis. Blood sample will be collected in a test tube and sent to a lab for analysis. Normal Results A normal result ranges from 0.5 to 2.0 nanograms per milliliter (ng/mL). People with type 2 diabetes, obesity, and insulin resistance may have a high C-peptide level which is normal for them. What Abnormal Results Mean A low level or no level indicates that your pancreas is producing little or no insulin. A low level may be normal if you have not eaten recently. Your blood sugar and insulin levels would naturally be low then. A low level is abnormal if your blood sugar is high and your body should be making insulin at that time.

LimitationsC-peptide levels are increased with renal failure. (C-peptide is normally excreted by the kidneys.) Instances of insulinoma have been described in which proinsulin was increased but insulin and C-peptide were not.As with all tests containing monoclonal mouse antibodies, erroneous findings may be obtained from samples taken from patients who have been treated with monoclonal mouse antibodies or who have received them for diagnostic purposes.1 In rare cases, interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur.1 The test contains additives, which minimize these effects.
0.8 mL
Red-top tube or gel-barrier tube.
Type Gender Age-Group Value
C Peptide
All age groups
0.8 - 3.1 ng/ml
Average price range of the test is between Rs.600 to Rs.2100 depending on the factors of city, quality and availablity.
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Popular Questions & Answers

Hi my mom is having diabetes. She was on medicine. She was having Glynase -MF 1 and half tablet twice a day. But from last few days she is having a lot urine at night. She is having a loss of weight as well. If there is any cut or injury its taking a lot of time to recover and heal. We did the fasting and blood test. Test results:- Haemoglobin= 11.5 gms% = 78%(By Hellige Method) True Glucose (Fasting):- 260 mgm% We are not sure about the type of diabetes. She is herself a nurse. Help me with a suggestion what should we do? Should we do a C-peptide test first? Before taking any medication. Suggestions please.

MBBS, CCEBDM, Diploma in Diabetology, Diploma in Clinical Nutrition & Dietetics, Cetificate Course In Thyroid Disorders Management (CCMTD)
Endocrinologist, Hubli-Dharwad
Hi my mom is having diabetes. She was on medicine. She was having Glynase -MF 1 and half tablet twice a day. But from...
Mr. lybrate-user, Thanks for the query. Since she has been taking oral anti-diabetic drugs for controlling blood glucose, it has to T2 diabetes. In T1 only Insulin Injection has to be given. No other drug works. She now has an uncontrolled diabetes that is the reason for excess urination at night and weight loss, because more of glucose is being lost in the urine. She needs to achieve a strict blood glucose control with FBG < 100 mg, PP 170 to 180 mg & HbA1c% <7. That means there has to be a change in the current treatment. New drugs have to be added or Insulin may have to be started. There are other options also, but in this communication we are supposed to give general guidelines only. No prescriptions are allowed. If you are keen for improving her blood glucose levels and achieve better control, please come in a private conversation with following details: FBG, PP glucose levels, HbA1c%, dietary pattern extent of exercise or physical activity, lipid profile, BP readings. Based on those details I will be able to guide specifically and help improve the condition. There is no need for C- peptide testing. Thanks.
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Hi! My mom age is 40 years and weight is 95 kgs recently had sugar check up and thyroid check up. T3 &t4 are normal but TSH id 6.8uIU/ml doctor said she has thyroid what are the precaution and food should be taken? How to control? Also sugar test -Fasting blood sugar 120 mg/dL Post lunch blood sugar -129 mg/dl doctor said she has sugar what food should she take I am worried about her how to control sugar help me.

Hi! My mom age is 40 years and weight is 95 kgs recently had sugar check up and thyroid check up. T3 &t4 are normal b...
Patients likelihood of developing diabetes 50% if they are also diagnosed with hypothyroidism it is autoimmune do anti tpo antibody Thyroid hormone is important for all organ proper metabolism, and production of insulin thus important in controlling weight and cholesterol metabolism. Low thyroid hormone factor in the development of type 2 diabetes. Since fasting is 120 mg / dl its prediabetic need HBAIC &CPEPTIDE TEST for cnfrm she is diabetic and also anti tpo free t3 freet4 iodine selenium cortisol level lipid profile is imp as hypothyrodism lead increase in lipid level 1) IMP start thyroid harmone supplement first with proper diet decrease BMI WEIGHT 2) IMP DO TEST HBAIC CPEPTIDE FASTING SUGAR againdiagnose is she cnfrm diabetic with L thyroxine homeopathy can act as best treatment at this stage of HYPO& DM it will help to regain fuction of thyroid thus metabolism of organ homeopathy is cure to such immune abnormality.
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