EVALUATION OF SERUM C-PEPTIDE LEVELS IN INDIAN TYPE 2 DIABETES INDIVIDUALS ATTENDING TERTIARY DIABETIC INSTITUTE

*Dr. R. Anil Kumar and Dr Surekha B. Shetty

ABSTRACT

Background: Diabetes mellitus is a chronic metabolic disorder characterized by chronic hyperglycemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action or both. It is a major cause of mortality and morbidity worldwide. While evaluating diabetes, C-peptide has been a widely used measure of pancreatic beta cell function. It is produced in equimolar amounts to endogenous insulin but is excreted at a more constant rate over a longer time. The measurement of C-peptide provides a better index of endogenous insulin production and pancreatic beta cell function than insulin measurements. C-peptide level is associated with diabetes type and duration of disease. It is useful for differentiating type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). C-peptide level may also correlate with microvascular and macrovascular complications. It has been proposed as one of the predictors of future use of insulin therapy, as well as likely response to other individual therapies. The current study was conducted to know the utility of c peptide levels in assessing the endogenous insulin secretory function in Indian patients with type 2 diabetes. Methods: The present study was conducted in 150 adult patients of type 2 diabetes mellitus presenting in outpatient department of Karnataka institute of endocrinology and research. Subjects with Type 1 diabetes, pregnant women with diabetes, subjects presenting with acute infections, septicemia, patients with acute or chronic pancreatitis, and subjects with pancreatic carcinoma were excluded from the study. In this study C-Peptide levels were estimated by electro chemiluminescence immunoassay method. Results: 150 type 2 diabetes subjects were selected randomly. Age group <30 to >70 years, 68.7% were males. Family history for diabetes was positive in 58.7% subjects. Duration of diabetes vary between new to > 10 years. 82% of subjects had BMI 18.5 to 30. 58% of subjects had waist circumference 90 to 110 centimeters. 49.3% had HBA1c 6 to 9% and in 49.3% HBA1c was >9%. Fasting C-peptide levels were normal in 20.7% and high in 70.3% of type 2 diabetes subjects. None of the patients fasting C-peptide was less than normal. BMI, waist circumference and triglyceride levels were high in type 2 diabetes subjects with high C-peptide levels. Conclusions: The current clinical role of C-peptide in diabetes is to differentiate type 1 diabetes from type 2 diabetes especially in subjects with overlapping clinical features. There is a limited role in the diagnosis of Type 2 diabetes with marked hyperglycemia where C-peptide testing may support a clinical decision on initial insulin therapy. Routine C-peptide testing in type 2 diabetes with poor glycaemic control can help to decide treatment modalities. It can also help in creating awareness about insulin resistance and need for aggressive lifestyle modification.

Keywords: C-Peptide, HBA1c, triglyceride.