UTILITY OF FASTING C-PEPTIDE LEVELS IN THE CLASSIFICATION OF YOUNG DIABETES SUBJECTS WITH THE AGE OF ONSET OF DIABETES BETWEEN 15 TO 35 YEARS

*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. Type 2 diabetes in youth has increased enormously in India and in addition the incidence of even type 1 diabetes is increasing in youth. So there are some patients who have mixed features. The objective of this study is to use fasting C-Peptide levels and classify diabetes in the young individuals from 15 to 35 years. Methods: The present study was conducted in the outpatient department of Karnataka Institute of Endocrinology and Research Bangalore, in 426 subjects with age of onset of diabetes between 15 to 35 years, over a period of 5 years. Informed consent was taken from all the subjects included in the study and the approval from hospital ethical committee was taken. Pregnant women with diabetes, subjects presenting with acute infections, septicaemia, 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: 426 subjects with the age of onset of diabetes between 15 to 35 years were studied. 71.4% of the subjects are males. 55.4% were in the age of onset between 20 to 30 years. Duration of diabetes varied between new to 15 years. 54% of subjects had BMI from 18.5 to 24.9. Waist circumference was more than 80 cms in 78.2% of subjects. Study results show that 2.8% were type 1 diabetes, 11.5% could be either type 1 or type 2 diabetes and 85.7% were type 2 diabetes. Subgroup analysis showed that 5.5% type 1, 27.8% type 1 or type 2 and 66.7% type 2 diabetes were between 15 to 20 years. Similarly, between 20 to 35 years, 2.5% were type 1 diabetes, 10% could be either type 1 or type 2 diabetes and 87.5% were type 2 diabetes. Conclusions: C-peptide is secreted in equimolar amounts of insulin, so it can be used for estimation of residual insulin secretion in patients with diabetes. This C-peptide can be of great value in this era of precision medicine in classification of diabetes, with very low secretion in T1DM, high values in T2DM. C-peptide measurement is an inexpensive, widely available test that may assist the clinical management of diabetes, particularly in young and insulin-treated patients where there is uncertainty about diabetes subtype.

Keywords: Fasting C-Peptide, type 1 diabetes, type 2 diabetes.