Serum C peptide level and renal function in diabetes mellitus

C peptide is an active peptide hormone with potentially important physiological effects. C peptide has the capacity to diminish glomerular hyperfiltration and reduce urinary albumin excretion in both experimental and human type 1 diabetes. The present study is aimed at correlating the serum C peptide level with that of renal clearance, urinary albumin excretion and duration of diabetes. This is a prospective cross sectional study. Patients with diagnosis of type 2 diabetes mellitus were evaluated for their baseline clinical and laboratory profile. Both males and females above the age of 18 years were included in the study. The laboratory investigations include fasting serum C peptide, HbA_1C , serum creatinine, blood urea nitrogen, urine albumin and creatinine. Creatinine clearance was calculated using modification of diet in renal disease formula from serum creatinine value. A total of 168 patients were included in the study, among them 90 were females (53.57%) and 78 males (46.43%). Mean age of the patients was 57.64 years. Pearson correlation test showed negative correlation of serum C peptide level with creatinine clearance, though statistically not significant. Negative correlation was also seen between serum C peptide, and urine albumin, urine albumin creatinine ratio, HbA_1C and duration of diabetes. Mean urine albumin was higher in patients with subnormal C peptide level. Duration of disease was more in patients with lower serum C peptide level. The study has shown weak association of serum C peptide level with microalbuminuria and creatinine clearance. Risk of albuminuria is more in patients with low serum C peptide level.