Glomerular filtration rate and cystatin c as markers for diabetic nephropathy

Diabetes is recognized as a major risk factor for the development of kidney disease. Diabetic subjects with kidney disease may be at high risk for developing other health complications. The early detection of kidney dysfunction in subject with type 1 diabetes is of vital important to treat the progression to diabetic nephropathy. The aim of this study is to assess the level of cystatin C for studying early renal function decline in type 1 diabetic patients. This study included 64 type 1 diabetes mellitus patients (male and female) all the patients were hyperglycaemic with poor glucose control and control group included 30 healthy age matching subjects. Levels of HbA1c, serum fasting blood glucose, lipid profile, uric acid, creatinine and cystatin C were determined. Glomerular filtration rate was detected according to cockcroft-gault (CG) and modification of diet in renal disease (MDRD) formulas. For uric acid level a significant reduction was found in patients with GFRMDRD>90. The serum levels of cholesterol showed a significant increase (P< 0.05) and a very highly significant increase (P< 0.005) in high density lipoprotein in patients with GFRMDRM ˃ 90 ml/min/1.73m2, meanwhile the serum level of low density lipoprotein showed a non-significant increase in patients with GFRMDRM ˃ 90 ml/min/1.73m2. A highly significant decrease was found in cystatin C and creatinine (P< 0.01) and a very highly significant decrease (P< 0.001), (P< 0.000) in both formulas CG and MDRD > 90. This study may suggest that age, BMI, gender, glycaemic control and duration of the diabetes may influence the level of cystatin C and the GFR provides a good index for the decline of kidney function.