Microalbuminuria and Serum Cystatin C Correlation as Early Markers of Kidney Dysfunction in Patients with Type 1 Diabetes Mellitus
Room No. 19, RDF 1 Quarters, MBBS Ladies Hostel Campus, Government Thiruvannamalai Medical College and Hospital, Thiruvannamalai-606604, Tamil Nadu, India.
Introduction: Diabetes mellitus is the most common single cause of End Stage Renal Disease (ESRD). About 20-30% of patients with Type 1 Diabetes Mellitus (Type 1 DM) develop diabetic nephropathy as a serious complication which is the major cause of morbidity and mortality. Early identification of renal impairment is crucial to prevent the progression of nephropathy to a significant degree, because several interventions have greatest impact if initiated very early in the course of the disease.
Aim: To study the correlation of microalbuminuria and serum cystatin C for the early prediction of renal impairment in patients with Type 1 DM.
Materials and Methods: This was a cross-sectional study conducted from January 2016 to June 2016 on type 1 DM patients attending Diabetology Outpatient Department (OPD). According to the duration of diabetes, pateints were divided into two groups, Group I with <5 years and Group II with >5 years duration. The patients in each group were categorised as cases and controls, based on the Albumin Creatinine Ratio (ACR), serum urea, creatinine, cystatin C, glycated haemoglobin (HbA1c), and urine ACR levels were estimated. Student’s unpaired t-test was used to compare the means between two independent groups. Pearson correlation coefficient was used to estimate the degree of correlation between two quantitative variables.
Results: Seventy-two patients with type 1 DM were included in the study. Cystatin C levels in cases (0.89±0.35) when compared to controls (0.67±0.26) in more than five years duration of type 1 DM was found to be statistically significant (p<0.01). Positive correlation between cystatin C and ACR (r=0.4, p<0.05) was found to be statistically significant in more than five years duration. It indicates that serum cystatin C levels increases as the values of ACR increases. There was no significant difference in cystatin C levels in patients with less than five years duration of type 1 DM.
Conclusion: Serum cystatin C may be considered as an early predictor of renal impairment in type 1 DM patients with more than five years duration. However, in this study cystatin C carries no significance in less than five years duration of type 1 DM patients.