PREVALENCE AND RISK FACTORS OF DIABETIC NEPHROPATHY IN AN URBAN SOUTH INDIAN POPULATION: THE CHENNAI URBAN RURAL EPIDEMIOLOGY STUDY (CURES - 45)

Abstract

Objective: The aim of this study was to determine the prevalence of diabetic nephropathy among urban Asian Indian type 2 diabetic subjects.

Research design and Methods: Type 2 diabetic subjects [n=1716], inclusive of ‘known’ diabetic (KD) subjects (1363/1529, response rate 89.1%) and randomly selected newly diagnosed diabetic (NDD) subjects [n=353] were selected from the Chennai Urban Rural Epidemiology Study (CURES). Microalbuminuria was estimated by immunoturbidimetric assay and diagnosed if albumin excretion was between 30 -- 299 μg/mg of creatinine and overt nephropathy if it was ≥300 μg/mg of creatinine in the presence of diabetic retinopathy, which was assessed by stereoscopic retinal colour photography.

Results: The prevalence of overt nephropathy was 2.2% [95% confidence interval [CI]:1.51-2.91]. Microalbuminuria was present in 26.9% [95% CI:24.8-28.9]. Compared to the NDD subjects, KD subjects had greater prevalence rates of both microalbuminuria with retinopathy and overt nephropathy [8.4% vs. 1.4%, p<0.001 and 2.6% vs. 0.8% p=0.043, respectively]. Logistic regression analysis showed that HbA1c [odds ratio [OR]:1.325,95% CI:1.256-1.399,p<0.001], smoking [OR:1.464, p=0.011],duration of diabetes [OR:1.023,p=0.046], systolic blood pressure [OR:1.020,p<0.001] and diastolic blood pressure [OR:1.016,p=0.022] were associated with microalbuminuria. HbA1c [OR:1.483,p<0.0001], duration of diabetes [OR:1.073,p=0.003] and systolic blood pressure [OR:1.031,p=0.004] were associated with overt nephropathy.

Conclusions: The results of the study suggest that in urban Asian Indians, the prevalence of overt nephropathy was 2.2% and macroalbuminuria, 26.9%. Duration of diabetes, HbA1c and systolic blood pressure were the common risk factors for overt nephropathy and microalbuminuria.