Prevalence of normoalbuminuric chronic kidney disease among individuals with type 2 diabetes mellitus from India

Background & objectives: A subset of diabetic individuals are known to develop progressive renal insufficiency without albuminuria, referred to as normoalbuminuric chronic kidney disease (NACKD). There is, however, a paucity of studies regarding this condition in India. So, this study, aimed to find the prevalence of normoalbuminuric renal dysfunction and its clinical associations in diabetic Indian population. Methods: Medical record search of patients with type 2 diabetes mellitus at a tertiary care centre was done. Based on the urinary albumin:creatinine ratio (>30 mg/g creatinine) and estimated glomerular filtration rate (e-GFR) (<60 ml/min/1.73m(2)), individuals were classified as having, (i) no kidney disease (NKD), (ii) chronic kidney disease (CKD), (iii) albuminuria alone (ALB), (iv) normoalbuminuric low e-GFR (NACKD) and (v) albuminuria with low e-GFR albuminuric CKD (ACKD). Furthermore, the clinical and biochemical parameters of these groups were also compared. Results: Data from 3534 diabetes patients with a mean age of 53.8 +/- 10.9 yr and mean duration of diabetes of 10.3 +/- 7.5 yr were available for the analysis. NACKD constituted 39.1 per cent of the patients with reduced e-GFR, NACKD was found in 2.1 per cent and ACKD in 3.4 per cent of all diabetic patients. Compared to NKD patients, was found an independent association between NACKD and higher age, male sex, lower body weight and statin intake but not with glycated haemoglobin, fasting and postprandial plasma glucose. Patients with NACKD were found to be older than those with ACKD. Retinopathy was found to be more prevalent in the ACKD patients, whereas the rates of macrovascular complications were found to be similar between the groups. The prevalence of NACKD relative to ACKD decreased in CKD stages 3b, 4 and 5. Interpretation & conclusions: The results of this study suggest that NACKD constituted greater than one third of patients with diabetes and decreased e-GFR, which showed a strong association with age but not with duration or severity of hyperglycaemia or the presence of retinopathy. Both NACKD and ACKD showed similar associations with macrovascular disease.