Prevalence of impaired kidney function & its association with diabetes & hypertension in India: The ICMR-INDIAB study (ICMR-INDIAB-22).

Background & objectives Chronic kidney disease remains a leading cause of morbidity and mortality in developing nations like India. This study was conducted to assess the prevalence of impaired kidney function (IKF) and its association with type 2 diabetes(T2D) and systemic hypertension (HTN) in India. Methods A total of 25,408 individuals (with/without HTN and T2D), a nationally representative sample, were included from the Indian Council of Medical Research-INdia-DIABetes (ICMR-INDIAB) cross-sectional study. IKF was defined as estimated glomerular filtration rate eGFR <60 mL/min/1.73 m2 (CKD-EPI-2009 equation-race free). Results The overall weighted prevalence of IKF was 3.2 per cent [95% confidence interval (CI): 2.9-3.5] with no significant differences between urban [3.3% (2.8-3.7)] and rural areas [3.2% (2.9-3.5)], but higher among males [3.8% (3.4-4.2)] compared to females [2.6% (2.3-2.9)]. Four States in the country had prevalence of IKF ≥6 per cent and another four States had prevalence ≥4 per cent. The decrease in eGFR for every year increase in age was around 1.0 ml/min/1.73 m2; this was greater in urban areas, females, and in those with both HTN and T2D. Presence of T2D alone was associated with significantly higher risk of IKF compared to HTN alone (Odds Ratio 3.2 vs. 2.4); however, the risk was six fold higher in individuals with both HTN and T2D. Interpretation & conclusions The burden of IKF is high across India and is likely to rise further owing to high prevalence of metabolic risk factors. T2D seems to confer higher risk of IKF compared to HTN in this population.