Risk of mortality associated to chronic kidney disease in patients with type 2 diabetes mellitus: A 13-year follow-up

Objective Our aim was to assess the usefulness of glomerular filtration rate (GFR) and urinary albumin excretion (UAE) to predict the risk of mortality in patients with type 2 diabetes mellitus. Material and methods This is a prospective cohort study in patients with type 2 diabetes mellitus. Clinical end-point was mortality rate. GFR was measured in ml/min/1.73 m 2 and stratified in 3 categories (≥60; 45–59; <45); UAE was measured in mg/24 h and was also stratified in 3 categories (<30; 30–300; >300). Mortality rates were reported per 1000 patient-years. Cox regression models were used to predict mortality risk associated with combined GFR and UAE. The predictive power was estimated with C-Harrell statistic. Results A total of 453 patients (39.3% males), aged 64.9 (SD 9.3) years were included; mean diabetes duration was 10.4 (SD 7.5) years. Median follow-up was 13 years. Total mortality rate was 39.5/1000. The progressive increase in mortality in the successive categories of GFR and UAE was statistically significant ( P < .001). In a multivariable analysis, UAE (HR30-300 = 1.02 and HR > 300 = 2.83; χ 2 = 11.6; P = .003) and GFR (HR45-59 = 1.34 and HR < 45 = 1.84; χ 2 = 6.4; P = .041) were independent predictors for mortality, with no significant interaction. Simultaneous inclusion of GFR and UAE improved the predictive power of models (C-Harrell 0.741 vs. 0.726; P = .045). Conclusions GFR and UAE are independent predictors for mortality in type 2 diabetic patients and do not show a statistically significant interaction.