Chronic kidney disease in Russia: the Ural eye and medical study

Background To examine the prevalence of chronic kidney disease (CKD) and its associations in a Russian population. Methods Out of 7328 eligible individuals, the population-based cross-sectional Ural Eye and Medical Study included 5899 (80.5%) individuals aged 40+ years and undergoing a detailed medical examination. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic-Kidney-Disease-Epidemiology-Collaboration (CKD-EPI) equation. Results The mean eGFR was 72.3 +/- 19.1 mL/min/1.73m(2) (median:70.3 mL/min/1.73m(2)). Prevalence of CKD stage 3a (eGFR< 60 mL/min/1.73m(2) and > 45 mL/min/1.73m(2)), CKD stage 3b (eGFR< 45 mL/min/1.73m(2) and > 30 mL/min/1.73m(2)) and CKD stage 4+ (eGFR< 30 mL/min/1.73m(2)) were 1351/5841 (23.1%;95% confidence interval (CI):22.1,24.2), 294/5841 (5.0%;95%CI:4.5,5.6), and 29/5841 (0.5%;95%CI:0.3,0.7), respectively. The CKD stage 3+ prevalence increased (P < 0.001) from 11.1% (95%CI:8.4,13.9) in 40-44-year-olds to 56.8% (95%CI:52.8,60.8) in 75 + year-olds. In univariate analysis, CKD stage 3a + prevalence increased with higher systolic blood pressure (P < 0.001). In multivariable analysis, higher prevalence of CKD stage 3a + was associated with older age (P < 0.001;odds ratio (OR):1.06;95%CI:1.05,1.07), female sex (P < 0.001;OR:2.29;95%CI:1.94,2.69), rural region of habitation (P = 0.001;OR:1.29;95%CI:1.11,1.50), higher body mass index (P = 0.03;OR:1.02;95%CI:1.002,1.03), lower prevalence of house ownership (P = 0.02;OR:0.57;95%CI:0.35,0.92), higher prevalence of mostly sitting or standing during work (P < 0.001;OR:1.40;95%CI:1.20,1.64), higher serum concentration of triglycerides (P < 0.001;OR:1.23;95%CI:1.12,1.35) and blood urea nitrogen (P < 0.001;OR:1.33;95%CI:1.27,1.40), lower serum concentration of hemoglobin (P = 0.03;OR:0.99;95%CI:0.99,0.999), and lower prevalence of chronic obstructive pulmonary disease (P < 0.001;OR:0.57;95%CI:0.42,0.78). Conclusions In this population from Russia aged 40+ years, prevalence of CKD stage 3+ (28.7%;95%CI:27.5,29.8) was relatively high as compared to populations from other countries. Associated factors were older age, female sex, rural region, higher body mass index, a sedentary lifestyle, and lower socioeconomic background.