CKD and CKDu in northern Peru: a cross-sectional analysis under the DEGREE protocol

Background: This study estimated the prevalence and risk factors for decreased estimated glomerular filtration rate (eGFR) in those without known hypertension, type 2 diabetes mellitus, or heavy proteinuria as a surrogate marker for chronic kidney disease of unknown cause (CKDu) among adults in the North of Peru. Methods: A cross-sectional study was conducted following the Disadvantaged Populations eGFR Epidemiology (DEGREE) Study protocol. Low eGFR was defined based on a single eGFR ≤60 mL/min/1.7m² estimated using the CKD-EPI equation. Environmental conditions related to CKDu (i.e., work in agriculture or sugarcane, water source, heat intolerance, and pesticide exposure) were evaluated, in addition to traditional risk factors for CKD (i.e., smoking, heavy drinking, physical activity, hypertension, type 2 diabetes mellitus, urolithiasis, among others). Results: A total of 1514 subjects were included in the study, mean age 45.1 (SD: 16.4), and 55.2% were females. Overall, only 26 cases (1.7%; 95%CI: 1.1–2.5%) had an eGFR < 60 mL/min/1.7m² compatible with CKD definition; when those with hypertension and type-2 diabetes or heavy proteinuria were excluded, according to the DEGREE protocol, the estimate fell to 0.9% (95%CI: 0.4–1.5%). Low physical activity levels (OR = 1.99; 95%CI: 1.18–3.34), hypertension (OR = 2.07; 1.26–3.41), and urolithiasis (OR = 1.97; 95%CI: 1.18–3.27) were factors associated with low eGFR. Conclusions: A low population-based prevalence of low eGFR (as a surrogate for CKDu), both in rural and urban settings areas, in the Northern Peru, was found. Low physical activity levels, hypertension and urolithiasis were factors associated with low eGFR. Interventions to prevent CKD cases may be focused on well-known CV risk factors and urolithiasis.