Prevalence and factors associated with chronic kidney disease among Fulni-ô Indigenous adults in Brazil

Background Chronic kidney disease (CKD) affects approximately 14% of the global adult population, with Indigenous peoples disproportionately affected due to historical, structural, and social vulnerabilities. Epidemiological data on CKD among Brazilian Indigenous populations remain scarce. This study aimed to estimate the prevalence of CKD and identify associated factors among Fulni-ô Indigenous adults in Northeastern Brazil. Methods This cross-sectional study recruited Fulni-ô Indigenous adults (≥ 18 years) residing in Águas Belas, Pernambuco, Brazil. Sociodemographic, anthropometric, and clinical data were collected, along with venous blood and urine samples. Estimated glomerular filtration rate (eGFR) was calculated using the race-free CKD-EPI 2021 equation, and CKD was defined according to KDIGO criteria (eGFR < 60 mL/min/1.73 m² and/or urinary albumin-to-creatinine ratio [UACR] ≥ 30 mg/g). Associations were assessed using logistic and linear regression. Results Of 911 adults initially evaluated, 569 met inclusion criteria. The estimated prevalence of CKD was 14.9% (95% CI 12.1–18.1). In univariate analysis, older age, diabetes, hypertension, and dyslipidemia were significantly associated with CKD; sex and obesity were not. After multivariable adjustment, only age ≥ 60 years (adjusted OR 3.58; 95% CI 2.03–6.27) and diabetes (adjusted OR 3.03; 95% CI 1.53–5.90) remained independently associated with the composite outcome. In phenotype-specific analyses, diabetes was independently associated with isolated albuminuria. In the adjusted linear regression analysis, older age, hypertension, and dyslipidemia were associated with lower eGFR, while female sex was associated with higher eGFR. Isolated albuminuria with preserved eGFR was the most frequent CKD phenotype. Conclusions The estimated prevalence of CKD among Fulni-ô Indigenous adults was substantial, with older age and diabetes independently associated with the composite outcome. The predominance of isolated albuminuria underscores the importance of routine urinary albumin screening, even among individuals with preserved eGFR, to enable earlier detection of kidney abnormalities and culturally appropriate management strategies in this population. These findings should be interpreted considering the use of single eGFR and UACR measurements, the limited coverage of the target population, and the potential for selection bias.