Prevalence and risk factors of chronic kidney disease among Iranian adults with and without diabetes: a cross-sectional study using STEPS 2021 national survey.

Abstract

Chronic kidney disease (CKD) is a global health concern and a major long-term complication of diabetes, yet its burden remains understudied in regions with limited epidemiological data. This study aimed to evaluate the prevalence of CKD and its associated risk factors in the Iranian adult population, stratified by diabetes status. Population-based cross-sectional study. Nationally representative survey across Iran (STEPS 2021). 17 607 adults aged ≥25 years with complete kidney function and albuminuria data, selected through systematic sampling with weighting to ensure national representativeness. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² (CKD-EPI equation) or urine albumin-to-creatinine ratio (UACR) ≥30 mg/g and categorised into four KDIGO (Kidney Disease: Improving Global Outcomes) 2024 risk groups for CKD progression. Logistic regression assessed the associations between CKD and sociodemographic, clinical and behavioural factors; multinomial logistic regression examined diabetes associations with KDIGO risk categories. The national prevalence of CKD was 11.9% (95% CI 11.2% to 12.6%), with 9.1% (8.5% to 9.9%) among individuals without diabetes and 28.6% (26.2% to 31.1%) among those with diabetes. According to KDIGO classification, 88.1% (87.4% to 88.8%) were at low risk, 9.0% (8.4% to 9.6%) at moderate risk, 2.0% (1.6% to 2.4%) at high risk and 0.9% (0.7% to 1.1%) at very high risk. Albuminuria was more prevalent than low eGFR in both groups with (22.5% (20.4% to 24.8%) vs 10.3% (8.7% to 12.1%)) and without (5.7% (5.2% to 6.3%) vs 4.3% (3.8% to 4.8%)) diabetes. Diabetes was more strongly linked to albuminuria than low eGFR and was progressively associated with higher risk categories (adjusted ORs (aORs) 2.41 (2.03-2.86) for moderate, 2.63 (1.74-3.97) for high, 3.93 (2.56-6.07) for very high vs low-risk). CKD prevalence was highest in northwest Iran, increased significantly with age, with a stronger association observed for low eGFR than albuminuria, and was associated with hypertension (aOR 2.41 (2.07-2.82)), dyslipidaemia (1.60 (1.31-1.94)), obesity (1.94 (1.59-2.36)), ischaemic heart disease (1.53 (1.25-1.87)) and physical inactivity (1.40 (1.20-1.62)). Higher socioeconomic status and education were associated with lower odds of CKD. CKD is a major burden, especially in individuals with diabetes, with regional and socioeconomic disparities. Addressing risk factors, integrating CKD into non-communicable disease surveillance and prioritising it in global health agendas, including the Sustainable Development Goals, are essential.