Patterns of cardiovascular-kidney-metabolic (CKM) syndrome stages and prevalence of lifestyle risk factors in a nationally representative iranian population study

Cardiovascular-kidney-metabolic (CKM) syndrome contributes substantially to mortality and places a substantial burden on healthcare systems. Despite the high prevalence of cardiac, renal, and metabolic disorders in Iran, nationally representative data describing the CKM stage distribution and associated unhealthy lifestyle factors are lacking. We aimed to investigate the national pattern of CKM stages and the prevalence of unhealthy lifestyle behaviors among Iranian adults. This secondary analysis used data from the 2021 STEPS survey. Sociodemographic characteristics, lifestyle factors, and renal, metabolic, and cardiovascular risk indicators were presented across CKM stages (0–4). Geographical variations in stage distribution were also assessed. Categorical variables were presented as weighted percentages with corresponding 95% confidence intervals (CIs). A total of 16,208 participants aged ≥ 25 years were analyzed. Overall, 94.26% of participants met the criteria for CKM stages 1–4, with stage 2 accounting for the largest proportion (65.73%, 95% CI: 64.68, 66.78), followed by stage 1 (13.08%, 95% CI: 12.35, 13.82). Hypertension and metabolic syndrome were the most prevalent cardiometabolic conditions, whereas moderate- to high-risk and very high-risk CKD were the least prevalent. Geographic variations were observed, with northwestern and southwestern provinces showing high stage 3 prevalence but relatively low stage 4 prevalence. Overall, 63.83% (95% CI: 59.74, 67.92) of participants in stage 3 and 57.89% (95% CI: 54.20, 61.58) in stage 4 reported at least two unhealthy lifestyle factors, while 10.19% (95% CI: 7.77, 12.61) and 11.85% (95% CI: 8.98, 14.72), respectively, reported three or more factors. Insufficient fruit and vegetable intake was the most prevalent unhealthy lifestyle factor across all CKM stages. CKM syndrome affects most Iranian adults, predominantly at stage 2. These findings provide descriptive evidence of the national and regional distribution of CKM stages.