The burden of cardiovascular-kidney-metabolic syndrome in high versus upper-middle-income countries: integrated analysis of trends, inequality, and risk factors.

BACKGROUND AND AIM: Cardiovascular-kidney-metabolic (CKM) syndrome links vascular, renal, and metabolic dysfunction, but its long-term burden transition and inequality patterns across development settings remain unclear. We compared trends, demographic drivers, inequalities, efficiency gaps, and risk-factor signatures of CKM-related burden in high-income countries (HICs) and upper-middle-income countries (UMICs) from 1990 to 2023, with projections to 2038. METHODS AND RESULTS: Using Global Burden of Disease 2023 estimates, we analyzed seven CKM-related components across 127 countries and territories, including 74 HICs and 53 UMICs. Outcomes included deaths, disability-adjusted life years (DALYs), incidence, prevalence, and age-standardized rates by sex and age. Analyses combined trend, decomposition, forecasting, inequality, frontier, and Random Forest-SHAP risk-attribution methods. From 1990 to 2023, age-standardized DALY rates declined for ischemic heart disease by 57.06% in HICs and 33.07% in UMICs, and for stroke by 57.73% and 61.70%, respectively. Diabetes burden increased in both strata, whereas chronic kidney disease diverged, with age-standardized DALY rates increasing by 23.48% in HICs but decreasing by 16.64% in UMICs. Despite declining standardized vascular rates, UMICs experienced rising absolute ischemic heart disease burden, with DALYs increasing by 77.00% and deaths by 109.14%. Inequality and risk profiles differed by setting: the chronic kidney disease age-standardized DALY concentration index was -0.363 in HICs versus -0.233 in UMICs, and the diabetes population-attributable fraction for high body-mass index was 54.7% versus 26.6%. CONCLUSIONS: CKM prevention should be stratified: HICs need metabolic-renal and equity-focused chronic care, while UMICs need vascular protection, early metabolic prevention, tobacco control, and clean household energy transitions.