Associations of access to exercise opportunities and physical inactivity with cardiovascular-kidney-metabolic mortality: a nationwide ecological study.

Objectives: To systematically investigate the associations of macro-environmental exposures-specifically, county-level access to exercise opportunities (ATEO)-and population-level physical inactivity (PI) with overall and subtype-specific cardiovascular-kidney-metabolic (CKM) mortality across the United States, and to explore the heterogeneity of these associations across distinct sociodemographic and geographic subgroups. Methods: We conducted a county-level ecological study using 2014-2019 data from CDC WONDER for CKM mortality and from County Health Rankings for physical activity measures. County-level age-adjusted CKM mortality rates were compared across quartiles of access to exercise opportunities and physical inactivity, with stratification by sex, race, and urbanization. Rate ratios (RRs) for CKM mortality and its three components (cardiovascular, kidney, and metabolic) were estimated using quasi-Poisson generalized linear models, with adjustment for year only (Model 1) or for comprehensive demographic and socioeconomic covariates (Model 2). Results: A clear geographic gradient emerged: counties in the South had the least exercise access, the highest inactivity levels, and the greatest CKM mortality burden. Greater access to exercise opportunities was inversely associated with total CKM mortality [Q4 vs. Q1, RR,0.89 (0.87-0.90)], but this benefit was not uniform across CKM components-while cardiovascular mortality decreased with better access (RR, 0.89), diabetes and renal failure mortality showed unexpectedly higher rates in high-access counties. Regarding physical inactivity, higher levels were associated with an overall elevation in total CKM mortality [Q4 vs. Q1, RR 1.23 (1.22-1.25)], primarily driven by cardiovascular disease (RR 1.24). However, the associations with the other two components were less consistent: diabetes mortality showed a modest increase (RR 1.23) but with a non-monotonic gradient across quartiles, while renal failure mortality unexpectedly decreased in the highest inactivity quartile. These general patterns were observed across most demographic and geographic subgroups, although the effect magnitudes varied by sex, race, and urbanization. Conclusion: Our findings demonstrate that limited access to exercise opportunities and higher physical inactivity are associated with elevated total CKM mortality, with cardiovascular disease being the predominant driver. While the associations with diabetes and renal failure showed some heterogeneity, these results support population-wide efforts to reduce physical inactivity and targeted environmental investments in underserved communities as potential strategies to alleviate the combined burden of cardiovascular, diabetic, and renal mortality.