Divergent epidemiologic, shared risks: a comparative global analysis of COPD, ischemic stroke, and intracerebral hemorrhage

BACKGROUND: Although COPD and stroke share pathological mechanisms and risk factors, their epidemiological patterns differ significantly. This study investigates the global burden of COPD and stroke, analyzing their shared risk factors and epidemiological disparities to inform targeted prevention strategies. METHODS: Using Global Burden of Disease (GBD) 2021 estimates, we conducted a repeated cross-sectional comparison of COPD, IS, and ICH from 1990 to 2021. Historical age-standardized rates were taken directly from archived GBD records labelled 'Age-standardized', whereas age-specific analyses used groups aged ≥20 years. We examined temporal, geographical, age-specific, sex-specific, and Socio-demographic Index (SDI) patterns, shared risk-attributable DALY rates, and exploratory Bayesian age-period-cohort (BAPC) projections through 2050. RESULTS: From 1990 to 2021, absolute incident cases for all three conditions increased, while age-standardized incidence rates declined. In 2021, COPD had the highest global ASIR, ASMR, and ASDR among the three diseases. Country-level first-place counts differed by metric: COPD had the highest ASIR in 187 countries and territories, IS the highest ASMR in 110, and ICH the highest ASDR in 95. Air pollution accounted for the largest global attributable DALY burden among the shared Level 2 categories, whereas tobacco predominated in high-SDI settings. Exploratory BAPC projections suggested continued ASDR declines through 2050, with IS potentially having the highest projected ASDR, while age-specific burden increasingly shifted toward older populations. CONCLUSION: Prevention priorities should reflect disease burden and local resources, with sustained attention to tobacco exposure and air pollution. The observed geographical overlap supports population-level planning and motivates individual-level research, but it does not establish COPD-stroke comorbidity, causality, or clinical predictive value.