INTRODUCTION: Dementia persists as a critical global health challenge. Smoking is a modifiable behavioral factor associated with dementia, although improvements in healthcare have reduced dementia prevalence and mortality. Evaluating long-term changes in the smoking-attributable dementia burden provides a useful reference for informing and contextualizing dementia prevention efforts. METHODS: This study is a secondary analysis of Global Burden of Disease (GBD) 2021 estimates. We examined smoking-attributable deaths and disability-adjusted life years (DALYs) for dementia among adults aged ≥40 years, across 204 countries and territories from 1990 to 2021. We assessed temporal trends using age-standardized rates and estimated annual percentage changes (EAPC), evaluated inequality across sociodemographic development levels, and projected the burden to 2035 using a Bayesian age-period-cohort (BAPC) model. RESULTS: In 2021, the global burden of dementia attributable to smoking reached 1533214 DALYs (95% UI: 635494-3540712), representing an approximate twofold increase compared with 1990. However, the age-standardized DALY rate (ASDR) declined significantly over the same period, with an EAPC of -0.88 (95% CI: -0.92 - -0.83). Population growth and population ageing were the dominant contributors to the increase in DALYs, accounting for 112.17% and 26.02%, respectively, whereas epidemiological improvements partially offset the burden (-38.19%). In terms of regional variation, East Asia bore the heaviest absolute burden. BAPC projections indicated that despite continued declines in ASDR, smoking-attributable dementia DALYs are expected to keep increasing through 2035. CONCLUSIONS: Despite declining age-standardized rates, the absolute burden of smoking-attributable dementia continues to rise, partly because reductions in smoking exposure are insufficient to counter demographic pressures from population ageing and growth. Persistent disparities across sociodemographic index groups further indicate that gains in tobacco control do not consistently translate into proportional reductions in dementia burden. Aligning tobacco control with ageing-responsive health system strategies will be essential to moderating future burden growth.
Hu et al. (Sat,) studied this question.