Global, regional, and national trends in disease burden attributable to high temperature exposure in adults aged 65 years and older from 1990 to 2021

Background Climate change significantly impacts health, particularly for individuals aged 65 and older, increasing heat-related illnesses and mortality. Understanding this burden is vital for public health planning. Methods This study analyzes data from the Global Burden of Disease (GBD) Study 2021, focusing on deaths, disability-adjusted life years (DALYs), and age-standardized ratios related to high-temperature exposure in individuals aged 65+ across 204 nations and territories. It examines trends from 1990 to 2021, assesses health inequities using measures like the Inequality Slope Index and Concentration Index, and projects future trends using a Bayesian Age-Period-Cohort (BAPC) model. Results In 2021, there were 247,098 heat-related deaths globally among those aged 65+, with an age-standardized mortality rate (ASMR) increase from 26.3 to 27.1 per 100,000 (annual average percentage change (AAPC): 0.22). Aggregate DALYs reached 3,986,215, with the age-standardized DALYs rate (ASDR) rising from 419.6 to 526.7 per 100,000. South Asia and East Asia experienced higher burdens, while Oceania and Western Australia had lower rates. Lower-middle Socio-demographic Index (SDI) regions faced greater burdens, with absolute inequality increasing and relative inequality slightly declining. Non-communicable diseases (NCDs), such as ischemic heart disease and stroke, accounted for a significant proportion of heat-related deaths and DALYs, with upward trends. Projections indicate continued increases in deaths and DALYs by 2050. Conclusions This study highlights the growing global burden of high-temperature exposure on older adults, emphasizing regional disparities and the dominance of NCDs. These findings underscore the need for targeted public health strategies to address climate-related health risks in vulnerable populations.