Projected extreme temperature event-attributable dementia deaths in China: a climate-ageing-adaptation framework

Area of Science:

• Environmental Health
• Gerontology
• Epidemiology

Background:

• Climate change exacerbates global health risks, yet its specific impact on Alzheimer's disease and other dementias (ADD) mortality from extreme temperatures is unclear.
• Population aging in China presents a growing challenge for public health, particularly concerning age-related diseases like ADD.

Purpose of the Study:

• To project future deaths from Alzheimer's disease and other dementias (ADD) attributable to extreme temperature events in China.
• To account for the combined influences of climate change, population aging, and adaptation strategies on ADD mortality.
• To inform climate-resilient public health policies for aging populations.

Main Methods:

• Utilized a time-stratified case-crossover design with 399,036 ADD deaths (≥60 years) in China (2013-2020) to assess mortality risks from extreme temperatures.
• Developed an integrated climate-ageing-adaptation framework incorporating exposure-response functions, high-resolution climate projections, and demographic forecasts.
• Projected county-level ADD deaths under various Shared Socioeconomic Pathways (SSP)-Representative Concentration Pathways (RCP) and adaptation scenarios for the 2030s, 2050s, and 2080s.

Main Results:

• Without adaptation, heatwave-attributable ADD deaths are projected to increase 11-fold by the 2080s under the SSP5-RCP8.5 scenario, reaching 59,088 deaths.
• While cold spell-related deaths may decline, the rise in heatwave mortality will lead to a net increase in total temperature-attributable ADD deaths.
• Adaptation measures could potentially prevent up to 76.4% of heatwave-attributable ADD deaths.

Conclusions:

• The synergy between climate change and population aging is expected to significantly elevate dementia mortality in China.
• Urgent greenhouse gas emission reductions and tailored adaptation strategies are crucial to mitigate projected increases in ADD deaths.
• Integrating dementia care into climate resilience planning is essential for protecting vulnerable aging populations.