Global burden,trends,and projections of Alzheimer's disease and other dementias attributable to high body mass index from 1990 to 2040: A comprehensive analysis of the Global Burden of Disease Study 2021

Abstract

Background

High body mass index (BMI) is a modifiable risk factor for Alzheimer's disease and other dementias (ADODs), but a global assessment of BMI-attributable ADOD burden and its future trends is limited.

Objective

To quantify the spatiotemporal patterns, inequalities, and projections of BMI-attributable ADOD burden across 204 countries and territories from 1990 to 2021, with forecasts to 2040.

Methods

Using Global Burden of Disease (GBD) 2021 risk estimates, we analyzed high BMI-attributable ADOD deaths, disability-adjusted life years (DALYs), age-standardized mortality rate (ASMR), and age-standardized DALY rate (ASDR) by age, sex, region, and Socio-demographic Index (SDI). Trends were assessed with estimated annual percentage change (EAPC). Drivers were examined using decomposition analyses, and future trends were projected with autoregressive integrated moving average (ARIMA) models. Population attributable fractions (PAFs) were calculated for selected countries.

Results

High BMI-attributable ADOD deaths increased from 31,577 in 1990 to 139,439 in 2021, with ASMR rising from 1.22 to 1.79 per 100,000 people (EAPC=1.17%). DALYs grew from 644,750 to 2,665,746, with ASDR increasing from 21.39 to 32.86 per 100,000 (EAPC=1.32%). Females faced a higher absolute burden, while males showed faster increases in standardized rates. Growth was concentrated in low- and middle-SDI regions, particularly East/Southeast Asia and parts of sub-Saharan Africa.

Conclusions

BMI-attributable ADOD burden has risen significantly since 1990, with notable socioeconomic disparities, and is expected to increase through 2040. Urgent action is needed for obesity prevention and integrated risk management.