Dementia burden among women in China: A cross-national comparative analysis with the United States and Japan using GBD 2021

This study aims to quantify the burden of Alzheimer's disease and other dementias among women in China from 1990 to 2021 and compare these patterns with those in the United States and Japan, identifying drivers and informing targeted prevention and intervention strategies. We extracted dementia data for women aged ≥ 40 years in China, the United States, and Japan from the GBD 2021 database, including prevalence, mortality, and disability-adjusted life years (DALYs). Trends in age-standardized prevalence rate, age-standardized death rate, and age-standardized DALY rate from 1990 to 2021 were summarized using estimated annual percentage change (EAPC) and percent change. Factor decomposition quantified the contributions of population aging, population growth, and epidemiological change to female dementia mortality. Pearson correlation examined associations between age-standardized DALY rates and the socio-demographic index. A Bayesian age-period-cohort model projected dementia prevalence and mortality among Chinese women from 2022 to 2036. In 2021, China had 10.83 million women living with dementia and 3,28,400 dementia-related deaths. The age-standardized prevalence rate, age-standardized death rates, and age-standardized DALY rate among Chinese women were 1025.11, 33.80, and 631.38 per 1,00,000, respectively - each higher than the corresponding rates in the United States (855.19, 31.60, and 563.46 per 1,00,000) and Japan (759.99, 29.57, and 516.08 per 1,00,000). Across all 3 countries, the dementia burden among women exceeded that among men. In China, prevalence peaked at ages 75 to 79. Elevated fasting plasma glucose and high body mass index were the principal risk factors. Population growth and aging were the main drivers of rising dementia mortality among Chinese women. Projections indicate that both prevalence and mortality among Chinese women will continue to increase through 2036. The burden of dementia among women in China exceeds that in the United States and Japan and is projected to grow further. Strengthening early detection, midlife health management, and health insurance coverage, with particular attention to women's health needs, is recommended to mitigate the future burden.