Global burden of young-onset Alzheimer's disease and other dementias: a secondary analysis of the global burden of disease study, 2019.

The aging of the world population has led to an increase in the epidemiology and burden of Alzheimer's disease and other dementias.

Objective: To describe the global burden of young-onset Alzheimer's disease and other dementias by world region and income through a secondary analysis of the Global Burden of Disease Study 2019.

Methods: This is a descriptive cross-sectional ecological study. Data by sex and five-year age groups from 40 to 64 years were extracted from the Global Burden of Disease Study results tool. We performed a descriptive analysis of prevalence, incidence, deaths, disability-adjusted life years, years of life lost, and years lived with disability.

Results: In 2019, young-onset Alzheimer's disease and other dementias presented a prevalence of 2.67 cases and an incidence of 0.44 per 1,000 inhabitants globally. It carried a significant burden, resulting in 1.16 disability-adjusted life years per 1,000 inhabitants, primarily due to years of life lost, and to a lesser extent due to years lived with disability. East Asia & the Pacific, Latin America & the Caribbean, and North America are the most affected regions. Burden rates are consistently higher among women; no gradient was observed by country income. Smoking was the most relevant risk factor, presenting a broad difference by country income level.

Conclusion: The global burden of young-onset Alzheimer's disease and other dementias may reshape healthcare requirements and the societal impact of dementias, and its understanding is relevant to inform decisions related to service offerings and research agendas.