Global burden of dementia in younger people: an analysis of data from the 2021 Global Burden of Disease StudyResearch in context

Abstract

Summary: Background: Dementia among younger people is rapidly emerging as a global health concern; however, comprehensive research on its shifting burden trends remains insufficient. Methods: Data on the prevalence, incidence, mortality, and disability-adjusted life years (DALYs) associated with dementia occurring in individuals <70 years were extracted from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021. Average annual percentage changes (AAPCs) were calculated to assess trends in age-specific rates (ASRs), including age-specific prevalence rates (ASPRs), age-specific incidence rates (ASIRs), age-specific mortality rates (ASMRs), and age-specific DALY rates (ASDRs) while young-onset dementia (YOD) burden trends were analyzed. The correlation between ASR/AAPC and the sociodemographic index (SDI) was evaluated. Findings: In 2021, the global prevalence of dementia in individuals <70 years increased by 122.33%, with a 128% increase in new cases since 1990. Concurrently, deaths and DALYs of individuals <70 years with dementia rose by 119.28% and 119.77%, respectively. The AAPCs of YOD ASRs during 1990–2021 initially increased and then decreased with increasing SDI levels, with the highest AAPCs of ASPR (2.20 [95%CI: 2.08–2.32] per 100,000), ASIR (2.25 [95%CI: 2.06–2.45] per 100,000), ASMR (2.04 [95%CI: 1.93–2.15] per 100,000), and ASDR (2.06 [95%CI: 1.99–2.13] per 100,000) observed in middle-SDI levels. Additionally, females <70 years bore a higher burden of dementia globally, and gender differences are still widening. Interpretation: The growth rate of YOD is accelerating, particularly in the middle to high SDI region with females bearing a disproportionately higher burden of YOD. Funding: This work was supported by grants from the National High level Hospital Clinical Research Funding, CAMS Innovation Fund for Medical Sciences, and the National Natural Science Foundation of China.

Keywords

• Young-onset dementia
• Global burden of disease
• Risk factors
• Prevalence
• Incidence