Women at Higher Risk for Dementia Than Men

TOPLINEWomen developed dementia at higher age-standardized rates than men across diverse populations, a meta-analysis spanning participants from 18 countries showed. Age- and sex-standardized incidence rates were higher in low- and middle-income countries than in high-income countries.METHODOLOGYResearchers conducted a meta-analysis of harmonized individual-level data from 22 population-based longitudinal cohorts across 18 countries or territories spanning six continents.Recruitment began between 1990 and 2011, and follow-up was conducted through 2021 (median of four assessment waves).The study included 38,418 adults without dementia at baseline (age, 60-102 years; 57.7% women; 30.6% individuals from low- and middle-income countries).Incidence of all-cause dementia was estimated per 1000 person-years at risk. All-cause dementia was identified using clinically based diagnoses at each wave.TAKEAWAYOver the follow-up period, 3001 participants developed dementia. Age- and sex-standardized incidence of all-cause dementia was 9.7, equating to approximately 11.4 million new dementia cases globally in 2023. Age-standardized incidence of all-cause dementia was higher among women than among men (10.6 vs 8.6; P < .001).Age- and sex-standardized incidence of all-cause dementia was higher in low- and middle-income countries than in high-income countries (13.6 vs 8.3; P = .02). Age-standardized incidence of all-cause dementia was higher in low- and middle-income countries than in high-income countries (15.3 vs 9.3 among women and 12.6 vs 7.5 among men).Age- and sex-standardized incidence of all-cause dementia was the highest in Latin America (13.1) and Asia (13) and the lowest in Oceania (7.6), but the differences were not statistically significant. Assuming age- and sex-specific incidence rates to be stable and applying them to the projected 2050 population yielded an incidence of 11.7 (12.8 among women vs 10.5 among men), corresponding to 24.7 million new cases globally.IN PRACTICE"The observed sex- and income-stratified differences, together with substantial cross-country variation, highlight the need for targeted equitable prevention strategies and expanded diagnostic and care capacity, particularly for women and in underresourced settings," the authors wrote.SOURCEThe study was led by Ashleigh S. Vella, PhD, Centre for Healthy Brain Ageing, Discipline of Psychiatry & Mental Health, School of Clinical Medicine, University of New South Wales, Sydney, Australia. It was published online on October 12 in JAMA Neurology.LIMITATIONSThe projections assumed stable age-sex-specific incidence and country-income classifications over time. Diagnostic criteria and assessment methods were varied, and large heterogeneity was observed in pooled estimates. Additional limitations included potential interval-censoring bias, the underrepresentation or absence of several regions, and the potential underrepresentation of institutionalized older adults, people with lower socioeconomic status, and certain ethnic or rural groups.DISCLOSURESThe study was funded by the National Institute on Aging. Disclosure information for the study investigators is available in the original study publication.This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.