Cardiometabolic Multimorbidity and Dementia Onset among Middle-aged and Older Adults: Differences by Race/Ethnicity

Abstract Background Racial/ethnic minoritized groups in the U.S. have higher prevalence of cardiometabolic multimorbidity and experience higher risk of dementia. This study evaluates the relationship between cardiometabolic multimorbidity and dementia onset according to racial/ethnic group in a nationally representative cohort of U.S. middle-aged and older adults. Methods Data from the Health & Retirement Study (1998-2018, N=7,960, mean baseline age 59.4 years) and discrete-time survival models were used to estimate differences in the risk of dementia onset, defined by Langa-Weir classification. Models included race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic), chronic disease/multimorbidity categories (no disease, one disease, cardiovascular multimorbidity, metabolic multimorbidity, cardiometabolic multimorbidity, other multimorbidity), age, sex, education, wealth, body-mass index, and proxy status. Results Over a mean follow-up of 14.6 years, 7.7% of the participants (n=614) developed dementia. In the fully adjusted model, participants with cardiometabolic multimorbidity had the highest risk of dementia onset (HR:3.27, 95%CI: 2.06,5.21), followed by metabolic (HR:1.83, 95%CI: 1.14,2.94) and cardiovascular (HR:1.81, 95%CI: 1.24,2.64) multimorbidity, relative to participants with no disease. The risk of dementia was significantly greater among Black (HR: 6.40, 95% CI: 3.84,10.67) and Hispanic participants (HR: 4.90, 95% CI: 2.85,8.43) with cardiometabolic multimorbidity, compared to White adults with no disease. Conclusions Individuals from racial/ethnic minoritized groups have a higher risk of dementia. The risk of dementia onset was significantly greater for Black and Hispanic participants experiencing cardiometabolic multimorbidity, highlighting the value of intervening on cardiometabolic conditions among middle-age and older adults, in particular those from racial/ethnic minoritized backgrounds to reduce the risk of developing dementia.