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

Background: Racial/ethnic minoritized groups in the United States have a higher prevalence of cardiometabolic multimorbidity and experience a 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, and 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 with 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 in cardiometabolic conditions among middle-Aged and older adults, in particular, those from racial/ethnic minoritized backgrounds to reduce the risk of developing dementia.