Cardiovascular risk factors and accelerated cognitive decline in midlife

ObjectiveIncreasing evidence supports an association between midlife cardiovascular risk factors (CVRFs) and risk of dementia, but less is known about whether CVRFs influence cognition in midlife. We examined the relationship between CVRFs and midlife cognitive decline.MethodsIn 2,675 black and white middle-aged adults (mean age 50.2 ± 3.6 years, 57% female, 45% black), we measured CVRFs at baseline: hypertension (31%), diabetes mellitus (11%), obesity (43%), high cholesterol (9%), and current cigarette smoking (15%). We administered cognitive tests of memory, executive function, and processing speed at baseline and 5 years later. Using logistic regression, we estimated the association of CVRFs with accelerated cognitive decline (race-specific decline ≥1.5 SD from the mean change) on a composite cognitive score.ResultsFive percent (n = 143) of participants had accelerated cognitive decline over 5 years. Smoking, hypertension, and diabetes mellitus were associated with an increased likelihood of accelerated decline after multivariable adjustment (adjusted odds ratio [AOR] 1.65, 95% confidence interval [CI] 1.00–2.71; AOR 1.87, 95% CI 1.26–2.75; AOR 2.45, 95% CI 1.54–3.88, respectively), while obesity and high cholesterol were not associated with risk of decline. These results were similar when stratified by race. The likelihood of accelerated decline also increased with greater number of CVRFs (1–2 CVRFs: AOR 1.77, 95% CI 1.02–3.05; ≥3 CVRFs: AOR 2.94, 95% CI 1.64–5.28) and with Framingham Coronary Heart Disease Risk Score ≥10 (AOR 2.29, 95% CI 1.21–4.34).ConclusionsMidlife CVRFs, especially hypertension, diabetes mellitus, and smoking, are common and associated with accelerated cognitive decline at midlife. These results identify potential modifiable targets to prevent midlife cognitive decline and highlight the need for a life course approach to cognitive function and aging.
Methods
CARDIA is a multicenter longitudinal study designed to measure risk factors for coronary artery disease in a cohort of black and white women and men (n=5115), initially aged 18 to 30 years and healthy at enrollment. To assess the effect of CVRF exposure on cognitive changes during midlife, we included participants who completed cognitive testing at Year 25 (2010-11), our study’s baseline, and five years later (follow up mean (SD)=5.02 (0.34) years, range=3.90-6.11 years) .