BMI across the lifespan and midlife cognitive function: The Bogalusa Heart Study

Abstract

AbstractBackgroundGreater adiposity in middle age or earlier has been associated with both poorer and greater cognitive functioning late in life, as well as greater and poorer risk of AD (Buchman et al., 2005; Cournot et al., 2006; Sturman et al., 2008), but prior studies were primarily conducted on populations with low African American representation and have scarce data with adolescent BMI. Therefore, this investigation examined the association between adiposity from early life to mid‐life and mid‐life cognition in a bi‐racial, semi‐rural Deep Southern epidemiological cohort.MethodThe Bogalusa Heart Study has followed participants from childhood to adulthood since 1973. Adiposity (i.e., BMI), was collected at roughly biannual visits from 1973 to today and cognitive measures were collected between 2013‐2016. Cognitive measures (n = 1295) included memory, executive function (EF), and global cognition. BMI was averaged within specific age epochs (<20 (adolescent), 21‐40 (early adulthood) and >40 (adulthood). BMI within adolescence was converted into percentiles (Kuczmarski et al., 2002). Separate linear regression models were run with BMI, sex, race, and education as predictors, and each cognitive measure as outcomes.ResultGreater BMI within the adolescent and early‐adulthood epochs was associated with greater memory performance (Average Est. 0.006, p ≤ 0.045). None of the BMI measures in any epoch were associated with global cognition or EF.ConclusionAlthough a large body of evidence has shown that greater adiposity is associated with a wide variety of adverse health outcomes, in this study greater adiposity in adolescence and young adulthood was associated with better memory performance in mid‐life. Although paradoxical, these results are aligned with several prior studies of similar longitudinal design and racial composition. Higher‐fidelity measurement of adiposity (e.g., subcutaneous vs. visceral fat) could help clarify the complex relationship between adiposity and cognitive function.