Aging
The association of midlife obesity and BMI with cognitive change in a diverse cohort of individuals 80+ Claire Meunier* Claire Meunier Paola Gilsanz Joseph Roscoe Maria M. Corrada Kristen M. George M. Maria Glymour Elizabeth Rose Mayeda Alexander Ivan B. Posis Brandon Gavett Rachel Whitmer
Midlife obesity elevates dementia risk, yet little is known regarding its effects on short term cognitive change in those who survived to age 80. We pooled data for participants aged 80+ from LifeAfter90, Kaiser Healthy Aging and Diverse Life Experiences Study, and Study of Healthy Aging in African Americans (n=671; 33% White, 12% Latino, 17% Asian, 35% Black) to examine the association between midlife obesity and cognitive decline (executive function (EF), verbal episodic (VEM), scores standardized to baseline sample). First clinical measure of body mass index (BMI;kg/m2) at ages 40-60 was categorized as normal (18.5-24.9), overweight (25-29.9), and obese (30). Linear models and linear mixed models with random intercepts/slopes adjusted for age of BMI, age at first clinical assessment, gender, race, education, visit mode, and practice effects analyzed the association between midlife obesity and cognition. Participants’ mean age at BMI assessment was 44.6±4.3 years, mean age at first cognitive assessment was 88.5±5.3 years; 9% obese and 31% overweight, with a mean of 2.7±1.7 visits over 1.4±1.2 years. Midlife BMI categories were not associated with baseline EF (compared to normal BMI: obesity β(95%CI)=-0.07(-0.30,0.15); overweight β=-0.01(-0.15,0.12)) or annual decline (obesity β=-0.03(-0.05,0.10); overweight β=-0.03(-0.06,0.02); Figure 1). Obesity was associated with lower baseline VEM (obesity β=-0.25(-0.49,-0.02)), though overweight did not significantly differ from normal BMI (β=-0.12(-0.26,0.01)). BMI was not associated with VEM decline (obesity β=-0.04(-0.04,0.07); overweight β=-0.01(-0.06,0.15); Figure 1). When modeled linearly, BMI was not associated with decline in EF (β<0.01(>-0.01,0.01)) or VEM (β<0.01(>-0.01,0.01)). In a diverse cohort of individuals aged 80+, midlife obesity was not associated with faster cognitive decline. While midlife obesity is a risk factor for dementia it may not be associated with short term cognitive changes after age 80.
