Aging
The association of change in obesity across mid and late-life with late-cognitive decline in a diverse cohort Claire Meunier* Claire Meunier Paola Gilsanz Kristen M. George Michelle C. Odden Brandon Gavett Alexander Ivan B. Posis Rachel Whitmer
The impact of late-life obesity on cognitive decline remains unclear, especially in racially diverse cohorts. Further, estimates of this association may be biased due to the competing risk of mortality. We pooled data from 1136 participants in the LifeAfter90 and Kaiser Healthy Aging and Diverse Life Experiences studies to explore whether change in weight status between mid- and late-life is associated with cognitive decline. Race-specific body mass index (BMI; kg/m2) cutoffs categorized participants into groups: 1) no obesity (no obesity at mid- and late-life), 2) obesity onset (obesity at late-life), 3) obesity resolution (obesity at midlife), and 4) consistent obesity (obesity at mid- and late-life). Midlife BMI was defined as the first clinical measure between ages 40-60, and late-life BMI as the first measure starting at age 65. BMI between ages 60-65 were excluded as part of the transition period. Cognitive decline in executive function (EF) and verbal episodic memory (VM) were assessed using the Spanish English Neuropsychological Assessment Scale with up to 4.3 years of follow-up. Joint models were used to account for competing risk of mortality, combining Cox proportional hazards for mortality and linear mixed models for cognitive change. At the start of cognitive follow up, participants had a mean age of 80, with 66% categorized as no obesity, 16% obesity onset, 3% obesity resolution, and 16% consistent obesity. Obesity onset was associated with faster decline in EF compared to no obesity (β(95% CI) = -0.04(-0.07, -0.004)). There were no differences in decline in VM (consistent obesity: -0.02(-0.07, 0.04), obesity resolution: 0.04(-0.07, 0.16), and obesity onset: -0.03(-0.07, 0.02)). Findings were similar to models not accounting for mortality. In this diverse cohort, obesity onset in late-life was associated with accelerated decline in EF, underscoring the importance of interventions targeting late-life obesity as a strategy to mitigate cognitive decline.