Lower Body Mass Index at Baseline Is Related to Steeper Cognitive Decline in the Alzheimer's Disease Neuroimaging Initiative Cohort

Abstract

Objective Midlife obesity is a risk factor for dementia, whereas obesity in older age may be protective of cognition, a phenomenon known as the "obesity paradox."The mechanisms underlying this phenomenon and the relationship between body mass index (BMI) and cognitive function over time remain unclear. Methods In 1399 adults with and without mild cognitive impairment (median age 73.6 years) from the Alzheimer's Disease Neuroimaging Initiative, we modeled the effects of baseline BMI on within-person trajectories of cognitive decline using Latent Growth Curve Modeling. We also tested if the effects of BMI on cognitive decline are global or specific to memory, executive function, or language. Results Higher baseline BMI was associated with better memory (βBMI = 0.06, p