The Association of Body Mass Index with Cognition and Alzheimer’s Disease Biomarkers in the Elderly with Different Cognitive Status: A Study from the Alzheimer’s Disease Neuroimaging Initiative Database

Background: The association of body mass index (BMI) with cognition and Alzheimer’s disease (AD) biomarkers of the elderly remains inconclusive. Objective: To investigate the relationship between BMI and cognition as well as AD biomarkers in the elderly with different cognitive status. Methods: Participants with cognitively normal (CN) were included as the CN group. Participants with mild cognitive impairment and mild dementia were included as the cognitive impairment (CI) group. The relationship between BMI and AD biomarkers (cerebrospinal fluid Aβ42 and p-tau181, hippocampal volume [HV]), global cognition (Mini-Mental State Examination [MMSE]), memory, and executive function were explored. Results: In the CI group, BMI was associated with MMSE (β= 0.03, p = 0.009), Aβ42 (β= 0.006, p = 0.029), p-tau181/Aβ42 ratio (β= -0.001, p = 0.011), and HV (β= 0.05, p