hide
Free keywords:
Cognitive ageing; VBM; Cognitive performance; Healthy aging; Lifestyle factors; Overweight; Adiposity; Cohort studies
Abstract:
Midlife obesity has been associated with increased dementia risk, yet reports on brain structure and function are mixed. We therefore assessed the effects of body mass index (BMI) on gray matter volume (GMV) and cognition in a well-characterized sample of community-dwelled older adults. GMV was measured using 3T-neuroimaging in 617 participants (258 women, 60-80 years, BMI 17-41 kg/m2). Also, cognitive performance and various confounders including hypertension, diabetes and APOE-genotype were assessed. A higher BMI correlated significantly with lower GMV in multiple brain regions, including (pre)frontal, temporal, insular and occipital cortex, thalamus, putamen, amygdala and cerebellum, even after adjusting for confounders. Also, lower GMV in prefrontal and thalamic areas partially mediated negative effects of (1) higher BMI and (2) higher age on memory performance. We here showed that a higher BMI in older adults is associated with widespread gray matter alterations, irrespective of obesity-related co-morbidities and other confounders. Our results further indicate that a higher BMI induces structural alterations that translate into subtle impairments in memory performance in aging.
