Overweight and Obesity in Midlife and Brain Structure and Dementia 26 Years Later

Abstract

High adiposity in midlife might increase risk for late-life brain pathology, including dementia. Using data from the prospective Age, Gene/Environment Susceptibility-Reykjavik Study of men and women (born 1907-1935), we studied the associations of overweight and obesity at midlife (mean age, 50 (standard deviation, 4.7) years) with 1.5-T brain magnetic resonance imaging measures of infarct-like brain lesions, cerebral microbleeds, total brain volume, and white matter lesions volume, as well as dementia, in late life (mean age, 76 (standard deviation, 5.2) years). We used linear and Poisson models to estimate associations in 3,864 persons after adjustment for sociodemographic, health, and lifestyle characteristics. In midlife, the prevalence of overweight was 39% and that of obesity was 8%. After a mean follow-up of 26.2 (standard deviation, 4.9) years, midlife overweight and obesity were not associated with infarct-like brain lesions (relative risk (RR) = 0.82, 95% confidence interval (CI): 0.61, 1.10), cerebral microbleeds (RR = 0.69, 95% CI: 0.37, 1.32), total brain volume (β = 0.05, 95% CI: -0.34, 0.45), white matter lesions volume (β = -0.10, 95% CI: -0.20, 0.01), or dementia (RR = 0.91, 95% CI: 0.49, 1.72) compared with normal weight. These findings do not support the hypothesis that high body mass index in midlife modulates the risk for dementia.

Increasing Body Mass Index at Midlife is Associated with Increased Cortical Thinning in Alzheimer’s Disease-Vulnerable Regions

“…Excess adipose tissue is thought to play a role, perhaps via adipocyte-produced hormones and pro-inflammatory cytokines (interleukin 6, for example) that are known to cross the blood-brain barrier [9]. Interestingly, obesity has been associated with tauopathy in a mouse model [26] and AD-related brain atrophy has been shown to reflect tau-related neurodegeneration [19,27].…”

“…In elderly individuals, findings have been mixed. For example, Raji et al found higher BMI was associated with lower brain volumes in overweight and obese elderly subjects [5], whereas Albanese et al found no association between midlife overweight and obesity and total brain volume at later life [9]. Given animal studies suggest that obesity has an even greater impact on oxidative stress and inflammatory processes at older age [10], contradictory associations between BMI and brain health in the elderly may be due to complicating factors including the impact of age-related pathology on BMI.…”

Body mass index and the risk of dementia – what do we know and what should we do?

“…Whitmer et al were also able to use body composition measurements in addition to BMI. 3 Most recently, Albanese et al 4 The rate of incident dementia in the sample is low, 5 due in part to the inclusion of people aged >40 when the peak dementia incidence occurs in the oldest old, 6 and in part to the comparatively short follow-up. The use of routine data to explore these issues, rather than relying on people recruited to studies, is to be commended, but the recording of dementia in the clinical record is far from complete.…”

Relationship between Physical Activity, Anthropometry, and Forced Expiratory Volume in One Second with 6-Minute Walk Distance in Elderly

“…18,19 Walk distance can be predicted through several variables, including age, sex, body weight, body height, and BMI which influence 26-66% distance variability. 9,18 This study also found that there was a correlation between six-minute walk distance with BMI in females.…”