Leisure‐time physical activity from mid‐ to late life, body mass index, and risk of dementia

Abstract

The window of opportunity for preventive physical activity interventions may extend from midlife to older ages.

Weight Change in Midlife and Risk of Mortality From Dementia up to 35 Years Later

“…Our result regarding weight loss being associated with increased dementia related mortality risk fits with studies using clinical dementia as end point (10)(11)(12)(13)(14)(15)(16)(17)(18). Most previous studies investigate weight change in old age, typically above 65 years or older, where reverse causality might be a plausible explanation for the association between weight loss and dementia.…”

“…We identified five studies which have, like us, linked weight change from midlife into old age to dementia outcomes, and in accordance with our findings, weight loss was associated with increased dementia risk in all these studies (14,(17)(18)(19)28). First, in the Honolulu-Asia Aging Study, a study of Japanese American men, where age at inclusion was from late 40s and 60s and follow-up was until 90s for the oldest, it was reported that men that developed dementia lost significantly more weight during the years prior to the diagnosis, especially during the three year period prior to the diagnosis (14).…”

“…We were not able to investigate this in detail, but we question if the dementia prodromal could cause weight loss as early as ages between 35 and 62 years. Fourth, in the Finnish CAIDE study, both men and women were included, and weight loss between age 50 and 70 years was associated a 20% increased dementia in risk per unit BMI loss, which was robust to adjustment for a range of health related variables (17). Fifth, midlife weight variability (in either direction) was associated with increased dementia risk in the Israel Ischemic Heart Disease Project (19).…”

“…A better understanding of the association between body weight and dementia may be achieved by studying weight trajectories and patterns from midlife into old age (1). Studies with weight at multiple time points have generally reported weight loss (10)(11)(12)(13)(14)(15)(16)(17)(18) or weight instability (19) to be associated with increased dementia risk. However, many of these studies are limited to weight trajectories in old age, and might be prone to reverse causality because dementia and preclinical dementia might cause weight loss (1,20).…”

Aging and Alzheimer’s disease: Comparison and associations from molecular to system level

“…Conversely, exercise can convey a protective effect (Ahlskog, Geda, Graff‐Radford, & Petersen, 2011; Geda et al, 2012; Ngandu et al, 2015; Wirth, Haase, Villeneuve, Vogel, & Jagust, 2014) even if initiated after midlife (Tolppanen et al, 2015). In humans, higher levels of physical activity, as measured by the International Physical Activity Questionnaire, are associated with lower plasma Aβ in APOEε4 noncarriers (Okonkwo et al, 2014; Vidoni et al, 2012).…”