Premium
Body mass index and risk of dementia: Analysis of individual‐level data from 1.3 million individuals
Author(s) -
Kivimäki Mika,
Luukkonen Ritva,
Batty G. David,
Ferrie Jane E.,
Pentti Jaana,
Nyberg Solja T.,
Shipley Martin J.,
Alfredsson Lars,
Fransson Eleonor I.,
Goldberg Marcel,
Knutsson Anders,
Koskenvuo Markku,
Kuosma Eeva,
Nordin Maria,
Suominen Sakari B.,
Theorell Töres,
Vuoksimaa Eero,
Westerholm Peter,
Westerlund Hugo,
Zins Marie,
Kivipelto Miia,
Vahtera Jussi,
Kaprio Jaakko,
SinghManoux Archana,
Jokela Markus
Publication year - 2018
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2017.09.016
Subject(s) - dementia , hazard ratio , body mass index , medicine , confidence interval , cohort , cohort study , proportional hazards model , demography , gerontology , disease , sociology
Higher midlife body mass index (BMI) is suggested to increase the risk of dementia, but weight loss during the preclinical dementia phase may mask such effects. Methods We examined this hypothesis in 1,349,857 dementia‐free participants from 39 cohort studies. BMI was assessed at baseline. Dementia was ascertained at follow‐up using linkage to electronic health records (N = 6894). We assumed BMI is little affected by preclinical dementia when assessed decades before dementia onset and much affected when assessed nearer diagnosis. Results Hazard ratios per 5‐kg/m 2 increase in BMI for dementia were 0.71 (95% confidence interval = 0.66–0.77), 0.94 (0.89–0.99), and 1.16 (1.05–1.27) when BMI was assessed 10 years, 10‐20 years, and >20 years before dementia diagnosis. Conclusions The association between BMI and dementia is likely to be attributable to two different processes: a harmful effect of higher BMI, which is observable in long follow‐up, and a reverse‐causation effect that makes a higher BMI to appear protective when the follow‐up is short.