Open AccessBody mass index in midlife and dementia: Systematic review and meta‐regression analysis of 589,649 men and women followed in longitudinal studies
Author(s) -
Albanese Emiliano,
Launer Lenore J.,
Egger Matthias,
Prince Martin J.,
Giannakopoulos Panteleimon,
Wolters Frank J.,
Egan Kieren
Publication year - 2017
Publication title -
alzheimer's and dementia: diagnosis, assessment and disease monitoring
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.497
H-Index - 37
ISSN - 2352-8729
DOI - 10.1016/j.dadm.2017.05.007
Subject(s) - dementia , underweight , overweight , medicine , body mass index , meta analysis , demography , confidence interval , relative risk , confounding , population , gerontology , obesity , environmental health , disease , sociology
We conducted a meta‐analysis of the conflicting epidemiologic evidence on the association between midlife body mass index (BMI) and dementia. Methods We searched standard databases to identify prospective, population‐based studies of dementia risk by midlife underweight, overweight, and obesity. We performed random‐effects meta‐analyses and meta‐regressions of adjusted relative risk (RR) estimates and formally explored between‐study heterogeneity. Results We included 19 studies on 589,649 participants (2040 incident dementia cases) followed up for up to 42 years. Midlife (age 35 to 65 years) obesity (BMI ≥ 30) (RR, 1.33; 95% confidence interval [CI], 1.08–1.63), but not overweight (25 < BMI < 30) (RR, 1.07; 95% CI, 0.96–1.20), was associated with dementia in late life. The association with midlife underweight (RR, 1.39; 95% CI, 1.13–1.70) was potentially driven by residual confounding ( P from meta‐regression = .004), selection ( P = .046), and information bias ( P = .007). Discussion Obesity in midlife increases the risk of dementia. The association between underweight and dementia remains controversial.