Disclosure: The authors declared no conflicts of interest.
Article first published online: 12 MAR 2013
Copyright © 2012 The Obesity Society
Volume 21, Issue 1, pages E51–E55, January 2013
How to Cite
Loef, M. and Walach, H. (2013), Midlife obesity and dementia: Meta-analysis and adjusted forecast of dementia prevalence in the united states and china. Obesity, 21: E51–E55. doi: 10.1002/oby.20037
Funding agencies: This study was supported by the Samueli Institute and the Hans Gottschalk-Stiftung.
- Issue published online: 12 MAR 2013
- Article first published online: 12 MAR 2013
- Accepted manuscript online: 18 SEP 2012 03:03PM EST
- Manuscript Accepted: 5 JUL 2012
- Manuscript Received: 6 FEB 2012
- Samueli Institute and the Hans Gottschalk-Stiftung
Obesity is a risk factor of dementia. Current forecasts of dementia prevalence fail to take the rising obesity prevalence into account.
Design and Methods:
Embase and Medline were searched for observational studies on the association between overweight (BMI 25-30 kg/m2) or obesity (BMI > 30 kg/m2) and dementia and pooled the effect sizes by meta-analysis. The population attributable risk (PAR) was calculated for different time points and adjusted them for confounders. Based on current prevalence rates of dementia and demographic forecasts, patient numbers were calculated and adjusted by the growth rates of PAR.
Compared to normal weight, midlife obesity increases the risk of dementia later in life (BMI 25-30: RR = 1.34 [95% CI 1.08, 1.66], BMI > 30: RR = 1.91 [1.4, 2.62]). If obesity is included into forecast models, the prevalence of dementia is estimated to be 7.1 million (6.9, 7.3) and 11.3 million (10.9, 11.7) for the United States in 2030 and 2050, respectively. In China, the estimate is 13.1 million (12.8, 13.3) in 2030 and 26.2 million (25.1, 27.4) in 2050. These figures are 9% and 19% higher for the United States and China, respectively, than forecasts that rely solely on the demographic change.
The past and ongoing increase in midlife obesity prevalence will contribute significantly to the future prevalence of dementia and public health measures to reduce midlife obesity are simultaneously primary prevention measures to reduce the risk of dementia.