Association between body mass index and cognitive function among Chinese nonagenarians/centenarians.
OBJECTIVE
We examined the individual association between body mass index (BMI) and cognitive function among the very elderly.


METHODS
The present study analyzed data from a survey that was conducted on all residents aged 90 years or more from a district which had 2,311,709 inhabitants in 2005. The subjects were divided into 4 groups according to quartiles of BMI (<16.6, 16.6-18.9, 18.9-21.1 and >21.1), and according to classification criteria of underweight, normal weight, overweight and obesity in BMI (<18.5, 18.5-23.0, 23.0-27.5 and >27.5), respectively.


RESULTS
The subjects included in the statistical analysis were 211 men and 427 women. Those in the 3rd quartile of BMI (18.9-21.1) had higher cognitive function scores (p < 0.001) and were less likely to present possible dementia (p = 0.016) than the others. However, there was no difference in cognitive function scores (p = 0.350) or prevalence of possible dementia (p = 0.263) among obesity, overweight, normal weight and underweight groups.


CONCLUSIONS
Concerning longevity in Chinese, there is an association between BMI and cognitive function. BMI of around 20 (18.9-21.1) is associated with the lowest risk of prevalence of possible dementia and the highest cognitive function scores.
Department of Geriatrics, West China Hospital, Sichuan University, Guoxuexiang 37, Chengdu, Sichuang, China. hxzhouyan@hotmail.com
Yan
Y
Zhou
Joseph H
JH
Flaherty
Chang-Quan
CQ
Huang
Zhen-Chan
ZC
Lu
Bi-Rong
BR
Dong
D000369:Aged, 80 and over / Q000523:psychology*; D000428:Alcohol Drinking / Q000523:psychology; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D002681:China; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D003627:Data Interpretation, Statistical; D003704:Dementia / Q000453:epidemiology / Q000523:psychology; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008019:Life Style; D008136:Longevity; D008297:Male; D009483:Neuropsychological Tests; D050177:Overweight; D012306:Risk; D012907:Smoking / Q000523:psychology; D012959:Socioeconomic Factors; D013662:Tea; D013851:Thinness
D013662:Tea