Objective: To investigate the associations of obesity and physical activity with cognition in the elderly. Methods: A cross-sectional survey was conducted from October 2009 to June 2010 among people aged ≥50 years selected through multistage random cluster sampling in Shanghai. The subjects' body weight, body height, waist circumference and hip circumference were measured to calculate body mass index (BMI) and waist-hip ratio (WHR), and the data on self-reported physical activity level were collected through questionnaire survey. A comprehensive battery of cognitive tests was conducted to assess subjects' cognitive functions, including verbal recall, forward digit span (FDS), backward digit span (BDS), and verbal fluency (VF). General linear model was used to examine the associations of BMI, WHR and physical activity with cognition. Results: A total of 7 913 participants were included, with a median age of 60 years. Age, sex, education level, income level, BMI, WHR and physical activity level were significantly associated with cognitive scores in univariate analysis. After adjusted for age, sex, education level and income level, BMI was no longer significantly associated with cognitive scores in all cognitive functions (all P>0.01). WHR was significantly associated with VF score (P<0.01). Abdominally obese participants had lower VF score than non-abdominally obese participants (P<0.01). Physical activity level was significantly associated with all cognitive functions (P<0.01). Compared with participants with moderate physical activity level, participants with low physical activity level had lower scores in all cognitive functions (P<0.01). Conclusion: Abdominal obesity and low physical activity level were negatively associated with cognition level in the elderly, suggesting that waist circumference control and physical activity might help maintain cognition in the elderly.
目的： 探索老年人群肥胖和体力活动与认知功能的关系。 方法： 从2009年10月至2010年6月，通过多阶段随机整群抽样，在上海市抽取≥50岁人群，通过问卷调查收集研究对象社会人口学信息，并进行体格测量、认知能力测试（包括词语回忆、顺序数字跨度、倒序数字跨度、语言流畅度）。采用一般线性模型分析BMI、腰臀比、体力活动与认知功能的关系。 结果： 共纳入研究对象7 913名，中位年龄60岁。在单因素分析中，年龄、性别、文化程度、年经济收入、BMI、腰臀比和体力活动水平与认知得分都有显著性关联。在控制了年龄、性别、文化程度和年经济收入后，BMI与4项认知功能得分的关联都不显著（P>0.01）。腰臀比与语言流畅度有显著关联（P<0.01），中心性肥胖者的语言流畅度得分低于腰臀比正常者0.61分，差异有统计学意义（P<0.01）。体力活动水平与4项认知功能得分都有显著关联（均P<0.01），轻度体力活动者的4项认知功能得分都比中度体力活动者低（均P<0.01）。 结论： 中心性肥胖和体力活动不足的老年人认知功能得分更低，提示腰围控制和适当的体力活动有助于老年人维持其认知功能。.
Keywords: Cognition; Elderly; Obesity; Physical activity.