Objective: To analyze the relationship between cumulative body mass index (BMI) and cognitive score or cognitive impairment at different age groups among elderly adults aged≥60 years old. Methods: Participants were recruited from the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR). A total of 27 227 participants aged≥60 years old, who completed at least 2 physical examinations between 1992-1994 and 2018-2021, and completed cognitive function tests from 2018 to 2021, were included in the final analysis. Cognitive score was assessed using the Minimum Mental State Examination (MMSE). Cognitive impairment was defined based on education level: illiterate individuals with MMSE≤17, primary school graduates with MMSE≤20, and secondary school graduates with MMSE≤24. Multivariate linear regression or multivariate logistic regression models were used to analyze the association between 10-year weighted cumulative BMI and cognitive score or cognitive impairment in the general population, as well as in specific age groups (including 60-64 years, 65-69 years, 70-74 years, and≥75 years). Restricted cubic spline was adopted to explore the dose-response relationship. Results: The age of enrolled participants was (72.3±5.8) years, and 10 639 (39.1%) were males. The mean MMSE score was (24.9±6.8), and 4 171 (15.4%) participants had cognitive impairment. In the general population, the MMSE score increased and the risk of cognitive impairment decreased with the increase in cumulative BMI when cumulative BMI was280 kg/m2 (β=0.095, 95%CI: 0.060-0.130; OR=0.962, 95%CI: 0.946-0.978). When cumulative BMI≥280 kg/m2, the associations between cumulative BMI level and MMSE score and cognitive impairment risk were not statistically significant (β=-0.105, 95%CI:-0.212-0.001; OR=1.047, 95%CI: 0.992-1.102). Subgroup analysis according to age groups revealed a potential"U-shaped"correlation between cumulative BMI and MMSE score or cognitive impairment risk in participants aged75 years old. For cumulative BMI levels280 kg/m2, the OR and 95%CI for cognitive impairment were 0.983 (0.904-1.069), 0.953 (0.919-0.987), and 0.951 (0.922-0.982) for each 10 kg/m2 increment in cumulative BMI in the 60-64, 65-69, and 70-74 years old groups, respectively. For cumulative BMI≥280 kg/m2, the OR and 95%CI were 1.548 (1.134-2.186), 1.037 (0.938-1.139), and 1.109 (1.014-1.208) in the 60-64, 65-69, and 70-74 age groups. Among those aged≥75 years old, the cumulative BMI level was statistically associated with the increased MMSE score and decreased cognitive impairment (β=0.132, 95%CI: 0.074-0.190; OR=0.961, 95%CI: 0.944-0.979). Conclusions: Overall, when cumulative BMI is280 kg/m2, an increase in cumulative BMI is associated with a reduced risk of cognitive impairment in the general population. However, the association varies among individuals aged75 years old and those≥75 years old when cumulative BMI is≥280 kg/m2. The findings highlight the necessity of personalized weight management strategies for elderly individuals across different age groups.
目的： 分析我国60岁及以上老年人群累积体质指数（BMI）与认知功能的关联。 方法： 研究对象来自中国动脉粥样硬化性心血管疾病风险预测研究（China-PAR），纳入于1992—1994年至2018—2021年至少参加2次体格检查并于2018—2021年参加认知功能调查的27 227名≥60岁老年人。采用简易智力状态检查量表（MMSE）测量认知评分，根据教育水平定义文盲人群MMSE≤17分、小学学历人群MMSE≤20分、中学或以上学历人群MMSE≤24分为认知功能受损。采用多元线性回归或多元logistic回归模型，分析总人群与60~64、65~69、70~74、≥75岁年龄段人群10年加权累积BMI与认知评分或认知功能受损的关联。采用限制性立方样条探讨暴露-反应关系。 结果： 研究对象年龄为（72.3±5.8）岁，男性10 639名（39.1%），MMSE得分（24.9±6.8）分，认知功能受损者4 171例（15.4%）。总人群中，累积BMI280 kg/m2时，随累积BMI增加，认知评分增加、认知功能受损风险降低（β=0.095，95%CI：0.060~0.130；OR=0.962，95%CI：0.946~0.978）；累积BMI≥280 kg/m2时，累积BMI与认知评分、认知功能受损风险的关联均无统计学意义（β=-0.105，95%CI：-0.212~0.001；OR=1.047，95%CI：0.992~1.102）。年龄分层分析显示，75岁老年人群中，累积BMI与认知评分及认知功能受损均呈现潜在“U型关联”；当累积BMI280 kg/m2时，60~64、65~69、70~74岁年龄组累积BMI每增加10 kg/m2，与认知功能受损关联OR值（95%CI）分别为0.983（0.904~1.069）、0.953（0.919~0.987）和0.951（0.922~0.982）；累积BMI≥280 kg/m2时，OR值（95%CI）分别为1.548（1.134~2.186）、1.037（0.938~1.139）和1.109（1.014~1.208）。而在≥75岁人群中，累积BMI增加与认知评分增加、认知功能受损风险降低相关（β=0.132，95%CI：0.074~0.190；OR=0.961，95%CI：0.944~0.979）。 结论： 总人群中，10年累积BMI280 kg/m2时，随累积BMI增加，认知功能受损风险降低，10年累积BMI≥280 kg/m2时，累积BMI与认知功能的关联在不同年龄段老年人中存在差异，提示应针对不同年龄老年人提供个体化体重管理建议。.