[A prospective cohort study on the association between grip strength and cognitive function in adults aged 50 years and above].

Objective: To evaluate the association between grip strength (GS) and cognitive function in a population-based longitudinal cohort of Chinese adults aged ≥50 years. Methods: The study population of 3 600 adults was from the baseline survey and two rounds of follow up of World Health Organization (WHO) study of global ageing and adult health (SAGE) in five districts of Shanghai (Hongkou, Huangpu, Minhang, Qingpu and Pudong) after excluding individuals with self-report stroke and depression. The effects of baseline GS on cognitive function and its changes were evaluated. Factor analysis was applied to generate an overall cognition score based on verbal recall trials, verbal fluency test, forward digit span test and backward digit span test. Linear mixed effects model was used to examine the predictive capability of baseline GS for changes in cognitive function. Results: A total of 3 600 participants aged (61.2±8.1) years at baseline survey were included in this study, including 1 668 (46.3%) men and 1 932 (53.7%) women. The average of baseline GS and total cognitive function score were (28.19±12.18) kg and (58.93±14.56) respectively. Cognitive function score declined significantly during the follow-up, however, the changes were different among different age groups, education level groups and household income groups. After adjusted for age, education level, marital status, household income, co-morbidity of chronic conditions, drinking status, smoking status, physical activity level, vegetable/fruit intakes and BMI, no relationships between the baseline GS and cognitive score at baseline survey and at 1st follow-up were observed, however, compared with lower GS quartile group, there was a significant relationship between higher baseline GS level and better cognitive function at 2nd follow-up. The participants with highest GS quartile had better cognitive performance over time (male: β=1.938,95%CI:0.644-3.231,P=0.003, female: β=2.192,95%CI:0.975-3.409,P<0.001 and those aged 50-64 years: β=1.652,95%CI:0.646-2.659,P=0.001) than those with the lowest quartile. Conclusions: Higher baseline GS was significantly related to better cognitive function with slow decline. Thus, it is an indicator of cognitive function in middle-aged and elderly Chinese.目的： 探讨≥50岁人群握力水平对认知功能及其变化的影响。 方法： 数据来源于WHO“全球老龄化与成人健康研究”（SAGE）上海现场基线及两次随访调查，对其中参加全部3轮调查、排除自报脑卒中或抑郁症患者后共计3 600人进行分析，评估基线时不同水平的握力状况对认知功能及其变化的影响。认知功能通过评估词语回忆、语言流畅度及数字跨度测试结果，并采用因子分析方法进行综合，得到认知功能总分。使用线性混合效应模型分析基线握力水平对认知功能变化的影响。 结果： 研究对象中男性1 668人（46.3%），女性1 932人（53.7%），基线年龄为（61.2±8.1）岁、握力为（28.19±12.18）kg、认知功能得分为58.93±14.56。研究对象认知功能得分在随访中呈下降趋势，且不同年龄组、文化程度和家庭经济水平者，其认知功能得分随时间下降幅度不同。在调整年龄、文化程度、婚姻状况、家庭经济水平、慢性病共患情况、吸烟、饮酒、体力活动、蔬菜水果摄入和BMI等后，未发现基线握力水平与基线及第一次随访认知功能相关，但与基线握力较低者相比，握力水平较高的调查对象，其第二次随访认知功能较好，且其认知功能的下降速度较慢（男性：β=1.938，95%CI：0.644~3.231，P=0.003；女性：β=2.192，95%CI：0.975~3.409，P<0.001；50~64岁：β=1.652，95%CI：0.646~2.659，P=0.001）。 结论： 较高的握力水平，能减缓认知功能的衰退，可作为中老年人认知状况的预测因素。.