Xiong Jian, Xue Wen-Xiong
Department of Rehabilitation, Affiliated Zhangjiagang Hospital of Soochow University, Suzhou, China.
Front Nutr. 2022 Jul 22;9:922673. doi: 10.3389/fnut.2022.922673. eCollection 2022.
Physical frailty and cognitive aging have important influences on poor clinical outcomes in older adults. Many studies have investigated the association between frailty and cognitive function, but whether vitamin D mediates the association between frailty and cognitive function is unclear. We explored the mediating role of vitamin D on the cross-sectional association between physical frailty and cognitive function using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS).
We analyzed data from 1944 subjects aged 60 years and older from the 2011 CLHLS cohort. Frailty status was identified by the Osteoporotic Fracture Study (SOF) index. The Chinese version of the Mini-Mental State Examination (MMSE) was used to assess cognitive function. Linear regression models were used to examine the association between frailty, vitamin D, and cognition, adjusted for a range of covariates. Mediation analyses tested the indirect effects of vitamin D on physical frailty and cognitive function.
Physical frailty was negatively associated with vitamin D levels and scores on the MMSE, and vitamin D levels were positively associated with scores on the MMSE. Linear regression analysis showed that physical frailty and serum vitamin D concentration were significant predictors of cognitive function. Importantly, mediation analysis showed that serum vitamin D concentration significantly mediated the relationship between physical frailty and cognitive function.
The association between physical frailty and cognitive function appears to be mediated by vitamin D. Future studies should explore whether serum vitamin D concentrations may mediate the association between physical frailty and cognitive decline and whether this mediating role is moderated by other factors.
身体虚弱和认知老化对老年人不良临床结局有重要影响。许多研究调查了虚弱与认知功能之间的关联，但维生素D是否介导了虚弱与认知功能之间的关联尚不清楚。我们使用中国老年健康长寿纵向调查（CLHLS）的数据，探讨了维生素D在身体虚弱与认知功能横断面关联中的中介作用。
我们分析了2011年CLHLS队列中1944名60岁及以上受试者的数据。采用骨质疏松性骨折研究（SOF）指数确定虚弱状态。使用中文版简易精神状态检查表（MMSE）评估认知功能。采用线性回归模型，在调整一系列协变量的情况下，检验虚弱、维生素D与认知之间的关联。中介分析测试了维生素D对身体虚弱和认知功能的间接影响。
身体虚弱与维生素D水平及MMSE评分呈负相关，维生素D水平与MMSE评分呈正相关。线性回归分析表明，身体虚弱和血清维生素D浓度是认知功能的重要预测因素。重要的是，中介分析表明血清维生素D浓度显著介导了身体虚弱与认知功能之间的关系。
身体虚弱与认知功能之间的关联似乎由维生素D介导。未来的研究应探讨血清维生素D浓度是否可能介导身体虚弱与认知衰退之间的关联，以及这种中介作用是否受其他因素的调节。
