AUTHOR=Liu Xinya , Jiang Yihua , Peng Wenjia , Wang Meng , Chen Xiaoli , Li Mengying , Ruan Ye , Sun Shuangyuan , Yang Tingting , Yang Yinghua , Yan Fei , Wang Feng , Wang Ying TITLE=Association between physical activity and mild cognitive impairment in community-dwelling older adults: Depression as a mediator JOURNAL=Frontiers in Aging Neuroscience VOLUME=14 YEAR=2022 URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2022.964886 DOI=10.3389/fnagi.2022.964886 ISSN=1663-4365 ABSTRACT=Introduction

Dementia has become a public health priority and is irreversible. Mild cognitive impairment (MCI), an intermediate state between normal cognition and dementia, is the prime time for early diagnosis and intervention. The activities of daily living of dementia patients are usually insufficient. Therefore, continuing to explore the risk factors of MCI, especially the influence of physical activity on MCI and its mechanism can enrich the relevant research fields in China.

Materials and methods

For this cross-sectional study, 2,518 adults aged 60 years or older in Xinzhuang, Minhang District, Shanghai were recruited between July 2019 and April 2019, using a multistage, cluster-sampling method. A binary unconditional logistic regression model was used with MCI status as the dependent variable. Different types of physical activity were separately included in the multifactor model to test their correlations. Sensitivity analysis was performed using BADL as a stratification factor. The mediating effect of depression between physical activity and MCI was examined using the Bootstrap method.

Results

This research includes 271 (10.8%) MCI. Old age (odds ratio 2.967 [95%CI 2.063∼4.269]), having diabetes (1.816 [1.302∼2.534]), and depression (3.012 [2.209∼4.108]) were possible risk factors for MCI. High education level (0.722 [0.523∼0.999]), medium level of physical activity (0.459 [0.326∼0.645]), and high level of physical activity (0.396 [0.270∼0.580]) were possible protective factors. Medium (0.548 [0.396∼0.757]) and high levels (0.557 [0.366∼0.846]) of physical exercise and medium (0.433 [0.318∼0.590]) and high levels (0.487 [0.296∼0.801]) of household chores are possible protective factors of MCI and their significance remained in the mutually adjusted model. Sensitivity analysis showed that physical activity and household chores were possible protective factors in all strata (P < 0.05). Physical exercise and work-related activities showed a protective effect in fully independent older adults, but the effect disappeared in those who cannot be fully independent. Depression played a partially mediating role with an indirect effect of 6.67%.

Discussion

Overall, our results highlight that physical activity is a possible protective factor for MCI. Physical exercise and household chores have strong protective effects and future interventions could be targeted from this perspective. Depression plays a partially mediating role and more attention should be paid to the mental health of older adults.