Sex differences in reduction of trunk muscle mass related to falls and cognitive function during the COVID-19 pandemic in older adults

Aim: This study aimed to examine the influence of the COVID-19 pandemic on physical components and activity, and its relationship to physical performance in older adults. Methods: Sixty-seven participants aged 75 and older (81 +/- 2 years, female: 66%), who underwent medical checkups continuously from 2018 to 2022 in one clinic, were enrolled. Muscle mass was assessed by the biometrical impedance analysis method, which was adjusted by height squared. Physical, oral, and cognitive performance data were obtained from Japanese standard questionnaires at medical checkups. Values obtained in 2018 and 2019 were defined as pre-pandemic, and those in 2021 and 2022 were defined as during the pandemic. Results: Body weight, grip strength, and skeletal mass index did not change from 2018 to 2022, but trunk muscle mass index decreased significantly. A difference in the trunk muscle mass index (TMI) was observed between 2022 and 2018/2019 in men; however, a significant difference was found between 2021 and 2022 in women. Compared with the pre-pandemic period, TMI during the pandemic decreased only in men. The difference in TMI between the pre-pandemic period and during the pandemic (Delta TMI) was significantly decreased in participants with low physical activity and poor oral performance before the pandemic, and in those with falls and poor cognitive function during the pandemic only in men. Conclusion: Reduction of trunk muscle mass was related to falls and poor cognitive function during the COVID-19 pandemic in older male adults. These data suggest that the difference in response to the COVID-19 pandemic between men and women necessitates different types of support for older adults. Geriatr Gerontol Int 2024; center dot center dot: center dot center dot-center dot center dot.