高齢期における日常的な座位行動時間は中高強度身体活動時間から独立して下肢パフォーマンスと関連するか −1軸加速度計を用いた横断的検討−

抄録

Habitual moderate- to vigorous-intensity physical activity positively impacts lower extremely performance in older adults. However, little is known whether habitual sedentary behaviour time independently impacts lower extremity performance. The purpose of this cross-sectional study was to identify whether sedentary behaviour time is associated with lower extremity performance independent of moderate- to vigorous-intensity physical activity time in older adults. Eight-hundred-and-two community-dwelling older Japanese adults (72.5 ± 5.9 years) participated in this study. Sedentary behavioir time and moderate- to vigorous-intensity physical activity time were assessed using a uniaxial accelerometer. Lower extremity performance was assessed by repeated chair stand, single leg stance, and timed up and go tests. Jonckheere terpstra trend test and Spearman rank correlation coefficient were used to identify the single relation between sedentary behaviour time and lower extremity performance. A hierarchical multiple regression analysis was used to identify whether sedentary behaviour time is associated with lower extremity performance independent of moderate- to vigorous-intensity physical activity time. Results of single relation analysis showed there were negative associations between sedentary behaviour time and all lower extremity performance tests. Multivariable analysis indicated that sedentary behaviour time was not significantly associated with any lower extremity performances but moderate- to vigorous-intensity physical activity time was positively associated with all lower extremity performance tests. In conclusion, sedentary behaviour time would be less useful than moderate- to vigorous-intensity physical activity time as an indicator for modifying habitual behavior to maintain good lower extremity performance in community-dwelling older adults.