虚弱高齢者における加速度計評価による座位行動を身体活動へ置き換えることと抑うつの横断的関連: Isotemporal Substitution modelによるアプローチ

The purpose of the present study was to examine the associations of replacing accelerometer-measured sedentary behavior (SB) with physical activity (PA) and depression in a sample of Japanese frail older adults using an Isotemporal Substitution (IS) model. Among 139 frail older adults, accelerometer was utilized to identify the daily average time spent in SB, light-intensity PA (LPA), and moderate- to vigorous-intensity PA (MVPA). Depression was assessed using the Geriatric Depression Scale-Short Version-Japanese (GDS-S-J). The relationship between SB, LPA, and MVPA with depression was examined with three models of multiple regression analysis: single factor model, partition model, and IS model. As results, LPA times was negatively associated with GDS-S-J scores in the single factor model (B = -0.09, p = 0.007) and the partition model (B = -0.13, p < 0.001). In the IS model, replacement of 10 minutes of SB with an equal amount of LPA time showed a significant negative association with GDS-S-J scores (B = -0.09, p=0.003). These results suggest that replacing a small amount of SB with LPA may be associated with an improvement in depression in frail older adults.