Faculty of Liberal Arts and Sciences, Bunka Gakuen University, 3-22-1 Yoyogi, Shibuya-ku, Tokyo, Japan.
Faculty Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Health Qual Life Outcomes. 2018 Dec 27;16(1):240. doi: 10.1186/s12955-018-1067-8.
The isotemporal substitution (IS) approach can be used to assess the effect of replacing one activity with the equal duration of another activity on relevant outcomes. This study examined the associations of objectively assessed sedentary behavior (SB) and physical activity (PA) with health-related quality of life (HRQOL) in older Japanese adults, using the IS approach.
Participants were 287 older Japanese adults (aged 65-84 years) who wore accelerometers for at least 7 days. We calculated the average daily time spent in SB (≤1.5 METs); light-intensity PA (LPA: > 1.5 to < 3.0 METs); and moderate- to vigorous-intensity PA (MVPA: ≥3.0 METs) per day. HRQOL was assessed using the Medical Outcomes Survey Short Form-8 questionnaire.
The IS models showed replacing SB or LPA with MVPA to be significantly associated with better physical component summary scores. Replacing SB with MVPA was marginally associated with better mental component summary scores.
These findings indicate that replacing SB with the same amount of MVPA may contribute to better physical HRQOL in older adults.
等时替代（IS）方法可用于评估用同等时长的另一活动替代某一活动对相关结局的影响。本研究采用 IS 方法，探讨了客观评估的久坐行为（SB）和体力活动（PA）与老年日本成年人健康相关生活质量（HRQOL）之间的关联。
参与者为 287 名年龄在 65-84 岁的老年日本成年人，他们佩戴加速度计至少 7 天。我们计算了每天平均久坐时间（≤1.5 METs）；低强度体力活动（LPA：>1.5 至 <3.0 METs）；以及中等到剧烈强度体力活动（MVPA：≥3.0 METs）。使用医疗结局调查短式 8 项问卷评估 HRQOL。
IS 模型显示，用 MVPA 替代 SB 或 LPA 与更好的生理成分综合评分显著相关。用 MVPA 替代 SB 与更好的心理成分综合评分呈边缘相关。
这些发现表明，用等量的 MVPA 替代 SB 可能有助于改善老年人的身体 HRQOL。
