School of Physiotherapy, Dalhousie University, Halifax, Nova Scotia, Canada.
Geriatric Medicine, Dalhousie University and Nova Scotia Health, Halifax, Nova Scotia, Canada.
J Am Geriatr Soc. 2022 Oct;70(10):2915-2924. doi: 10.1111/jgs.17941. Epub 2022 Jul 2.
Physical activity (PA) interventions may reduce the burden of frailty and can prevent mobility disability for older adults. We explored whether a 2-year PA intervention would improve frailty trajectory, lead to clinically meaningful frailty changes (CMC), or impact major mobility disability (MMD) across baseline frailty levels.
We analyzed data for 1635 community-dwelling participants who were 70-89 years old (mean baseline age [SD]: 78.9 [5.2] years, 67.2% female) from the Lifestyle Interventions and Independence Study. Participants were randomized to either PA or health education (HE) intervention. A 44-item frailty index (FI) was constructed at baseline and 0.5, 1, 1.5, and 2 years after baseline. CMC was defined as change in FI of ≥0.03. MMD was the inability to complete a 400 m-walk within 15 min without assistance. Mixed-effects models were used to estimate frailty trajectory and CMC. Cox regression models were used to determine whether the effect of PA on the composite of MMD or death differed by baseline FI.
Mean FI (SD) at baseline for both the PA and HE groups was 0.18 (0.10). Two years after baseline, mean FIs were 0.23 (0.12) for PA and 0.24 (0.12) for HE. The MMD rates were 30.1% (246/818) and 35.5% (290/817) for PA and HE, respectively. There was no time-by-intervention interaction for frailty trajectory or for CMC. Regarding the composite MMD and death, there was no FI-by-intervention interaction. Simple association analyses revealed that when baseline FI was centered at 0.15 or higher, the PA intervention was associated with lower risk of MMD or death compared to HE (HR [CI] range for FI ≥ 0.15: 0.65-0.81 [0.43-0.67, 0.90-0.98]).
Participants in both groups showed similar frailty trajectories and CMC. Those who were frailer benefitted more from the PA intervention regarding MMD and death and may be a focus of recruitments for future PA program.
身体活动（PA）干预措施可能减轻衰弱负担，并可预防老年人的移动性残疾。我们探讨了为期 2 年的 PA 干预是否会改善衰弱轨迹，导致临床有意义的衰弱变化（CMC），或影响基线衰弱水平的主要移动性残疾（MMD）。
我们分析了来自生活方式干预和独立研究的 1635 名居住在社区的参与者的数据，他们年龄在 70-89 岁（平均基线年龄[SD]：78.9 [5.2]岁，67.2%为女性）。参与者被随机分配到 PA 或健康教育（HE）干预组。在基线和 0.5、1、1.5 和 2 年后构建了一个 44 项衰弱指数（FI）。CMC 定义为 FI 变化≥0.03。MMD 是指无法在没有帮助的情况下在 15 分钟内完成 400 米步行。使用混合效应模型估计衰弱轨迹和 CMC。使用 Cox 回归模型确定 PA 对 MMD 或死亡的复合终点的影响是否因基线 FI 而异。
PA 和 HE 组在基线时的平均 FI（SD）分别为 0.18（0.10）和 0.18（0.10）。两年后，PA 组的平均 FI 为 0.23（0.12），HE 组为 0.24（0.12）。PA 和 HE 的 MMD 发生率分别为 30.1%（246/818）和 35.5%（290/817）。衰弱轨迹或 CMC 均无时间与干预的交互作用。关于 MMD 和死亡的复合终点，FI 与干预无交互作用。简单关联分析显示，当基线 FI 中心化在 0.15 或更高时，与 HE 相比，PA 干预与较低的 MMD 或死亡风险相关（FI≥0.15 的 HR [CI]范围：0.65-0.81[0.43-0.67，0.90-0.98]）。
两组参与者的衰弱轨迹和 CMC 相似。那些更脆弱的人从 PA 干预中获益更多，在 MMD 和死亡方面，这可能是未来 PA 计划招募的重点。
