Supplementary Material for: Light-Intensity Physical Activity in a Large Prospective Cohort of Older US Adults: A 21-Year Follow-Up of Mortality

Background: Studies show that regular moderate to vigorous physical activity is associated with a lower risk of cardiovascular disease, certain cancers, and premature death, but few studies have examined associations of light-intensity physical activity (LPA) and mortality, especially among older adults. Objectives: The aim of this study was to investigate the association of LPA with the risks of death from all causes, cancer, cardiovascular diseases, and respiratory diseases among older adults in the Cancer Prevention Study-II Nutrition Cohort (CPS-II NC). Methods: Analyses included 123,232 participants in CPS-II NC, among whom 46,829 died during follow-up (1993–2014). Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for self-reported leisure time LPA associated with mortality. Results: Engaging in little or no LPA (pint = 0.003). Conclusions: In this prospective study of older adults, accumulating little/no leisure time LPA was associated with a higher risk of mortality. It is of substantial public health value to demonstrate the potential benefits of engaging in any activity, even if light in intensity, among older adults given the aging US population.

研究背景：已有研究证实，规律的中等至高强度体力活动与更低的心血管疾病、特定癌症及过早死亡风险相关，但目前鲜有研究探讨轻强度体力活动（light-intensity physical activity, LPA）与死亡率的关联，尤其在老年人群体中。
研究目标：本研究旨在针对癌症预防研究-II营养队列（Cancer Prevention Study-II Nutrition Cohort, CPS-II NC）中的老年人群，分析闲暇时间LPA与全因死亡、癌症、心血管疾病及呼吸系统疾病死亡风险的关联。
研究方法：本分析共纳入CPS-II NC队列的123232名参与者，在1993年至2014年的随访周期内，共计46829名参与者死亡。本研究采用Cox比例风险回归模型，估算自我报告的闲暇时间LPA与死亡率相关的风险比（hazard ratios, HR）及95%置信区间（95% confidence intervals, 95% CI）。
研究结果：几乎不进行或完全未进行LPA的参与者死亡风险显著升高（pint=0.003）。
研究结论：此项针对老年人群的前瞻性研究表明，闲暇时间LPA进行量较少或完全未进行与更高的死亡风险存在显著关联。鉴于美国人口老龄化的现状，阐明老年人群开展任何强度体力活动（即便为轻强度活动）的潜在获益，具备重要的公共卫生价值。