Cheung Ying Kuen, Moon Yeseon P, Kulick Erin R, Sacco Ralph L, Elkind Mitchell S V, Willey Joshua Z
Department of Biostatistics, Columbia University, New York, NY, USA.
Department of Neurology, Columbia University, 710 West 168th street, New York, NY, 10032, USA.
J Gen Intern Med. 2017 Feb;32(2):168-174. doi: 10.1007/s11606-016-3884-y. Epub 2016 Oct 17.
Previous studies of exercise have focused on measuring physical activity in totality using summary statistics such as metabolic equivalent score for total intensity or total energy count.
We aimed to examine the multidimensionality of leisure-time physical activity (LTPA) and to identify the specific LTPA components that were associated with cardiovascular mortality in the elderly.
The Northern Manhattan Study (NOMAS) is a multiethnic prospective cohort of elderly stroke-free individuals consisting of a total of 3298 participants recruited between 1993 and 2001, with a median follow-up of 17 years.
Physical activity questionnaire data were available in 3293 NOMAS participants, who were categorized into subgroups with similar exercise patterns by model-based cluster analysis. Three subgroup-defining LTPA features were identified and were considered as primary exposures in Cox proportional hazard models: frequency of activity, number of activity types (variety), and energy-to-duration ratio (EDR). We considered cardiovascular mortality and non-cardiovascular mortality as outcomes in Cox cause-specific proportional hazard models, and all-cause mortality as outcome in Cox models.
A high activity frequency was associated with reduced cardiovascular mortality (hazard ratio, HR = 0.93, P = 0.03), but demonstrated no effect on non-cardiovascular death. A high EDR was associated with increased risk of cardiovascular death (HR = 1.30, P = 0.01). A high number of activity types was beneficial in reducing all-cause mortality (HR = 0.87, P = 0.01).
Exercise frequency was protective against cardiovascular mortality, and a high variety of activity was protective against all-cause mortality. The performance of frequent and varied non-intense exercise in an elderly population such as ours is achievable and can reduce the risk of death.
以往关于运动的研究主要集中在使用诸如总强度的代谢当量评分或总能量计数等汇总统计数据来整体测量身体活动。
我们旨在研究休闲时间身体活动（LTPA）的多维性，并确定与老年人心血管死亡率相关的特定LTPA组成部分。
北曼哈顿研究（NOMAS）是一项针对无中风老年人的多民族前瞻性队列研究，共有3298名参与者于1993年至2001年间招募，中位随访时间为17年。
3293名NOMAS参与者有身体活动问卷数据，通过基于模型的聚类分析将他们分为具有相似运动模式的亚组。确定了三个定义亚组的LTPA特征，并在Cox比例风险模型中作为主要暴露因素：活动频率、活动类型数量（多样性）和能量与持续时间比（EDR）。在Cox特定病因比例风险模型中，我们将心血管死亡率和非心血管死亡率作为结局，在Cox模型中将全因死亡率作为结局。
高活动频率与心血管死亡率降低相关（风险比，HR = 0.93，P = 0.03），但对非心血管死亡无影响。高EDR与心血管死亡风险增加相关（HR = 1.30，P = 0.01）。活动类型数量多有利于降低全因死亡率（HR = 0.87，P = 0.01）。
运动频率可预防心血管死亡率，活动多样性高可预防全因死亡率。在我们这样的老年人群中进行频繁且多样的非剧烈运动是可行的，并且可以降低死亡风险。
