Department of Medicine, Howard University College of Medicine, 2041 Georgia Ave., Washington, DC 20060, USA.
Ann Epidemiol. 2010 Apr;20(4):251-7. doi: 10.1016/j.annepidem.2010.01.005. Epub 2010 Feb 19.
Increasing physical activity is postulated to slow cognitive decline associated with aging. Low levels of both physical activity and cognitive function are associated with increased risk of mortality. We test the hypothesis that the relative protective effect of high physical activity level as related to mortality is greater in persons with impaired cognitive function than in others.
Data were analyzed from a longitudinal mortality follow-up study of 5903 American men and women aged 60 years and older examined in 1988 to 1994 who were followed an average of 8.5 years. Measurements at baseline included self-reported leisure-time physical activity (LTPA), a short index of cognitive function (SICF), sociodemographic data, health status, and physical and biochemical measurements.
Death during follow-up occurred in 2431 persons. In bivariate cross-sectional analyses, more frequent LTPA was associated with greater cognitive function. In proportional hazards regression analysis, no significant interaction of LTPA with cognitive function was found; however, there was a significant age-LTPA interaction. After adjusting for confounding by baseline sociodemographic data and health status at ages 60 to 74, the hazards ratio (95% confidence intervals) was for LTPA more than 8 times weekly compared with none (0.51; 0.38-0.76, p < .001) and for low SICF score compared with high 1.43 (1.36; 1.00-1.84, p < .05). After controlling for health behaviors, blood pressure, and body mass, C-reactive protein, and high-density lipoprotein cholesterol, the LTPA hazards ratio was 0.52 (0.35-0.78; p = .002), but cognitive function was no longer significant. At ages 75 and older, results were similar for LTPA, but cognitive function remained significant after adjustment.
In a nationwide cohort of older Americans, analyses demonstrated a lower risk of death independent of confounders among those with frequent LTPA. Much of the effect of low cognitive function could be explained by other risk factors at ages 60 to 74 but not 75 years and older.
增加身体活动被认为可以减缓与衰老相关的认知能力下降。身体活动水平和认知功能水平低与死亡率增加有关。我们检验了这样一个假设，即与死亡率相关的高身体活动水平的相对保护作用在认知功能受损的人群中比在其他人中更大。
对 5903 名年龄在 60 岁及以上的美国男女进行了纵向死亡率随访研究，这些人在 1988 年至 1994 年期间接受了检查，平均随访 8.5 年。基线测量包括自我报告的休闲时间体力活动（LTPA）、认知功能简短指数（SICF）、社会人口统计学数据、健康状况以及身体和生化测量。
在随访期间有 2431 人死亡。在双变量横断面分析中，更频繁的 LTPA 与更好的认知功能相关。在比例风险回归分析中，没有发现 LTPA 与认知功能之间存在显著的交互作用；然而，存在显著的年龄-LTPA 交互作用。在校正 60 至 74 岁时的基线社会人口统计学数据和健康状况混杂因素后，与无 LTPA 相比，每周 LTPA 超过 8 次的危险比（95%置信区间）为 0.51（0.38-0.76，p<.001），与低 SICF 评分相比，高 1.43（1.36；1.00-1.84，p<.05）。在校正健康行为、血压、体重、C 反应蛋白和高密度脂蛋白胆固醇后，LTPA 的危险比为 0.52（0.35-0.78；p=0.002），但认知功能不再显著。在 75 岁及以上的人群中，LTPA 的结果相似，但认知功能在调整后仍然显著。
在一项针对美国老年人的全国性队列研究中，分析表明，在排除混杂因素后，那些经常进行 LTPA 的人死亡风险较低。在 60 至 74 岁时，认知功能较低的大部分影响可以通过其他风险因素来解释，但在 75 岁及以上时则不能。
