Smith Lee, Gardner Benjamin, Fisher Abigail, Hamer Mark
Health Behaviour Research Centre, University College London, London, UK.
Physical Activity Research Group, University College London, London, UK.
BMJ Open. 2015 Apr 15;5(4):e007423. doi: 10.1136/bmjopen-2014-007423.
Few studies have examined how levels of activity intensity fluctuate throughout later life in older adults and no study has identified correlates of sustained activity levels in this age group. The aim of the present analysis was to investigate stability of activity over a 10-year period and identify potential correlates of sustained activity levels in older adults.
Analyses of data from the English Longitudinal Study of Ageing. Participant-reported physical activity data were collected in 2002 (baseline), 2004, 2006, 2008, 2010 and 2012. Participant age, sex, smoking, depressive symptoms, work status, wealth, and long-standing illness were recorded at baseline. Multiple logistic regression was used to examine associations between baseline exposure variables and persistent physical activity (reporting moderate and/or vigorous physical activity at least once a week at all 6 assessments over the 10-year time period).
A total of 5022 participants (mean age 61 years; 2114 male) were included in the analyses. There was reasonable stability in the physical activity measure over the 6 time points (Cronbach's α 0.85). There was an overall trend for increasing levels of inactivity and a reduction in vigorous activity. Age, female sex, having ever smoked, long-standing illness, arthritis, obesity, and depressive symptoms were associated with a lower likelihood of being persistently active (defined as reporting moderate and/or vigorous physical activity at least once a week over all 6 assessment points). Those with greater wealth were 4 times more likely to be persistently active.
In the present analyses time spent in vigorous-intensity activity declined in later life. A range of sociodemographic and biomedical factors were associated with being persistently active in older adults.
很少有研究考察老年人在晚年时活动强度水平是如何波动的，且尚无研究确定该年龄组持续活动水平的相关因素。本分析的目的是调查10年间活动的稳定性，并确定老年人持续活动水平的潜在相关因素。
对英国老龄化纵向研究的数据进行分析。在2002年（基线）、2004年、2006年、2008年、2010年和2012年收集了参与者自我报告的身体活动数据。在基线时记录参与者的年龄、性别、吸烟情况、抑郁症状、工作状态、财富和慢性病情况。采用多因素logistic回归分析来检验基线暴露变量与持续身体活动之间的关联（在10年期间的所有6次评估中，每周至少报告一次中等强度和/或剧烈身体活动）。
共有5022名参与者（平均年龄61岁；男性2114名）纳入分析。在6个时间点上，身体活动测量值具有合理的稳定性（Cronbach's α为0.85）。总体趋势是不活动水平增加，剧烈活动减少。年龄、女性、曾经吸烟、慢性病、关节炎、肥胖和抑郁症状与持续活跃的可能性较低相关（定义为在所有6个评估点上每周至少报告一次中等强度和/或剧烈身体活动）。财富较多的人持续活跃的可能性高4倍。
在本分析中，晚年剧烈强度活动的时间减少。一系列社会人口学和生物医学因素与老年人的持续活跃相关。
