Carlsson Sofia, Andersson Tomas, Wolk Alicja, Ahlbom Anders
Division of Epidemiology and Social Medicine, Stockholm Centre for Public Health, Stockholm, Sweden.
Scand J Public Health. 2006;34(5):480-7. doi: 10.1080/14034940600551293.
The aim of this study was to investigate the association between physical activity and mortality in post-menopausal women. In addition, the authors wanted to investigate to what extent this association could be attributed to confounding from other lifestyle factors, and to reverse causation due to a number of common health problems that may inhibit the ability to exercise.
A total of 27,734 women aged 51-83 years from the Swedish Mammography Cohort were investigated. In 1997 they responded to a detailed questionnaire including questions on physical activity, diet, alcohol intake, smoking, and medical problems. During follow-up in 1999-2004, 1,232 deaths were identified by linkage to the National Population Register.
Women with low physical activity (35 METh/day) had a 3.22 times increased mortality (95% confidence interval (CI) = 2.35-4.43) compared with the most active women (>50 METh/day). No increased risk was seen in women with moderate compared with high physical activity. Sedentary women tended to have a less healthy lifestyle and more health problems at baseline, e.g. almost 30% of them reported high blood pressure compared with less than 20% of active women. Baseline medical problems and lifestyle factors such as smoking, diet, and education accounted for 30% of the excess risk seen in sedentary women (24% and 6% respectively).
This study indicates that even fairly small amounts of activity will reduce mortality in older women. However, sedentary women seemed to be a selected group with more medical problems and a less healthy lifestyle. The findings indicate that the association between physical inactivity and mortality will be overestimated if this is not taken into account.
本研究旨在调查绝经后女性的身体活动与死亡率之间的关联。此外，作者还想研究这种关联在多大程度上可能归因于其他生活方式因素的混杂作用，以及由于一些可能抑制运动能力的常见健康问题导致的反向因果关系。
对瑞典乳腺X线摄影队列中27734名年龄在51 - 83岁的女性进行了调查。1997年，她们回答了一份详细问卷，内容包括身体活动、饮食、饮酒、吸烟和医疗问题等。在1999 - 2004年的随访期间，通过与国家人口登记处的链接确定了1232例死亡病例。
身体活动水平低（<35代谢当量·小时/天）的女性与最活跃的女性（>50代谢当量·小时/天）相比，死亡率增加了3.22倍（95%置信区间（CI）= 2.35 - 4.43）。中等身体活动水平的女性与高身体活动水平的女性相比，未发现风险增加。久坐不动的女性在基线时往往生活方式不太健康，健康问题更多，例如，近30%的久坐女性报告患有高血压，而活跃女性中这一比例不到20%。基线医疗问题和吸烟、饮食、教育等生活方式因素占久坐女性额外风险的30%（分别为24%和6%）。
本研究表明，即使是相当少量的活动也会降低老年女性的死亡率。然而，久坐不动的女性似乎是一个有更多医疗问题和不太健康生活方式的特定群体。研究结果表明，如果不考虑这一点，身体不活动与死亡率之间的关联将被高估。
