Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
PLoS One. 2013 Jun 12;8(6):e65279. doi: 10.1371/journal.pone.0065279. Print 2013.
Population-based studies have reported conflicting findings on the relationship between physical activity and pain, and most studies reporting a relationship are cross sectional. Temporal relationships are therefore difficult to infer and associations may be subject to confounding from a variety of other factors. The aim of the current study was to investigate the association between exercise and pain longitudinally and to use within subjects analyses to remove between subjects confounding.
In the population-based HUNT 3 study, participants reported both pain and level of exercise. A random sub-sample of 6419 participants was in addition invited to report their last week pain and exercise every three months over a 12 month period (five measurements in total). We used multilevel mixed effects linear regression analyses to prospectively estimate the association between regular levels of exercise (measured in HUNT 3) and subsequent longitudinal reporting of pain. We also estimated within-subjects associations (i.e. the variation in pain as a function of variation in exercise, over time, within individuals) to avoid confounding from between subject factors.
Among those invited to participate (N = 6419), 4219 subjects returned at least two questionnaires. Compared with subjects who reported no or light exercise, those who reported moderate levels of exercise or more at baseline, reported less pain in repeated measures over a 12 month period in analyses adjusted for age, sex,education and smoking. Adjusting for baseline level of pain distinctly attenuated the findings. Within subjects, an increase in exercise was accompanied by a concurrent reduction in intensity of pain. However, we found no indication that exercise level at one occasion was related to pain reporting three months later.
This longitudinal population-based study indicates that exercise is associated with lower level of pain and that this association is close in time.
基于人群的研究报告了体力活动与疼痛之间的关系存在相互矛盾的发现，而且大多数报告存在关系的研究都是横断面研究。因此，很难推断时间关系，并且关联可能受到来自各种其他因素的混杂影响。本研究的目的是纵向研究运动与疼痛之间的关联，并使用个体内分析来消除个体间的混杂。
在基于人群的 HUNT 3 研究中，参与者报告了疼痛和运动水平。另外还邀请了随机子样本的 6419 名参与者，在 12 个月的时间内每三个月报告一次他们上周的疼痛和运动情况（总共进行了五次测量）。我们使用多层次混合效应线性回归分析前瞻性估计定期运动水平（在 HUNT 3 中测量）与随后的纵向疼痛报告之间的关联。我们还估计了个体内的关联（即在个体内，随着时间的推移，疼痛随运动变化的变化），以避免来自个体间因素的混杂。
在受邀参与的参与者中（N=6419），有 4219 名参与者至少返回了两份问卷。与报告没有或轻度运动的参与者相比，那些在基线时报告中度或更高水平运动的参与者，在调整了年龄、性别、教育和吸烟因素后，在 12 个月的重复测量中报告的疼痛较少。调整基线疼痛水平明显减弱了这些发现。在个体内，运动的增加伴随着疼痛强度的同时降低。然而，我们没有发现一次运动水平与三个月后疼痛报告之间存在关联的迹象。
这项基于人群的纵向研究表明，运动与较低水平的疼痛相关，而且这种关联在时间上很接近。
