METHODS: Five databases were systematically searched up to May 2024 to identify systematic reviews with meta-analyses and prospective cohort studies. A qualitative synthesis of previous reviews and an updated meta-analysis of cohort studies were performed. Pooled hazard ratios (HRs) with their 95% confidence intervals (CIs) were calculated using a random-effects model.
RESULTS: Eleven systematic reviews with meta-analyses and 14 cohort studies were included, revealing considerable variability in result presentation. Our updated meta-analysis showed a nonlinear association, indicating a lower risk of all-cause mortality with increased daily steps, with a protective threshold at 3143 steps/day, and a pooled HR of 0.91 (95% CI: 0.87, 0.95) per 1000 steps/day increment. Physical activity categories consistently indicated progressively reduced mortality risk, with the highly active category (>12,500 steps/day) exhibiting the lowest risk (0.35 (95% CI: 0.29, 0.42)).
CONCLUSIONS: Systematic reviews and meta-analyses showed considerable variability in effect estimates due to different methods of quantifying exposure. Despite it, our study underscores the importance of increased daily steps in reducing all-cause mortality, with a minimum protective dose of 3000 steps/day, although the optimal dose differed according to age and sex. It is recommended that future studies categorise daily steps by physical activity category, perform dose-response analyses, and use increments of 1000 steps/day.
方法:截至2024年5月,系统搜索了5个数据库,以通过荟萃分析和前瞻性队列研究确定系统评价。对以前的综述进行了定性综合,并对队列研究进行了更新的荟萃分析。使用随机效应模型计算集合风险比(HR)及其95%置信区间(CI)。
结果:纳入了11项系统综述和荟萃分析和14项队列研究,揭示了结果呈现的相当大的可变性。我们更新的荟萃分析显示出非线性关联,表明随着每日步数的增加,全因死亡率的风险较低,保护阈值为3143步/天,每1000步/天增量的合并HR为0.91(95%CI:0.87,0.95)。身体活动类别一致表明死亡风险逐渐降低,高活性类别(>12,500步/天)表现出最低风险(0.35(95%CI:0.29,0.42))。
结论:系统评价和荟萃分析显示,由于定量暴露的方法不同,效果估计存在相当大的差异。尽管如此,我们的研究强调了增加每日步骤对降低全因死亡率的重要性,最低保护剂量为3000步/天,尽管最佳剂量因年龄和性别而异。建议未来的研究按身体活动类别对每日步数进行分类,进行剂量反应分析,并使用1000步/天的增量。