Long Term Effects on Risk Factors for Cardiovascular Disease after 12-Months of Aerobic Exercise Intervention - A Worksite RCT among Cleaners

ObjectivesOccupational groups exposed to high occupational physical activity have an increased risk for cardiovascular disease (CVD). This may be explained by the high relative aerobic workload. Enhanced cardiorespiratory fitness reduces the relative aerobic workload. Thus, the aim was to evaluate the 12-months effects of worksite aerobic exercise on risk factors for CVD among cleaners.MethodsOne hundred and sixteen cleaners aged 18–65 years were randomized to a group performing aerobic exercise and a reference group receiving lectures. Outcomes were collected at baseline and after 12-months. A repeated measures 2×2 multi-adjusted mixed-model design was applied to compare the between-group differences using intention-to-treat analysis.ResultsBetween-group differences (p2/min/kg, aerobic workload -2.15 (SE 1.06) %HRR, resting HR -5.31 (SE 1.61) beats/min, high sensitive C-reactive protein -0.65 (SE 0.24) μg/ml. The blood pressure was unaltered. Stratified analyses on relative aerobic workload at baseline revealed that those with relative aerobic workloads ≥30% of HRR seems to impose a notable adverse effect on resting and ambulatory blood pressure.ConclusionThis long-term worksite aerobic exercise intervention among cleaners led to several beneficial effects, but also potential adverse effects among those with high relative aerobic workloads.Trial RegistrationControlled-Trials.com ISRCTN86682076

研究目标：暴露于高水平职业体力活动的职业人群，其心血管疾病（Cardiovascular Disease, CVD）发病风险升高，该现象可由较高的相对有氧负荷予以解释。提升心肺耐力可降低相对有氧负荷。本研究旨在评估工作场所有氧运动对清洁工人心血管疾病风险因素的12个月干预效果。
方法：本研究纳入116名年龄介于18~65岁的清洁工人，将其随机分为有氧运动干预组与接受健康讲座的对照组。分别于基线及12个月随访时采集结局指标。本研究采用重复测量2×2多调整混合模型设计，通过意向性分析（intention-to-treat）比较组间差异。
结果：组间具有统计学意义的差异指标包括：峰值摄氧量+2.31（标准误SE 1.01）ml O₂/min/kg、有氧负荷-2.15（SE 1.06）%心率储备（Heart Rate Reserve, HRR）、静息心率-5.31（SE 1.61）次/分钟、高敏C反应蛋白-0.65（SE 0.24）μg/ml。血压未出现显著变化。针对基线相对有氧负荷的分层分析显示，基线相对有氧负荷≥30%HRR的人群，其静息血压与动态血压出现了显著的不良改变。
结论：针对清洁工人的长期工作场所有氧运动干预可产生多项有益效应，但对于基线相对有氧负荷较高的人群，也可能带来潜在的不良影响。
试验注册：Controlled-Trials.com ISRCTN86682076