Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, United Kingdom.
University of New South Wales, Sydney, Australia.
PLoS Med. 2021 Jan 12;18(1):e1003487. doi: 10.1371/journal.pmed.1003487. eCollection 2021 Jan.
Higher levels of physical activity (PA) are associated with a lower risk of cardiovascular disease (CVD). However, uncertainty exists on whether the inverse relationship between PA and incidence of CVD is greater at the highest levels of PA. Past studies have mostly relied on self-reported evidence from questionnaire-based PA, which is crude and cannot capture all PA undertaken. We investigated the association between accelerometer-measured moderate, vigorous, and total PA and incident CVD.
We obtained accelerometer-measured moderate-intensity and vigorous-intensity physical activities and total volume of PA, over a 7-day period in 2013-2015, for 90,211 participants without prior or concurrent CVD in the UK Biobank cohort. Participants in the lowest category of total PA smoked more, had higher body mass index and C-reactive protein, and were diagnosed with hypertension. PA was associated with 3,617 incident CVD cases during 440,004 person-years of follow-up (median (interquartile range [IQR]): 5.2 (1.2) years) using Cox regression models. We found a linear dose-response relationship for PA, whether measured as moderate-intensity, vigorous-intensity, or as total volume, with risk of incident of CVD. Hazard ratios (HRs) and 95% confidence intervals for increasing quarters of the PA distribution relative to the lowest fourth were for moderate-intensity PA: 0.71 (0.65, 0.77), 0.59 (0.54, 0.65), and 0.46 (0.41, 0.51); for vigorous-intensity PA: 0.70 (0.64, 0.77), 0.54 (0.49,0.59), and 0.41 (0.37,0.46); and for total volume of PA: 0.73 (0.67, 0.79), 0.63 (0.57, 0.69), and 0.47 (0.43, 0.52). We took account of potential confounders but unmeasured confounding remains a possibility, and while removal of early deaths did not affect the estimated HRs, we cannot completely dismiss the likelihood that reverse causality has contributed to the findings. Another possible limitation of this work is the quantification of PA intensity-levels based on methods validated in relatively small studies.
In this study, we found no evidence of a threshold for the inverse association between objectively measured moderate, vigorous, and total PA with CVD. Our findings suggest that PA is not only associated with lower risk for of CVD, but the greatest benefit is seen for those who are active at the highest level.
更高水平的身体活动（PA）与心血管疾病（CVD）的风险降低有关。然而，PA 与 CVD 发病率之间的反比关系是否在最高水平的 PA 中更大仍存在不确定性。过去的研究主要依赖于基于问卷的 PA 的自我报告证据，这种证据是粗略的，无法捕捉到所有的 PA。我们调查了加速度计测量的中等强度、剧烈强度和总 PA 与 CVD 发病之间的关系。
我们在 UK Biobank 队列中获得了 90211 名无既往或同时 CVD 的参与者在 2013-2015 年期间 7 天内的加速度计测量的中等强度和剧烈强度身体活动和总 PA 量。总 PA 最低组的参与者吸烟更多，体重指数和 C 反应蛋白更高，并且被诊断为高血压。在 440004 人年的随访中（中位数（四分位距 [IQR]）：5.2（1.2）年），使用 Cox 回归模型发现 PA 与 3617 例 CVD 发病事件相关。无论以中等强度、剧烈强度还是总容量来衡量，PA 与 CVD 发病风险之间均存在线性剂量反应关系。与最低四分位数相比，PA 分布的每增加一个四分位数的危险比（HR）和 95%置信区间为：中等强度 PA：0.71（0.65，0.77），0.59（0.54，0.65）和 0.46（0.41，0.51）；剧烈强度 PA：0.70（0.64，0.77），0.54（0.49，0.59）和 0.41（0.37，0.46）；总 PA 量：0.73（0.67，0.79），0.63（0.57，0.69）和 0.47（0.43，0.52）。我们考虑了潜在的混杂因素，但仍存在未测量的混杂因素，而且虽然去除早期死亡并未影响估计的 HR，但我们不能完全排除反向因果关系对研究结果的影响。这项工作的另一个可能的局限性是基于在相对较小的研究中验证的方法来量化 PA 强度水平。
在这项研究中，我们没有发现客观测量的中等、剧烈和总 PA 与 CVD 之间的反比关系存在阈值的证据。我们的研究结果表明，PA 不仅与 CVD 风险降低有关，而且最高水平的活动带来的益处最大。
