Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston.
Department of Cardiology, The University of Texas MD Anderson Cancer Center, Houston.
JAMA Oncol. 2020 Aug 1;6(8):1210-1217. doi: 10.1001/jamaoncol.2020.2045.
Sedentary behavior is associated with several health outcomes, including diabetes, cardiovascular disease, and all-cause mortality. Less is known about the association between objectively measured sedentary behavior and cancer mortality, as well as the association with physical activity.
To examine the association between accelerometer-measured sedentary behavior (total volume and accrual in prolonged, uninterrupted bouts) and cancer mortality.
DESIGN, SETTING, AND PARTICIPANTS: A prospective cohort study conducted in the contiguous US included 8002 black and white adults aged 45 years or older enrolled in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. The present analysis was performed from April 18, 2019, to April 21, 2020.
Sedentary time, light-intensity physical activity (LIPA), and moderate- to vigorous-intensity physical activity (MVPA) were measured using a hip-mounted accelerometer worn for 7 consecutive days.
Cancer mortality.
Of the 8002 study participants, 3668 were men (45.8%); mean (SD) age was 69.8 (8.5) years. Over a mean (SD) follow-up of 5.3 (1.5) years, 268 participants (3.3%) died of cancer. In multivariable-adjusted models, including MVPA, greater total sedentary time was associated with a greater risk of cancer mortality (tertile 2 vs tertile 1: hazard ratio [HR], 1.45; 95% CI, 1.00-2.11; tertile 3 vs tertile 1: HR, 1.52; 95% CI, 1.01-2.27). Longer sedentary bout duration was not significantly associated with greater cancer mortality risk: after adjustment for MVPA (tertile 2 vs tertile 1: HR, 1.26; 95% CI, 0.90-1.78; tertile 3 vs tertile 1: HR, 1.36; 95% CI, 0.96-1.93). Replacing 30 minutes of sedentary time with LIPA was significantly associated with an 8% (per 30 minutes: HR, 0.92; 95% CI, 0.86-0.97) lower risk of cancer mortality; MVPA was significantly associated with a 31% (per 30 minutes: HR, 0.69; 95% CI, 0.48-0.97) lower risk of cancer mortality.
In this cohort study, greater sedentary time, as measured with accelerometry, appeared to be independently associated with cancer mortality risk. Replacing sedentary time with either LIPA or MVPA may be associated with a lower risk of cancer mortality. These findings suggest that the total volume of sedentary behavior is a potential cancer mortality risk factor and support the public health message that adults should sit less and move more to promote longevity.
久坐行为与多种健康结果有关，包括糖尿病、心血管疾病和全因死亡率。关于客观测量的久坐行为与癌症死亡率之间的关系，以及与身体活动的关系，人们了解得还比较少。
研究加速度计测量的久坐行为（总时长和长时间连续不中断的积累）与癌症死亡率之间的关系。
设计、地点和参与者：这项在美国大陆进行的前瞻性队列研究纳入了年龄在 45 岁或以上的 8002 名黑人和白人成年人，他们参加了 Reasons for Geographic and Racial Differences in Stroke（REGARDS）研究。本分析于 2019 年 4 月 18 日至 2020 年 4 月 21 日进行。
使用佩戴在臀部的加速度计连续 7 天测量久坐时间、低强度体力活动（LIPA）和中等到剧烈强度体力活动（MVPA）。
癌症死亡率。
在 8002 名研究参与者中，3668 人为男性（45.8%）；平均（标准差）年龄为 69.8（8.5）岁。在平均（标准差）随访 5.3（1.5）年后，268 名参与者（3.3%）死于癌症。在包括 MVPA 的多变量调整模型中，久坐时间越长，癌症死亡风险越高（第 2 三分位与第 1 三分位：风险比[HR]，1.45；95%置信区间[CI]，1.00-2.11；第 3 三分位与第 1 三分位：HR，1.52；95%CI，1.01-2.27）。较长的久坐时间与更高的癌症死亡率风险之间没有显著关联：在调整 MVPA 后（第 2 三分位与第 1 三分位：HR，1.26；95%CI，0.90-1.78；第 3 三分位与第 1 三分位：HR，1.36；95%CI，0.96-1.93）。用 LIPA 取代 30 分钟的久坐时间与癌症死亡率降低 8%显著相关（每 30 分钟：HR，0.92；95%CI，0.86-0.97）；MVPA 与癌症死亡率降低 31%显著相关（每 30 分钟：HR，0.69；95%CI，0.48-0.97）。
在这项队列研究中，加速度计测量的久坐时间与癌症死亡率风险似乎呈独立相关。用 LIPA 或 MVPA 取代久坐时间可能与癌症死亡率降低有关。这些发现表明，久坐行为的总时长可能是癌症死亡率的一个潜在风险因素，并支持这样一个公共健康信息，即成年人应该减少久坐时间，增加活动量，以延长寿命。
