Cancer Prevention Fellowship Program, Center for Cancer Training, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
Breast Cancer Res Treat. 2012 Aug;134(3):1279-90. doi: 10.1007/s10549-012-2129-y. Epub 2012 Jul 1.
Epidemiologic studies suggest that physical activity reduces breast cancer risk by 20-40 %. However, prior studies have relied on measures of self-report. In a population-based case-control study, we evaluated accelerometer measures of active and sedentary behavior in relation to breast cancer among 996 incident cases and 1,164 controls, residents of Warsaw, Poland (2000-2003), who were asked to wear an accelerometer for 7 days. Accelerometer values were averaged across valid wear days and summarized as overall activity (counts [ct]/min/day); in minutes spent in sedentary behavior (0-99 ct/min); and light (100-759 ct/min) and moderate-to-vigorous (760+ ct/min) activity. Odds ratios (OR) and 95 % confidence intervals (CI) were estimated using unconditional logistic regression. Comparing women in the highest quartile (Q4) of activity to those in the lowest (Q1), time spent in moderate-to-vigorous activity was inversely associated with breast cancer odds after adjustment for known risk factors, sedentary behavior and wear time (OR(Q4vsQ1) 0.39, 95 % CI 0.27-0.56; P-trend < .0001). Sedentary time was positively associated with breast cancer, independent of moderate-to-vigorous activity (OR(Q4vsQ1) 1.81, 95 % CI 1.26-2.60; P-trend = 0.001). Light activity was not associated with breast cancer in multivariable models including both moderate-to-vigorous activity and sedentary behavior. Our findings support an inverse association between accelerometer-based measures of moderate-to-vigorous physical activity and breast cancer while also suggesting potential increases in risk with sedentary time.
流行病学研究表明，身体活动可使乳腺癌风险降低 20-40%。然而，先前的研究依赖于自我报告的测量方法。在一项基于人群的病例对照研究中，我们评估了加速度计测量的活跃和久坐行为与 996 例新发病例和 1164 例对照者（波兰华沙居民，2000-2003 年）之间的关系，这些人被要求佩戴加速度计 7 天。将加速度计值在有效的佩戴天数内平均，并总结为总体活动（计数/分钟/天）；以分钟计算的久坐行为时间（0-99 计数/分钟）；以及轻（100-759 计数/分钟）和中到剧烈（760+计数/分钟）活动。使用非条件逻辑回归估计比值比（OR）和 95%置信区间（CI）。将活动最高四分位（Q4）的女性与活动最低四分位（Q1）的女性进行比较，调整已知危险因素、久坐行为和佩戴时间后，中到剧烈活动的时间与乳腺癌的比值呈负相关（OR（Q4vsQ1）0.39，95%CI 0.27-0.56；P-trend <.0001）。久坐时间与乳腺癌呈正相关，独立于中到剧烈活动（OR（Q4vsQ1）1.81，95%CI 1.26-2.60；P-trend = 0.001）。在包括中到剧烈活动和久坐行为的多变量模型中，轻活动与乳腺癌无关。我们的研究结果支持基于加速度计的中到剧烈体力活动与乳腺癌之间的反比关系，同时还表明久坐时间可能会增加乳腺癌的风险。
