Department of Cancer Epidemiology and Prevention Research, Cancer Care Alberta, Alberta Health Services, Calgary, AB, Canada.
Department of Biomedical Sciences, Area of Sport and Physical Education (GRIGEDE), University of Alcalá, Alcalá de Henares, Madrid, Spain.
Int J Obes (Lond). 2021 Jun;45(6):1298-1309. doi: 10.1038/s41366-021-00799-1. Epub 2021 Mar 16.
BACKGROUND/OBJECTIVE: Exercise may reduce the risk of breast cancer through adiposity changes, but the dose-response effects of exercise volume on adiposity markers are unknown in postmenopausal women. We aimed to compare the dose-response effects of prescribed aerobic exercise volume on adiposity outcomes.
PARTICIPANTS/METHODS: Data from the Alberta Physical Activity and Breast Cancer Prevention (ALPHA) and Breast Cancer and Exercise Trial in Alberta (BETA) were pooled for this analysis (N = 720). These were 12-month randomized controlled trials, where participants were randomized to 225 min/week (mid-volume) of aerobic exercise versus usual inactive lifestyle (ALPHA), or 150 min/week (low-volume) versus 300 min/week (high-volume) (BETA). Fat mass and fat-free mass were measured using DXA and intra-abdominal and subcutaneous fat area were assessed with computed tomography.
After 12 months of aerobic exercise, increasing exercise volumes from no exercise/control to 300 min/week resulted in statistically significant reductions in BMI, weight, fat mass, fat percentage, intra-abdominal and subcutaneous fat area (P < 0.001). Compared with controls, fat mass loss was -1.13, -1.98 and -2.09 kg in the low-, mid- and high-volume groups, respectively. Similarly, weight loss was -1.47, -1.83, -2.21 kg in the low-, mid- and high-volume groups, respectively, compared to controls, and intra-abdominal fat area loss was -7.44, -15.56 and -8.76 cm in the low-, mid- and high-volume groups, respectively, compared to controls. No evidence for a dose-response effect on fat-free mass was noted.
A dose-response effect of exercise volume on adiposity markers was noted, however, the differences in adiposity markers were smaller when comparing 225 min/week to 300 min/week of exercise. Given the strong positive associations between obesity and postmenopausal breast cancer risk, this study provides evidence on the importance of exercise volume as part of the exercise prescription to reduce adiposity and, ultimately, postmenopausal breast cancer risk.
背景/目的：运动可能通过体脂变化降低乳腺癌风险，但绝经后女性运动量与脂肪标志物之间的剂量-反应关系尚不清楚。本研究旨在比较规定的有氧运动量对肥胖结果的剂量-反应关系。
参与者/方法：对 Alberta Physical Activity and Breast Cancer Prevention (ALPHA) 和 Alberta 乳腺癌与运动试验 (BETA) 的数据进行了汇总分析（N=720）。这些是为期 12 个月的随机对照试验，参与者被随机分配到每周 225 分钟（中等量）的有氧运动与通常的不活动生活方式（ALPHA），或每周 150 分钟（低量）与每周 300 分钟（高量）（BETA）。使用 DXA 测量脂肪量和去脂体重，使用计算机断层扫描评估腹内和皮下脂肪面积。
经过 12 个月的有氧运动，与不运动/对照组相比，运动量从无运动增加到 300 分钟/周，导致 BMI、体重、脂肪量、体脂百分比、腹内和皮下脂肪面积显著降低（P<0.001）。与对照组相比，低、中、高运动组的脂肪量分别减少了-1.13、-1.98 和-2.09kg。同样，与对照组相比，体重分别减少了-1.47、-1.83 和-2.21kg，低、中、高运动组的腹内脂肪面积分别减少了-7.44、-15.56 和-8.76cm。没有证据表明运动量对去脂体重有剂量反应效应。
运动量与脂肪标志物之间存在剂量-反应关系，但与每周 225 分钟相比，每周 300 分钟的运动对脂肪标志物的影响较小。鉴于肥胖与绝经后乳腺癌风险之间存在很强的正相关关系，本研究提供了关于运动量作为运动处方的一部分以减少肥胖、最终降低绝经后乳腺癌风险的重要性的证据。
