Increased Duration of Exercise Decreases Rate of Nonresponse to Exercise but May Not Decrease Risk for Cancer Mortality.
Increased Duration of Exercise Decreases Rate of Nonresponse to Exercise but May Not Decrease Risk for Cancer Mortality.
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DOI：
10.1249/mss.0000000000002539
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发表时间：
2021-05-01
影响因子：
4.1
通讯作者：
Sturgeon K
中科院分区：
文献类型：
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作者：
Lin D;Potiaumpai M;Schmitz K;Sturgeon K
以前的研究已经观察到运动和乳腺癌风险之间的反比关系。然而，有个体间的差异，在运动训练干预。我们研究了增加有氧运动的剂量（150分钟·周-1或300分钟·周-1），同时保持运动强度恒定（70%-80% HRmax），是否会减少运动无应答者的数量，并进一步降低我们研究人群中遗传上易患乳腺癌的女性癌症死亡率的相关风险。乳腺癌风险升高的健康绝经前妇女被随机分为对照组（<75分钟·周-1，n=47），低剂量运动组（150分钟·周-1，n=39）和高剂量运动组（300分钟·周-1，n=39），持续约6个月。我们评估：1）临床有效性（CE），定义为预测的VO 2 max改善≥1 mL·kg-1·min-1，并且是VO 2 max典型误差（2x TE）的两倍，作为分类运动“无应答者”的阈值; 2）CE和2x TE相对于运动坚持水平; 3）VO 2 max与预测癌症死亡风险的相关变化。在我们六个月的干预后，我们观察到低剂量组中23.5%的女性和高剂量组中5.6%的女性是临床无应答者（p=0.04）。临床无应答状态与依从性水平无关，低剂量组87.2%的女性和高剂量组94.9%的女性观察到癌症死亡风险降低（p=0.43）。通过运动时间增加运动量（而不是强度）可以显著减少“无反应者”的数量。观察到真正的无应答者，因为一些女性尽管坚持锻炼水平很高，但并没有提高她们的健身能力。最后，150分钟·周-1似乎足以降低癌症死亡率的预测风险。
Previous studies have observed an inverse relationship between exercise and breast cancer risk. However, there is inter-individual variability in response to exercise training interventions. We investigated whether increasing the dose of aerobic exercise (150 min·week−1 or 300 min·week−1), while keeping intensity of exercise constant (70%−80% HRmax), decreases the number of exercise non-responders, and further decreases associated-risk for cancer mortality in our study population of women genetically pre-disposed for breast cancer. Healthy premenopausal women at elevated risk of breast cancer were randomized into control (<75 min·week−1, n=47), low-dose exercise (150 min·week−1, n=39), and high-dose exercise groups (300 min·week−1, n=39) for approximately six months. We assessed: 1) clinical effectiveness (CE), defined as an improvement in predicted VO2max of ≥1 mL·kg−1·min−1, and, twice the typical error (2x TE) of VO2max, as thresholds to classify exercise “non-responders”; 2) CE and 2x TE relative to exercise adherence levels, and 3) related changes in VO2max to predicted cancer mortality risk. Following our six month intervention we observed 23.5% of women in the low-dose group and 5.6% of women in the high-dose group were clinical non-responders (p=0.04). Clinical non-responder status was independent of adherence level Associated reduction in risk for cancer mortality was observed among 87.2% of women in the low-dose group and 94.9% in the high dose group (p=0.43). Increasing volume (not intensity) of exercise via time spent exercising significantly decreases the number of “non-responders”. True non-responders were observed as some women did not improve their fitness capacity despite high exercise adherence levels. Lastly, it appears 150 min·week−1 is sufficient to decrease predicted risk of cancer mortality.