Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Richard Doll Building, Old Road Campus, Oxford, OX3 7LF, UK.
Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK.
Cancer Causes Control. 2021 Nov;32(11):1197-1212. doi: 10.1007/s10552-021-01466-6. Epub 2021 Jul 3.
Physical activity may reduce the risk of some types of cancer in men. Biological mechanisms may involve changes in hormone concentrations; however, this relationship is not well established. Therefore, we aimed to investigate the associations of physical activity with circulating insulin-like growth factor-I (IGF-I), sex hormone-binding globulin (SHBG, which modifies sex hormone activity), and total and free testosterone concentrations, and the extent these associations might be mediated by body mass index (BMI).
Circulating concentrations of these hormones and anthropometric measurements and self-reported physical activity data were available for 117,100 healthy male UK Biobank participants at recruitment. Objectively measured accelerometer physical activity levels were also collected on average 5.7 years after recruitment in 28,000 men. Geometric means of hormone concentrations were estimated using multivariable-adjusted analysis of variance, with and without adjustment for BMI.
The associations between physical activity and hormones were modest and similar for objectively measured (accelerometer) and self-reported physical activity. Compared to men with the lowest objectively measured physical activity, men with high physical activity levels had 14% and 8% higher concentrations of SHBG and total testosterone, respectively, and these differences were attenuated to 6% and 3% following adjustment for BMI.
Our results suggest that the associations of physical activity with the hormones investigated are, at most, modest; and following adjustment for BMI, the small associations with SHBG and total testosterone were largely attenuated. Therefore, it is unlikely that changes in these circulating hormones explain the associations of physical activity with risk of cancer either independently or via BMI.
身体活动可能降低男性某些类型癌症的风险。生物学机制可能涉及激素浓度的变化；然而，这种关系尚未得到很好的确立。因此，我们旨在研究身体活动与循环胰岛素样生长因子-I（IGF-I）、性激素结合球蛋白（SHBG，调节性激素活性）以及总睾酮和游离睾酮浓度的关联，以及这些关联可能通过体重指数（BMI）来介导的程度。
在招募时，117100 名英国生物库健康男性参与者提供了这些激素的循环浓度以及人体测量学和自我报告的身体活动数据。在 28000 名男性中，还在招募后平均 5.7 年收集了客观测量的加速度计身体活动水平。使用多变量调整方差分析估计激素浓度的几何平均值，同时调整和不调整 BMI。
身体活动与激素之间的关联是适度的，与客观测量（加速度计）和自我报告的身体活动相似。与客观测量身体活动水平最低的男性相比，身体活动水平较高的男性的 SHBG 和总睾酮浓度分别高 14%和 8%，而这些差异在调整 BMI 后分别降低到 6%和 3%。
我们的结果表明，身体活动与所研究的激素之间的关联最多是适度的；并且在调整 BMI 后，与 SHBG 和总睾酮的微小关联在很大程度上减弱了。因此，循环激素的变化不太可能独立于 BMI 或通过 BMI 来解释身体活动与癌症风险之间的关联。
