Exercise effects on oxidative damage among women

描述(由申请人提供)： 体力活动可降低患结肠癌、乳腺癌和子宫内膜癌的风险。已经研究了几种解释这些联系的机制，包括运动对炎症、胰岛素样生长因子、胰岛素抵抗、类固醇激素和脂代谢的潜在癌症预防作用。然而，这些机制并不能完全解释运动和癌症之间的联系。人们对运动对氧化应激和脂质过氧化的影响的研究较少；尽管最近的证据表明：(1)脂质过氧化的特定标记物8-iso-前列腺素F2(8-iso-PGF2a)与乳腺癌有关；以及(2)在实验室动物和男性短期试验中，8-iso-PGF2a通过运动或饮食和运动相结合而减少。 这项拟议研究的主要目的是评估为期一年的中等强度运动干预(n=87)与为期一年的拉伸控制计划(n=86)对最近完成的随机对照运动干预试验的尿8-iso-PGF2a的影响。运动干预的效果将在意向治疗的基础上进行评估，使用广义估计方程，该方程考虑了重复测量的受试者内部8-iso-PGF2a的相关性。受试者为绝经后女性，年龄50-75岁，不服用外源性激素，超重或肥胖，不吸烟，愿意随机选择，居住在大西雅图地区。运动干预组的女性被要求每天至少进行45分钟的中等强度运动，每周5天。随机对照试验具有良好的保留率；98%的参与者完成了试验。对运动处方的坚持程度也很高；参加运动的妇女平均每周参加体育或娱乐活动3.7天，每周171？88分钟(占规定活动的87%)。作为次要目标，我们将评估8-iso-PGF2a与以前从这项研究收集的数据之间的基线和纵向相关性，包括衡量肥胖的指标(例如体重、身高、皮下和腹内脂肪表面积、体脂百分比、全身脂肪以及腰围和臀围)、炎症标志物(例如C-反应蛋白、血清淀粉样蛋白A和白细胞介素6)、膳食补充剂的使用以及有氧健身。总之，这项应用建立在先前建立的随机对照试验的现有高质量数据的基础上，以检查为期一年的中等强度运动计划对一种新的癌症风险生物标记物的影响。

DESCRIPTION (provided by applicant): Physical activity reduces the risk of cancers of the colon, breast, and endometrium. Several mechanisms that explain these links have been studied, including potential cancer preventative effects of exercise on inflammation, insulin-like growth factors, insulin resistance, steroid hormones, and lipid metabolism. Yet these mechanisms do not fully explain the links between exercise and cancer. Less explored is the effect of exercise on oxidative stress and lipid peroxidation; although recent evidence suggests: (1) a specific marker of lipid peroxidation, 8-iso-prostaglandin F2 (8-iso-PGF2a), is linked with breast cancer; and (2) in laboratory animals and short-term trials of men, 8-iso-PGF2a is decreased by exercise or diet and exercise combined. The primary aim of the proposed study is to assess the impact of a 1-year moderate-intensity exercise intervention (n =87) compared to a 1-year stretching control program (n = 86) on urinary 8-iso-PGF2a from a recently completed randomized controlled exercise intervention trial. The effect of the exercise intervention will be assessed on an intention-to-treat basis, using generalized estimating equations that account for within subject correlation of 8-iso-PGF2a over repeated measurements. Participants were postmenopausal women, aged 50-75 years, not taking exogenous hormones, overweight or obese, non-smokers, willing to be randomized, and residing in the greater Seattle area. Women in the exercise intervention arm were prescribed at least 45 minutes/day of moderate-intensity activity, 5 days/week. The randomized controlled trial had excellent retention; 98% of the participants completed the trial. Adherence to the exercise prescription was high as well; women in the exercise arm participated in sport or recreational activity an average of 3.7 ¿ 1.4 days/week for 171 ¿ 88 min/week (87% of prescribed activity). As secondary aims we will evaluate baseline and longitudinal correlations between 8-iso-PGF2a and previously collected data from this study, including a measures of adiposity (e.g. weight, height, subcutaneous and intra-abdominal fat surface area, percent body fat, total body fat, and waist and hip circumferences), inflammatory markers (e.g. C-reactive protein, serum amyloid A, and interleukin-6), use of dietary supplements, and aerobic fitness. In summary, this application builds on existing high quality data from a previously established randomized controlled trial to examine the effect of a 1-year of moderate-intensity exercise program on a novel biomarker of cancer risk.