Exercise effects on oxidative damage among women

描述（由申请人提供）： 体力活动可以降低患结肠癌、乳腺癌和子宫内膜癌的风险。已经研究了解释这些联系的几种机制，包括运动对炎症、胰岛素样生长因子、胰岛素抵抗、类固醇激素和脂质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与癌症之间的联系。运动对氧化应激和脂质过氧化的影响较少探讨;尽管最近的证据表明：（1）脂质过氧化的一种特异性标志物8-异前列腺素F2（8-iso-PGF 2a）与乳腺癌有关;（2）在实验室动物和短期男性试验中，运动或饮食和运动联合会降低8-iso-PGF 2a。 这项拟议研究的主要目的是评估1年中等强度运动干预（n =87）与1年拉伸对照计划（n = 86）对最近完成的随机对照运动干预试验中尿8-iso-PGF 2a的影响。将在意向治疗的基础上，使用广义估计方程评估运动干预的效果，该方程解释了重复测量中8-iso-PGF 2a的受试者内相关性。参与者为绝经后妇女，年龄50-75岁，未服用外源性激素，超重或肥胖，不吸烟，愿意随机分配，居住在大西雅图地区。运动干预组的女性每天至少进行45分钟的中等强度活动，每周5天。随机对照试验的保持力非常好; 98%的参与者完成了试验。坚持运动处方也很高;运动组的女性平均每周参加3.7 <$1.4天的运动或娱乐活动，每周171 <$88分钟（87%的规定活动）。作为次要目的，我们将评估8-iso-PGF 2a与本研究先前收集的数据（包括肥胖指标）之间的基线和纵向相关性。（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）、膳食补充剂的使用和有氧健身。总之，本申请基于先前建立的随机对照试验的现有高质量数据，以检查1年中等强度运动计划对癌症风险新生物标志物的影响。

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.