Exercise effect on oxidative stress is independent of change in estrogen metabolism.
ABSTRACT The effect of exercise training on lipid peroxidation and endogenous estrogens is not well understood in premenopausal women. Exercise effects on these variables could mediate observed associations of exercise with hormonally related cancers, including breast cancer. The purpose of the study is to determine the effect of 15 weeks of aerobic exercise on lipid peroxidation, endogenous estrogens, and body composition in young, healthy eumenorrheic women.
Fifteen sedentary premenopausal women (18-25 years) participated. Pre- and post-exercise training urine collection (three 24-h samples) started 48 h after most recent exercise session for analysis of a marker of lipid peroxidation (F(2)-isoprostane) and endogenous estrogens, including 2-hydroxyestrogens, 4-hydroxyestrogens, 16-alpha-hydroxyestrone, and ratios of these metabolites (2:16, 2:4). Body composition was measured by dual-energy X-ray absorptiometry, and F(2)-isoprostanes and estrogens were measured by gas chromatography-mass spectrometry.
Aerobic exercise resulted in a 34% decrease in F(2)-isoprostane (P = 0.02), a 10% increase in fitness (P = 0.004), a 1.2 kg decrease in body mass (P = 0.007), and a 1.8 kg decrease in fat mass (P = 0.04). No significant changes were noted in estrogens.
The effect of exercise training on oxidative stress may be relevant to risk for hormonally related cancers.
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ABSTRACT: Background: Lifetime physical activity (PA) is associated with decreased breast cancer (BC) risk; reports suggest that PA during adolescence contributes strongly to this relationship. PA lowers production of sex hormones, specifically estradiol, or decreases insulin resistance (IR), thereby lowering risk. Overweight Latina adolescents are insulin resistant and exhibit low levels of PA, potentially increasing their future BC risk. Methods: 37 obese Latina adolescents (15.7 ± 1.1 yrs) provided measures of PA using accelerometry; plasma follicular phase estradiol, sex-hormone binding globulin, total and free testosterone, dehydroepiandrosterone-sulfate (DHEAS); IR using HOMA-IR; and body composition via DEXA. Partial correlations and stepwise linear regressions assessed cross-sectional relationships between sex hormones, IR and PA. Body composition, and age were included a priori as covariates. Results: Estradiol was negatively associated with accelerometer counts per minute (CPM; r = -0.4; P = .02), percent time spent in moderate PA (%MPA; r = -0.5; P = .006), and percent time in moderate or vigorous PA (%MVPA; r = -0.5; P = .007). DHEAS was positively associated with CPM (r = .4, P = .009), %MPA (r = .3, P = .04), and %MVPA (r = .3, P = .04). Other sex hormones and IR were not associated with PA measures. Conclusion: This study is the first to show that higher habitual PA was inversely associated with estradiol in obese adolescents.Journal of Physical Activity and Health 07/2013; 10(5):727-33. · 1.95 Impact Factor
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ABSTRACT: BACKGROUND: Accumulation of excess body fat increases breast cancer risk after menopause. Whether the localized breast is differently influenced by adipose tissue compared to the rest of the body, has not been well studied. Our purpose was to demonstrate feasibility and preliminarily evaluate serum-based and localized breast biomarker changes resulting from a weight loss intervention among obese postmenopausal women. METHODS: We conducted a 12-week pilot controlled dietary and exercise intervention among healthy obese postmenopausal women, collected serum and breast ductal fluid before and after the intervention, and estimated the association with systemic and localized biomarker changes. We recruited 7 obese (mean body mass index = 33.6 kg/m2) postmenopausal women. We collected samples at baseline and the 12th week for: anthropometry; phlebotomy; dual-energy x-ray absorptiometry (lean and fat mass); exercise fitness (maximum oxygen consumption (VO2Max); 1-repetition strength maximum); and breast ductal lavage. RESULTS: Changes from baseline occurred in body composition and exercise performance including fat mass loss (14% average drop), VO2Max (+36% increase) and strength improvement (+26%). Breast ductal fluid markers declined from baseline with estradiol showing a 24% reduction and IL-6 a 20% reduction. We also observed serum biomarker reductions from baseline including leptin (36% decline), estrone sulfate (-10%), estradiol (-25%), and Il-6 (-33%). CONCLUSIONS: Conduct of the diet and exercise intervention, collection of ductal fluid, and measurement of hormones and cytokines contained in the ductal fluid were all feasible. We preliminarily demonstrated estradiol and IL-6 reductions from baseline in both serum and breast ductal fluid among obese postmenopausal women who participated in the 12-week weight loss diet and exercise intervention.Nutrition Journal 12/2012; 11(1):102. · 2.65 Impact Factor
- Comprehensive Reviews in Food Science and Food Safety 01/2013; 12:565-597. · 5.05 Impact Factor