Effects of Aerobic Exercise Training on Estrogen Metabolism in Premenopausal Women: A Randomized Controlled Trial

Abstract

Background: Regular physical activity may alter estrogen metabolism, a proposed biomarker of breast cancer risk, by shifting metabolism to favor production of 2-hydroxyestrone (2-OHE1). Few studies, however, have examined this question using a randomized controlled trial. Purpose: To examine the effects of 12 weeks of aerobic exercise training on 2-OHE1 and 16A-hydroxyestrone (16A-OHE1) in premenopausal women. Methods: Participants were healthy, regularly menstruating, Caucasian women, 20 to 35 years, body mass index of 18 to 29.9, not using pharmacologic contraceptives, with average or below average fitness [maximal oxygen consumption (VO 2max ), <40 mL/kg/min]. Following a baseline menstrual cycle, participants (N = 32) were randomly assigned to a 12-week aerobic exercise training intervention (n = 17) or usual lifestyle (n = 15). Height, body mass, body composition by dual-energy X-ray absorptiometry, and VO 2max were measured at baseline and following the intervention. Urine

Diabetes, Overweight and Risk of Postmenopausal Breast Cancer: A Case-Control Study in Uruguay

“…Aromatization is stimulated bearing an excessive adipose mass, especially in the thighs, buttocks and abdominal-pelvic regions (gynoid obesity, sharing features with high endomorphism), with a high intake of Ω-6 polyunsaturated fatty acids (PUFAs) and having increased circulating glucocorticoids (McTernan et al, 2002) A recent study suggested that the ratio of 2/16-α-hydroxyestrogen metabolites may be a marker for lifestyle influences on estrogen metabolism associated with westernization (Falk et al, 2005). In particular, body composition was associated with 2-α-and 16-α-OHestrone levels: while thicker skinfolds were associated with higher 16-α-OH levels, (Campbell et al, 2005) an increase in lean body mass was associated with an improvement in 2/16-α-OH estrogens ratio (Campbell et al, 2007). Women who metabolize a large proportion of their estrogens via the 16-α-hydroxylation pathway could be at a higher risk of BC (Cauley et al, 2003).…”

Physical activity and breast cancer risk: impact of timing, type and dose of activity and population subgroup effects

“…The latter pathways are considered more oestrogenic and possibly genotoxic, whereas the 2-hydroxylation pathway can promote apoptosis, anti-inflammatory actions and inhibition of tumour growth 162 172 173. However, despite body fat playing a role,162 174 epidemiological studies have not shown physical activity to alter this pathway 175 176…”

Lifestyle changes and breast cancer prognosis: a review

“…A randomized controlled trial concluded that a 12-week aerobic exercise training intervention did not alter oestrogen metabolism in premenopausal women [21].…”