title: Physical activity and inactivity in relation to sex hormone, prolactin, and insulin-like growth factor concentrations in premenopausal women - exercise and premenopausal hormones.
abstract: An association between physical activity and premenopausal breast cancer risk may be due, in part, to relationships with sex hormones or growth factors. Therefore, we assessed whether MET-h/week of total physical activity (moderate-to-vigorous intensity), walking, or vigorous physical activity, and h/week of standing or sitting were associated with plasma concentrations of several hormones. We examined levels of estrogens, androgens, progesterone, prolactin, sex hormone binding globulin (SHBG), insulin-like growth factor-1 (IGF-1), IGF binding protein-3, and growth hormone (GH) in 565 premenopausal women, ages 33-52 years, from the Nurses' Health Study II (NHSII). About 87% of women had both timed follicular and luteal samples; other women had one untimed sample. In general we observed few associations between sex hormone or IGF levels and measures of physical activity or inactivity. However, free testosterone was modestly inversely associated with total physical activity (p-trend = 0.02). Luteal estradiol, free estradiol, and estrone also were inversely associated with total physical activity (p-trend = 0.10, 0.04, 0.01, respectively); however, the trend was substantially attenuated when excluding women with anovulatory cycles or irregular cycles. These cross-sectional results suggest that physical activity and inactivity have limited associations with premenopausal sex hormone and growth factor levels, except possibly luteal estrogens.
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Ave., 3rd Floor, Boston, MA 02115, USA. nhsst@channing.harvard.edu
authors.forename: Shelley S
authors.initials: SS
authors.lastname: Tworoger
authors.forename: Stacey A
authors.initials: SA
authors.lastname: Missmer
authors.forename: A Heather
authors.initials: AH
authors.lastname: Eliassen
authors.forename: Robert L
authors.initials: RL
authors.lastname: Barbieri
authors.forename: Mitch
authors.initials: M
authors.lastname: Dowsett
authors.forename: Susan E
authors.initials: SE
authors.lastname: Hankinson
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D017697:Premenopause / Q000097:blood* / Q000502:physiology*; D011388:Prolactin / Q000097:blood*; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*
chemical_list: D012739:Gonadal Steroid Hormones; D018972:Insulin-Like Growth Factor Binding Protein 3; D012738:Sex Hormone-Binding Globulin; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D011388:Prolactin