caa a22 4500 445315687 CHVBK 20180317142646.0 cr unu---uuuuu 170323e20110401xx s 000 0 eng 10.1007/s10552-011-9731-x doi (NATIONALLICENCE)springer-10.1007/s10552-011-9731-x Associations of body size and reproductive factors with circulating levels of sex hormones and prolactin in premenopausal Japanese women [Elektronische Daten] [Chisato Nagata, Keiko Wada, Kozue Nakamura, Makoto Hayashi, Noriyuki Takeda, Keigo Yasuda] Objective: Body size and reproductive factors are important risk factors of breast cancer. The aim of the present study was to examine the associations of these factors with blood concentrations of sex hormones and prolactin in premenopausal Japanese women. Methods: We measured the plasma concentrations of estradiol, estrone, testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG), follicle-stimulating hormone, luteinizing hormone, and prolactin among 436 women who had regular menstrual cycles less than 40days long. Information on menstrual and reproductive factors including history of breastfeeding was obtained using a self-administered questionnaire. Height and weight were measured. Results: After controlling for age and the phase of the menstrual cycle, the body mass index (BMI) was significantly inversely associated with total estradiol, estrone and SHBG and significantly positively associated with total and free testosterone and DHEAS. Nulliparous women had significantly higher levels of total and free testosterone, DHEAS, and prolactin than parous women. Duration of breastfeeding for the first child was significantly inversely associated with free testosterone and prolactin levels. Conclusions: The data suggest that an increased risk of premenopausal breast cancer associated with low BMI is partially mediated by an increased total estradiol. Androgens and prolactin may explain the breast cancer protection provided by giving birth and breastfeeding. Springer Science+Business Media B.V., 2011 Body mass index nationallicence Breastfeeding nationallicence Sex hormones nationallicence Prolactin nationallicence Premenopausal nationallicence Nagata Chisato Department of Epidemiology & Preventive Medicine, Gifu University Graduate School of Medicine, 501-1194, Gifu, Japan aut Wada Keiko Department of Epidemiology & Preventive Medicine, Gifu University Graduate School of Medicine, 501-1194, Gifu, Japan aut Nakamura Kozue Department of Epidemiology & Preventive Medicine, Gifu University Graduate School of Medicine, 501-1194, Gifu, Japan aut Hayashi Makoto Department of Internal Medicine, Matsunami General Hospital, Gifu, Japan aut Takeda Noriyuki Department of Endocrinology and Metabolism, Murakami Memorial Hospital, Asahi University, Gifu, Japan aut Yasuda Keigo Department of Internal Medicine, Matsunami General Hospital, Gifu, Japan aut Cancer Causes & Control Springer Netherlands 22/4(2011-04-01), 581-588 0957-5243 22:4<581 2011 22 10552 https://doi.org/10.1007/s10552-011-9731-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10552-011-9731-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nagata Chisato Department of Epidemiology & Preventive Medicine, Gifu University Graduate School of Medicine, 501-1194, Gifu, Japan aut NATIONALLICENCE 700 1- Wada Keiko Department of Epidemiology & Preventive Medicine, Gifu University Graduate School of Medicine, 501-1194, Gifu, Japan aut NATIONALLICENCE 700 1- Nakamura Kozue Department of Epidemiology & Preventive Medicine, Gifu University Graduate School of Medicine, 501-1194, Gifu, Japan aut NATIONALLICENCE 700 1- Hayashi Makoto Department of Internal Medicine, Matsunami General Hospital, Gifu, Japan aut NATIONALLICENCE 700 1- Takeda Noriyuki Department of Endocrinology and Metabolism, Murakami Memorial Hospital, Asahi University, Gifu, Japan aut NATIONALLICENCE 700 1- Yasuda Keigo Department of Internal Medicine, Matsunami General Hospital, Gifu, Japan aut NATIONALLICENCE 773 0- Cancer Causes & Control Springer Netherlands 22/4(2011-04-01), 581-588 0957-5243 22:4<581 2011 22 10552 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer