Sex hormone changes during weight loss and maintenance in overweight and obese postmenopausal African-American and non-African-American women
1 Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, 6120 Executive Boulevard, Rockville, MD 20854, USA
2 Reproductive Endocrine Research Laboratory, Livingston Research Building, 1321 N. Mission Road, Room 201, Los Angeles, CA 90033, USA
3 Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Medical Institutions, 2024 East Monument Street, Room 2-642, Baltimore, MD 21287, USA
4 Epidemiology and Prevention, Maya Angelou Center for Health Equity, Wake Forest University Baptist Medical Center, Medical Center Boulevard, Winston Salem, NC 27157, USA
5 Division of Endocrinology, Metabolism and Nutrition, Duke University Medical Center, 200 Trent Drive, Duke South Orange Zone, DUMC Box 3031, Durham, NC 27710, USA
6 Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, 600 N. Wolfe Street, Meyer 101, Baltimore MD 21287, USA
7 Division of Endocrinology, Metabolism, and Nutrition, Sarah Stedman Nutrition and Metabolism Center, Duke University Medical Center, Box 2956 DUHS, 201 Trent Drive, Durham, NC 27710, USA
8 Sarah W. Stedman Nutrition and Metabolism Center, Duke Hypertension Center, 3475 Erwin Road, Suite 101D, Durham, NC 27705, USA
Breast Cancer Research 2012, 14:R141 doi:10.1186/bcr3346Published: 31 October 2012
Changes in sex hormones with weight loss might have implications for breast cancer prevention but have not been examined extensively, particularly in African-American (AA) women.
We conducted a prospective study of 278 overweight/obese postmenopausal women (38% AA) not taking hormone therapy within the Weight Loss Maintenance Trial. All participants lost at least 4 kg after a 6-month weight-loss phase and attempted to maintain weight loss during the subsequent 12 months. We evaluated the percentage changes in estrone, estradiol, free estradiol, testosterone, free testosterone, androstenedione, dehydroepiandrosterone sulfate and sex hormone-binding globulin (SHBG) using generalized estimating equations.
In all study phases, AA women had higher levels of estrogen and testosterone concentrations, independent of adiposity. On average, participants lost 7.7 kg during the weight-loss phase, and concentrations of estrone (-5.7%, P = 0.006), estradiol (-9.9%, P <0.001), free estradiol (-13.4%, P <0.0001), and free testosterone (-9.9%, P <0.0001) decreased, while the SHBG concentration (16.2%, P <0.001) increased. Weight change did not significantly affect total testosterone or other androgen concentrations. Compared with non-AA women, AA women experienced less change in estrogens per kilogram of weight change (that is, per 1 kg weight loss: estrone, -0.6% vs. -1.2%, P-interaction = 0.10; estradiol, -1.1% vs. -1.9%, P-interaction = 0.04; SHBG, 0.9% vs. 1.6%, P-interaction = 0.006; free estradiol, -1.4% vs. -2.1%, P-interaction = 0.01).
To the best of our knowledge this is the first study to examine and compare the effects of intentional weight loss and maintenance on a panel of sex hormones in AA women and non-AA women. Although speculative, these data suggest hormonal differences may contribute to different racial patterns of breast cancer incidence and mortality and encourage further investigations to understand the long-term effects of weight loss on sex hormones in obese postmenopausal women.