We tested the effects of weight loss on serum estradiol, estrone, testosterone, and sex hormone-binding globulin (SHBG) in overweight/obese women 18 months after completing a year-long, 4-arm, randomized-controlled dietary weight loss and/or exercise trial.
From 2005 to 2008, 439 overweight/obese, postmenopausal women (BMI >25 kg/m2), 50 to 75 years, were randomized to a year-long intervention: diet (reduced calorie, 10% weight loss, N = 118), exercise (225 min/wk moderate-to-vigorous activity, N = 117), combined diet + exercise (N = 117), or control (N = 87). At 12 months, 399 women provided blood; of these, 156 returned at 30 months and gave a blood sample. Hormones and SHBG were measured by immunoassay. Changes were compared using generalized estimating equations, adjusting for confounders.
At 30 months, participants randomized to the diet + exercise intervention had statistically significant increases in SHBG levels versus controls (P = 0.001). There was no statistically significant change in SHBG in the exercise or diet intervention arms. Hormone levels did not vary by intervention arm from baseline to 30 months. Participants who maintained weight loss at 30 months had statistically significantly greater decreases in free estradiol and free testosterone (Ptrend = 0.02 and Ptrend = 0.04, respectively) and increases in SHBG (Ptrend < 0.0001) versus those who did not have sustained weight loss. Levels of other analytes did not vary by weight loss at 30 months.
Sustained weight loss results in reductions in free estradiol and testosterone and increases in SHBG 18-month post-intervention.
1Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
2Department of Obstetrics, Gynecology, and Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA
3School of Medicine, University of Washington, Seattle, WA
4Department of Epidemiology, University of Washington, Seattle, WA.
Address correspondence to: Catherine Duggan, PhD, Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109. E-mail: firstname.lastname@example.org
Received 20 August, 2018
Revised 12 September, 2018
Accepted 12 September, 2018
Funding/support: This work was supported by grants from the National Cancer Institute at the National Institutes of Health (P30 CA015704, R01 CA105204-01A1 and U54-CA116847), and the Breast Cancer Research Foundation (BCRF-16-106, BCRF-17-105).
Financial disclosure/conflicts of interest: None reported.