The impact of supervised weight loss and intentional weight regain on sex hormone binding globulin and testosterone in premenopausal women

Abstract

What is the impact of intentional weight loss and regain on serum androgens in women? We conducted an ancillary analysis of prospectively collected samples from a randomized controlled trial. The trial involved supervised 10% weight loss (8.5 kg on average) with diet and exercise over 4–6 months followed by supervised intentional regain of 50% of the lost weight (4.6 kg on average) over 4–6 months. Participants were randomized prior to the partial weight regain component to either continuation or cessation of endurance exercise. Analytic sample included 30 obese premenopausal women (mean age of 40 ± 5.9 years, mean baseline body mass index (BMI) of 32.9 ± 4.2 kg/m2) with metabolic syndrome. We evaluated sex hormone binding globulin (SHBG), total testosterone (T), free androgen index (FAI), and high molecular weight adiponectin (HMWAdp). Insulin, homeostasis model assessment (HOMA), and quantitative insulin sensitivity check index (QUICKI), and visceral adipose tissue (VAT) measured in the original trial were reanalyzed for the current analytic sample. Insulin, HOMA, and QUICKI improved with weight loss and were maintained despite weight regain. Log-transformed SHBG significantly increased from baseline to weight loss, and then significantly decreased with weight regain. LogFAI and logVAT decreased similarly and increased with weight loss followed by weight regain. No changes were found in logT and LogHMWAdp. There was no significant difference in any tested parameters by exercise between the groups. SHBG showed prominent sensitivity to body mass fluctuations, as reduction with controlled intentional weight regain showed an inverse relationship to VAT and occurred despite stable HMWAdp and sustained improvements with insulin resistance. FAI showed opposite changes to SHBG, while T did not change significantly with weight. Continued exercise during weight regain did not appear to impact these findings.

Associations between the rate, amount, and composition of weight loss as predictors of spontaneous weight regain in adults achieving clinically significant weight loss: A systematic review and meta‐regression

“…Body composition was measured using dual energy X‐ray absorptiometry (DXA; n = 21); water displacement (n = 6); deuterium dilution (n = 7); bioelectrical impedance (BIA; n = 5), and air displacement plethysmography (ADP; n = 4). In 27 studies, there was a passive follow‐up period where no contact with participants occurred, whereas 16 studies conducted an active WLM intervention . The median weight loss period was 13 (4‐52) weeks, and the median follow‐up period was 44 (18‐249) weeks.…”

Circulating sex hormone binding globulin levels are modified with intensive lifestyle intervention, but their changes did not independently predict diabetes risk in the Diabetes Prevention Program

“… 32 In another study, intentional weight loss followed by intentional weight gain in premenopausal women demonstrated both an initial increase in SHBG followed by the reciprocal decrease, with free androgen index and visceral adipose tissue changing in opposite direction to SHBG changes, again speaking to a dynamic change in SHBG in response to decreases in weight and adiposity. 33 With bariatric surgery, resulting in significant and sustained amounts of weight loss, 30 31 sustained increases in circulating SHBG have been seen even several years after surgery. 31 …”

Weight loss since early adulthood, later life risk of fracture hospitalizations, and bone mineral density: a prospective cohort study of 0.5 million Chinese adults

“…All these findings together suggest that weight loss at any stage of adulthood may associate with increased bone loss and fracture risk, particularly the risk of hip fracture. Potential mechanisms underlying this association include inadequate intakes of dietary calcium [23], vitamin D [24], and protein [25], and changes in mechanical loading [26], muscle mass [27], fat mass [14], and hormonal regulation on bone metabolism, such as estrogen [28], adiponectin [29], leptin [30], sex hormone-binding globulin (SHBG) [31,32].…”