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

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.

女性有意体重减轻与体重反弹对血清雄激素的影响如何？本研究针对一项随机对照试验（randomized controlled trial）的前瞻性收集样本开展辅助分析。该试验先通过饮食与运动的有监督干预，在4-6个月内达成10%的体重减轻目标（平均减重8.5kg）；随后在4-6个月内开展有监督的有意体重反弹干预，使受试者恢复其减重重量的50%（平均反弹4.6kg）。在部分体重反弹阶段开始前，受试者被随机分为两组，分别继续或停止耐力运动。本研究的分析样本共纳入30名合并代谢综合征（metabolic syndrome）的肥胖绝经前女性，平均年龄40±5.9岁，基线体质量指数（body mass index, BMI）为32.9±4.2 kg/m²。我们检测了性激素结合球蛋白（sex hormone binding globulin, SHBG）、总睾酮（total testosterone, T）、游离雄激素指数（free androgen index, FAI）以及高分子量脂联素（high molecular weight adiponectin, HMWAdp）；同时针对本分析样本，重新分析了原始试验中检测的胰岛素、稳态模型评估（homeostasis model assessment, HOMA）、定量胰岛素敏感性检测指数（quantitative insulin sensitivity check index, QUICKI）以及内脏脂肪组织（visceral adipose tissue, VAT）。胰岛素、HOMA及QUICKI在体重减轻后得到改善，且在体重反弹期间仍维持改善状态。经对数转换的SHBG从基线至体重减轻阶段显著升高，随后在体重反弹阶段显著降低。对数转换后的FAI（logFAI）与VAT（logVAT）在体重减轻阶段均出现下降，随后在体重反弹阶段上升，二者变化趋势一致。对数转换后的总睾酮（logT）与高分子量脂联素（logHMWAdp）未出现显著变化。两组间各检测指标均未因运动干预产生显著差异。SHBG对体质量波动具有显著敏感性：在有控制的有意体重反弹期间，SHBG水平下降与VAT呈负相关，且该变化发生时HMWAdp保持稳定，胰岛素抵抗仍维持改善状态。FAI的变化趋势与SHBG恰好相反，而总睾酮水平未随体质量变化出现显著改变。体重反弹期间继续进行耐力运动并未对上述研究结果产生显著影响。