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.

女性刻意减重（intentional weight loss）与体重反弹对血清雄激素的影响如何？本研究对一项随机对照试验（randomized controlled trial, RCT）中前瞻性收集的样本开展了辅助分析。该试验的干预流程为：通过饮食与运动在4-6个月内实现10%的体重降幅（平均减重8.5kg），随后在4-6个月内通过监督下的刻意反弹，恢复减重重量的50%（平均反弹4.6kg）。在进入部分体重反弹阶段前，参与者被随机分配至持续耐力运动组或停止耐力运动组。本研究的分析样本共纳入30名合并代谢综合征的肥胖绝经前女性，平均年龄为40±5.9岁，基线体重指数（body mass index, BMI）为32.9±4.2 kg/m²。本研究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）。同时对原始试验中已测量的胰岛素、稳态模型评估指数（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）进行了二次分析。结果显示，胰岛素水平、HOMA指数与QUICKI指数在减重阶段得到改善，且在体重反弹阶段仍可维持该改善效果。经对数转换后的SHBG水平从基线至减重阶段显著升高，随后在体重反弹阶段显著降低。经对数转换后的FAI（logFAI）与VAT（logVAT）变化趋势一致：减重阶段降低，体重反弹阶段升高。经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耐力运动干预产生显著差异。进一步分析显示，SHBG对体重波动具有显著敏感性：在受控的刻意体重反弹阶段，SHBG水平的降低与内脏脂肪体积呈负相关，且尽管脂联素水平保持稳定、胰岛素抵抗的改善效果持续存在，该变化仍会发生。FAI的变化趋势与SHBG恰好相反，而总睾酮水平未随体重变化出现显著改变。体重反弹阶段持续进行耐力运动并未对上述研究结果产生显著影响。