Department of Endocrinology and Metabolism, Shanghai Sixth People's Hospital, affiliated to Shanghai Jiao Tong University, Shanghai, China.
Shanghai Diabetes Institute, Shanghai Clinical Center of Diabetes, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Diseases, Shanghai, China.
Obes Facts. 2019;12(3):272-280. doi: 10.1159/000499385. Epub 2019 May 10.
Leptin has been shown to stimulate the hypothalamus-pituitary-thyroid (HPT) axis in vivo and vitro. Its role in thyroid axis regulation after weight loss induced by bariatric surgery is still unknown. The aim of this study was to evaluate the influence of leptin on weight loss and thyroid function variation induced by Roux-en-Y gastric bypass (RYGB) surgery in euthyroid individuals with obesity and type 2 diabetes mellitus (T2DM).
65 Chinese individuals with obesity and T2DM who underwent RYGB, and 27 healthy volunteers were enrolled in this retrospective study. Participants were evaluated for changes in anthropometric parameters, metabolic indexes, thyroid function, and leptin levels before and 12 months after surgery.
After RYGB, all of these patients experienced significant weight reduction and improved glucose control. Metabolic parameters were significantly ameliorated after surgery compared with baseline. Thyroid hormones including free triiodothyronine (FT3), free thyroxine (FT4), and thyroid-stimulating hormone (TSH) declined in parallel. Median (IQR) plasma leptin levels decreased from 33.7 ng/mL (17.9-63.1) to 10.3 ng/mL (4.0-18.5). Pearson correlation analysis showed that TSH was significantly positively correlated with body mass index, C-reactive protein (CRP), and leptin. Multiple stepwise linear regression indicated that leptin and CRP were independent factors affecting TSH. The β coefficients were 0.38 (p = 0.001) and 0.32 (p = 0.004), respectively. There was a significant positive correlation between ΔTSH and Δleptin (r = 0.33, p = 0.01).
Decreased or normalized TSH levels after weight loss induced by RYGB might be mediated by the decline in leptin. There could be cross talk between adipose tissue and the HPT axis.
瘦素已被证明可在体内和体外刺激下丘脑-垂体-甲状腺（HPT）轴。但其在肥胖合并 2 型糖尿病（T2DM）患者接受减重手术后的甲状腺轴调节中的作用尚不清楚。本研究旨在评估瘦素对接受 Roux-en-Y 胃旁路术（RYGB）肥胖合并 T2DM 患者体重减轻和甲状腺功能变化的影响。
本回顾性研究纳入了 65 例接受 RYGB 的肥胖合并 T2DM 患者和 27 例健康志愿者。在术前和术后 12 个月评估患者的人体测量参数、代谢指标、甲状腺功能和瘦素水平的变化。
RYGB 术后，所有患者体重明显减轻，血糖控制得到改善。与基线相比，术后代谢参数明显改善。甲状腺激素包括游离三碘甲状腺原氨酸（FT3）、游离甲状腺素（FT4）和促甲状腺激素（TSH）均呈平行下降。中位数（IQR）血浆瘦素水平从 33.7ng/ml（17.9-63.1）降至 10.3ng/ml（4.0-18.5）。Pearson 相关分析显示，TSH 与体重指数、C 反应蛋白（CRP）和瘦素呈显著正相关。多元逐步线性回归显示，瘦素和 CRP 是影响 TSH 的独立因素。β系数分别为 0.38（p=0.001）和 0.32（p=0.004）。ΔTSH 与 Δleptin 呈显著正相关（r=0.33，p=0.01）。
RYGB 诱导的体重减轻后 TSH 水平降低或恢复正常可能是瘦素下降介导的。脂肪组织和 HPT 轴之间可能存在相互作用。
