Lu Difei, Yuan Zhenfang, Gao Ying, Liu Wei, Zhang Junqing
Peking University First Hospital, Department of Endocrinology, Beijing, China.
Int J Endocrinol. 2022 Mar 10;2022:3830380. doi: 10.1155/2022/3830380. eCollection 2022.
The interactions of central obesity and body composition with thyroid hormones and the hypothalamus-pituitary-adrenal (HPA) axis are unclear; both central obesity and body composition have an impact on energy homeostasis. Our study aimed to investigate the association between body composition and pituitary hormones, including the HPA axis and pituitary-thyroid axis, in a Chinese population of euthyroid overweight and obese individuals.
This was a cross-sectional study. Overweight and obese patients who regularly visited the multidisciplinary team (MDT) for obesity at Peking University First Hospital were enrolled in the study. Thyroid function, morning serum ACTH and cortisol levels, thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), body composition, and metabolic indicators, including liver function and the lipid profile, were measured at the first visit. Statistical analysis was performed using SPSS version 21.0 (IBM, USA).
In total, 441 patients with overweight or obesity were enrolled (male/female, 123/318). Patients were assigned to four groups according to the thyroid-stimulating hormone (TSH) level stratified by quartiles, and increased body mass index (BMI) was revealed in the highest TSH quartile group (=0.002). Hip circumference (HC) of patients in the highest TSH quartile group was significantly increased (=0.021). Morning ACTH levels and fasting insulin levels were significantly elevated in patients in the highest TSH quartile group (=0.027 for fasting insulin, < 0.001 for ACTH). In the female subgroup, patients in the highest TSH quartile group showed increases in BMI (=0.010), waist circumference (WC) (=0.007), muscle mass of the lower extremities (=0.020), fasting C-peptide (=0.031), and ACTH (=0.002). In the male subgroup, patients in the highest TSH quartile group exhibited higher BMI (=0.017), HC (=0.036), and ACTH (=0.003). Among patients in the highest ACTH quartile group, there was an elevated proportion of males (=0.003), and FT3 (=0.005), fasting insulin (=0.037), and cortisol ( < 0.001) levels were increased. Weight ( < 0.001), BMI ( < 0.001), WC ( < 0.001), HC ( < 0.001), muscle mass of the upper extremities (=0.003), muscle mass of the lower extremities (=0.005), and total muscle mass (=0.003) were elevated in patients in the highest ACTH quartile group. HC was found to be an independent factor after adjustment for other confounders and was positively associated with the TSH level (=0.004 for the regression model, = 0.152, =0.004).
BMI is positively correlated with TSH and ACTH levels in both male and female obese individuals. The ACTH level was positively associated with male sex and increased BMI and muscle mass. Hip circumference was an independent factor that was positively related to TSH levels.
中心性肥胖和身体成分与甲状腺激素以及下丘脑 - 垂体 - 肾上腺（HPA）轴之间的相互作用尚不清楚；中心性肥胖和身体成分均对能量平衡有影响。我们的研究旨在调查中国甲状腺功能正常的超重和肥胖人群中身体成分与垂体激素之间的关联，包括HPA轴和垂体 - 甲状腺轴。
这是一项横断面研究。纳入了北京大学第一医院定期到肥胖多学科团队（MDT）就诊的超重和肥胖患者。首次就诊时测量甲状腺功能、清晨血清促肾上腺皮质激素（ACTH）和皮质醇水平、甲状腺过氧化物酶抗体（TPOAb）、甲状腺球蛋白抗体（TgAb）、身体成分以及代谢指标，包括肝功能和血脂谱。使用SPSS 21.0版（美国IBM公司）进行统计分析。
共纳入441例超重或肥胖患者（男/女，123/318）。根据促甲状腺激素（TSH）水平四分位数分层将患者分为四组，TSH最高四分位数组的体重指数（BMI）升高（P = 0.002）。TSH最高四分位数组患者的臀围（HC）显著增加（P = 0.021）。TSH最高四分位数组患者的清晨ACTH水平和空腹胰岛素水平显著升高（空腹胰岛素P = 0.027，ACTH P < 0.001）。在女性亚组中，TSH最高四分位数组患者的BMI（P = 0.010）、腰围（WC）（P = 0.007）、下肢肌肉量（P = 0.020）、空腹C肽（P = 0.031）和ACTH（P = 0.002）增加。在男性亚组中，TSH最高四分位数组患者的BMI（P = （此处原文有误，推测应为P = 0.017））、HC（P = 0.036）和ACTH（P = 0.003）更高。在ACTH最高四分位数组患者中，男性比例升高（P = 0.003），游离三碘甲状腺原氨酸（FT3）（P = 0.005）、空腹胰岛素（P = 0.037）和皮质醇（P < 0.001）水平升高。ACTH最高四分位数组患者的体重（P < 0.001）、BMI（P < 0.001）、WC（P < 0.001）、HC（P < 0.001）、上肢肌肉量（P = 0.003）、下肢肌肉量（P = 0.005）和总肌肉量（P = 0.003）升高。调整其他混杂因素后，发现HC是一个独立因素，且与TSH水平呈正相关（回归模型P = 0.004，β = =0.152，P = 0.004）。
在男性和女性肥胖个体中，BMI与TSH和ACTH水平呈正相关。ACTH水平与男性性别以及BMI和肌肉量增加呈正相关。臀围是与TSH水平呈正相关的独立因素。
