Impaired Sensitivity to Thyroid Hormones is Associated with Central Obesity in Euthyroid Type 2 Diabetes Mellitus Patients with Overweight and Obesity

Fei Chen,1,2 Rujun Chen,3,* Jiangfeng Zhou,1,2,* Weiyi Xu,1,2,* Jiahui Zhou,1,4 Xianxian Chen,1,5 Xiaohua Gong,1 Zimiao Chen1 1Department of Endocrinology and Metabology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, People’s Republic of China; 2Wenzhou Medical University, Zhejiang, People’s Republic of China; 3Department of Burn, 906 Hospital of the Joint Logistics Team, PLA, Wenzhou, People’s Republic of China; 4Department of Internal Medicine, The First People’s Hospital of Longwan District, Wenzhou, People’s Republic of China; 5Department of Internal Medicine, The People’s hospital of Pingyang, Wenzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xiaohua Gong; Zimiao Chen, Department of Endocrinology and Metabology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, People’s Republic of China, Email [email protected]; [email protected]: Thyroid hormone levels are associated with the distribution of body components in humans.Objective: This study aimed to investigate the associations between thyroid hormone (TH) levels, central sensitivity to THs, and body composition in overweight and obese patients with euthyroid type 2 diabetes mellitus (T2DM).Methods: This cross-sectional study included 1215 euthyroid T2DM patients (721 men and 494 women) aged 20– 80 years. The thyroid hormone sensitivity indices included the thyroid feedback quartile-based index (TFQI), thyrotroph T3 resistance index (TT3RI), thyrotroph T4 resistance index (TT4RI), and thyroid-stimulating hormone index (TSHI). The appendicular fat ratio, trunk fat ratio, android fat ratio, gynoid fat ratio, and appendicular skeletal muscle mass (ASM) were measured via dual-energy X-ray absorptiometry.Results: The data revealed a greater proportion of subjects with impaired central sensitivity to THs in the obese group. TFQIFT4 and TFQIFT3 levels were positively correlated with the upper limb fat ratio, lower limb fat ratio, gynoid fat ratio, and total fat ratio. TSHI was positively correlated with body mass index (BMI), upper limb fat ratio, lower limb fat ratio, trunk fat ratio, android fat ratio, gynoid fat ratio, total fat ratio, and appendicular skeletal muscle mass index (ASMI) in women. In men, TSHI was only positively correlated with upper limb fat ratio, lower limb fat ratio, and total fat ratio. Logistic regression analysis indicated that TT3RI and TFQIFT3 were independently and positively associated with central obesity and low muscle mass in overweight and obese men. No significant differences were found among the women.Conclusion: THs central sensitivity is related to the body composition of euthyroid T2DM patients. Specifically, high levels of TT3RI and TFQIFT3 are associated with central obesity and low muscle mass in T2DM men with overweight and obesity.Keywords: thyroid hormones central sensitivity, euthyroid, body components, muscle mass, fat ratio, obese