Association Between Thyroid Function and Body Composition in Type 2 Diabetes Mellitus (T2DM) Patients: Does Sex Have a Role?

BACKGROUND The relationship between thyroid hormones and body anthropometric measures in type 2 diabetes mellitus (T2DM) patients with normal thyroid function is unclear. The purpose of this study was to evaluate the association between thyroid hormones and body composition in euthyroid T2DM patients in men and women. MATERIAL AND METHODS This was a cross-sectional study that included 561 euthyroid T2DM patients. Fasting venous blood was collected to test laboratory indexes. Bioelectric impedance analysis (BIA) was used to measure body composition. Propensity score matching (PSM) was used to enroll patients with similar baseline characteristics. The least absolute shrinkage and selection operator (LASSO) algorithm was used to establish a linear regression model of thyroid hormone and body composition. PSM was performed to match 159 men and 159 women. RESULTS The LASSO regression analysis suggested that thyroid-stimulating hormone (TSH) level was not correlated with body composition parameters in females. In females, free triiodothyronine (FT3) level was positively correlated with body mass index (BMI), fat-free mass index (FFMI), and skeletal muscle index (SMI), and was negatively correlated with extracellular water fraction (EWF). In males, FT3 level was positively correlated with waist circumference (WC) and SMI and negatively correlated with EWF. Free thyroxine (FT4) level in both women and men was positively correlated with body fat mass (BFM) and left lower-limb muscle mass (LLLMM). Moreover, in males, FT4 level was correlated with more body composition parameters. In euthyroid T2DM patients, FT3 level was positively correlated with SMI and negatively correlated with EWF, while FT4 level was positively correlated with BFM and LLLMM. CONCLUSIONS Thyroid function can affect body composition in euthyroid T2DM patients. Thyroid function is more likely to affect the fat and muscle distribution of males than females.

Salubrinal abrogates palmitate-induced leptin resistance and endoplasmic reticulum stress via nuclear factor kappa-light-chain-enhancer of activated B cell pathway in mHypoE-44 hypothalamic neurons.

BACKGROUND: The prevalence of obesity is growing rapidly and has become a global problem that increases the risk for many diseases. It is influenced by many factors, including consumption of the Western-style diet, characterized as a high-fat diet. Within the central nervous system, the hypothalamus is a critical site in maintaining energy homeostasis and sensing nutrient status, including palmitate, the major component of high-fat-diet. METHODS: In the present study, we conducted a variety of studies to investigate the specific role of salubrinal on palmitate-induced hypothalamic cell death, leptin signaling, and ER stress in an embryonic hypothalamic cell line. Experiments were also performed to identify the underlying mechanisms of the protective effect of salubrinal. RESULTS: Our results indicate that salubrinal protects hypothalamic cells against PA-induced ER stress and improves hypothalamic leptin sensitivity. CONCLUSION: Taken together, our findings conclusively reveal that salubrinal abrogates palmitate-induced hypothalamic leptin resistance and ER stress via NF-κB pathway.