Impaired thyroid hormone sensitivity increases the risk of papillary thyroid cancer and cervical lymph node metastasis.

BACKGROUND: The association of thyroid hormone sensitivity with papillary thyroid carcinoma (PTC) is unclear. This study investigated the relationship between the thyroid hormone sensitivity indices and the risk of PTC and the influence of thyroid hormone sensitivity on the aggressive clinicopathologic features of PTC. METHODS: This retrospective study recruited 1225 PTC patients and 369 patients with benign nodules undergoing surgery in Zhongshan Hospital in 2020. The thyroid hormone sensitivity indices were thyroid feedback quantile-based index (TFQI), TSH index (TSHI) and thyrotropin thyroxine resistance index (TT4RI). We employed logistic regression models to explore the correlation between the thyroid hormone sensitivity indices and the risk of PTC and its cervical lymph node metastasis (LNM). RESULTS: PTC patients had significantly higher levels of TSH, TFQI, TSHI and TT4RI compared to the patients with benign nodules, but thyroid hormone levels did not differ significantly between the two groups. Logistic regression analysis revealed that the higher levels of TFQI, TSHI, and TT4RI were associated with an increased risk of PTC after adjustment for multiple risk factors (TFQI: OR = 1.92, 95% CI: 1.39-2.65, P < 0.001; TSHI: OR = 2.33, 95% CI:1.67-3.26, P < 0.001; TT4RI: OR = 2.41, 95% CI:1.73-3.36, P < 0.001). In addition, patients with decreased thyroid hormone sensitivity had a higher risk of cervical LNM in multiple logistic regression analysis (TFQI: OR = 1.38, 95% CI:1.03-1.86, P = 0.03; TSHI: OR = 1.37, 95% CI:1.02-1.84, P = 0.04; TT4RI: OR = 1.41, 95% CI:1.05-1.89, P = 0.02). CONCLUSION: Impaired sensitivity to thyroid hormone was associated with an increased risk of PTC, and it is also associated with a higher risk of cervical LNM in PTC patients.

Effect of thyroid function on pre-ß1 high-density lipoprotein levels in patients with Graves' disease undergoing radioiodine treatment.

CONTEXT: The metabolism of HDL is altered in thyroid dysfunctions. Preß-1 HDL is a very small discoidal precursor HDL and promotes cholesterol efflux via ABCA1. The effects of thyroid dysfunctions on pre-ß1 HDL are unknown. Thyroid hormone regulates ANGPTL3 expression, which may participate in HDL metabolism in thyroid dysfunctions. OBJECTIVE: To determine the variation of HDL subfractions, especially preß-1 HDL in thyroid dysfunctions, and whether ANGPTL3 mediates the effect of thyroid function on HDL metabolism. METHODS: We recruited 26 patients with Graves' disease undergoing radioiodine treatment. They were evaluated at three time points: at baseline, when they were hypothyroid after radioiodine treatment, and when they were on stable levothyroxine replacement and euthyroid. RESULTS: The concentrations of smaller HDL particles Preß-1 HDL and HDL3 were highest at the hyperthyroid state, and lowest at the hypothyroid state. While the larger HDL particles HDL2 and HDL1 changed just the opposite. Preß1-HDL and HDL3 were positively correlated to fT3 and fT4, while were negatively correlated to TSH. In contrast, HDL1 was negatively associated with fT3 and fT4, while was positively associated with TSH. The correlations between thyroid hormones and HDL subfractions remained significant after adjusting for ANGPTL3. CONCLUSIONS: There is a shift form smaller HDL particles pre-ß1 HDL and HDL3 to larger HDL particles HDL2 and HDL1 in hypothyroidism, while the change is just the opposite in hyperthyroidism. In future, cholesterol efflux capacity should be measured to determine if the function of HDL particles also changes with the shifting of HDL subfractions.