Sensitivity to thyroid hormone and risk of components of metabolic syndrome in a Chinese euthyroid population

Abstract

IntroductionTo evaluate the association of sensitivity to thyroid hormone with metabolic syndrome (MetS) and its components in a Chinese euthyroid population.MethodsA total of 3573 participants from Pinggu Metabolic Disease Study were analyzed. Serum‐free triiodothyronine (FT3), free thyroxine (FT4), thyrotropin (TSH), total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) area of abdominal, and lumbar skeletal muscle area (SMA) were measured. Central thyroid hormone resistance was calculated by the Thyroid Feedback Quantile‐based Index (TFQI) and Chinese‐referenced Parametric TFQI (PTFQI), Thyrotroph T4 Resistance Index (TT4RI) and TSH Index (TSHI). Peripheral thyroid hormone resistance was assessed by FT3/FT4 ratio.ResultsHigher values of TSHI (odds ratio [OR] = 1.167, 95% confidence interval [CI]: 1.079–1.262, p < .001), TT4RI (OR = 1.115, 95% CI: 1.031–1.206, p = .006), TFQI (OR = 1.196, 95% CI: 1.106–1.294, p < .001), PTFQI (OR = 1.194, 95% CI: 1.104–1.292, p < .001), and lower values of FT3/FT4 ratio (OR = 0.914, 95% CI: 0.845–0.990, p = .026) were associated with MetS. Increased levels of TFQI and PTFQI were associated with abdominal obesity, hypertriglyceridemia, and hypertension. Increased levels of TSHI and TT4RI were associated with hypertriglyceridemia, abdominal obesity, low high‐density lipoprotein cholesterol. Reduced levels of FT3/FT4 ratio were associated with hyperglycemia, hypertension, and hypertriglyceridemia. The levels of TSHI, TFQI, and PTFQI were negatively related to SMA and positively related to VAT, SAT, and TAT (all p < .05).ConclusionsReduced thyroid hormone sensitivity was associated with MetS and its components. Impaired thyroid hormone sensitivity might affect the distribution of adipose tissue and muscle.

Vitamin D Deficiency Is Associated with Impaired Sensitivity to Thyroid Hormones in Euthyroid Adults

“…Another study confirmed that TFQI was the indicator of resistance to thyroid hormones and was associated with diabetes and hypertension in euthyroid Tehranian populations [41]. Recently, emerging studies investigated the relationship between sensitivity to thyroid hormones, metabolic disorders, and non-alcoholic fatty liver disease in Chinese subjects [18][19][20]42]. However, the influencing factors of thyroid hormone sensitivity is unclear.…”

“…Subsequently, Teng et al demonstrated that impaired sensitivity to thyroid hormones was related to higher risks of cardiovascular disease and hyperuricemia and a lower risk of obesity in patients with subclinical hypothyroidism [18]. Recently, the association of impaired sensitivity to thyroid hormones with high levels of homocysteine [17], components of metabolic syndrome [19], and non-alcoholic fatty liver disease [20] were also revealed. However, the influencing factors of sensitivity to thyroid hormones and whether vitamin D deficiency is correlated with reduced sensitivity to thyroid hormones are unknown.…”

Association of sensitivity to thyroid hormones with all-cause mortality in euthyroid US adults: a nationwide cohort study

“…However, TSHI and TT4RI were not ( 20 ). One possible reason may be that TFQI FT4 is more stable than TT4RI and TSHI, as it does not reach extreme values ( 20 ), indicating that the mechanisms of resistance to thyroid hormones were complex and challenging ( 40 ). Previous studies have made it clear that low T3 syndrome is associated with death.…”

“…It is caused by mutations in the thyroid hormone receptor beta (THRB) gene, which modulates the negative regulation of the HPT axis ( 41 ). RTH ( 40 ) is characterized by elevated serum TH levels without TSH suppression. In contrast, these individuals exhibit symptoms of thyrotoxicosis in other tissues that typically express TRα1 predominantly, such as the heart, bone, muscle, and adipose tissue, leading to various metabolic disorders ( 25 , 42 ).…”

Lipoprotein alterations in endocrine disorders - a review of the recent developments in the field

“…Interestingly, some patients who are euthyroid and don’t have a history of thyroid disease might still be at risk of developing dyslipidemia due to impaired sensitivity to thyroid hormones. A study on 3573 euthyroid participants has shown that reduced thyroid hormone sensitivity is associated with metabolic syndrome and some alterations in lipoproteins, mainly TG ( 12 ).…”