Abstract
BACKGROUND: It is unclear if impaired thyroid hormone sensitivity interacts with homocysteine (Hcy), a known risk factor for cardiovascular diseases (CVD), despite the fact that it has been identified as a prevalent metabolic condition.We aimed to analyze the association between thyroid hormone sensitivity indices and homocysteine levels in a Chinese health check-up population. METHODS: Thyroid hormone sensitivity was assessed by the Thyroid Feedback Quantization Index (TFQI), the parameter TFQI (PTFQI), the TSH index (TSHI) and the thyrotropin thyroxine resistance index (TT4RI) and FT3/FT4 ratio. Linear regression analyses, logistic regression analyses and restricted cubic spline were used to investigate the relationship between thyroid hormone sensitivity and Hcy levels. RESULTS: This study included 11144 medical examiners. Subjects with impaired thyroid hormone sensitivity had higher Hcy levels, according to the results (P < 0.001). Quartiles of TFQI, PTFQI, TSHI, and TT4RI were linked to Hcy levels, according to logistic regression analysis, and these associations persisted even after controlling for a number of risk factors. The odds ratio (95% CI) for Hyperhomocysteinemia (HHcy) in the highest quartile of TFQI was 1.294(1.114,1.504), for PTFQI was 1.293 (1.113, 1.503), and for TSHI was 1.222 (1.050, 1.422) (P < 0.001) after controlling for age, sex, body mass index, dyslipidemia, diabetes, and hypertension. CONCLUSIONS: A significant association between impaired thyroid hormone sensitivity and elevated Hcy levels exists in a Chinese population with normal thyroid function.