Sensitivity to Thyroid Hormone Indices Are Closely Associated With NAFLD

BACKGROUND: Previous studies on the association between thyroid function and non‐alcoholic fatty liver disease (NAFLD) have contradicted. Acquired resistance to thyroid hormone theory might provide a reasonable explanation for these contradictions. We aimed to analyze the association between sensitivity to thyroid hormone indices with NAFLD. METHODS: A total of 4,610 individuals from the health medical center of the First Hospital of China Medical University were included in this study. The previously used thyroid feedback quantile-based index (TFQI(FT4)) was calculated. Also, we substituted free triiodothyronine (FT(3)) into the TFQI formulas to get the TFQI(FT3) index. NAFLD was defined using abdominal ultrasound. RESULTS: Study results showed that FT(3)/FT(4) and TFQI(FT3) were positively correlated with the triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels (P<0.05) and negatively correlated with high-density lipoprotein cholesterol (HDL-C) level (P<0.05). In contrast, TFQI(FT4) was positively correlated with HDL-C level (P < 0.05). After adjustment for multiple confounders, FT(3), FT(3)/FT(4), and TFQI(FT3) were positively associated with the risks of dyslipidemia and NAFLD (P < 0.05). TFQI(FT3) and FT(3)/FT(4) performed better than TFQI(FT4) on ROC analyses for NAFLD prediction, although the diagnostic sensitivity and specificity at the optimal cut-points were low. However, no association was observed between TFQI(FT4) with the risks of dyslipidemia and NAFLD. CONCLUSION: TFQI(FT3) and FT(3)/FT(4) can be used as new indicators for predicting dyslipidemia and NAFLD, although with low sensitivity and specificity at the optimal cut-points, while TFQI(FT4) has insufficient evidence in predicting dyslipidemia and NAFLD.