The Clinical Value of Thyroid Hormone Levels and Correlation with Severity of Liver Cirrhosis

BACKGROUND: The aims of this study were to expound the effect of thyroid hormone on the occurrence of liver cirrhosis and the severity classification of liver cirrhosis with meta-analysis. METHODS: A comprehensive search of PubMed, EMbase, The Cochrane Library, Web of Science, Google Scholar, CNKI, and WanFang Data databases and reference lists of retrieved articles was performed since the inception of each database until September 2021. Two reviewers independently screened literature, extracted data, and assessed the risk of bias by RevMan 5.3 software. In continuous variable analysis, the standardized mean difference (SMD) and 95% confidence interval (95% CI) were calculated through a random-effect model. RESULTS: Eighteen case-control studies involving 3336 subjects were included for review. The results of the meta-analysis showed free triiodothyronine (FT3) and free thyroxine (FT4) levels in the liver cirrhosis group were lower than the control group (SMD = −1.29, 95% CI [−1.85, −0.74], P < 0.001), (SMD = −0.61, 95% CI [−0.96, −0.26], P < 0.001), thyroid-stimulating hormone (TSH) levels in liver cirrhosis group were higher than the control group (SMD = 0.34, 95%CI [0.06, 0.63], P < 0.001) and that FT3 levels in Child-Pugh A VS B and Child-Pugh B VS C group were higher than the control group (SMD = 1.08, 95%CI [0.80, 1.37], P = 0.008), (SMD = 0.68, 95%CI [0.38, 0.98], P < 0.001). CONCLUSIONS: Cirrhosis has decreased FT3 and FT4 levels and increased TSH levels. FT3 levels correlate negatively with the Child-Pugh score, and it is a measure of the severity of liver cirrhosis dysfunction. FT3 serum levels of thyroid hormones are a prognostic marker in liver cirrhosis.