Recovery of chronic hepatitis by treatment of concomitant hyperthyroidism

Abnormal Liver Blood Tests in Patients with Hyperthyroidism: Systematic Review and Meta-Analysis

Background: Abnormal liver blood tests (LBTs) in hyperthyroid patients are not uncommonly encountered. One major adverse event of antithyroid drug (ATD) therapy is drug-induced hepatotoxicity. Abnormal LBT in the hyperthyroidism scenario is a main diagnostic and therapeutic dilemma. We aimed to assess the prevalence and the response to ATD therapy of LBT abnormalities in newly diagnosed and uncomplicated hyperthyroidism through a systematic review and meta-analysis. Methods: A literature search was performed reporting LBTs at presentation and after ATD therapy in hyperthyroid patients. A proportion meta-analysis was performed with random-effects model. Pooled data were presented with 95% confidence intervals (CI). I² statistic index was used to quantify the heterogeneity. Sensitivity analyses for prevalence of hyperthyroid patients with at least one abnormal LBT were performed. p-Value of <0.05 was regarded as significant. Results: The literature search yielded 2286 studies, of which 25 were included for systematic review and meta-analysis. The prevalence of untreated hyperthyroid and Graves' disease patients with at least one abnormal LBT was 55% ([CI 46-63%], I² 96%) and 60% ([CI 53-67%], I² 92%), respectively. The prevalence of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (BIL), and γ-glutamyltransferase (GGT) abnormalities in hyperthyroid patients were 33% ([CI 24-44%], I² 95%), 23% ([CI 17-29%], I² 89%), 44% ([CI 35-52%], I² 93%), 12% ([CI 7-20%], I² 92%), and 24% ([CI 16-36%], I² 95%), respectively. ATD therapy, along with euthyroidism restoration, was accompanied by normalization of LBT abnormalities in the following percentage of cases: ALT 83% ([CI 72-90%], I² 46%), AST 87% ([CI 74-94%], I² 2%), ALP 53% ([CI 32-73%], I² 76%), BIL 50% (CI cannot be calculated), and GGT 70% ([CI 47-87%], I² 74%). The sensitivity analyses showed similar results as those of the main analyses. The publication bias was not statistically significant for all outcomes, except for the prevalence of resolved BIL abnormalities that was not calculable. Conclusions: LBT abnormalities are common in newly diagnosed and untreated hyperthyroidism setting. A high chance of safely normalizing elevated transaminases, up to fivefold above the upper limit of normal, accompanies the use of ATDs in the treatment of hyperthyroidism.

Incidence of abnormal liver biochemical tests in hyperthyroidism

OBJECTIVE

Abnormal serum liver function tests are common in patients with untreated thyrotoxicosis, even prior to the initiation of antithyroidal medications that may worsen the severity of the abnormal serum liver biochemistries. There is a wide range of the incidence of these abnormalities in the published literature. The aim of this study was to assess the risks factors and threshold of thyrotoxicosis severity for developing an abnormal liver biochemical test upon the diagnosis of new thyrotoxicosis.

DESIGN

Single-institution retrospective cohort study.

PATIENTS

Patients of ≥18 years old receiving medical care at a large, academic, urban US medical centre between 2002-2016.

MEASUREMENTS

Inclusion criteria were a serum thyroid stimulating hormone (TSH) concentration of <0·3 mIU/l or ICD-9 code for thyrotoxicosis, with thyrotoxicosis confirmed by either a concurrent elevated serum triiodothyronine (T3) or thyroxine (T4) concentration ([total or free] within 3 months), and an available liver biochemical test(s) within 6 months of thyrotoxicosis. The biochemical liver tests assessed were serum aspartate transaminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), gamma-glutamyltransferase (GGT), total bilirubin, and conjugated bilirubin concentrations.

RESULTS

In this cohort of 1514 subjects, the overall incidence of any biochemical liver test abnormality within 6 months of thyrotoxicosis was 39%. An initial serum TSH concentration <0·02 mIU/l, male gender, and African-American race were significant predictors of an abnormal serum liver biochemical test within 6 months of the diagnosis of new-onset untreated thyrotoxicosis.

CONCLUSIONS

This study identifies risk factors for patients who develop an abnormal serum liver biochemical test result within 6 months of a diagnosis of untreated thyrotoxicosis.