Factors predicting abnormal liver function tests induced by graves' disease alone

Abstract

Abnormal liver function tests (LFTs) are often observed in patients with Graves' disease (GD). To date, there are limited data demonstrating the factors or biochemical indexes contributing to LFT abnormalities in this patient population. The aim of this study was to explore factors predicting abnormal LFTs induced by GD alone. This was a retrospective study of 289 consecutive cases of newly diagnosed and untreated patients with GD. All patients were divided into abnormal LFTs (group A) and normal LFTs (group B). In total, 205 (70.9%) cases were found to have at least 1 LFT abnormality. Among them, the frequencies of ALT, AST, ALP, γ-GTP, TBIL and DBIL abnormalities were 52.7%, 32.2%, 45.9%, 38.5%, 23.4%, 2.9%, respectively, and the number of patients with 1 to 6 hepatic variable abnormalities were 89, 64, 30, 16, 6 and 0, respectively. Logistic regression analysis was used to determine predictive factors contributing to abnormal LFTs. A receiver operating characteristic (ROC) curve was also plotted to verify the accuracy of predictors. In the univariate analysis, patients in group A had significantly higher FT3 concentration (37.5 vs 33.4pmol/L, P=0.009), FT4 concentration (85.7 vs 77.4pmol/L, P=0.002) and TRAb level (22.2 vs 17.4IU/L, P<0.001) when compared with those in group B. Binary logistic regression analysis identified higher FT4 concentration (odds ratio [OR]: 1.017, 95% confidence interval [CI]: 1.005-1.030, P=0.006) and higher TRAb value (OR: 1.038, 95% CI:1.013-1.064, P=0.003) to be independent risk factors predicting abnormal LFTs. The optimal cutoffs for FT4 and TRAb to predict abnormal LFTs were 75pmol/L and 15IU/L, respectively, based on ROC analysis.