Hyperthyroidism and hepatic dysfunction: Report of 17 cases

Abstract

Aims: Hyperthyroidism has been known to be associated with abnormalities of serum liver chemistry. The objective of our study is to describe clinical, biochemical and therapeutic features of hepatic dysfunction in hyperthyroidism. Methods and Results: This retrospective study was conducted on patients hospitalized in our endocrinology department over 20 years. We included patients with untreated and noniatrogenic hyperthyroidism among whom biochemical findings noted hepatic dysfunction and excluded those with concomitant liver disease. Our population is composed of 10 men and 7 women. The average age was 41.4 years. The mean serum level of free thyroxine was 83.8 pmol/L. The serum thyrotropin level was below the detection limit in 10/17 cases. Graves' disease was the most frequently found etiology of hyperthyroidism. Fourteen patients had hyperthyroidism's complications. Eleven patients manifested congestive heart failure. Hepatic dysfunction was moderate and severe in eight and two cases, respectively. Fifteen patients had cholestasis, associated with jaundice in five cases. Hepatocellular injury and synthetic liver dysfunction were noted in seven and five cases, respectively. Thyroid peroxidase antibodies were positively correlated with the serum level of bilirubin (ρ = 0.695; P = 0.038). A negative correlation was noted between alanine aminotransferase and left ventricular ejection fraction (ρ = −0.812; P = 0.05). Radioactive iodine was indicated in 15/17 cases. Follow-up liver tests were performed in 11 cases. They all had normalized hepatic function once euthyroidism restored. Conclusion: Liver injury in hyperthyroidism is relatively common, ranging from mild to severe. Therefore, patients presenting unexplained hepatic abnormalities require close examination and an evaluation of the thyroid function should be sought.