Endocrine Abstracts

Introduction: Thyrotoxicosis is a common endocrine disorder; variable degree of hepatic dysfunction is often seen with thyrotoxicosis. Severe liver dysfunction associated with thyrotoxicosis occurs rarely. The prevalence of liver abnormality with thyrotoxicosis is reported to be ~ 15–30%. The mechanism of liver abnormality is not well understood; direct thyroid hormone mediated hepatocyte injury has been raised as a possible mechanism. We conducted a retrospective review of all patients’ with concomitant thyrotoxicosis and deranged liver function test who attended our endocrine clinic over 12 months period.

Methods: We reviewed all patients who attended our clinic for a period of 12 months with thyrotoxicosis. Those with abnormal LFT were selected; patients were excluded, if abnormal LFT predate the diagnosis of thyrotoxicosis, or if there is a known history of liver disease. 200 patients were diagnosed with thyrotoxicosis, 27 patients (13%) were suitable for analysis; 20 females and five males.

Results: There is female preponderance of 74%. The aetiology is: Graves’ 52%; toxic goitre 19%, AIT 2%; unclear in 6%. 81% were treated with carbimazole, 19% with PTU.ALP was abnormal in 100%; in 23% both ALP and ALT were raised. Mean time to normalisation of TFT and LFT in weeks was 9.8±4.6; 6.5±3.6 (mean ± s.d.).The mean to normalisation of LFT depending of treatment was 6.5±3.4 vs 7.4±3.8 (carbimazole vs PTU). LFT normalised in all patients treated with PTU (100%).

Conclusion: We demonstrated that hepatic dysfunction is commonly associated with thyrotoxicosis (13% prevalence). The degree of abnormality does not correlate with the severity of thyrotoxicosis. Both PTU and carbimazole are safe for the treatment of moderate liver dysfunction associated with thyrotoxicosis. There is no difference in the time to resolution between the two drugs; however PTU results in 100% resolution of liver abnormality.