Hypoglycaemia in patients with liver diseases administered levothyroxine

OBJECTIVE: Experience of a few hypoglycaemic patients with liver disease and receiving levothyroxine suggested to us that the prevalence of hypoglycaemia might be higher in such patients. The purpose of this study was to ascertain whether the prevalence of hypoglycaemia this was actually the case. METHODS: This study was a retrospective, cross-sectional analysis of a medical computerized database and/or written reports from our university hospital. Patients with primary liver disease who were admitted to our hospital between April 1998 and August 2000 were divided into two groups; the first group received levothyroxine and the second group did not. The patients in the second group were selected from three different time periods within the period shown. The prevalence of hypoglycaemia (blood glucose level <70 mg/dL) was compared between the two groups. RESULTS: The prevalence of hypoglycaemia was significantly higher in the group receiving levothyroxine compared with the group not receiving levothyroxine (four of eight patients (50.0%) vs. three of 59 (5.1%), P = 0.003, Fisher's exact test). CONCLUSIONS: The results suggest that levothyroxine may be a risk factor for hypoglycaemia in patients with liver disease. While a larger study, perhaps with an alternative study design is needed to confirm this, and to investigate possible mechanisms of effect, it would be prudent to monitor the blood glucose level of such patients closely.