Background: Ursodeoxycholic acid (UDCA) is the established treatment of primary biliary cirrhosis (PBC) and is a safe and well-tolerated medication. Nevertheless, patients often anecdotally complain of weight gain while on this drug.
Goals: We compared weight changes in patients treated with UDCA and those on placebo to characterize this potential side effect.
Study: One-hundred eighty patients with PBC who were enrolled into a randomized, controlled trial received either UDCA (13-15 mg/kg/d) or an identical placebo. Changes from baseline weight were calculated at 12, 24, 36, and 48 months. Other markers of disease activity, including liver biochemistries, serum lipids, histologic stage, and Mayo Risk Score were evaluated in both groups.
Results: The proportion of patients who gained weight during the first 12 months of therapy was significantly greater in the UDCA than placebo group (67/86 [78%] versus 43/73 [57%] respectively, P = 0.005). Patients in the UDCA group gained an average of 3.6 +/- 6.5% kg (2.2 +/- 5.1 kg) which was significantly greater than the average of 0.6 +/- 6.9% kg (0.6 +/- 4.9 kg) gained in the placebo group (P = 0.04). The biggest change in weight occurred in the first 12 months of treatment (P < 0.001); after this, weight was maintained for the 4-year duration of treatment. There was no significant correlation between initial body mass index (BMI) and weight change or changes in disease activity and weight.
Conclusion: UDCA treatment in patients with PBC is associated with a significant weight gain that occurs in the first 12 months of treatment, persists for the duration of treatment, and occurs independent of baseline BMI. Discussions with PBC patients beginning UDCA treatment should include the beneficial effects this medication has on disease outcome, but should also mention weight gain as a possible side effect.