Metformin use and cirrhotic decompensation in patients with type 2 diabetes and liver cirrhosis

Aims: To compare the risks of all-cause mortality, hepatic outcomes, major adverse cardiovascular events between metformin users and nonusers for patients with diabetes and cirrhosis.

Methods: From the Taiwan's National Health Insurance Research Database, we selected propensity-score matched metformin users and nonusers from the cohorts of type 2 diabetes mellitus with compensated (n = 26 164) or decompensated liver cirrhosis (n = 15 056) between 1 January 2000 and 31 December 2009, and followed them until 31 December 2010. Cox proportional hazards models with robust sandwich standard error estimates were used to assess risk of investigated outcomes for metformin users.

Results: The incidence rates of mortality during follow-up were 3.8 and 3.3 per 100 patient-years (adjusted hazard ratio [aHR] 1.13, 95% confidence interval 1.01-1.25) for metformin users and nonusers, respectively. The incidence rates of cirrhotic decompensation during follow-up were 5.9 and 4.9 per 100 patient-years (aHR 1.15, 95% confidence interval 1.04-1.27) for metformin users and nonusers. The risk of death (P for trend <.01) and cirrhotic decompensation (P for trend <.0001) associated with metformin use was significant for those taking metformin for >40 defined daily doses in 90 days or >1000 mg/d. The outcomes of metformin use vs nonuse for type 2 diabetes mellitus with decompensated liver cirrhosis were not statistically different, except that metformin users had higher risk of mortality (aHR 1.15).

Conclusion: Metformin use was associated with higher risks of mortality and cirrhotic decompensation in patients with compensated liver cirrhosis. Prospective studies are required to confirm our results.