According to results of a recent combined cohort and case-control study, the incidence rate of acute hospitalization due to lactic acidosis in patients with type 2 diabetes mellitus is 391/100,000 person years and the risk of lactic acidosis is not influenced by metformin use.
The population-based study included 10,652 type 2 diabetic patients acutely hospitalized for lactic acidosis (pH <7.35 and lactate ≥2.0mmol/L) at the Odense University Hospital in Denmark between June 1, 2009 to October 1, 2013.
The authors explained “For each case, we identified 24 age- and sex-matched controls sampled from the same cohort with type 2 diabetes mellitus.” They added, “Analyses included multivariable logistic regression and adjusting for predefined confounding: renal function, HbA1c, comorbidity and diabetes duration.”
The median age of patients included in the cohort was 74 years and 51.5% of the patients were male. Results demonstrated an incidence rate of 391/100,000 person years was calculated based on the 163 patients who were hospitalized with lactic acidosis during the follow-up period. Additionally, There was no association between metformin use and lactic acidosis (adjusted odds ratio: 0.79; 95% CI: 0.54, 1.17).
The authors concluded that “use of metformin did not increase the risk of lactic acidosis.”
Aharaz A et al. Risk of lactic acidosis in type 2 diabetes patients using metformin: A case control study. Plos One. 2018. doi.org/10.1371/journal.pone.0196122.