Risk Factors Related to Mortality of Metformin Associated Lactic Acidosis in Patients with type 2 Diabetes Mellitus of Buriram Hospital, Thailand

Abstract

Currently metformin is the first-line oral medication recommended for type 2 Diabetes mellitus. How­ever, although metformin is effective, it is also associated with an increased risk of lactic acidosis, a rare but potentially life-threatening adverse effect leading to high mortality rates of 25-50% around the world. In 2012- 2017, more than 140 cases of metformin associated lactic acidosis (MALA) were reported in Buriram hospital. This study aimed to evaluate the mortality rate of MALA, the risk factors relate to mortality of MALA, and correlation between prescribed daily doses of metformin with lactate, pH and serum creatinine. It was con­ducted as a cross sectional study. All cases of MALA (lactate >5 mmol/L and pH<7.35) admitted to Buriram hospital between October 2012 and September 2017 were included. Data were collected by the retrospective medical record review; and were analyzed by using multivariable logistic regression and Spearman correlation. A total of 108 cases of MALA were included in this study. The overall mortality rate was 33.33%. Risk factors related to mortality of MALA were significantly associated with lactate >10mmol/L (OR=7.00; 95%CI=1.90- 25.69; p=0.003), pH <7 (OR=7.79; 95%CI=1.29-47.24; p=0.026) and time to dialysis >12 hours (OR=4.91; 95%CI=1.01-23.66; p=0.047). Prescribed daily doses of metformin was not significantly correlated with lactate (r=-0.09, p=0.38), creatinine (r=0.08, p=0.39) and pH (r=0.06, p=0.52). In summary, This study can help Clini­cians assess the patient’s severity of symptoms and provide appropriate interventions to reduce mortality in Type 2 diabetes mellitus patients with MALA.