[Relation between metformin treatment and the development of hyperlactacidemia at the emergency room].

INTRODUCTION

In type 2 diabetic patients treated with metformin the development of hyperlactacidemia or even lactic acidosis seems to result from an acute precipitating event. This study aims to assess the prevalence and relative risk of hyperlactacidemia in diabetic patients admitted in the Emergency Room, the predictive factors for high lactate concentration and the influence of hyperlactacidemia in patients' prognosis.

MATERIAL AND METHODS

Transversal observational study including patients observed between June and October 2012: 138 type 2 diabetics, 66 treated with metformin, and 83 non-diabetic patients. Studies' variables: age, sex, cause of admition, blood pressure, drugs, personal history, analytical study (biochemistry and arterial blood gas analyses with lactate) and destination. Statistical analysis was performed using SPSS 21.0(®).

RESULTS

Mean lactate concentration and hyperlactacidemia prevalence were significantly higher in diabetic patients (2.1 ± 0.1 mmol/L vs 1.1 ± 0.1 mmol/L, p < 0.001 and 39.1% vs 3.6%, p < 0.001, respectively) and in those under metformin compared to other diabetics (2.7 ± 0.2 mmol/L vs 1.6 ± 0.1 mmol/L, p < 0.001 and 56.9% vs 23.3%, p < 0.001, respectively). Diabetics on metformin presented a 25-fold increased risk of hyperlactacidemia (OR = 25.10, p < 0.05). Creatinine was the only independent predictive factor for lactate concentrations (B = 1.33, p < 0.05). Patients with hyperlactacidemia had 4.4 times higher odds of being hospitalized or dying (OR = 4.37, p < 0.05). When hospitalized, they had longer hospitalization periods (21.66 ± 5.86 days vs 13.68 ± 5.33 days, p < 0.001) and higher rate of deaths (12.5% (n = 4) vs 4.3% (n = 2), p < 0.05).

CONCLUSION

There was an increased risk of hyperlactacidemia in patients with type 2 diabetes, particularly for those under metformin. Serum creatinine represented the only independent associated factor of lactate concentration. The presence of hyperlactacidemia was associated with worse prognosis.