Lactic acidosis in patients with diabetes

INTRODUCTION Lactic acidosis is a relatively rare complication diagnosed in patients with diabetes.
OBJECTIVES The aim of this study was to identify causes of lactic acidosis in patients with diabetes and to measure the extent of metabolic disturbances based on the available laboratory test results.
PATIENTS AND METHODS A total of 29 diabetic patients aged 20–87 years were admitted to the Intensive Diabetes Care Unit of the Warsaw Medical University in the years 2007–2012 with the diagnosis of lactic acidosis (lactate level >5 mmol/l). A detailed medical history was taken from all patients or their caregivers. Lactate levels, glycemia, acetonuria, and gasometry were measured on admission.
RESULTS Eight patients with type 1 diabetes, 18 patients with type 2 diabetes, and 3 patients with other types of diabetes were hospitalized with the diagnosis of lactic acidosis. Lactic acidosis (lactate levels, 5.2–27 mmol/l) was associated with increased glycemia (13.3–91.7 mmol/l) and low pH (6.73–7.28). Alcohol abuse was reported in 12 subjects based on medical history. In 3 women, acute diabetic complication was caused by psychogenic eating disorders. There were 5 fatal cases including 3 cases of metformin treatment. 
CONCLUSIONS Alcohol abuse and its effects on health seem to be the main cause of lactic acidosis in diabetic patients. Metformin‑treated patients, especially elderly ones, are at a risk of sudden deterioration of renal function, which in turn may increase the risk of lactic acidosis.