Endocrine Abstracts

Introduction

Hyperlactatemia is defined by a lactate value > 2 mmol/l and a lactate value above > 4 mmol/l is commonly used to define more severe hyperlactatemia. It is a common disorder in critically ill patients, associated with adverse prognosis. Diabetes mellitus (DM), however, can also be associated with increased lactate levels at baseline.

Objectives

To document the development of severe hyperlactatemia in acute situations in patients with and without DM; to analyze potential contributors to lactate elevation and its impact on mortality; to analyze whether lactate values > 4 mmol/l have equal prognostic significance in patients with and without DM.

Materials and methods

A retrospective cross-sectional study was performed with patients admitted to internal medicine wards in the context of acute disease, displaying lactate values ≥ 2 mmol/l. Data was collected regarding age, sex, independence-index, highest lactate values, contributors to hyperlactatemia, DM and mortality.

Results

A sample of 151 patients with lactate ≥ 2 mmol/l was analyzed, median age of 83.00 ± 17.00 years, 55.00% female. DM was present in 55.60% and these patients had higher lactatemia (5.35 ± 4.84 vs 3.90 ± 3.56 mmol/l, P = 0.003), with the majority reaching values > 4 mmol/l (vs 34.8% in non-DM patients). The most frequently identified potential contributors to the development of severe hyperlactatemia (lactate > 4 mmol/l) in DM patients were metformin consumption concomitantly with factors potentiating its accumulation, sepsis/septic shock, ischemia and neoplasia. In non-DM patients the last three factors were the most frequently found. The 30-day mortality rate was 25.82% and deceased patients also displayed higher lactatemia during hospital stay (5.93 ± 5.19 vs 4.52 ± 4.21; P = 0.037). Lactate values > 4 mmol/l were more frequently associated with mortality and these values were observed more often in patients with DM. However, a tendency towards higher lactate values in DM patients was registered not only in those who died, but also in the patients who survived. In multivariate analysis, lactate values > 4 mmol/l were an independent predictor of mortality in the global sample and in the subgroup without DM, but not in DM patients.

Conclusion

In our sample, patients with DM reached higher lactate levels than non-DM patients. Our analysis, however, raises the possibility that the same lactate values may not have equal capacity to assess prognosis in acute situations in patients with and without DM, since a lactate value > 4 mmol/l was an independent predictor of mortality only in non-DM patients. Large-scale studies are needed to optimize cut-off points for lactatemia in patients with high baseline values, such as DM patients.