Closing the anion gap: Contribution of D-lactate to diabetic ketoacidosis

Background: A high anion gap in diabetic ketoacidosis (DKA) suggests that some unmeasured anions must contribute to the generation of the anion gap. We investigated the contribution of D-lactate to the anion gap in DKA. Methods: Diabetic patients with and without DKA and high anion gap were recruited. Plasma D-lactate was quantified by HPLC. Plasma methylglyoxal was assayed by liquid chromatography-tandem mass spectrometry. Results: The plasma fasting glucose, beta-hydroxybutyrate, and blood HbA1c levels were highly elevated in DKA. Plasma anion gap was significantly increased in DKA (20.59 +/- 6.37) compared to either the diabetic (7.50 +/- 1.88) or the control group (6.53 +/- 1.75) (p<0.001. respectively). Moreover, plasma is-lactate levels were markedly increased in DKA (3.82 +/- 2.50 mmol/l) compared to the diabetic (0.47 +/- 0.55 mmol/l) or the control group (0.25 +/- 0.35 mmol/l) (p<0.001, respectively). Regression analysis demonstrated that D-lactate was associated with acidosis and anion gap (r = 0.686, p<0.001). Conclusions: Plasma D-lactate levels are highly elevated and associated with metabolic acidosis and the high anion gap in DKA. Laboratory monitoring of D-lactate will provide valuable information for assessment of patients with DKA. (C) 2010 Elsevier B.V. All rights reserved.