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

BackgroundA 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.MethodsDiabetic 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.ResultsThe plasma fasting glucose, β-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 d-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).ConclusionsPlasma 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.