Objective: To evaluate an enzymatic method for determining serum beta-hydroxybutyrate (beta-HB) with the National Committee for Clinical Laboratory Standards (NCCLS) projects, and to discuss its clinical values in diabetic ketoacidosis (DKA).
Methods: The precision, accuracy, specificity, linearity and interference of the enzymatic method were analyzed. This method was used to determine serum beta-HB in 60 cases of normals, 50 cases of diabetes, and 34 cases of DKA by autochemistry analyzer.
Results: Enzymatic beta-HB assay was precise (within-run CV, day-to-day CV, and total CV < 5%). The linearity studies showed the method was linear up to 4 mmol/L. Recovery rate was 98.5%-104.1%. Hemolysis (Hemoglobin up to 18.2 g/L), icteric samples with total bilirubin up to 224 mumol/L, and lipemia up to triglyceride concentration of 2.28 mmol/L did not interfere with the beta-HB results in this method. Serum beta-HB levels were significantly elevated in DKA patients compared with DM patients and controls (P < 0.01). Positive rate of serum beta-HB in DKA patients was significantly higher than that of urinary ketone (P < 0.05).
Conclusions: Enzymatic method is convenient and reliable, allows full automation, and is rapid enough to be used for both routine and urgent determinations of serum beta-HB. It can be used in diagnosing and monitoring treatment of DKA.