Efficacy of Quantitative Capillary Beta-Hydroxybutyrate Measurement in the Diagnosis of Diabetic Ketoacidosis: A Comparison to Quantitative Serum Ketone Measurement by Nitroprusside Reaction
Raweewan Lertwattanarak MD*, Parit Plainkum PhD, MD**
Affiliation : * Division of Endocrinology and Metabolism, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Division of Emergency Medicine, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To examine the efficacy of using capillary beta-hydroxy butyrate (β-OHB) levels in comparison with serum ketone
levels in distinguishing diabetic ketoacidosis (DKA) from non-DKA states in patients who had severe hyperglycemia and to
determine a cut-off level of capillary β-OHB that is best for the diagnosis of DKA.
Material and Method: Diabetic patients who presented with capillary blood glucose of >400 mg/dL were studied. Capillary
β-OHB levels were measured by using a ketometer (OptiumXceedTM) at the same time as blood sample collection for
biochemical tests and serum ketone measurement using nitroprusside reaction. The American Diabetes Association (ADA)
criteria 2012 were used as the gold standard in the diagnosed of DKA.
Results : There were 13 cases (34.2%) with DKA (DKA group) and 25 cases (65.8%) without DKA (non-DKA group). There
was no difference in plasma glucose levels between both groups. (DKA group = 714.2+367.6 mg/dl vs. non-DKA group =
589.4+220.2 mg/dl). The DKA group had significantly higher serum ketone (7.2+3.6 vs. 0.28+0.05 mmol/L, p<0.001) and
capillary β-OHB levels (4.3+0.7 vs. 1.0+1.1 mmol/L, p<0.001) than did the non-DKA group. Capillary β-OHB levels
significantly correlated to serum anion gap values (r = 0.828, p<0.001), serum bicarbonate (r = 0.715, p<0.001), and ketone
(r = 0.72, p<0.001) levels. ROC analyses showed that a capillary β-OHB level of >3.1 mmol/L was the best cut-off level for
the diagnosis of DKA, and yielded a sensitivity of 100% (95% CI = 75.1-100) with a specificity of 96% (95% CI = 79.6-99.3).
Conclusion : Using a cut-off capillary β-OHB level of >3.1 mmol/L is highly effective in the diagnosis of DKA in patients who
presented with hyperglycemia. Quantitative measurement of capillary β-OHB levels using a ketometer offers an immediate
result that is useful for a reliable triage of screening for DKA in patients presented with severe hyperglycemia.
Keywords : Triage, Diabetic ketoacidosis, Ketone, Beta-hydroxybutyrate
