What is considered a positive beta-hydroxybutyrate (BHB) value for diabetic ketoacidosis (DKA)?

From the Guidelines

A beta-hydroxybutyrate (BHB) value greater than 3.0 mmol/L is generally considered positive for diabetic ketoacidosis (DKA).

Diagnosis of DKA

The diagnosis of DKA typically requires the triad of hyperglycemia (blood glucose >250 mg/dL), metabolic acidosis (pH <7.3 or bicarbonate <18 mEq/L), and elevated ketones 1.

BHB Levels

BHB is the predominant ketone body produced during DKA and provides a more accurate assessment of ketosis than urine ketone testing 1.

• BHB levels between 1.0-3.0 mmol/L indicate ketonemia but may not necessarily represent full DKA, especially if the patient's blood glucose and pH levels are not significantly abnormal.
• A decrease in BHB levels to below 0.6 mmol/L generally indicates resolution of ketosis.

Monitoring DKA

Point-of-care BHB testing allows for rapid assessment and is particularly useful in emergency settings 1.

• BHB levels should be monitored during DKA treatment, with values decreasing as insulin therapy resolves the ketosis.
• The nitroprusside method should not be used as an indicator of response to therapy, as it only measures acetoacetic acid and acetone, and not BHB 1.

From the Research

Definition of Positive Beta-Hydroxybutyrate Value for DKA

• A positive beta-hydroxybutyrate (BHB) value for diabetic ketoacidosis (DKA) is generally considered to be above a certain threshold, which may vary depending on the study or clinical context 2, 3, 4, 5.
• According to a study published in 2022, a BHB value of <1.5 mmol/L can be used to define resolution of DKA, with a sensitivity of 83% and specificity of 87% 3.
• Another study from 2006 found that a BHB value of 1.5 mmol/L had a sensitivity of 98% and specificity of 85% for diagnosing DKA 4.
• A 2021 study in pediatric patients found that a BHB value of 5.3 mmol/L predicted DKA with optimal accuracy, with a sensitivity of 76.7% and specificity of 96.4% 5.
• It is essential to note that the optimal BHB threshold for diagnosing or resolving DKA may vary depending on the population, clinical context, and other factors, and should be interpreted in conjunction with other clinical and laboratory findings 2, 6.

Factors Associated with BHB Levels

• Baseline BHB levels and changes in BHB over time have been associated with an increased risk of DKA 6.
• Age, insulin pump use, and sotagliflozin use have also been identified as factors associated with DKA risk and BHB levels 6.
• The relationship between BHB and other laboratory parameters, such as pH, bicarbonate, and anion gap, can provide valuable information for diagnosing and managing DKA 2, 3, 4, 5.

Clinical Implications

• BHB measurement can be a useful tool for monitoring and managing DKA, particularly in conjunction with other clinical and laboratory findings 2, 3, 4, 5.
• Point-of-care testing for BHB can provide rapid and accurate results, allowing for timely diagnosis and treatment of DKA 4.
• Further research is needed to fully understand the relationship between BHB and DKA, and to establish evidence-based guidelines for BHB testing and interpretation in clinical practice 2, 3, 6, 4, 5.