β-hydroxybutyrate

1. Diagnosis of Diabetic Ketoacidosis (DKA)

β-HB accounts for ~70–80% of total ketone bodies in DKA.

Rises earlier and to a greater extent than acetoacetate.

Clinical importance:

• More accurate than urine ketone tests (which detect mainly acetoacetate)
• Best marker for confirming and grading severity of DKA

2. Monitoring Treatment of DKA

During effective therapy:

• β-HB levels fall rapidly
• Acetoacetate may transiently rise → false-positive urine ketones

👉 β-HB is the preferred marker for monitoring resolution of DKA.

3. Differentiation of Ketoacidosis Types

• β-HB is elevated in:
• Diabetic ketoacidosis
• Alcoholic ketoacidosis
• Starvation ketoacidosis
• Clinical context + labs help differentiate causes.

4. Detection of Euglycemic Ketoacidosis

Seen in:

• Patients on SGLT2 inhibitors
• Prolonged fasting or pregnancy
• Blood glucose may be normal or mildly elevated

👉 β-HB measurement is crucial, as urine glucose/ketones may be misleading.

5. Critical Illness & Metabolic Stress

Elevated β-HB may be seen in:

• Sepsis
• Prolonged fasting
• Severe illness
• Reflects shift to fatty-acid metabolism.

6. Assessment of Nutritional Ketosis

• Used to monitor ketogenic diets or therapeutic ketosis (e.g., epilepsy management).
• Levels are lower than in ketoacidosis and without acidosis.