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beta-Hydroxybutyric acid

SI UNITS (recommended)


* The SI units is the recommended method of reporting clinical laboratory results

β-Hydroxybutyric Acid, b-Hydroxybutyric Acid, 3-hydroxybutyric acid, beta-hydroxybutyrate, β-hydroxybutyrate, 3-hydroxybutyrate
Units of measurement
mmol/L, µmol/L, mg/L, mg/dL, mg/100mL, mg%, µg/mL

β-Hydroxybutyric acid, also known as 3-hydroxybutyric acid, is an organic compound and a beta hydroxy acid with the formula CH3CH(OH)CH2CO2H; its conjugate base is beta-hydroxybutyrate, also known as 3-hydroxybutyrate.

In diabetic ketoacidosis (DKA), three ketone bodies are produced: β-hydroxybutyrate (BHB), acetoacetic acid, and acetone. β-hydroxybutyrate is present in the greatest concentration and accounts for approximately 75% of the three ketone bodies. During periods of ketosis, β-hydroxybutyrate increases even more than acetoacetate and acetone and has been shown to be a better indicator of ketoacidosis, including subclinical ketosis. Other names for this test include 3-hydroxybutyric acid and ketones. Testing for ketones is generally performed with nitroprusside (Acetest) tablets or reagent sticks. A 4+ reaction with serum diluted 1:1 is strongly suggestive of ketoacidosis. Nitroprusside reacts with acetoacetate and acetone but not with BHB. This is important because β-hydroxybutyrate is the predominant ketone, particularly in severe DKA. It is, therefore, possible to have a negative serum nitroprusside reaction in the presence of severe ketosis.

  • Monitoring therapy for DKA.
  • Investigating the differential diagnosis of any patient presenting to the emergency department with hypoglycemia, acidosis, suspected alcohol ingestion, or an unexplained increase in the AG.
  • In pediatric patients, the presence or absence of ketonemia/urea is an essential component in the differential diagnosis of inborn errors of metabolism.
  • Key parameter monitored during controlled 24-hour fasts.

Increased In

  • Alcoholic ketoacidosis
  • Lactic acidosis (shock, renal failure)
  • Liver disease
  • Infections
  • Phenformin and salicylate poisoning

Lab units Conversion Calculator. Convert beta-Hydroxybutyric acid level to mmol/L, µmol/L, mg/L, mg/dL, mg/100mL, mg%, µg/mL. Clinical laboratory units online conversion from conventional or traditional units to Si units. Table of conversion factors for beta-Hydroxybutyric acid.