Preferred Sample Type

3 Hydroxy Butyrate

Suitable Specimen Types

  • Fluoride Oxalate
1mL blood. Min.vol.100 uL plasma

Specimen Transport

Send sample on the first available transport

Sample Processing in Laboratory

No special transport conditions.  Sample should be transported to laboratory asap

Sample Preparation

Centrifuge and send to reference laboratory ASAP.

Turnaround Time

2 weeks

Sample Stability

Freeze plasma at -20 oC if not sent immediately.

3 Hydroxy Butyrate

General Information

The measurement of 3-hydoxy-butyrate is used together with free fatty acids (FFA) as a useful first line indicator of inherited defects of mitochondrial fatty acid catabolism. Ideally specimens should be taken during acute hypoglycaemic episodes or after a provocative fast. In most circumstances, as blood glucose falls, lipolysis and subsequently ketogenesis are stimulated; thus the plasma concentration of FFA and 3-hydroxybutyrate increase in an approximately equimolar fashion. In fatty acid oxidation defects, lipolysis will still be stimulated in response to a drop in blood glucose, but ketogenesis will be reduced. Therefore, a disproportionately high free fatty acid concentration relative to a low 3-hydroxy-butyrate concentration is found, particularly during periods of stress i.e. infection, coma, fasting and hypoglycaemia. In patients with hyperinsulinism, FFA and 3- hydroxybutyrate levels will both be low, as insulin suppresses lipolysis. This pattern will also be observed in patients with hypopituitarism, therefore this test can not be used to diagnose hyperinsulinism. However, hyperinsulinism can be ruled out by the demonstration of ketosis, i.e. elevated FFA and 3-hydroxy butyrate in the presence of hypoglycaemia. See for Best Practice Guidelines for the Investigation of Hypoglycaemia in Infants and Children.

Patient Preparation

Please supply glucose result and details of fasting.


None Given

Reference Range

Provided by reference laboratory.


  • EQA Scheme?: Yes
  • EQA Status:

    Referral Laboratory participates in an EQA scheme

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HTA licence number is 12366

Protection of Personal Information – Laboratory Medicine comply with the Trust Data Protection Policy and have procedures in place to allow the Directorate and it’s employees to comply with the Data Protection Act 1998 and associated best practice and guidance.

The Trust Laboratories at Heartlands Hospital, Good Hope Hospital and Solihull Hospital were awarded UKAS (United Kingdom Accreditation Service) accreditation to the internationally recognised ISO 15189 standard in May 2015. For a list of accredited tests and other information please visit the test database
Tests not appearing on this scope are either under consideration or in the process of accreditation and so currently remain outside of our scope of accreditation. However, these tests have been validated to the same high standard as accredited tests and are performed by the same trained and competent staff.

For further information contact Louise Fallon, Quality Manager, 0121 424 1235