Normal Range for Beta-Hydroxybutyrate (BHB)
The normal range for beta-hydroxybutyrate in peripheral blood is 0.02 to 0.28 mmol/L, with levels below 0.6 mmol/L generally considered normal. 1, 2
Established Reference Ranges
- Standard normal range: 0.02 to 0.28 mmol/L based on population-based validation studies using 304 randomly selected serum samples 2
- Clinical threshold for normal: BHB levels <0.6 mmol/L are considered within normal range 1
- Baseline median in healthy populations: Approximately 0.13 mmol/L 3
Clinical Interpretation Thresholds
The interpretation of BHB levels follows a tiered approach based on clinical significance:
Normal to Mild Elevation
- <0.6 mmol/L: Normal range, no intervention needed 1
- 0.6-1.5 mmol/L: Mild to moderate ketosis requiring monitoring and possible intervention 1
- ≥0.6 mmol/L: Caution threshold in diabetic patients, particularly during illness or with SGLT2 inhibitor use 1
Clinically Significant Elevation
- ≥1.5 mmol/L: Significant ketosis with high risk for diabetic ketoacidosis (DKA) when accompanied by hyperglycemia and acidosis 1
- ≥3.0 mmol/L (children) or ≥3.8 mmol/L (adults): Diagnostic threshold for DKA in the presence of uncontrolled diabetes 4
- >10,000 μmol/L (10 mmol/L): Extremely elevated levels associated with pathophysiological conditions producing ketone bodies 5
Important Clinical Caveats
Exercise restriction: In patients with type 1 diabetes, intense physical activity should be postponed when BHB ≥1.5 mmol/L due to risk of worsening ketosis 6, 1
SGLT2 inhibitor users: These patients require heightened vigilance as they can develop "euglycemic DKA" with normal or only mildly elevated blood glucose, making BHB monitoring particularly critical 1, 7
Measurement superiority: Direct BHB blood measurement is superior to urine ketone testing for diagnosing and monitoring ketoacidosis, as urine tests using nitroprusside reaction do not quantify BHB specifically 1
Analytical Performance
The validated peripheral blood assay demonstrates excellent precision with coefficients of variation ranging from 1.5% at high concentrations (3.1 mmol/L) to 6.5% at low concentrations (0.1 mmol/L), with a limit of detection of 0.037 mmol/L 2