From the Guidelines
Blood ketone testing, specifically measuring beta-hydroxybutyrate (BHB), is the most accurate method for assessing ketosis, with levels above 0.5 mmol/L indicating nutritional ketosis and levels exceeding 3.0 mmol/L potentially signaling diabetic ketoacidosis in appropriate clinical contexts.
Laboratory Tests for Ketosis
The following laboratory tests can be used to assess ketosis:
- Blood ketone levels: This is the most accurate method for assessing ketosis, with BHB being the predominant ketone body 1.
- Urine ketone tests: These tests detect acetoacetate but not BHB, making them less reliable but more accessible for home monitoring 1.
- Serum bicarbonate levels: Decreased serum bicarbonate (below 18 mEq/L) can indicate ketoacidosis 1.
Additional Laboratory Markers
Additional laboratory markers that can be used to assess ketoacidosis severity include:
- Elevated anion gap
- Glucose levels: particularly in diabetic ketoacidosis where glucose typically exceeds 250 mg/dL 1
- Electrolytes
- Arterial blood gases
Routine Monitoring
For routine monitoring of nutritional ketosis, blood ketone meters provide the most reliable results 1. In medical settings, a comprehensive metabolic panel including electrolytes, glucose, and arterial blood gases may be employed to assess ketoacidosis severity 1. It is essential to note that the nitroprusside method should not be used to monitor treatment of DKA, as it only measures acetoacetic acid and acetone, and not BHB 1.
From the Research
Labs to Assess for Ketosis
To assess for ketosis, several lab tests can be used, including:
- Blood beta-hydroxybutyrate (β-hydroxybutyrate) testing 2, 3, 4, 5
- Urine acetoacetate testing 3, 4, 5
- Serum beta-hydroxybutyrate measurement 6
- Measurement of ketones in interstitial fluid 3
- Exhaled breath acetone measurement, although no device is currently FDA-cleared for this purpose 3
Comparison of Lab Tests
Studies have compared the effectiveness of different lab tests for assessing ketosis, including:
- Blood β-hydroxybutyrate testing vs. urine acetoacetate testing: Blood β-hydroxybutyrate testing was found to be more effective in reducing emergency department assessment, hospitalization, and time to recovery from diabetic ketoacidosis 4
- Urinary acetoacetate vs. capillary beta-hydroxybutyrate: Capillary beta-hydroxybutyrate measurement was found to be faster and more effective than urinary acetoacetate testing in detecting ketoacidosis in the Emergency Department setting 5
Interpretation of Lab Results
The interpretation of lab results for ketosis can be complex and requires consideration of multiple factors, including: