Does a Comprehensive Metabolic Panel Include Fasting Glucose?
Yes, a Comprehensive Metabolic Panel (CMP) includes glucose measurement, which reflects fasting glucose when the patient is fasting at the time of blood draw. 1
What the CMP Measures
The CMP includes 14 components: electrolytes (sodium, potassium, carbon dioxide, chloride), kidney function tests (BUN, creatinine), glucose, and liver function tests (ALT, AST, total bilirubin, albumin, total protein, alkaline phosphatase). 1
The glucose measurement in a CMP is simply reported as "glucose" - it becomes a "fasting glucose" only if the patient has fasted for 8-14 hours before the blood draw. 2
The American Diabetes Association specifies that fasting plasma glucose ≥126 mg/dL (7.0 mmol/L) is diagnostic of diabetes, and this can be measured as part of a CMP. 2
Clinical Context and Interpretation
For diagnostic purposes, fasting is required: The patient must fast for at least 8 hours (and no more than 14 hours) before the blood draw for the glucose value to be interpreted as a fasting plasma glucose. 2
If the CMP is drawn without fasting, the glucose value is still reported but should be interpreted as a random (non-fasting) glucose rather than fasting glucose. 2
A random plasma glucose ≥200 mg/dL (11.1 mmol/L) in the presence of classic symptoms of hyperglycemia is diagnostic of diabetes, regardless of fasting status. 2
Important Caveats
The CMP does not automatically mean the glucose is fasting - you must verify the patient's fasting status at the time of blood draw to interpret the glucose value correctly. 2
Normal fasting glucose is <100 mg/dL (5.6 mmol/L), prediabetes (impaired fasting glucose) is 100-125 mg/dL (5.6-6.9 mmol/L), and diabetes is ≥126 mg/dL (7.0 mmol/L) on two separate occasions. 2, 3
Biological variation in fasting glucose ranges from 4.8% to 6.1% within the same person on different days, so abnormal results should be confirmed with repeat testing. 3
The CMP does not include a lipid panel - that must be ordered separately if needed for cardiovascular risk assessment. 1