About C-Peptide to Glucose Ratio
When to Use
- To evaluate endogenous insulin production
- In diabetes classification
- To distinguish Type 1 from Type 2 diabetes
- When assessing insulin resistance
- In cases of suspected insulinoma
Pearls/Pitfalls
- More reliable than insulin levels alone
- Not affected by exogenous insulin
- Must consider renal function (C-peptide clearance)
- Results may vary with timing of blood draw
- Should be interpreted with clinical context
Why Use
- Helps differentiate diabetes types
- Assesses beta cell function
- Guides treatment decisions
- More stable than insulin measurement
- Useful in insulin resistance evaluation
About the Calculation
C-Peptide to Glucose Ratio
The C-peptide to glucose ratio is a useful tool for assessing endogenous insulin production. C-peptide is produced in equal amounts to insulin and has a longer half-life, making it a more reliable marker of insulin production.
Formula: C-peptide (ng/mL) ÷ Glucose (mg/dL) × 100
Calculate C-Peptide to Glucose Ratio
Results
Interpretation Guide
| Ratio | Interpretation | Clinical Significance |
|---|---|---|
| <1.0 | Low | Suggests decreased insulin production |
| 1.0-2.0 | Normal | Normal insulin production |
| >2.0 | High | Suggests insulin resistance or insulinoma |