C-Peptide to Glucose Ratio
Assesses beta cell secretory function in patients with diabetes/prediabetes.
- This tool supports both postprandial (approximately 2 hours after a meal) and fasting (8–12 hours) measurements.
- Select the measurement state that reflects when the laboratory samples were obtained, and verify all units, as these inputs can significantly affect results.
Advice
- Results reflect the patient’s insulin secretory capacity.
- Insulin deficiency supports a diagnosis of type 1 diabetes, whereas preserved secretion is more consistent with type 2 diabetes; however, be aware that insulin deficiency may also develop in patients with long-standing or severe type 2 diabetes due to progressive β cell failure.
Management
Proposed interpretation and management considerations:
- Insulin deficiency/loss of β cell function: Insulin therapy is necessary.
- Impaired insulin secretion: Basal insulin plus other antidiabetic agents may be appropriate.
- Preserved insulin secretion/β cell function: Insulin is usually unnecessary.
Critical Actions
Use results in conjunction with clinical judgment and the broader clinical context when diagnosing and managing patients with diabetes.