Is a C-peptide level of 3.34 a qualifier for an insulin pump like Tandem (insulin pump system) or Beta Bionics (automated insulin delivery system)?

C-peptide Level of 3.34 and Insulin Pump Qualification

A C-peptide level of 3.34 does not disqualify a patient from insulin pump therapy such as Tandem or Beta Bionics systems, as current guidelines explicitly state that C-peptide levels do not correlate with response to intensive insulin therapy and should not be required for insulin pump coverage. 1

Understanding C-peptide in Diabetes Management

C-peptide is a byproduct of insulin production, secreted in equal amounts to insulin by pancreatic beta cells. It serves as a reliable marker of endogenous insulin production and can help differentiate between diabetes types.

Key points about C-peptide in relation to insulin pumps:

• The American Diabetes Association's 2025 Standards of Care explicitly states: "For people with diabetes judged to be clinically insulin deficient who are treated with intensive insulin therapy, the presence or absence of measurable C-peptide levels does not correlate with response to therapy." 1
• The guidelines further emphasize that "a low C-peptide value should not be required for insulin pump coverage in individuals with type 2 diabetes." 1

Insulin Pump Qualification Criteria

Qualification for insulin pumps like Tandem or Beta Bionics (automated insulin delivery systems) should be based on:

1. Clinical need for intensive insulin therapy - regardless of C-peptide level
2. Patient capability to safely use the device
3. Potential clinical benefit from pump therapy

The 2023 Diabetes Care guidelines state that if C-peptide measurement is required by a payer for coverage of insulin pump therapy, it should be measured when fasting plasma glucose is <220 mg/dL, but this is a payer requirement rather than a clinical necessity. 1

Interpreting Your C-peptide Value

A C-peptide value of 3.34 ng/mL indicates preserved beta-cell function, which is typically associated with:

• Type 2 diabetes pattern (>1.8 ng/mL) 2
• Substantial endogenous insulin production

However, this does not mean an insulin pump would not be beneficial. In fact:

• Automated insulin delivery systems have shown benefits in both type 1 and type 2 diabetes 1
• Recent studies have demonstrated improvements in time in range for patients with type 2 diabetes using automated insulin delivery systems 1

Clinical Decision Making

The decision to use an insulin pump should be based on:

• Current glycemic control with existing therapy
• Patient preference and ability to manage the technology
• Potential for improved outcomes (reduced hypoglycemia, better time in range)
• NOT solely on C-peptide levels

Key Takeaway

Your C-peptide level of 3.34 should not be a barrier to insulin pump therapy if clinically indicated. The most recent guidelines explicitly state that C-peptide levels do not correlate with response to intensive insulin therapy, and insurance requirements for specific C-peptide cutoffs are not clinically justified according to current medical evidence. 1