From the Guidelines
In Type 1 diabetes, C-peptide levels are typically low or undetectable due to the autoimmune destruction of beta cells, and measuring C-peptide provides valuable information about a person's remaining beta cell function. Measuring C-peptide levels can help distinguish between Type 1 and Type 2 diabetes, with normal C-peptide levels ranging from 0.5-2.0 ng/mL, but in established Type 1 diabetes, levels are often below 0.2 ng/mL 1. C-peptide testing is particularly useful during the initial diagnosis of diabetes, when evaluating unusual presentations, or when considering treatment adjustments, and can be performed fasting or after stimulation with a meal or glucagon 1. Some key points to consider when evaluating C-peptide levels in Type 1 diabetes include:
- The rate of beta-cell destruction is variable, with some individuals experiencing rapid destruction and others experiencing slower destruction 1
- Preserving any remaining C-peptide production may be beneficial, as even small amounts of endogenous insulin secretion can improve glycemic control and reduce complications 1
- Early intensive insulin therapy, immunomodulatory treatments, or certain medications might help preserve beta cell function in newly diagnosed Type 1 diabetes, though complete restoration of normal C-peptide levels is not currently possible 1
- The selection of glycemic targets in each patient should be individualized to the lowest HbA1c level that does not cause severe hypoglycemia, that preserves hypoglycemia awareness, and that avoids long-term micro- and macrovascular complications 1. Therefore, measuring C-peptide levels is a crucial step in the management of Type 1 diabetes, as it provides valuable information about a person's remaining beta cell function and can help guide treatment decisions. Some of the benefits of preserving C-peptide production include:
- Improved glycemic control
- Reduced risk of complications
- Improved quality of life
- Reduced risk of severe hypoglycemia
- Reduced risk of micro- and macrovascular complications 1.
From the Research
Type 1 Diabetes and C-Peptide
- C-peptide is a marker of endogenous insulin production, and its levels are typically low or undetectable in individuals with type 1 diabetes 2, 3, 4, 5, 6.
- The destruction of pancreatic β-cells in type 1 diabetes leads to absolute insulin deficiency, resulting in low or absent C-peptide levels 6.
- Insulin therapy is essential for individuals with type 1 diabetes, and various regimens, including multiple daily injections and continuous subcutaneous insulin infusion, are available 2, 3, 4, 5.
- The goal of insulin therapy is to mimic physiologic insulin replacement and achieve near-normal glycemia, which reduces the risk of micro- and macrovascular complications 4, 5.
- Emerging technologies, such as continuous glucose monitoring and automated insulin delivery systems, are transforming the landscape of type 1 diabetes management and offering new opportunities for improved outcomes 6.
Insulin Therapy and C-Peptide
- Insulin analogues, including rapid-acting and long-acting analogues, have improved glycemic control and reduced the risk of hypoglycemia in individuals with type 1 diabetes 2, 3, 5.
- The choice of insulin regimen should be individualized based on patient preferences, lifestyle, and glycemic goals 2, 3, 4, 5.
- C-peptide levels are not typically used to guide insulin therapy in type 1 diabetes, as the focus is on exogenous insulin replacement rather than endogenous insulin production 2, 3, 4, 5, 6.
Future Directions
- Advances in digital health, regenerative medicine, and immunotherapy hold promise for improving type 1 diabetes management and potentially modifying the disease course 6.
- A multidisciplinary approach, combining biomedical research, artificial intelligence, and nanotechnology, will be essential to translate these innovations into clinical practice and improve the quality of life for individuals with type 1 diabetes 6.