What does an elevated fasting C-peptide level indicate?

C-peptide is a secretion product of pancreatic islet cells and can be used to evaluate islet cell function, as well as for diabetes diagnosis and classification. Elevated fasting C-peptide levels may indicate causes such as dietary factors, obesity, prediabetes, type 2 diabetes, or islet cell tumors, and management should be based on the specific situation.

1. Dietary factors: Consuming large amounts of high-protein or high-fat foods the day before testing may increase insulin secretion, thereby raising C-peptide levels accordingly. It is recommended to maintain a bland diet before the test and avoid foods that may affect test results.

2. Obesity: Increased fat cells may produce certain cytokines and hormones that affect insulin sensitivity, leading to insulin resistance and increased insulin secretion, thereby elevating C-peptide levels. It is recommended to lose weight through proper diet and moderate exercise. Dietary management should focus on controlling total calorie intake, along with aerobic exercise and strength training.

3. Prediabetes: In prediabetes, patients' pancreatic β-cell function becomes abnormal, with delayed insulin secretion peaks and possibly increased insulin secretion, causing elevated C-peptide levels. It is recommended to control the intake proportions of carbohydrates, fats, and proteins, eat regular and measured meals, increase physical activity, lower blood glucose levels, and improve insulin resistance.

4. Type 2 diabetes: This condition may be caused by genetic and environmental factors. Patients exhibit insulin resistance and pancreatic β-cell dysfunction. As the disease progresses, pancreatic β-cells continuously secrete insulin to maintain blood glucose levels, leading to elevated C-peptide levels. It is recommended to follow medical advice and use medications such as nateglinide tablets or metformin hydrochloride tablets for treatment.

5. Islet cell tumor: This condition may be related to environmental factors, infections, and other influences. The tumor cells autonomously secrete insulin, causing hypoglycemic symptoms in patients. Insulin and C-peptide molecules are secreted simultaneously, elevating C-peptide levels. It is recommended to promptly follow medical advice and undergo surgical removal of the tumor to prevent worsening of the condition.

If any physical discomfort occurs, it is recommended to seek medical attention at a hospital as soon as possible and follow medical advice for treatment.