Related Experiment Video
Updated: Mar 26, 2026

A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination
Published on: June 25, 2014
Fasting C-peptide and Related Parameters Characterizing Insulin Secretory Capacity for Correctly Classifying Diabetes
Background/Aims:
C-peptide allows estimation of insulin secretion even in the presence of insulin treatment. C-peptide may be suitable for the differential diagnosis of type 1 and type 2 diabetes, and, within type 2 diabetes, of insulin-requiring vs. non-insulin-requiring patients. Relating C-peptide concentrations to ambient glucose levels might improve its diagnostic potential.
Patients/Methods:
The diagnostic value (a) fasting C-peptide, (b) C-peptide/glucose ratios, and (c) the HOMA-ßC-peptide-index for predicting a diagnosis of type 1 (vs. type 2) diabetes were assessed.
Setting:
Specialised hospital for the care of diabetic patients (inpatient treatment). 303 patients with type 1 diabetes and 841 patients with type 2 diabetes.
Main Outcome Measure:
Odds ratios and 95% confidence intervals for a clinical diagnosis of type 1 diabetes or for insulin treatment by deciles of (a) fasting C-peptide, (b) C-peptide/glucose ratios, and (c) HOMA-ßC-peptide-index.
Results:
Low C-peptide concentrations were associated with a high odds ratio for type 1 diabetes and vice versa (p<0.0001). Concentrations of 0.13-0.36 nmol/l did not discriminate. C-peptide/glucose ratios or HOMA-ßC-Peptide did not perform better. The ability of all 3 parameters to predict the necessity for insulin treatment within the population of type 2-diabetic patients was low.
Conclusions:
Fasting C-peptide and derived parameters help to differentiate type 1 from type 2 diabetes, but there is a range of C-peptide concentrations that does not help discriminate. Relating C-peptide to glucose did not improve diagnostic accuracy. C-peptide does not help predicting a need for insulin treatment in patients with type 2 diabetes.
Related Concept Videos
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
Insulin and C-peptide are...
Diabetes Mellitus: Type 2 and Gestational
Diabetes: Symptoms, Diagnosis, and Complications
Dipeptidyl Peptidase 4 Inhibitors
Carbohydrate Metabolism
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in...
Insulin: Dosing Regimen and Adverse Effects
The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror...

