C-peptide in serum

Indications

• assessement of surreptitious insulin administration
• assessment of beta-cell function in the presence of exogenous insulin administration

Reference interval

• 0.78-1.89 ng/mL (0.26-0.63 nM)

Clinical significance

• a strong correlation between secreted insulin levels & C-peptide exists
• molar excess of C-peptide/insulin occurs due to the longer 1/2 life of C-peptide

Increases

• insulinoma
• pancreas or beta-cell transplant
• pharmaceutical agents
  • chloroquine
  • danazol
  • ethinyl estradiol
  • oral contraceptives

Decreases

• diabetes mellitus, type 1
• factitious hypoglycemia due to surreptitious insulin administration

Methods

• RIA

Specimen

• serum
• store at -70 C
• stable for 30 days frozen

More general terms

• C-peptide in body fluid

Additional terms

• C-peptide

Component of

• insulin-induced C-peptide suppression panel

Patient information

C peptide in serum patient information