C-peptide

Revision as of 23:28, 17 January 2009 by C Michael Gibson (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

WikiDoc Resources for C-peptide

Articles

Most recent articles on C-peptide

Most cited articles on C-peptide

Review articles on C-peptide

Articles on C-peptide in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on C-peptide

Images of C-peptide

Photos of C-peptide

Podcasts & MP3s on C-peptide

Videos on C-peptide

Evidence Based Medicine

Cochrane Collaboration on C-peptide

Bandolier on C-peptide

TRIP on C-peptide

Clinical Trials

Ongoing Trials on C-peptide at Clinical Trials.gov

Trial results on C-peptide

Clinical Trials on C-peptide at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on C-peptide

NICE Guidance on C-peptide

NHS PRODIGY Guidance

FDA on C-peptide

CDC on C-peptide

Books

Books on C-peptide

News

C-peptide in the news

Be alerted to news on C-peptide

News trends on C-peptide

Commentary

Blogs on C-peptide

Definitions

Definitions of C-peptide

Patient Resources / Community

Patient resources on C-peptide

Discussion groups on C-peptide

Patient Handouts on C-peptide

Directions to Hospitals Treating C-peptide

Risk calculators and risk factors for C-peptide

Healthcare Provider Resources

Symptoms of C-peptide

Causes & Risk Factors for C-peptide

Diagnostic studies for C-peptide

Treatment of C-peptide

Continuing Medical Education (CME)

CME Programs on C-peptide

International

C-peptide en Espanol

C-peptide en Francais

Business

C-peptide in the Marketplace

Patents on C-peptide

Experimental / Informatics

List of terms related to C-peptide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.

Overview

C-peptide is a peptide which is made when proinsulin is split into insulin and C-peptide. They split when proinsulin is released from the pancreas into the blood in response to a rise in serum glucose - one C-peptide for each insulin molecule.

  • In proinsulin, C-peptide is an amino-acid chain connecting A and B chains of insulin
  • The level of C-peptide in the body is indicative of how much insulin is being produced in the body [1]
  • Reference range: 0.33-1.20 nmol/l

Etymology and History

C-peptide is the abbreviation for "connecting peptide", although its name was probably also inspired by the fact that insulin is also composed of an "A" chain and a "B" chain.

C-peptide was discovered in 1967. The first documented use of the C-peptide test was in 1972.

It should not to be confused with c-reactive protein or Protein C.

Function

C-peptide functions in repair of the muscular layer of the arteries.

C-peptide also exerts beneficial therapeutic effects on many complications associated with diabetes mellitus [2] , [3], such as for instance diabetic neuropathy[4] and other diabetes-induced ailments. In the kidneys, C-peptide prevents diabetic nephropathy [5], [6], and in the heart [7] blood flow is improved in diabetic patients.

In spite of these physiological functions, C-peptide is actually removed from pharmaceutical preparations of insulin sold by drug companies when they manufacture the synthetic human insulin that is in widescale clinical usage today.

Uses

  • Newly diagnosed diabetes patients often get their C-peptide levels measured, to find if they are type 1 diabetes or type 2 diabetes. The reason that the C-peptide levels are measured instead of the insulin levels themselves is because insulin concentration in the portal vein ranges from two to ten times higher than in the peripheral circulation. The liver extracts about half the insulin reaching it (the plasma), but this varies with the nutritional state. The pancreas of patients with type 1 diabetes is unable to produce insulin and they will therefore usually have a decreased level of C-peptide, while C-peptide levels in type 2 patients is normal or higher than normal. Measuring C-peptide in patients injecting insulin can help to determine how much of their own natural insulin these patients are still producing.
  • C peptide is also used for determining the possibility of gastrinomas associated with Multiple endocrine neoplasia (MEN). Since a significant amount of gastrinomas also include MEN which include pancreatic, parathyroid, and pituitary adenomas, higher levels of c-protein in addition to a gastrinoma may suggest other organs than just the stomach may include neoplasms.
  • Can be used for identifying malingering: hypoglycemia with low C-peptide level may indicate abuse of insulin.

C-peptide levels are also checked to determine how insulin resistant women with Polycystic Ovarian Syndrome may be.

Differential Diagnosis

Decreased

Increased

Normal Values in Patients with Injections of Insulin

References


Template:SIB

de:C-Peptid


Template:WikiDoc Sources