Low levels of C-peptide have clinical significance for established Type 1 diabetes.

Abstract

AIM:

To determine whether the low C-peptide levels (< 50 pmol/l) produced by the pancreas for decades after onset of Type 1 diabetes have clinical significance.

METHODS:

We evaluated fasting C-peptide levels, duration of disease and age of onset in a large cross-sectional series (n = 1272) of people with Type 1 diabetes. We then expanded the scope of the study to include the relationship between C-peptide and HbA1c control (n = 1273), as well as diabetic complications (n = 324) and presence of hypoglycaemia (n = 323). The full range of C-peptide levels was also compared with 1,5-Anhydroglucitol, a glucose responsive marker.

RESULTS:

C-peptide levels declined for decades after diagnosis, and the rate of decline was significantly related to age of onset (P < 0.0001), after adjusting for disease duration. C-peptide levels > 10 pmol/l were associated with protection from complications (e.g. nephropathy, neuropathy, foot ulcers and retinopathy; P = 0.03). Low C-peptide levels were associated with poor metabolic control measured by HbA1c (P < 0.0001). Severe hypoglycaemia was associated with the lowest C-peptide levels compared with mild (P = 0.049) or moderate (P = 0.04) hypoglycaemia. All levels of measurable C-peptide were responsive to acute fluctuations in blood glucose levels as assessed by 1,5-Anhydroglucitol (P < 0.0001).

CONCLUSIONS:

Low C-peptide levels have clinical significance and appear helpful in characterizing groups at-risk for faster C-peptide decline, complications, poorer metabolic control and severe hypoglycaemia. Low C-peptide levels may be a biomarker for characterizing at-risk patients with Type 1 diabetes.

• Authors: W M Kuhtreiber, S L L Washer, E Hsu, M Zhao, P Reinhold 3rd, D Burger, H Zheng, D L Faustman
• Journal: Diabetic medicine : a journal of the British Diabetic Association (Diabet Med) Vol. 32 Issue 10 Pg. 1346-53 (Oct 2015) ISSN: 1464-5491 [Electronic] England
• PMID: 26172028 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

Chemical References

• Blood Glucose
• C-Peptide
• Glycated Hemoglobin A
• 1,5-anhydroglucitol
• Deoxyglucose

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Blood Glucose (metabolism)
• C-Peptide (blood)
• Child
• Cross-Sectional Studies
• Deoxyglucose (blood, metabolism)
• Diabetes Mellitus, Type 1 (blood, complications, diagnosis, epidemiology)
• Glycated Hemoglobin (metabolism)
• Humans
• Middle Aged
• Prognosis
• Young Adult