Mixed-meal tolerance test to assess residual beta-cell secretion: Beyond the area-under-curve of plasma C-peptide concentration

Pediatr Diabetes. 2019 May;20(3):282-285. doi: 10.1111/pedi.12816. Epub 2019 Feb 19.


Aims: Residual beta-cell secretion in type 1 diabetes is commonly assessed by area-under-curve of plasma C-peptide concentration (AUCCpep ) following mixed-meal tolerance test (MMTT). We aimed to investigate alternative measures of beta-cell responsiveness.

Methods: We analyzed data from 32 youth (age 7 to 17 years) undergoing MMTT within 6 months of type 1 diabetes diagnosis. We related AUCCpep with (a) validated mechanistic index of postprandial beta-cell responsiveness MI accounting for glucose level during MMTT, and (b) pragmatic marker calculated as baseline plasma C-peptide concentration corrected for baseline plasma glucose concentration.

Results: Postprandial responsiveness MI was correlated with age and BMI SDS (Rs = 0.66 and 0.44, P < 0.01 and P < 0.05) and was more correlated with glycated hemoglobin than AUCCpep (Rs = 0.79, P = 0.04). The pragmatic marker was highly correlated with AUCCpep (Rs = 0.94, P < 0.01).

Conclusions: Postprandial responsiveness MI may be more relevant to glucose control than AUCCpep . Baseline C-peptide corrected for baseline glucose appears to be a suitable surrogate of AUCCpep if MMTT is not performed.

Keywords: C-peptide; beta-cell secretion; mixed-meal tolerance test; type 1 diabetes.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Area Under Curve
  • Blood Glucose / metabolism
  • C-Peptide / blood*
  • Child
  • Diabetes Mellitus, Type 1 / diagnosis
  • Diabetes Mellitus, Type 1 / metabolism*
  • Diagnostic Techniques, Endocrine*
  • Feasibility Studies
  • Female
  • Glycated Hemoglobin A / analysis
  • Glycated Hemoglobin A / metabolism
  • Humans
  • Insulin Secretion / physiology*
  • Insulin-Secreting Cells / metabolism*
  • Male
  • Meals*
  • Postprandial Period


  • Blood Glucose
  • C-Peptide
  • Glycated Hemoglobin A