Evaluation of the 24-hour profiles of physiological insulin, glucose, and C-peptide in healthy Japanese volunteers

Diabetes Technol Ther. 2009 Aug;11(8):499-508. doi: 10.1089/dia.2009.0029.


Background: Some studies have demonstrated the benefit of blood glucose control as close as possible to physiological conditions. Not enough reports have investigated in detail the 24-h plasma profiles of insulin/glucose/C-peptide. Here we investigated the 24-h plasma profiles of physiological insulin/glucose/C-peptide in healthy Japanese adults.

Methods: In order to evaluate the 24-h profiles of physiological insulin/glucose/C-peptide profiles, 42 blood samples were taken from each subject in our group of healthy Japanese volunteers to measure the 24-h profile with three standardized meals.

Results: Plasma glucose and insulin increased rapidly followed by a rapid decrease after each meal with little variation at night. The average peak values of insulin after each meal were as follows: 426.20 pmol/L (breakfast), 373.75 pmol/L (lunch), and 410.28 pmol/L (dinner). The average times to peak insulin were 0.651 h (breakfast), 0.677 h (lunch), and 0.689 h (dinner). The corresponding average maximum postprandial plasma glucose levels were 8.39 mmol/L (breakfast), 8.77 mmol/L (lunch), and 8.74 mmol/L (dinner). The average times to peak glucose were 0.738 h (breakfast), 0.650 h (lunch), and 0.625 h (dinner). The average maximum postprandial C-peptide levels were 2.64 nmol/L (breakfast), 2.55 nmol/L (lunch), and 2.67 nmol/L (dinner). No major differences were found in these parameters between the Caucasian and Japanese populations.

Conclusions: This is the first investigation to measure the 24-h profiles of insulin/glucose/C-peptide in healthy Japanese volunteers with standardized meals. It is hoped this information will provide useful reference for future research and clinical management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Glucose / metabolism*
  • Blood Pressure
  • Body Mass Index
  • C-Peptide / blood*
  • Eating / physiology
  • Glucose Tolerance Test
  • Humans
  • Insulin / blood*
  • Male
  • Patient Selection
  • Postprandial Period
  • Pulse
  • Reference Values
  • Young Adult


  • Blood Glucose
  • C-Peptide
  • Insulin