Related Experiment Video
Updated: Jul 24, 2026

Improving IV Insulin Administration in a Community Hospital
Published on: June 11, 2012
The relationship between 24-hour integrated glucose concentrations and % glycohemoglobin
Youssef Hassan1, Bradford Johnson, Nicole Nader
1Endocrinology, Metabolism and Nutrition Section, University of Minnesota, Minneapolis, Minnesota, USA.
Objective:
Since glycohemoglobin values are widely used clinically as a surrogate for average glucose concentration over an extended period of time, we decided to determine the actual relationship between 24-hour integrated glucose values and percent total glycohemoglobin (%tGHb) in cohorts of people with and without diabetes.
Research Design And Methods:
In 48 people without known diabetes with known stability of fasting glucose over a 1-year period of time, the calculated 24-hour integrated glucose concentration was compared with their %tGHb. In 15 normal young medical students, the glucose area response was determined from 46 venous blood samples obtained during a 24-hour period and compared with their %tGHb. In 18 people with type 2 diabetes, interstitial glucose concentrations were monitored using the Continuous Glucose Monitoring System (Medtronic MiniMed, Inc., Sylmar, Calif) for 3 days at 20-day intervals over 100 days. %tGHb was performed at 20-day intervals simultaneously. In 29 people with untreated type 2 diabetes, glucose area response was determined from 46 venous blood samples obtained during a 24-hour period and compared with their %tGHb after being on a standardized diet provided to the subjects for at least 5 weeks. The %tGHb and 24-hour profiles were stable.
Results:
There was an excellent correlation between the mean 24-hour glucose concentration and the %tGHb among subjects with diabetes. The correlation was poor among subjects without diabetes. The relationship was curvilinear when plotted as a single group. Alternatively when data from subjects with or without diabetes were plotted separately, the slopes were identical but the y-intercepts were different.
Conclusion:
The relationship between the mean glucose concentration integrated over an extended period of time and the %tGHb is not linear. The reason for this nonlinearity remains to be determined. This non-linearity needs to be considered in the clinical interpretation of %tGHb (and probably HbA(1c)) in reference to glucose values.
Related Concept Videos
Hormones Regulating Blood Glucose
In addition to accelerating glucose uptake and utilization, insulin has...
Glucose Homeostasis: Regulation of Blood Glucose
During fasting, when blood glucose levels are low, the pancreas secretes glucagon. it...
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
Insulin and C-peptide are co-secreted in...
Hypoglycemia and Glucagon
Hypoglycemia
Hyperglycemia

