Twenty-Four Hour Urinary C-peptide and Fasting Plasma C-peptide as Indicators of Metabolic Control in 83 Insulin Dependent Diabetic Patients

In order to evaluate the usefulness of 24-hour urinary C-peptide and fasting plasma C-peptide as metabolic index, C-peptide was measured in 24-hour urine and in fasting plasma of 83 insulin dependent diabetic patients. Using multiple linear regression, HbAlc was analyzed as a dependent variable versus independent variables such as daily insulin dose, fasting plasma C-peptide and 24-hour urinary C-peptide. Twentyfour hour urinary C-peptide was significantly correlated with fasting plasma C-peptide showed significant inverse correlations with the daily insulin dose. But neither 24-hour urinary C-peptide nor fasting plasma C-peptide was significantly correlated with HbAlc as a dependent variable. These results show that there was no difference of usefulness between 24-hour urinary C-peptide and fasting plasma C-peptide in relation to HbAlc and daily insulin dose in insulin dependent diabetic patients.