The secretion rate of insulin (SR-I) of 50 normal subjects was calculated from the 24-h integrated concentration of insulin (IC-I), the peripheral metabolic clearance of insulin (pMCR-I), and the mean fractional hepatic insulin extraction (fhMCR-I) that was derived from our data. fhMCR-I was determined as the difference in the molar secretory rate of C-peptide (SR-C) and the molar peripheral clearance of insulin (pMCR-IxIC-I) divided by SR-C. The IC-I in our 50 subjects was 1.19±0.38 ng/ml and the IC-C was 2.93±0.58 ng/ml. Based on these data, the fhMCR-I was 0.40 and the SR-I was estimated to be 54.8±18.0 U/24 h. The 24-h urinary C-peptide excretion (U-C), 44.9±20.4 μg/24 h, had a statistically significant correlation with SR-I (r = 0.823, P<0.0001). The U-C may thus serve as a practical method for estimating the SR-I.
ASJC Scopus subject areas
- Internal Medicine
- Endocrinology, Diabetes and Metabolism