Rayman G, Clark P, Schneider A E, Hales C N
Department of Clinical Biochemistry, Addenbrooke's Hospital, Cambridge, UK.
Diabetologia. 1990 Oct;33(10):631-4. doi: 10.1007/BF00400209.
To determine the reproducibility of the first phase insulin response to intravenous glucose, ten normal subjects underwent two intravenous glucose tolerance tests separated by at least two weeks. Intravenous dextrose (0.3 g/kg) was administered over 2 min by continuous infusion and arterialised-venous samples were taken from a retrogradely cannulated hand vein in the opposite arm. Within subjects, median coefficient of variation for the 3 min insulin was 4.0% (range 1.2-24.3%) and median coefficient of variation for the 0-10 min area was 6.7% (range 1.7-18.8%). These coefficients of variation are close to those of the assay itself (less than 10%). Despite this, between subject responses varied by greater than sixfold. In conclusion, contrary to previous reports the intravenous glucose tolerance test is highly reproducible. This makes it a very valuable tool for further studies of the pathogenesis of diabetes.
