Abstract
Changes in blood sugar, plasma immunoreactive insulin (IRI) and non-esterified fatty acid (NEFA) were followed serially after oral loading of 100g of glucose (SGTT) and after glucose-glucagon-tolbutamide test (GGTT) as advocated by Ryan et al. in normals and in diabetics.
1) Following SGTT, diabetics were divided in two groups according to the peak values of serum IRI. In group A with peak values higher than 80μU/ml, the highest blood sugar values was more than 300mg/dl in only one of the 5 cases. In groupB with peak values of plasma IRI less than 80μU/ml, the highest blood sugar values exceeded 300mg/dl in all 11 cases. This revealed a close correlation between plasma IRI response and blood sugar after SGTT.
2) In normals, plasma IRI after GGTT increased rapidly to 978±163μU/ml in 5 minutes and decreased steeply thereafter.
3) IRI response after GGTT in diabetics showed similar brisk response and rapid return. The peak values, however was much lower even in group A, who were supposed to have milder diabetes, showing a mean of 271±37.9μU/ml and the highest value of only 384μU/ml. The peak values were reached not later than the normal controls.
