[Different establishing conditions of hyperinsulinemic-euglycemic clamp technique among different groups]

To compare the different establishing conditions of hyperinsulinemic-euglycemic clamp technique among the groups of normal glucose tolerance (NGT), hyperinsulinemia with normal glucose (HINS) and impaired glucose tolerance (IGT).

The hyperinsulinemic-euglycemic clamp technique was applied to the study of methodology in 10 NGT, 11 HINS and 10 IGT subjects. Different establishing conditions were compared through variance analysis (ANOVA) among three groups. And the influencing factors resulting in these differences were analyzed through stepwise regression analysis.

The serum insulin concentration of three groups were acutely raised and maintained at above 100 mU/L. During the steady stage, the blood glucose level remained stable and all coefficient variations were under 5%. The secretion of endogenous insulin and hepatic glucose production were completely inhibited during the test. Under these steady-state hyperinsulinemic-euglycemic conditions, the glucose infusion rate (M value) was equal to glucose disposal rate by all tissues in body, M value of three groups were as follows: (11.6 ± 1.7), (6.1 ± 1.9) and (6.0 ± 1.5) mg×kg(-1)×min(-1). During clamping, the peak and steady-state serum insulin concentrations of IGT and HINS groups were significantly higher than those of NGT group. Although the peak and steady-state serum insulin concentration of HINS group were higher than those of IGT group, the differences had no statistical significance (P = 0.34, 0.11). The independent influencing factor of peak serum insulin concentration was waist-to-hip ratio (WHR) while the independent influencing factors of steady-state serum insulin concentration included insulin metabolic clearance rate (MCR) and body mass index (BMI). The peak and steady-state serum insulin concentrations were not the independent influencing factors of M value.

During the establishment of hyperinsulinemic-euglycemic clamp technique, the differences in peak and steady-state serum insulin concentrations existed among NGT, HINS and IGT groups. But the differences do not influence the use of M value in the evaluation of insulin resistance.