Objective To evaluate the effect of the needle free injection system (INJEX30) and insulin pen on insulin absorption and glycemic control in diabetic patients.Methods A total of 30 diabetic patients on insulin therapy without obvious complications were enrolled in the study with average BMI of 25.24 kg/m2.A comparison study was carried out in those subjects with the INJEX30 and insulin pen at 1 st day and 5th day.After an overnight fasting of 8-10 h,a standard mixed meal(50 g bread,50 g egg and 250 ml milk) was given to each patient.Blood samples at 0,20,40,60 min of the standard mixed meal were collected to test plasma glucose,serum insulin and C peptide.Results No difference was shown in fasting plasma glucose,serum insulin and C peptide between the patients with the two injection methods.The area under the curve (AUC) of plasma glucose and serum C peptide was significantly lower after the INJEX30 injection than that after insulin pen injection [plasma glucose AUC (542 ± 172) min · mmol · L-1 vs (601 ±199) min· mmol · L-1,P ＜0.01; C peptide AUC (70 ±53) min · μg · L-1 vs (80 ±58) min · μg · L-1,P ＜0.01].The AUC of serum insulin was significantly higher after the INJEX30 injection than that after insulin pen injection [serum insulin AUC(5621 ± 3790) min · mIU · L-1 vs(4285 ± 3376) min · mIU · L-1,P ＜0.01].No difference was found in the AUC of serum insulin between the two injection methods in the patients with BMI below 25.24 kg/m2,while the AUC of serum insulin was significantly higher after the INJEX30 injection than the insulin pen injection in the patients with BMI above 25.24 kg/m2 [serum insulin AUC(6453 ± 4099) min · mIU · L-1 vs (4879 ± 3701) min · mIU · L-1,P ＜0.01].Conclusion The INJEX30 improves the serum insulin level which may lead to a beneficial effect on the glycemic control.Such effect is more obvious in the overweight patients.

Objective To establish the technique of hyperinsulinemic euglycemic clamp and to study the reference value of insulin sensitivity index in healthy Chinese. Methods According to the feedback mathematical model developed by DeFronzo, the technique of hyperinsulinemic euglycemic clamp was used in 90 healthy Chi- nese [ male:female =71 = 19; age; (28. 3±6. 1) years; body mass index (20. 9±1.5) kg/m2 ] to study die glu-cose metabolized rate. Blood samples were obtained at timed intervals in the fasting state and during the clamp for the measurement of glucose, insulin and C peptide. Results During the clamp tests, the blood glucose levels were con-trolled within 10% of target value. The coefficient of variation of glucose levels was 3. 8% 0.1%. In the steady state, the insulin sensitivity index (glucose metabolized rate, M value ) was (7.78±2.30) mg· kg-1 min-1, which was distributed normally. The lowest quartile of M value was 6. 286 mg·kg -1 min-1'. The coefficient of variation of M value was 9.4%±2.8%. Conclusion The technique of hyperinsulinemic euglycemic clamp and the reference value of insulin sensitivity index in healthy Chinese are successfully established in our center.