Abstract

After an intravenous gIucose load, a series of serum glucose, insulin and C-peptide concentration were measured in 12 non insulin dependent diabetes meilitus and 10 age and sex matched normal control subjeets. Clucose disappearance rate, integrated insulin and C-peptide concentration, insulinogenic index, molar ratio of C-peptide and insulin and hepatic clearance rate of insulin were caIculated and compared. Followings were the results; 1.The fasting ccincentration of insuIin and C-peptide were 4.17+-0.75 pm/ml and 0.93+-0.07 ng/ml in control subjects,and 12.50+-1,85 pg/ml and 1.63+- 0.19 ng/Mi in diabetic respectively. Both fasting concentration of insulin and C-peptide were significantly higher in diabetics than in control subjects(p<0. 025) Five minutes after glucose load, the maximal insulin concentration in control subjets was 64.37+-12.17 pu/ml and it had increaed 15.4 times in comparing with fasting stage. But there was no acute response in diabetics. Sixty rninutes after glucose load, the concentration of insulin and C-peptide were 10.39+-1.46 pu/ml and 2.59+- 0. 02 ng/ml in control subjects, and 21. 55+-2.35 pu/ml and 3.36+-0.42 ng/ml in diabetics respectively, showing increased secretion of insulin and C-peptide in later stage of diabetics. 2.The glucose disappearance rates were 3. 35 +-0.51%/min in control subjects and 1.83+-0.16%/min, in diabetics, showing significantly lower value in diabetics(p<0.05) 3.Integrated insulin and C-peptide concentration of the first 10 minutes for acute response were 1.88+-0.35 ng/ml and 3.10 +-2.47 ng/ml in control subjects, and 0.58+-0.07 ng/ml and 2.04+-0.22 ng/ml in diabetics(p<0.05) But those of the 60 miniutes for total response were 1.00+- 0.15 ng/ml and 2.95+-0.29 ng/ml in control subjects, and 0.80 +-0.12ng/ml and 2.55+-0.32ng/ml in diabetics respectively,which were slightly lower than control subjects, but without significant statistical difference. 4. The insulinogenic index during 0~5min, and 0~ l0 min, period for aqutel response and 0~60min, period for total response were as follows; 0.186+- 0.234, 0.221+- 0.004 and 0.156+-0.039 in control subjects, and 0.005+-0.010, 0.003+-0.001 and 0.047+-0.025 in diabetics respectively (p<0.001) The correlation coefficient between insulinogeic index and integrated insulin concentration was 0,54(p<0.001) in control subjects and 0. 18(p< 0.001) in diabetics during 10 minutes and 0.80(p<0.001) in control subjects and 0.88(p<0.001) in diabetics during 60 minutes. There were significant correlation between the two indices except in diabetics during 10 minutes. 5. The molar ratio of C-peptide and insulin at fasting stage was 12. 56 +-0. 33, 3.27+- 0. 21 at 5 min. 5.47+- 0.84 at 10 min. and 10.86+-1.2 at 60 rnin. In control subjects, and in diabetics 7.03+- 0.96, 7.49+- 1.87, 10. 94+-2.85 and 6.18+-1,55 respectively. 6. The hepatic clearance rate of insulin was calculated and results were as folows: 55.1+- 2.7% in control subjects and 55.5+-4.6% in diabetics, showing no stastical ditference. But the correlation coeffieient between secretion rate and hepatic clearance rate of insulin was 0.72(p<0.5) in control subjects and 0.29(p<0.4) in diabetics, showing slightly negative correlation between the two in control subjects. 7. The correlation coefficient between fasting blood gIucose concentration and intergrated concentration of first 10 minutes for both group was 0.58%(p<0.025) ,showing negative correlation. This correlation was more accentuated by using natural logarithmic scale in integrated concentration. 8.There was significiant positive correlation btween integrated insuln conceritration of first 10 minutes and glucose disappearance rate with the correlation coefficient of 0.04 (p<0.01). From these dats, it was concluded that non insulin depenent diabetics were characterized mot only by increased fasting blood glucose, lowered glucose disapearance rate and insulinogenic index, and almosrt normal to