Investigation of Insulin Sensitivity in Treated Subjects with Ketosis-prone Diabetes Mellitus

Abstract

Two similar intravenous infusion techniques have been utilized to investigate insulin sensitivity in young subjects with recent-onset ketosis-prone diabetes mellitus. All subjects presented initially with mild to moderately severe ketoacidosis and had been treated with daily insulin therapy for two to eight weeks at the time of study. Six diabetics and 10 normal subjects (group A) received intravenous infusions of glucose (6 mg./kg./min.), insulin (80 mU./min.), epinephrine (6 μg./min.), and propranolol (0.08 mg./min.) for ISO minutes. Steady-state plasma glucose (SSPG) and insulin levels (SSPI) were reached by 90 minutes and maintained through the end of the study. As all subjects achieve similar SSPI while simultaneously receiving similar glucose loads, the SSPG can be used to measure individual insulin sensitivity. Under these conditions the diabetics in group A had a mean SSPG (± S. E.) of 99 ± 26 mg./lOO ml., which was not different from the level of 98 ± 14 mg./100 ml. for their control subjects. Six diabetics and six normal subjects (group B) received infusions of only glucose (6 mg./kg./min.) and insulin (80 mU./min.). Similar SSPI levels were attained in both the diabetic and control subjects, and their mean SSPG (± S.E.) levels were not significantly different (83 ± 13 vs. 61 ± 6mg./100 ml.). One diabetic in group A and two diabetics in group B had SSPG levels above the highest values measured in their control groups. However, all three had markedly elevated fasting plasma glucose levels on the day of study. In contrast, nine well-controlled diabetics had normal insulin sensitivity. These results suggest that well-controlled subjects with ketosis-prone diabetes mellitus have normal sensitivity to insulin.