EVALUATION OF THE ORAL GLUCOSE TOLERANCE TEST BY A CONTINUOUS SAMPLING TECHNIQUE.

Abstract

tions at the times of intey?ni.ttent sampling %.nderestiwted the muzimzlm and oz;erestimated the minimum concentratiolzs that ?uel’e actually achieved. The typical curces obtained by ccmtinuow sampling haue one or more seoondavy maxima. The obese group 101cs less tolerant of the glucose load than the normal group. Among the latter, comparison of those with and without a family history of diabetes mellitus revealed that the negative family history subjects had higher concentrations early in the test but these coacentmtions retwrneti to the fasting base line earlier than did those of subjects with a positice history. T he capa.city of an individual to dispose of administered glucose, referred to as glucose tolerance, has long been used in the evaluation of patients suspected of having diabetes mellitus. A host of tests have been described, differing in the dose of glucose used, in the route of its administration, or in the frequency of obtaining venous blood samples for glucose determination. Perhaps the most commonly used method today is the oral glucose tolerance test, in which either 100 Gm. or 1.75 Gm. per kilogram of ideal body weight is administered and blood samples taken half-hourly for 1 hour and hourly for 2 or 4 additional hours. The changes in glucose concentration over 3 or 5 hour periods following glucose administration are then inferred from 5 or 7 points. The availability of a method employing continuous sampling of venous blood has provided the means to characterize accurately changes in glucose concentration following glucose administration. A number of reports have described the use of continuous sampling procedures in animals and man. Ferrari and Kessler’ em