Oral glucose tolerance tests and their reliability

Standardized oral glucose tolerance tests have been performed on over 200 normal children who did not have a family history of diabetes, and their values have been compared with a group of siblings of children with overt diabetes mellitus. Values in the normal children are averaged at each time period without reference to the total curve on the individual child. The means, medians, standard deviations, and percentile values were calculated. Percentile values were chosen for use, since glucose values are not equally distributed about the mean. There is skewing toward the higher values especially at the 1 2 - and 1-hr values. In siblings of diabetics, fasting values are not different from the normals. The skewing toward higher values at 1 2 and 1 hr is more evident in the sibling group. This skewing is still evident at 2 hr in these children. Normal data on the serum insulin response to oral glucose have also been determined, as has the response of glucose and insulin during the triamcinalone glucose tolerance test. These tests are of value in evaluating children for chemical diabetes and for longitudinal study of the metabolic abnormalities of the disease.