Transient hyperglycemia in childhood: identification of a subgroup with imminent diabetes mellitus.

Transient hyperglycemia may represent the earliest manifestation of IDDM. In a series of 30 children referred for transient hyperglycemia, 8/30 (27%) developed IDDM within 10 months of their initial evaluation. Three children with detectable cytoplasmic islet cell antibodies (ICA) and/or positive insulin autoantibodies (CIAA) all developed IDDM, compared to 21% of ICA negative children and 13% who were CIAA negative. Of those with impaired glucose tolerance, 6/11 (55%) developed IDDM, as did 1/14 with normal OGTT. Of the children with a low "K rate" on IVGTT, 75% developed IDDM, compared to 1/13 with a normal "K rate". All four children (100%) whose first phase (1' + 3') insulin secretion never exceeded the first percentile developed IDDM within nine months, while no child with first phase insulin secretion above the first percentile (0/16) developed IDDM during 19 +/- 9 months (mean +/- SD) of follow-up. Thus, in our experience the oral glucose tolerance test is a less accurate predictor of impending IDDM; immunological abnormalities have the highest positive predictive value, while the first phase insulin secretion during an intravenous glucose tolerance test has the highest negative predictive value and the greatest overall accuracy of prediction.