Islet cell and glutamic acid decarboxylase antibodies present at diagnosisof diabetes predict the need for insulin treatment - A cohort study in young adults whose disease was initially labeled as type 2 or unclassifiable diabetes

RESEARCH DESIGN AND METHODS - The patient material was representative of th e entire Swedish population, consisting of patients who were 15-34 years ol d at diagnosis of diabetes in 1987-1988 but were not considered to have typ e 1 diabetes at onset. At follow-up, 6 years after the diagnosis, it was no ted whether the patient was treated with insulin. The presence of ICA was d etermined by an immunofluorescence assay, and GADAs were measured by a radi oligand assay RESULTS - Six years after diagnosis, 70 of 97 patients were treated with in sulin, and 27 of 97 patients were treated with oral drugs or diet alone. At diagnosis, ICAs and GADAs were present in 41 (59%) of 70 patients and 41 ( 60%) of 68 patients, respectively of those now treated with insulin, compar ed with only 1 (4%) of 26 patients and 2 (7%) of 27 patients who were Still not treated with insulin For either ICA or GADA, the corresponding frequen cies were 50 (74%) of 68 for patients who were later treated with insulin a nd 3 (12%) of 26 for those who were still not treated with insulin, respect ively The sensitivity for later insulin treatment was highest (74%) for the presence of ICA or GADA, and the specificity was highest (100%) for ICA an d GADA. The positive predictive value was 100% for the combination of ICA a nd GADA, 98% for ICA alone, and similar to 95% for GADA alone. CONCLUSIONS - Determination of the presence of ICA and GADA at diagnosis of diabetes improves the classification of diabetes and predicts the Future n eed of insulin in young adults.