FREQUENCY OF INSULIN-DEPENDENT DIABETES-MELLITUS IN TURKISH ADULT-ONSET DIABETIC POPULATION

The frequency of insulin-dependent diabetes mellitus in the Turkish ad ult-onset diabetic population has not been assessed previously, In the present study, we retrospectively evaluated the medical records of 80 1 Turkish patients with adult-onset (greater than or equal to 30 years ) diabetes to determine the frequency of cases diagnosed as insulin-de pendent diabetes, Fifty-two (6.5%) patients met our criteria of adult- onset insulin-dependent diabetes mellitus. At disease onset, 20 patien ts presented with ketoacidosis (38.5%), while 33 patients (61.5%) were non-ketotic. Tn the insulin-dependent diabetic group, islet cell anti bodies were positive in 10 out of 16 (62.5%) patients studied. In cont rast, none of the 16 patients had positive reactions with respect to i nsulin autoantibodies. Twelve out of 20 patients (60%) had glucagon-st imulated C-peptide levels above 0.6 nmol/l, suggesting a sufficient in sulin secretory reserve, In view of these observations, we conclude th at insulin-dependent diabetes mellitus is not rare among patients with adult-onset diabetes in the Turkish population. In a majority of case s, the disease onset is non-ketotic. Beta-cell function is relatively preserved, and insulin autoantibodies do not develop at diagnosis. In contrast, islet cell antibodies are frequently present at the onset of clinical insulin-dependent diabetes, possibly indicating continuing b eta-cell destruction.