**2.4 Diabetes-associated antibodies and c-peptide measurements**

A total of 86 T1D patients (42 males and 44 females), with a mean age of 27.5 years (0.86) and mean diabetes duration of 10.3 (0.72) years (SE), were randomly selected from four regional diabetes-mellitus registers: Chernihivska, Zaporizka; Ivano-Frankivska, and Chernivetska. The glutamic acid decarboxylase 65 antibody (GADA), insulin antibody (IA), and plasma c-peptide levels were determined using radioimmunoassay (RIA) kits (IMMUNOTECH™) after obtaining the patients' informed consent. The model of the logistic regression was used for the multifactor data analysis of GADA, IA, c-peptide persistence, OR, and the 95% CI that were determined. The plasma was considered GADA- or IApositive, if GADA >1 U/ml or IA >0.4 U/ml, and low c-peptide, if its level was <32.6 pmol/l.
