OBJECTIVE: The aim of this study was to evaluate if GADA+ and detectable CP had any influence in other autoimmune diseases, glycemic control, and risks of retinopathy in diabetes mellitus type 1 (T1DM) lasting longer than 3 years of duration. SUBJECTS AND METHODS: Fifty T1DM subjects were interviewed, performed fundoscopic examination, and measured CP before and after glucagon, HbA1C, and GADA. RESULTS: GADA+ (n = 17) had a higher frequency of other autoimmune diseases when compared to GADA (p = 0.02). Detectable CP was also associated with a higher prevalence of these diseases (p = 0.03), although, retinopathy was not influenced by either one. Detectable CP had no influence in the glycemic control (mean HbA1C) (p = 0.28). However, insulin daily doses were lower in this group (0.62 vs. 0.91 U/kg/day; p = 0.004). CONCLUSION: Although not recommend as a marker of other autoimmune diseases, GADA+ seems to be not only a pancreatic autoimmunity signal. Detectable CP may also have some promising influence in detecting these diseases. Neither influenced the presence of retinopathy, but insulin daily requirements were smaller when CP was present.
Diabetes mellitus type 1; C-peptide; GADA; insulin secretion; autoimmune disease
