BACKGROUND : Type 1 diabetes mellitus (T1D) is an autoimmune disorder that leads to pancreatic β-cells destruction and progressive decrease of insulin secretion. Specific islet autoantibodies (AAbs) are the main diagnostic marker T1D. Residual β-cell function, as measured by C-peptide, has repeatedly been demonstrated be clinically important. AIM: To study frequency levels residual C-peptide se...