Continuous C-peptide loss in patients with type 1 diabetes and multiethnic background

C peptide (CP) was evaluated in 88 individuals with type 1 diabetes, variable disease duration and multiethnic background. Initially, 28 patients had detectable CP, which persisted in 46.2% after 17.4 ± 4 months. CP decline was associated with ethnicity, HbA1c and baseline CP, but not with GADA, PTPN22 or insulin gene polymorphisms.