INS and type 1 diabetes mellitus: Early work by Heding and Ludvigsson (36), demonstrated that in newly diagnosed (3 months) T1D children with significant residual β function (fasting C-peptide values of 0.13-0.53 pmol.mL-1), plasma C-peptide and proinsulin fell over exercise (20 mins stationary cycling) but unlike in those without diabetes, failed to increase upon cessation.