GAD1 and type 1 diabetes mellitus: In 8608 individuals with a clinical diagnosis of T2D after 35 years of age, treated without insulin for at least 6 months following diagnosis, the same T1D rsPS predicted progression to insulin use at 5 years, but only in the small subset of GAD antibody-positive participants: the probability of insulin use ranged from 17.6% in those in the lowest tertile of T1D risk to 47.9% in the highest (65).