GAD1 and type 2 diabetes mellitus: Compared to older age groups, patients aged 25–34 had a higher frequency of autoantibodies, which may be as high as 21% for ICA and 34% for GAD.103 Although the frequency of autoantibodies against GAD has been reported at 2–5% in Asian patients with T2D,80,104,105 this may be even higher in young patients.