CHTOP and Impaired glucose tolerance: A more recent study by our group examined both methylated and unmethylated INS and CHTOP in obese youth across the spectrum of normal glucose tolerance to T2D; these categories included lean controls with normal glucose tolerance (NGT), overweight/obese with normal glucose tolerance (OB-NGT), overweight/obese with impaired glucose tolerance (IGT), and overweight/obese with T2D with and without evidence of autoantibodies [38].