INS and Impaired glucose tolerance: Notable aspects of our study include (1) HbA1c and GA levels were significantly increased in diabetic marmosets compared with normal marmosets; (2) diabetic marmosets had significantly impaired glucose tolerance; (3) all marmosets showed high sensitivity to human insulin; and (4) blood glucose level variations, evaluated in real-time using CGM, revealed that our diabetic marmosets had similar blood glucose values to those of diabetic patients.