Ten-year follow-up of Japanese overweight subjects with impaired glucose tolerance: identification of a diabetes-prone subpopulation.

Ninety-four overweight subjects with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) were followed for 10 years. No one from the NGT group developed diabetes, however 32% of the IGT subjects did develop diabetes. Initial data of the IGT subjects who developed diabetes were significantly different from those who did not develop diabetes. Fasting, peak and/or sigma plasma glucose (PG), IRI and CPR at 180 minutes and CPR/IRI at 0 and 180 minutes were increased, and the peak time of PG was delayed; also the prevalence of a positive family history was higher, and the body weight heavier. Seventy-nine percent of IGT subjects with the initial sigma PG of greater than or equal to 40 mM or a positive family history developed diabetes whereas only 3% of those with sigma PG of less than 40 mM and a negative family history developed diabetes. Therefore, it might be considered that among the overweight adults with IGT, those with sigma PG of greater than or equal to 40 mM or a positive family history are diabetes prone and those with sigma PG of less than 40 mM and a negative family history are diabetes resistant.