Characteristics Associated with Elevated 1‐hour Plasma Glucose Levels during a 75g Oral Glucose Tolerance Test in Nonobese Japanese Men

Elevated 1-hour plasma glucose (1h-PG) (>/=155 mg/dL) during an oral glucose tolerance test (OGTT) is a risk factor for type 2 diabetes. However, the metabolic characteristics of nonobese Asians with elevated 1h-PG are unknown. Thus, we studied 59 nonobese Japanese men with normal glucose tolerance. We divided study participants into the Low 1h-PG group ( /=155 mg/dL). We compared the metabolic characteristics of the groups, including tissue-specific insulin sensitivity measured using a two-step hyperinsulinemic-euglycemic clamp. Insulinogenic index and adiponectin levels were significantly lower in the High 1h-PG group than in the Low 1h-PG group. Other characteristics, including insulin sensitivity, adiposity, and ectopic fat accumulation, were similar between the groups. In conclusion, nonobese Japanese men with high 1h-PG have impaired early-phase insulin secretion and lower adiponectin levels. Insulin resistance and abnormal fat distribution were not evident in this population.