However, two studies, including UKPDS, have clearly demonstrated a decline in pancreatic β-cell function at the time of diagnosis.[1, 2] In fact, higher the fasting plasma glucose, greater is the reduction in β-cell function at the time of diagnosis.[1, 2] Moreover, a recent study has documented that the decline in the postprandial first-phase insulin secretion occurs simultaneously with worsening insulin resistance.[3] Both impaired glucose tolerance and postprandial hyperglycemia are caused by progressive decline in first-phase insulin secretion. This evidence concerns the gene INS and Impaired glucose tolerance.