A low insulin response in the first 30 minutes of an oral glucose tolerance test predicts future type 2 diabetes.

“one of the earliest things you can detect in people who are predisposed to develop diabetes is loss of first phase insulin secretion now first phase insulin secretion is strictly speaking can only be measured with the hypoglycemic clamp that we developed so when I acutely raise the glucose from say you know 90 and I raise it to 200 in the first 10 minutes there's a big spike of insulin that comes out that is typically lost in people who are going to develop type 2 diabetes in its counterpart during the ogtt is the insulin level at 30 minutes”