Is a lag-storage curve an early sign of diabetes? Early insulin responses to i.v. glucose in normal subjects, mild maturity-onset diabetics and patients with lag-storage curves.

Early insulin responses were measured after a high dose (50 g/1.73 m2) of rapidly injected glucose in 31 subjects who had repeatedly shown "lag-storage" curves in the OGTT, in 24 controls and in 19 mild maturity-onset diabetics. Division between controls and diabetics was virtually complete, when the insulin responses were expressed as "insulinogenic index" (delta insulin/delta glucose). Twenty out of 31 patients with lag curves showed normal early insulin responses and 11 patients showed diabetic responses. In patients with lag curves, presence of obesity, and absence of family history of diabetes were associated with normal insulin responses. It is concluded that the finding of a lag curve is of little consequence in obese persons but, when in conjunction with a genetic background of diabetes, is suggestive of diabetes.