Intravenous glucose tolerance and mortality in non-insulin-dependent diabetes mellitus

Two hundred and forty-nine patients with non-insulin-dependent diabetes were entered into a prospective study at diagnosis and examined at presentation and one, three, and five years later. Ten years after diagnosis, 34 patients were known to be dead and 214 alive. A number of factors were significantly associated with survival on univariate analysis and appeared to form two independent intra-related groups: a 'metabolic' group and a 'degenerative condition' group. Multivariate analysis of these two groups showed that glucose tolerance (the rate constant KG for decrease in plasma glucose concentration after its intravenous injection) was significantly related to survival in the 'metabolic' group, and age, blood pressure and anti-hypertensive therapy were significant in the 'degenerative' group of factors. A low KG value was more strongly associated with prognosis than any other factor. Values from the one year review were prognostically more useful than initial or later values. Indices of insulin secretion were similar irrespective of whether patients survived or died, and so we believe the lower KG values of dead patients were due to impaired insulin sensitivity. A regression equation using the above factors correctly allocated survival outcome in 81% of subjects.