Absence of muscle capillary basement membrane thickening and retinopathy in patients with myocardial infarction and impaired i.v. glucose tolerance.

We have investigated the possible contribution of an early capillaropathy to the increased incidence of myocardial infarction (MI) in patients who had impaired glucose tolerance (IGT) during an i.v. glucose tolerance test (IVGTT). In lieu of the myocardium, biopsies from the quadriceps femoris muscle were studied for muscle capillary basement membrane (MCBM) thickening. Fluorescence angiography was performed to detect capillary retinopathy. Plasma growth hormone (GH) concentrations were determined during IGT. Data were obtained from 14 male patients with MI and IGT on IVGTT. Nine healthy subjects served as controls. MCBM thickness was similar in patients and controls (1,107 +/- 55 vs 1,067 +/- 88 A). None of the patients had signs of capillary retinopathy, and plasma GH concentrations were not higher in the patients as compared to control subjects. It is concluded that, in patients with IGT on IVGTT, MCBM thickening is probably not a factor for the development of MI.