To determine whether hyperinsulinemia is associated with early atherosclerosis in normotensive men of a work site population.
Design and methods
Six hundred and seventeen subjects were screened from 8678 male transport workers for the further examination of cardiovascular disease and diabetes. Subjects aged less than 40 years, those with hypertension or diabetes, or both, and those being administered medications for hyperlipidemia were excluded. Finally, 164 normotensive, nondiabetic subjects were enroled. The intima-media thickness (IMT) was measured by B-mode ultrasonography with a 7.5 MHz probe. Electrocardiography, a 75 g oral glucose-tolerance test (OGTT) and blood chemistry measurements were also performed. The sum of insulin values (ΣIRI) and the ratio of the sum of insulin values to blood glucose levels (ΣIRI/ΣBG) in the 75 g OGTT were used as markers of hyperinsulinemia.
The mean age of the subjects was 52 ± 5 years (mean ± SD). In a univariate analysis, IMT was associated with age, systolic blood pressure, body mass index, ΣIRI, and ΣIRI/ΣBG. Multivariate analysis showed that age, total cholesterol, and SIRI (or ΣIRI/ΣBG) were independent risk factors for IMT.
These results suggest that, in addition to age and total cholesterol, hyperinsulinemia as assessed by an OGTT is associated with early atherosclerosis in normotensive, nondiabetic men of a work site population.