Different prevalence of asymptomatic atherosclerotic lesions in males and females

The detection of atherosclerotic lesions in asymptomatic healthy subjects is possible using ultrasound. Populations can be investigated in order to detect differences in early and asymptomatic atherosclerosis due to gender and risk factors. This study investigated 2605 male (21-69 years) and 1601 female (20-70 years) employees and civil servants of the city of Düsseldorf, Germany. The ultrasound investigations were performed with an ATL device, type Ultramark 4 plus, and a 7.5-MHz linear transducer on the carotid and proximal femoral arteries. An atherosclerotic lesion was defined as visibly different from the intima by its echogenicity and by being larger than 1 mm. A thickening of the intima media complex was not considered to be atherosclerosis. The prevalence of atherosclerotic lesions in male subjects was higher than those in female subjects regardless of age. In male subjects it was 5.3% (30-39 years), 19.8% (40-49 years), 36.7% (50-59 years) and 47.7% (60-70 years). The female subjects had a prevalence of 2.1%, 8.4%, 17.5% and 37.7% in the corresponding age groups. Risk factors such as smoking, hypertension and hypercholesterolemia were higher in men than in women. The increase of atherosclerotic lesions from one decade to another was highest in women between 50 and 59 years and 60 and 70 years. This large increase could not be explained by a similar increase in risk factors. It was therefore concluded that male subjects had a higher prevalence of atherosclerosis at earlier ages than females, but female subjects showed a postmenopausal rise in prevalence.