Detection of Early Atherosclerotic Changes of Peripheral Arteries: Determining the Extent of Atherosclerotic Process and Effects of Risk Factors
Non-invasive ultrasound methods have been increasingly used for detecting morphological and functional changes in the arterial wall, indicating the beginning of atherosclerotic process. Early detection of atherosclerosis is of utmost importance for timely deceleration of its further progression. The aim of this study was to determine the association of risk factors for atherosclerosis and intimal thickening (IMT) of the carotid arteries, which is regarded as the earliest morphological evidence of atherosclerotic disease. In addition, functional disturbances due to endothelial dysfunction were investigated. In four groups of subjects, including cigarette smokers, diabetics, patients with peripheral arterial occlusive disease and controls, early morphological and functional changes were studied by ultrasound. Each group comprised 13–14 subjects, aged 32 to 56 years. First, IMT was measured at three different sites of the carotid arteries. Next, relaxation disturbances were determined by measuring blood flow in the brachial artery at rest and during reactive hyperemia. In the control group, the mean IMT was 0.65 mm. The group of smokers had similar IMT values as control group. Diabetics showed increased IMT at all three sites (mean IMT = 0.71 mm), the value for the common carotid artery being statistically significant. Patients with peripheral arterial occlusive disease showed increased IMT in all three segments (mean IMT = 0.77 mm). The number of atherosclerotic plaques was seen to increase with the increasing IMT. Statistically significant correlations were found between IMT, the body mass index and fibrinogen levels, and especially between IMT and the number of plaques. All groups demonstrated a significant increase in blood flow (by 260%) during hyperemia. The group with peripheral arterial occlusive disease showed a significantly smaller increase in blood flow during reactive hyperemia. IMT measurement has proved to be a simple, accurate and reproducible method for detecting initial morphological changes of the arterial wall. The determination of flow alterations seems to be a less sensitive method, giving positive results only in clinically advanced forms of atherosclerosis.