Morphological and functional changes of the arterial wall in subjects at risk of atherosclerosis and in patients with peripheral arterial occlusive disease.

BACKGROUND

The aim of this study was to determine the intima-media thickness (IMT) of the carotid arteries, which is regarded as the earliest morphological evidence of the atherosclerotic process in subjects with risk factors of atherosclerosis. Changes of blood flow in the branchial artery during reactive hyperemia were also investigated.

PATIENTS AND METHODS

In 4 groups of subjects: smokers, diabetics, patients with peripheral arterial occlusive disease (PAOD) and controls, the above mentioned morphological and functional changes were studied by ultrasound. Each group comprised 18 subjects, aged 32 to 56 years. First, IMT was measured at three different sites of the carotid arteries. Then blood flow in the brachial artery was determined at rest and during reactive hyperemia (caused by handgrip test).

RESULTS

In the control group the mean IMT (all segments) was 0.65 +/- 0.08 mm. IMT of smokers was similar (0.65 +/- 0.07 mm), while in diabetics a tendency to IMT increase was detected at all three measuring sites, and in the common carotid artery the IMT was statistically significantly thicker than in the controls (0.75 +/- 0.08 mm vs. 0.65 +/- 0.08, p < 0.05). PAOD patients showed a significant increase of IMT at all three carotid segments (mean 0.77 +/- 0.10 mm p < 0.05). In all groups IMT was related to the number of atherosclerotic plaques (r = 0.6, p < 0.001), and was also correlated with body mass index (BMI) (r = 0.32, p < 0.01) and fibrinogen level (r = 0.32, p < 0.05). All groups demonstrated a significant increase of blood flow in the branchial artery during hyperemia. In PAOD patients this increase was significantly smaller than in the controls and other groups (212 +/- 61% vs 275 +/- 60%, p < 0.05).

CONCLUSIONS

The results of our study indicated that the most important factors determining increase of IMT are diabetes, fibrinogen level, BMI and the presence of clinically manifested atherosclerosis. Hyperemic blood flow, which is predominantly determinated by the vasodilation capacity of the resistance vessel, is reduced in patients with clinically manifested atherosclerosis and not in subjects with risk factors and without atherosclerotic manifestation.