Factors underlying the increase in carotid intima-media thickness in borderline hypertensives

To define the role played by various risk and behavioral factors in the inc rease of carotid intima-media thickness (WIT) observed in borderline hypert ensives. Using B-mode ultrasonography, we compared 97 borderline hypertensi ves enrolled in the HARVEST study to 27 normotensive controls. Intima-media thickness was measured in the right and left common carotid artery, bulb, and internal carotid artery. Mean IMT (m-IMT), maximum IMT (M-IMT), the mea n of M-IMT (M-MAX), and the prevalence of raised lesions (IMT> 1 mm) were e stablished. Compared to the controls, higher systolic BP, diastolic BP, mea n arterial blood pressure levels and body mass index (BMI) were present in the borderline hypertensives, whereas age, smoking, physical activity, seru m cholesterol, and triglycerides were similar. After adjusting for age, sex , heart rate, BMI, smoking, serum cholesterol, triglycerides, and physical activity, higher values of m-IMT and M-IMT were present in most carotid seg ments of borderline hypertensives compared with controls. After further adj ustment for systolic BP and diastolic BP, differences were no longer signif icant. The adjusted M-MAX was 0.59+/-0.12 in borderline hypertensives compa red with 0.50+/-0.10 in controls (P<0.001). After adjustment for systolic B P and diastolic BP it was 0.58+/-0.11 in borderline hypertensives compared with 0.50+/-0.12 in controls (P<0.005). In the various carotid segments, th e prevalence of raised lesions was 1.2% in borderline hypertensives compare d with 0.3% in controls (P<0.001). In the multivariate analysis m-IMT, M-IM T, and M-MAX were related to ambulatory mean arterial pressure, systolic BP and diastolic BP, serum cholesterol and triglycerides, BMI, age, and physi cal activity. Higher IMT values were found in subjects who were physically active than in those who were sedentary. In borderline hypertensives, an in crease in IMT takes place not only in the common carotid artery but also in the bulb and the internal carotid segment. Blood pressure levels are a mai n determinant of m-IMT while the interaction of BP with other risk factors such as age and plasma lipids is more relevant for advanced intima-media th ickening such as M-MAX.