CARDIAC AND VASCULAR STRUCTURAL-CHANGES - PREVALENCE AND RELATION TO AMBULATORY BLOOD-PRESSURE IN A MIDDLE-AGED GENERAL-POPULATION IN NORTHERN ITALY - THE VOBARNO STUDY

The aims of this study were to determine the prevalence of structural changes in the carotid arteries and heart and the correlation between these changes and the commonly recognized cardiovascular risk factors in the general population. Structural changes in the carotid arteries were defined as the intima-media thickness of the artery measured by B -mode ultrasound. Changes in the heart were defined as left ventricula r mass index (LVMI) measured by echocardiography. LVMI values greater than 134 g/m(2) in men and greater than 110 g/m(1) in women were consi dered abnormal, indicating the presence of left ventricular hypertroph y. Blood pressure (BP) was measured in the clinic setting with a mercu ry sphygmomanometer and by 24-hour noninvasive ambulatory monitoring. Hypertension was defined as a sustained systolic BP greater than or eq ual to 160 mm Hg and/or diastolic BP increase greater than or equal to 95 mm Hg. The study population consisted of 225 subjects (107 women a nd 118 men) 45 to 64 years old. Prevalence of intima-media thickening (intima-media thickness >1 mm) was 11% in normotensive subjects and 44 % in hypertensive subjects. The presence of plaque (wall thickening wi th either mineralization or focal protrusion in the lumen at least 50% greater than the surrounding wall, usually >2 mm) was observed in 35% of normotensive subjects and 44% of hypertensive subjects. The preval ence of left ventricular hypertrophy was 13% in normotensive subjects and 19% in hypertensive subjects. Intima-media thickness in the common and bifurcation segments of carotid arteries correlated well with LVM I (r=.20 and r=.19, respectively; P<.01). Intima-media thickness and L VMI were both positively related to 24-hour monitored BP (P<.01). Howe ver, in the multivariate analysis, body mass index (P=.027), sex (P<.0 01), and 24-hour mean BP (P=.025) were the most significant determinan ts of LVMI, whereas carotid artery intima-media thickness was found to be associated best with age (P<.001), cigarette smoking (P=.009), ser um cholesterol (P=.025), serum glucose (P=.038), and nighttime systoli c BP (P=.006). Logistic regression analysis confirmed the association between the presence of plaque and age (P<.001), nighttime systolic BP (P<.05), and cigarette smoking (P<.05); a negative association betwee n plaque and the decrease in mean systolic BP from daytime to nighttim e was also observed (P<.001). In conclusion, in a general population o f unselected middle-aged subjects, carotid wall thickness and LVMI wer e associated with each other and related to 24-hour BP levels although the major determinants of carotid wall and cardiac structure were dif ferent.