Effect of blood pressure and physical activity on carotid artery intima-media thickness in stage 1 hypertensives and controls

The aim of the study was to investigate whether hypertension and physical t raining induce parallel changes in the arterial wall. Ninety-seven never-tr eated stage 1 hypertensive patients (HT) (systolic blood pressure 140 to 15 9 mm Hg or diastolic blood pressure 90 to 99 mm Hg) aged 18 to 45 years tak ing part in the Hypertension and Ambulatory Recording Venetia Study and 27 normotensive volunteers (NT) aged 30 +/- 9 years were studied. Data on phys ical or sports activity were collected and scored, and target organ involve ment was investigated by assessing microalbuminuria, echocardiography, and carotid ultrasound study. The carotid arteries were examined according to t he Atherosclerosis Risk in Communities protocol. Mean (m-IMT) and maximal ( M-IMT) carotid intima-media thickness were measured at end-diastole in the far wall common carotid artery, in the bulb and internal carotid artery, in the lateral and posterior projection, averaging the left and right sides. A comparable level of physical activity was present in HT patients and NT s ubjects. Twenty-four-hour blood pressure and blood lipid levels, as well as target organ damage, were similar in physically active and sedentary HT. T he m-IMT of the common carotid was greater in sedentary HT than in sedentar y NT, as well as in active than in sedentary NT. The m-IMT of the internal carotid artery was also greater in active HT than in active NT,as well as i n active than in sedentary HT. In logistic regression, comparing the first and fourth quartile of m-IMT, scored physical activity was a predictor of m -IMT in the internal carotid artery. No statistical interaction was found b etween physical activity and hypertension, indicating that these two items have a cumulative effect and act independently of each other. Sedentary HT had significantly greater levels of M-IMT than sedentary NT in all sites bu t the bulbs; in the internal and common carotid arteries, HT exercisers had significantly greater M-IMT than NT exercisers. Therefore, physical activi ty appears to be an early independent predictor of carotid wall thickness. This factor should be taken into consideration in population-based studies aimed at investigating supraortic vessels as it can act as a confounder. Am J Hypertens 2000;13:1256-1262 (C) 2000 American Journal of Hypertension, L td.