Background: The evidence linking activation of the renin-angiotensin system with accelerated cerebro-vascular atherosclerosis remains controversial. We therefore prospectively investigated the relationships of plasma renin activity and aldosterone levels with carotid artery lesions (CAL) in essential hypertension.
Methods: We evaluated the prevalence and severity of CAL and the intimal-medial thickness (IMT) with a high-resolution echo-Doppler technique in 107 cerebrovascularly asymptomatic consecutive primary hypertensives (55 male, 52 female) and in 70 (42 male, 28 female) normotensive controls. We also measured supine plasma renin activity (PRA) and aldosterone before and 45 min after captopril administration, while daily urinary excretion of sodium was measured.
Results: Both the prevalence (59.4 versus 26.2%) and severity of sex- and age-adjusted and unadjusted CAL and IMT were significantly higher in hypertensives than in controls. Regression analysis showed different predictors of IMT (age and captopril-stimulated-PRA, R2 = 0.27, P < 0.0001), score of CAL (mean blood pressure, R2 = 0.15, F=12.73, P< 0.0001) and maximal stenosis (pulse pressure and known duration of hypertension R2 = 0.29, F = 14.58, P< 0.0001). Sex- and age-adjusted IMT did not differ between quartiles of renin-sodium profile. However, patients in the quartile with the highest PRA had the lowest score of CAL and an inverse relationship between age-adjusted PRA and IMT and CAL was found.
Conclusions: These results, besides confirming an association of both IMT and CAL with primary hypertension and ageing, demonstrate that CAL and IMT have different correlates. However, they do not support the contention that a high renin-sodium profile carries an excess risk of CAL in primary hypertensives with no clinical evidence of cerebro-vascular disease.