Enhanced Plasma Soluble CD40 Ligand Levels in Essential Hypertensive Patients With Blunted Nocturnal Blood Pressure Decrease

Abstract

Hypertensives with a blunted nocturnal blood pressure (BP) decrease have increased risk of developing atherosclerotic disease. Soluble CD40 ligand (sCD40L) is involved in the pathogenesis of risk factor-related vascular damage. Therefore, we evaluated the relationship between circulating sCD40L levels, circadian BP profile, and early carotid atherosclerosis in essential hypertensives. Plasma sCD40L concentrations were assessed in two groups of 25 never-treated hypertensives, without additional cardiovascular risk factors, differentiated on the basis of a nocturnal decrease of BP either of >10% (dippers) or <10% (nondippers) of daytime values, and in 25 matched normotensives. Carotid intima-media thickness (IMT) was also measured in all participants. Plasma sCD40L concentrations were higher in nondippers (4.9 +/- 1.2 ng/mL) than in dippers (3.7 +/- 0.7, P = .0005) and controls (1.6 +/- 0.6, P < .0001). These latter had lower sCD40L concentrations than dippers (P < .0001). The IMT was higher in both hypertensive groups than in normotensives (P < .0001). In the entire hypertensive population IMT directly correlated with circulating levels of sCD40L (r = 0.365, P = .01) and inversely correlated with nocturnal systolic BP decreases (r = -0.286, P = .043). In a multivariate regression analysis sCD40L was the main determinant of IMT (r(2) = 0.157, P = .004). Nondippers have enhanced plasma sCD40L levels, which may contribute to their increased susceptibility to develop vascular damage.