XXXX enhances endothelial function and reduces blood pressure in smokers: a randomized controlled trial.

@entity1501 @entity1255 @entity409 @entity1854 @entity2221 @entity122 @entity934
OBJECTIVE: Cigarette smoking is associated with increased plasma @entity1255 concentrations, @entity409 and arterial stiffening. @entity1255 per se induces @entity409 and arterial stiffening and might account, at least partly, for the vascular abnormalities observed in smokers. We sought to determine whether @entity1501 supplementation, by reducing plasma @entity1255 concentrations, enhanced endothelial function and reduced arterial stiffness in smokers. DESIGN: Double-blind, randomized controlled, parallel-group, trial. SETTING: Academic medical centre. SUBJECTS: A consecutive sample of 24 healthy cigarette smokers (age 37.8 +/- 2.5 years, mean +/- SEM). INTERVENTION: Subjects were randomly assigned to 4-week @entity1501 5 mg day-1 or placebo. MAIN OUTCOME MEASURES: The following were measured before and after treatment: (i) peripheral vasoreactivity (forearm arterial blood flow, FABF) during intra-arterial administration of endothelium-dependent ( @entity934 1.5, 4.5 and 15 microg min-1) and endothelium-independent ( @entity1854 1, 2 and 4 microg min-1) vasodilators; (ii) carotid-femoral pulse-wave velocity ( @entity122 ); (iii) blood pressure (BP). RESULTS: @entity1501 reduced @entity1255 concentrations (10.8 +/- 0.6 vs. 8.2 +/- 0.5 micromol L-1, P < 0.001) and enhanced endothelium-dependent vasodilatation during each @entity934 infusion rate (ratio between the FABF in the infused and control arm during increasing infusion rates at baseline 1.09 +/- 0.03 vs. 1.41 +/- 0.09 after treatment, P < 0.01; 1.39 +/- 0.07 vs. 1.83 +/- 0.12, P < 0.01; 1.65 +/- 0.16 vs. 2.72 +/- 0.36, P < 0.05) whilst endothelium-independent vasodilatation was unaffected. A significant fall in BP was also observed (mean BP 88 +/- 2 vs. 83 +/- 1 mmHg, P < 0.01). By contrast, @entity122 did not significantly change (8.4 +/- 0.3 vs. 7.8 +/- 0.4 m s-1). No significant changes in plasma @entity1255 concentrations, FABF, BP, and @entity122 were observed in the placebo group. A multiple regression analysis showed that changes in @entity1501 plasma concentrations independently predicted both FABF changes during maximal @entity934 -mediated vasodilatation (P < 0.01) and BP changes (P = 0.01). CONCLUSIONS: Short-term @entity1501 supplementation significantly enhanced endothelial function and reduced BP in young chronic smokers. These effects were largely independent from the @entity1255 lowering effects. Thus, a simple, nontoxic, and relatively inexpensive @entity2221 intervention might be useful in primary cardiovascular prevention in this high-risk group.
