title: Vitamin C prevents endothelial dysfunction induced by acute exercise in patients with intermittent claudication.
abstract: In patients with intermittent claudication, exercise is associated with a marked increase in oxidative stress, likely responsible for systemic endothelial perturbation. In 31 claudicant patients, we assessed the effect of vitamin C administration on the acute changes induced by maximal and submaximal exercise in endothelium-dependent, flow-mediated dilation (FMD), and in plasma levels of thiobarbituric acid-reactive substances (TBARS) and soluble intercellular adhesion molecule-1 (sICAM-1). In 16 claudicants, maximal exercise reduced FMD (from 8.5+/-0.9 to 3.7+/-0.8%, P<0.01), and increased plasma levels of TBARS (from 1.93+/-0.06 to 2.22+/-0.1 nmol/ml, P<0.02) and of sICAM-1 (from 282+/-17 to 323+/-19 ng/ml, P<0.01). In eight of these patients, randomized to vitamin C, exercise-induced changes in FMD and biochemistry were abolished. This beneficial effect was not observed in the eight patients randomized to saline. In 15 patients, who walked until the onset of claudication pain (submaximal exercise), and in ten control subjects, who performed maximal exercise, no changes were observed with exercise. Thus, in claudicants, vitamin C prevents the acute, systemic impairment in endothelial function induced by maximal exercise. This finding provides a rationale for trials investigating antioxidant therapy and cardiovascular risk in patients with intermittent claudication.
authors.affiliation: Department of Medicine, University of Naples "Federico II", Naples, Italy. antoniosilvestro@libero.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Silvestro
authors.forename: Francesco
authors.initials: F
authors.lastname: Scopacasa
authors.forename: Gabriella
authors.initials: G
authors.lastname: Oliva
authors.forename: Tiziana
authors.initials: T
authors.lastname: de Cristofaro
authors.forename: Luigi
authors.initials: L
authors.lastname: Iuliano
authors.forename: Gregorio
authors.initials: G
authors.lastname: Brevetti
mesh_terms: D000975:Antioxidants / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000627:therapeutic use*; D001916:Brachial Artery / Q000502:physiology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood*; D007383:Intermittent Claudication / Q000097:blood* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D016896:Treatment Outcome; D014664:Vasodilation
chemical_list: D000975:Antioxidants; D018799:Intercellular Adhesion Molecule-1; D001205:Ascorbic Acid