title: l-Citrulline supplementation attenuates blood pressure, wave reflection and arterial stiffness responses to metaboreflex and cold stress in overweight men.
abstract: Combined isometric exercise or metaboreflex activation (post-exercise muscle ischaemia (PEMI)) and cold pressor test (CPT) increase cardiac afterload, which may lead to adverse cardiovascular events. l-Citrulline supplementation (l-CIT) reduces systemic arterial stiffness (brachial-ankle pulse wave velocity (baPWV)) at rest and aortic haemodynamic responses to CPT. The aim of this study was to determine the effect of l-CIT on aortic haemodynamic and baPWV responses to PEMI+CPT. In all, sixteen healthy, overweight/obese males (age 24 (sem 6) years; BMI 29·3 (sem 4·0) kg/m2) were randomly assigned to placebo or l-CIT (6 g/d) for 14 d in a cross-over design. Brachial and aortic systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP), aortic augmented pressure (AP), augmentation index (AIx), baPWV, reflection timing (Tr) and heart rate (HR) were evaluated at rest and during isometric handgrip exercise (IHG), PEMI and PEMI+CPT at baseline and after 14 d. No significant effects were evident after l-CIT at rest. l-CIT attenuated the increases in aortic SBP and wave reflection (AP and AIx) during IHG, aortic DBP, MAP and AIx during PEMI, and aortic SBP, DBP, MAP, AP, AIx and baPWV during PEMI+CPT compared with placebo. HR and Tr were unaffected by l-CIT in all conditions. Our findings demonstrate that l-CIT attenuates aortic blood pressure and wave reflection responses to exercise-related metabolites. Moreover, l-CIT attenuates the exaggerated arterial stiffness response to combined metaboreflex activation and cold exposure, suggesting a protective effect against increased cardiac afterload during physical stress.
authors.affiliation: 1Department of Nutrition, Food and Exercise Sciences,Florida State University,Tallahassee,FL 32306,USA.
authors.forename: Arturo
authors.initials: A
authors.lastname: Figueroa
authors.affiliation: 1Department of Nutrition, Food and Exercise Sciences,Florida State University,Tallahassee,FL 32306,USA.
authors.forename: Stacey
authors.initials: S
authors.lastname: Alvarez-Alvarado
authors.affiliation: 1Department of Nutrition, Food and Exercise Sciences,Florida State University,Tallahassee,FL 32306,USA.
authors.forename: Salvador J
authors.initials: SJ
authors.lastname: Jaime
authors.affiliation: 2Department of Molecular Genetics,The Rappaport Family Institute for Research in the Medical Sciences,Technion - Israel Institute of Technology,Haifa 31096,Israel.
authors.forename: Roy
authors.initials: R
authors.lastname: Kalfon
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000328:Adult; D001011:Aorta / Q000187:drug effects* / Q000502:physiology / Q000503:physiopathology; D062186:Arterial Pressure / Q000187:drug effects; D002956:Citrulline / Q000494:pharmacology*; D003080:Cold Temperature; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D007511:Ischemia / Q000150:complications / Q000503:physiopathology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D009765:Obesity / Q000150:complications / Q000503:physiopathology*; D050177:Overweight; D063177:Pulse Wave Analysis; D013312:Stress, Physiological / Q000187:drug effects* / Q000502:physiology; D059289:Vascular Stiffness / Q000187:drug effects; D055815:Young Adult
chemical_list: D002956:Citrulline
keywords: AIx augmentation index; AP augmented pressure; Aortic blood pressure; Arterial stiffness; BP blood pressure; CPT cold pressor test; Cold pressor test; DBP diastolic blood pressure; IHG isometric handgrip exercise; Isometric exercise; MAP mean arterial pressure; Metaboreflex activation; NO nitric oxide; PEMI post-exercise muscle ischaemia; PWV pulse wave velocity; SBP systolic blood pressure; Tr transit time of the reflected wave; Wave reflection; baPWV brachial-ankle pulse wave velocity; l-CIT 
                    l-citrulline supplementation; l-Citrulline supplementation