title: An independent relationship between muscle sympathetic nerve activity and pulse wave velocity in normal humans.
abstract: OBJECTIVE
  Carotid-femoral pulse wave velocity (PWV) has been shown to be a powerful predictor of cardiovascular morbidity and mortality. Sympathetic neural mechanisms may have a stiffening influence on arterial mechanical properties. The relationship between direct measures of sympathetic traffic and PWV in healthy humans has not been previously studied. We, therefore, tested the hypothesis that PWV is independently linked to muscle sympathetic nerve activity (MSNA) in normal individuals.
  
  
  METHODS
  We measured MSNA (microneurography), PWV (Complior device), heart rate and blood pressure in 25 healthy male participants (mean age 43 +/- 10 years).
  
  
  RESULTS
  PWV correlated significantly with age (r = 0.63, P < 0.001), SBP (r = 0.43, P < 0.05) and MSNA (r = 0.43, P < 0.05) but not with BMI, waist circumference, waist-to-hip ratio, heart rate, pulse pressure or DBP. Robust multiple linear regression analysis revealed that only age and MSNA were linked independently to PWV (r2 = 0.62, P < 0.001), explaining 39 and 25% of its variance, respectively. After adjustment of PWV for age and SBP, we further divided individuals into 'excessive' PWV (i.e. higher than expected from age and SBP) and 'optimal' PWV (i.e. lower than expected). BMI and blood pressure were similar in both subgroups. Individuals with excessive PWV had significantly greater MSNA than individuals with optimal PWV (30 +/- 10 vs. 18 +/- 11 bursts/min, P = 0.01).
  
  
  CONCLUSIONS
  This study provides the first evidence that PWV is linked to MSNA in normal humans. The relationship between MSNA and PWV is independent of age, BMI, waist circumference, waist-to-hip ratio, heart rate, pulse pressure or blood pressure.
authors.affiliation: Department of Hypertension and Diabetology, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Swierblewska
authors.forename: Dagmara
authors.initials: D
authors.lastname: Hering
authors.forename: Tomas
authors.initials: T
authors.lastname: Kara
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kunicka
authors.forename: Piotr
authors.initials: P
authors.lastname: Kruszewski
authors.forename: Leszek
authors.initials: L
authors.lastname: Bieniaszewski
authors.forename: Pierre
authors.initials: P
authors.lastname: Boutouyrie
authors.forename: Virend K
authors.initials: VK
authors.lastname: Somers
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Narkiewicz
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D015992:Body Mass Index; D002339:Carotid Arteries / Q000502:physiology; D005263:Femoral Artery / Q000502:physiology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D018482:Muscle, Skeletal / Q000294:innervation*; D012044:Regression Analysis; D013564:Sympathetic Nervous System / Q000502:physiology*; D014655:Vascular Resistance / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology; D055105:Waist Circumference; D049629:Waist-Hip Ratio