An independent relationship between muscle sympathetic nerve activity and pulse wave velocity in normal humans.
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.
Swierblewska
Ewa
E
Department of Hypertension and Diabetology, Medical University of Gdansk, Gdansk, Poland.
Hering
Dagmara
D
Kara
Tomas
T
Kunicka
Katarzyna
K
Kruszewski
Piotr
P
Bieniaszewski
Leszek
L
Boutouyrie
Pierre
P
Somers
Virend K
VK
Narkiewicz
Krzysztof
K
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