Aging, Smoking Predict Aortic Stiffness
Activity of Rho-associated kinase predicted by aging, long-term smoking
MONDAY, Feb. 5 (HealthDay News) -- Aging and long-term smoking predict the activity of Rho-associated kinase (ROCK), which is thought to play a role in atherosclerosis, and which along with age predicts aortic stiffness, researchers report in the Feb. 13 issue of the Journal of the American College of Cardiology.
Yukihito Higashi, M.D., Ph.D., from Hiroshima University in Japan, and colleagues measured the forearm blood flow response in 51 healthy men after intra-arterial infusion of sodium nitroprusside, acetylcholine, and fasudil (a ROCK inhibitor) alone or co-infused with NG-monomethyl-L-arginine (L-NMMA). Aortic stiffness was assessed by measuring the carotid-femoral pulse wave velocity (cf-PWV).
The researchers found that all three compounds alone or with L-NMMA significantly increased the forearm blood flow response in a dose-dependent fashion. Before or after co-infusion with L-NMMA, age and number of pack-years smoked were significant independent predictors of ROCK activity, and age and ROCK activity were significant independent predictors of cf-PWV. They also found a significant correlation between a marker of oxidative stress, serum malondialdehyde-modified low-density lipoprotein, and ROCK activity and cf-PWV.
"These findings suggest that aging and accumulating smoking habit, which might induce excessive oxidative stress, are involved in ROCK activity in the vasculature, leading to an increase in aortic stiffness in humans," Higashi and colleagues conclude.