An 8-week handgrip training program decreased brachial artery wall thickness similarly in cuffed and noncuffed arms (P<0.001), suggesting exercise-induced shear rate changes are not obligatory.
Does exercise-induced shear stress mediate changes in conduit artery wall thickness in healthy men undergoing handgrip training?
Exercise-induced arterial wall remodeling occurs independently of increases in shear rate during handgrip training in healthy men.
p-value: p=<0.001
Episodic increases in shear stress have been proposed as a mechanism that induces training-induced adaptation in arterial wall remodeling in humans. To address this hypothesis in humans, we examined bilateral brachial artery wall thickness using high-resolution ultrasound in healthy men across an 8-wk period of bilateral handgrip training. Unilaterally, shear rate was attenuated by cuff inflation around the forearm to 60 mmHg. Grip strength, forearm volume, and girth improved similarly between the limbs. Acute bouts of handgrip exercise increased shear rate (P < 0.005) in the noncuffed limb, whereas cuff inflation successfully decreased exercise-induced increases in shear. Brachial blood pressure responses similarly increased during exercise in both the cuffed and noncuffed limbs. Handgrip training had no effect on baseline brachial artery diameter, blood flow, or shear rate but significantly decreased brachial artery wall thickness after 6 and 8 wk (ANOVA, P < 0.001) and wall-to-lumen ratio after week 8 (ANOVA, P = 0.005). The magnitude of decrease in brachial artery wall thickness and wall-to-lumen ratio after exercise training was similar in the noncuffed and cuffed arms. These results suggest that exercise-induced changes in shear rate are not obligatory for arterial wall remodeling during a period of 8 wk of exercise training in healthy humans.
Thijssen et al. (Fri,) conducted a other in Healthy. Bilateral handgrip training with unilateral cuff inflation vs. Noncuffed limb was evaluated on Brachial artery wall thickness (p=<0.001). An 8-week handgrip training program decreased brachial artery wall thickness similarly in cuffed and noncuffed arms (P<0.001), suggesting exercise-induced shear rate changes are not obligatory.