Habitual cigarette smoking attenuates shear‐mediated dilation in the brachial artery but not in the carotid artery in young adults

Abstract

In the present study, we hypothesized that habitual cigarette smoking attenuates endothelial function in the cerebral circulation as well as that of the peripheral circulation in young adults. To test this hypothesis, we measured cerebrovascular and peripheral flow‐mediated dilation (FMD) in young smokers and nonsmokers in the present study. Ten healthy nonsmokers and 10 smokers participated in the study. We measured blood velocity and diameter in the brachial artery and internal carotid artery (ICA) using Doppler ultrasound. We identified shear‐mediated dilation in the brachial artery and ICA by the percentage change in peak diameter during hyperemia stimulation (reactive hyperemia and hypercapnia). We measured the baseline diameter and the shear rate area under the curve from the onset of hyperemia to peak dilation in the brachial artery and ICA, finding the measurements of the smokers and those of the nonsmokers did not differ (p > .05). In contrast to brachial FMD (5.07 ± 1.79% vs. 7.92 ± 3.01%; smokers vs. nonsmokers, p = .019), FMD in the ICA was not attenuated in the smokers compared with that of the nonsmokers (5.46 ± 2.32% vs. 4.57 ± 2.70%; p = .442). These findings indicate that in young healthy smokers, cerebral endothelial function was preserved, and the response of cerebral endothelial function to smoking was different from that of peripheral vasculature.

Internal carotid and brachial artery shear‐dependent vasodilator function in young healthy humans

“…2018a, b , 2020; Suzuki et al . 2020), the current study found no relationship between CVR of Q ICA and cFMD diameter change ( r 2 = 0.06; P = 0.46, Fig. 4 C ).…”

“…Lavallée et al's (2006) findings are clearly not consonant with ours, and comparison is tenuous given several differences in the methods (e.g. non-standard BA FMD and steady-state vs. transient CO 2 tests) and the complex influences on vascular function of the various pathologies present in both of the study groups (Niedermaier et al 1993;Dzau et al 1994;Costa et al 2020;Suzuki et al 2020). Nonetheless, the inclusion of a larger sample with a greater range of vascular function may advance the current findings.…”

“…Although CVR tests are often interpreted as assays of cerebrovascular endothelial function (e.g. Ainslie et al 2007;Lavi et al 2006) and measurement of ICA diameter change during steady-state CVR tests taken to be representative of shear-mediated dilatation (Iwamoto et al 2018a(Iwamoto et al ,b, 2020Suzuki et al 2020), the current study found no relationship between CVR of Q ICA and cFMD diameter change (r 2 = 0.06; P = 0.46, Fig. 4C).…”

“…2020; Suzuki et al . 2020). Nonetheless, the inclusion of a larger sample with a greater range of vascular function may advance the current findings.…”

An Exploratory Study on the Relationship between Brachial Arterial Blood Flow and Cardiac Output

“…When the participants arrived at the echo lab, they needed to rest in bed in a supine position for at least 10 minutes before taking measurements. After this break, we took the measurements in a room at constant temperature (23°C–25°C) [ 12 ], which are as follows.…”