Smoking predisposes individuals to endothelial dysfunction. Flow-mediated dilation (FMD) and reactive hyperemia peripheral artery tonometry (RH-PAT) are used to assess endothelial function. However, whether smoking cessation demonstrates comparable effects on endothelial function evaluated by FMD and RH-PAT remains unclear. Thus, we aimed to evaluate the effects of smoking cessation on endothelial function evaluated simultaneously by FMD and RH-PAT and clarify the factors associated with these effects. Fifty-eight consecutive current smokers (mean ± standard deviation; age, 64 ± 11 years) who visited our smoking cessation outpatient department and succeeded with smoking cessation were enrolled. Twenty-one continued smokers were enrolled as age- and sex-matched controls. Clinical variables, FMD, and natural logarithmic transformation of the reactive hyperemia index (Ln-RHI) were examined before and 20 weeks after treatment initiation. In 58 smokers who succeeded with smoking cessation, FMD significantly improved (3.80 ± 2.24 to 4.60 ± 2.55%; p = 0.013), whereas Ln-RHI did not (0.59 ± 0.28 to 0.66 ± 0.22; p = 0.092). Spearman's rank correlation coefficient between changes in FMD and Ln-RHI was -0.004, and the intraclass correlation coefficient for a two-way mixed effects model was <0.001 (p = 0.499). In multivariate analysis, the presence of an increase in FMD was inversely correlated with the Brinkman index and changes in systolic blood pressure (SBP), whereas Ln-RHI was positively correlated with changes in SBP and inversely correlated with baseline body mass index. These factors may predict the varying effects of smoking cessation on the endothelial function of the conduit and digital vessels.
Keywords: Endothelial function; Flow-mediated dilation; Reactive hyperemia peripheral artery tonometry; Smoking cessation.