Predictors of the effects of smoking cessation on the endothelial function of conduit and digital vessels

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