Impact of long-term exposure to cigarette smoking on skin microvascular function

In order to evaluate the impact of cigarettes smoking and smokers' clinical characteristics on skin microvascular function, we measured the skin forearm blood flux, basally and during post-occlusive reactive hyperaemia, in 100 current smokers (mean age 51±11 years; range: 18 to 86 years) and in 66 healthy never-smokers matched for age and sex, by using laser Doppler fluximetry (LDF). Basal and post-ischemic LDF tracings were analyzed in the frequency domain within 0.009-0.02 Hz, 0.021-0.06 Hz and 0.061-0.2 Hz ranges, related to endothelial-dependent, sympathetic-dependent and myogenic-dependent vasomotion, respectively, using an adapted version of the Fourier analysis. The post-ischemic percentage change from baseline of the area under the LDF curve (AUC%) was significantly lower in smokers than in never-smokers [162.5% (139.3-183.0) vs 190.1% (156.3-216.8); p=0.00016]. Compared to controls, smokers also showed a reduced basal power spectral density (PSD) in the myogenic-dependent vasomotion (p=0.0034) and a reduced post-ischemic percentage increase in PSD of the endothelial-dependent vasomotion (p=0.0010) and sympathetic-dependent vasomotion (p=0.0016). An inverse relationship was observed in smokers between AUC% and smoking exposure duration (r=0.23, p=0.018), pack-years (r=0.33, p=0.0007), age (r=0.26, p=0.008) and body mass index (r=0.21, p=0.037). In the multiple linear regression model, pack-years was the only variable independently associated with AUC% (r=0.21, p=0.03). This study confirms that smoking is associated with cutaneous microvascular dysfunction and shows that the severity of this impairment is independently related to the duration and intensity of the exposure to smoking.