ABSTRACT
PURPOSE: To investigate the relative impacts of age and cigarette smoking on cutaneous blood flow and flow motion. EXPERIMENTAL DESIGN: Skin blood flux was measured before and during the hyperaemic response to thermal warming of the skin to 43 degrees C using laser Doppler fluximetry (LDF) in 28 habitual smokers (5.4 [11.4] (median [IQR]) pack years; pack years = packs/day x duration of smoking habit), aged between 18 and 63 years and their age, sex and body mass index. Flow motion was assessed using Fourier analysis of the LDF signal. RESULTS: Mean and total hyperaemic (area under the flux curve, AUC(10)) response during warming were reduced in smokers compared with their non-smoking controls (P<0.05). Attenuation of the response to warming in smokers was associated with a reduction in relative spectral power around 0.01 Hz, reflecting a reduced endothelial/metabolic activity (P<0.04). In regression modelling with AUC(10) as the outcome, and smoking (yes/no), age, sex and BMI, as explanatory variables, age (P<0.0001) and smoking (P=0.018) were independently associated with the hyperaemic response and together accounted for 31% of the variance in AUC(10). CONCLUSIONS: Age and smoking are associated with approximately one-third of the variance in the endothelium-associated microvascular vasomotor activity in habitual smokers.
