title: Age and cigarette smoking are independently associated with the cutaneous vascular response to local warming.
abstract: OBJECTIVE
  To investigate the relative impacts of age and cigarette smoking on cutaneous blood flow and flow motion.
  
  
  METHODS
  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.
authors.affiliation: School of Medicine,University of Southampton, Southampton, UK. .
authors.forename: Miriam R
authors.initials: MR
authors.lastname: Avery
authors.forename: David
authors.initials: D
authors.lastname: Voegeli
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Byrne
authors.forename: David M
authors.initials: DM
authors.lastname: Simpson
authors.forename: Geraldine F
authors.initials: GF
authors.lastname: Clough
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001783:Blood Flow Velocity; D004730:Endothelium, Vascular; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D012907:Smoking / Q000009:adverse effects*; D014666:Vasomotor System / Q000502:physiology*; D055815:Young Adult