title: Peripheral arterial disease: an underestimated aetiology of exercise intolerance in chronic obstructive pulmonary disease patients.
abstract: OBJECTIVE
  To assess the prevalence of peripheral arterial disease and its implications for exercise limitation in chronic obstructive pulmonary disease (COPD) patients.
  
  
  METHODS
  One hundred and fifty-one moderate-to-severe COPD patients (forced expiratory volume in 1 s: 37+/-6 SD% predicted) and 73 healthy age-matched control individuals (divided into 31 smokers and 42 nonsmokers) participated in this study. All COPD patients were either exsmokers or current smokers and their tobacco-smoking history was similar to that of healthy smokers. To evaluate the existence of arterial disease, lower limb perfusion pressure impairment was assessed using the ankle brachial index, whereas arterial stiffness was assessed by the pulse wave velocity (PWV). The definition of peripheral arterial disease required an ankle brachial index value of 0.90 or less, whereas the PWV increment was considered to be a direct witness of arterial stiffness increase. A 6-min walk test was performed to assess physical exercise capacity.
  
  
  RESULTS
  Prevalence of peripheral arterial disease was higher in COPD patients than in healthy participants (81+/-3 SD; 49+/-5 SD and 9+/-2 SD%, respectively, in COPD, healthy smokers and nonsmokers). PWV mean values were significantly higher in COPD patients compared with healthy smokers and nonsmokers (10.3+/-2.1 SD m/s; 9.2+/-1.3 SD m/s and 8.7+/-2.2 SD m/s, respectively). The distance covered during the 6-min-walk test was associated positively with the degree of peripheral arterial disease (r=0.78; P=0.05) and negatively with the PWV values (r=-0.74; P=0.05). Not only tobacco-smoking history but also COPD severity was shown to influence these associations.
  
  
  CONCLUSIONS
  The effect of peripheral arterial disease on exercise intolerance in COPD seems to be considerable. Therefore, COPD patients participating in a pulmonary rehabilitation programme should profit from a systematic search for arterial disease. Arterial dysfunction has to be taken into account in the multidisciplinary treatment of these patients.
authors.affiliation: I.M.N.S.S.A. B.P. 610-83800 Toulon Armées, Department of Ergonomics, University of Toulon Var, Toulon, France. olivier.castagna@wanadoo.fr
authors.forename: Olivier
authors.initials: O
authors.lastname: Castagna
authors.forename: Alain
authors.initials: A
authors.lastname: Boussuges
authors.forename: Eric
authors.initials: E
authors.lastname: Nussbaum
authors.forename: Louis
authors.initials: L
authors.lastname: Marqueste
authors.forename: Jeanick
authors.initials: J
authors.lastname: Brisswalter
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000453:epidemiology* / Q000503:physiopathology*; D015995:Prevalence; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects