VO₂ kinetics and clinical factors among patients with peripheral artery disease

PURPOSE: To investigate the association between oxygen uptake ( VO ₂ ) kinetics and demographic, behavioral, and clinical factors among patients with peripheral artery disease (PAD). METHODS: A total of 85 PAD patients with intermittent claudication performed a constant load treadmill test, and breath-by-breath VO₂ was obtained to assess VO₂ kinetics. Demographic information, anthropometry, cardiovascular risk factors, and comorbid conditions were recorded. RESULTS: Using univariate analyses, higher values of tau ([τ], ie, slowed VO₂ kinetics) were associated with female gender, non-Caucasian race, hypertension, dyslipidemia, and age ≤ 66 years. Smoking, diabetes, obesity, metabolic syndrome, height, and ankle brachial index were not significantly related to VO₂ kinetics. Using multiple regression procedures, the identified predictors of slowed VO₂ kinetics were female gender (4.76 [95% CI: 1.49-8.03] seconds; P = .0049), non- Caucasian race (4.70 [95% CI: 1.29-8.12] seconds; P = .0075), hypertension (12.06 [95% CI: 8.83-15.28] seconds; P < .0001), and age ≤ 66 years (4.97 [95% CI: 1.95-7.99] seconds; P = .0015). CONCLUSIONS: In PAD patients, slowed VO₂ kinetics are associated with demographic and clinical factors. The clinical significance is that female, non-Caucasian, and hypertensive PAD patients present central and/or peripheral limitations that may partially account for their walking impairment.