Ventilatory threshold may be a more specific measure of aerobic capacity than peak oxygen consumption rate in persons with stroke. Issue 2 (17th February 2017)

• Record Type: Journal Article
• Authors: Boyne, Pierce; Reisman, Darcy; Brian, Michael; Barney, Brian; Franke, Ava; Carl, Daniel; Khoury, Jane; Dunning, Kari
• Is Part Of: Topics in stroke rehabilitation. Volume 24:Issue 2(2017)
• Page Start: 149
• Page End: 157
• Publication Date: 2017-02-17
• Subjects: Stroke -- Exercise testing -- Aerobic capacity -- Motor function -- Paresis -- Deconditioning; Cerebrovascular disease -- Patients -- Rehabilitation -- Periodicals; Cerebrovascular disease -- Periodicals; 616.810305
• DOI: 10.1080/10749357.2016.1209831
• Languages: English
• ISSNs: 1074-9357

Abstract

Abstract : Background: After stroke, aerobic deconditioning can have a profound impact on daily activities. This is usually measured by the peak oxygen consumption rate achieved during exercise testing (VO2-peak). However, VO2-peak may be distorted by motor function. The oxygen uptake efficiency slope (OUES) and VO2 at the ventilatory threshold (VO2-VT) could more specifically assess aerobic capacity after stroke, but this has not been tested. Objectives: To assess the differential influence of motor function on three measures of aerobic capacity (VO2-peak, OUES, and VO2-VT) and to evaluate the inter-rater reliability of VO2-VT determination post-stroke. Methods: Among 59 persons with chronic stroke, cross-sectional correlations with motor function (comfortable gait speed [CGS] and lower extremity Fugl-Meyer [LEFM]) were compared between the different aerobic capacity measures, after adjustment for covariates, in order to isolate any distorting effect of motor function. Reliability of VO2-VT determination between three raters was assessed with intra-class correlation (ICC). Results: CGS was moderately correlated with VO2-peak ( r = 0.52, p < 0.0001) and weakly correlated with OUES ( r = 0.41, p = 0.002) and VO2-VT ( r = 0.37, p = 0.01). LEFM was weakly correlated with VO2-peak ( r = 0.26, p = 0.055) and very weakly correlated with OUES ( r = 0.19, p = 0.17) and VO2-VT ( r = 0.14, p = 0.31). Compared to VO2-peak, VO2-VT was significantly less correlated with CGS ( r difference = −0.16, p = 0.02). Inter-rater reliability of VO2-VT determination was high (ICC: 0.93, 95% CI: 0.89–0.96). Conclusions: Motor dysfunction appears to artificially lower measured aerobic capacity. VO2-VT seemed to be less distorted than VO2-peak and had good inter-rater reliability, so it may provide more specific assessment of aerobic capacity post-stroke.