Abstract
Background: The ratio of peak workload on incremental cycle ergometer tests (ICET) using 1 and 2 legs (ratio 1:2) may be a useful indicator of ventilatory limitation. We compared ratio 1:2 with other measures related to exercise performance in COPD.
Methods: Patients with COPD performed a 2-legged ICET and 1-legged ICET (at 50% ramp increment) with expiratory gas analysis and serial inspiratory capacity manoeuvres. Isokinetic concentric and eccentric strength, fat free mass (bioelectrical impedance), physical activity and functional capacity (timed-up-and-go test) were assessed. Vastus lateralis fibre type was evaluated in a subset (n=12). Ventilatory limitation was defined as peak VE>85% predicted MVV (FEV1 x 37.5).
Results: 24 individuals (79% male, age 68±9, FEV1 1.4±0.6, ratio 1:2 0.55±0.02) completed the study. Ratio 1:2 was higher in ventilatory limited individuals (0.58 vs 0.48, p=0.02). Ratio 1:2 was negatively associated with FEV1 (r=-0.51, p=0.01) with trends towards associations with dynamic hyperinflation (r=-0.41, p=0.06) and V̇O2peak (r=-0.37, p=0.08). There were no significant associations with any other measured variable.
Conclusion: In individuals with COPD, ratio 1:2 was positively associated with disease severity and possibly aerobic capacity and dynamic hyperinflation but appears to be independent of quadriceps strength, muscle composition and current physical activity.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 923.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020