Oxygen uptake efficiency slope in community-dwelling ambulant stroke survivors during walking and stair climbing: a cross-sectional study

ABSTRACT

Background

Oxygen uptake efficiency slope during submaximal tests has been proposed as a more appropriate measure of aerobic capacity after suffering a stroke, since some individuals cannot tolerate maximal exercise testing. However, it has not yet been investigated whether the oxygen uptake efficiency slope is able to differentiate between healthy individuals and those who have suffered a stroke.

Objectives

To compare the oxygen uptake efficiency slope during walking and stair climbing between stroke survivors and age- and sex-matched healthy controls.

Methods

This is a cross-sectional study in which 18 individuals who had suffered a stroke (stroke survivors) and 18 healthy controls matched for sex and age were included. Oxygen consumption and minute ventilation were collected breath-by-breath during walking (6-min Walk Test) and stair climbing. The oxygen uptake efficiency slope was estimated by the slope of the line obtained through linear regression.

Results

The stroke survivors had a lower oxygen uptake efficiency slope during the 6-min Walk Test than the healthy controls (MD 498, 95% CI 122 to 873, p = .01). The between-group difference for the Stair Test was smaller and not statistically significant (MD 349, 95%CI −73 to 772, p = .10).

Conclusions

Stroke survivors had lower oxygen uptake efficiency slope during the performance of the 6-min Walk Test when compared to sex- and age-matched healthy controls. This suggests that stroke survivors have worse cardiopulmonary capacity.

KEYWORDS:

• Oxygen consumption
• stroke
• gait
• stair climb test
• slope of oxygen consumption efficiency

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Janaine C. Polese, Raquel de Carvalho Lana and Karisa Boson. The first draft of the manuscript was written by Janaine C. Polese, Raquel de Carvalho Lana and Iza Faria-Fortini. The authors Louise Ada and Luci F. Teixeira-Salmela commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Additional information

Funding

The project was funded by the Fundação de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG).