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. 2020 Apr 22;46(3):e20180422.
doi: 10.36416/1806-3756/e20180422. eCollection 2020.

Construct validity and reproducibility of the six-minute step test in subjects with obstructive sleep apnea treated with continuous positive airway pressure

[Article in English, Portuguese]
Matheus Gustavo Silva Magalhães  1 , Juliana Baptista Teixeira  1 , Ana Maria Bezerra Santos  2 , Danielle Cristina Silva Clímaco  3 , Thayse Neves Santos Silva  4 , Anna Myrna Jaguaribe de Lima  5
Affiliations
Free PMC article

Construct validity and reproducibility of the six-minute step test in subjects with obstructive sleep apnea treated with continuous positive airway pressure

[Article in English, Portuguese]
Matheus Gustavo Silva Magalhães et al. J Bras Pneumol. .
Free PMC article

Abstract
in English, Portuguese

Objective: To evaluate the construct validity and reproducibility of the six-minute step test (6MST) in individuals with obstructive sleep apnea (OSA) treated with continuous positive airway pressure (CPAP).

Methods: We evaluated 48 volunteers diagnosed with OSA and treated with CPAP for at least two months. The volunteers underwent the six-minute walk test (6MWT) and the 6MST, in random order and on different days, with an interval of, at most, seven days between the two tests.

Results: A moderate positive correlation was found between the distance walked on the 6MWT and the number of steps climbed on the 6MST (r = 0.520; p < 0.001). There was no significant difference between the two 6MSTs in terms of the number of steps climbed (121.7 ± 27.1 vs. 123.6 ± 26.7). Reproducibility for performance on the 6MST and for cardiovascular variables was considered excellent (intraclass correlation coefficient > 0.8). Regarding cardiovascular responses, the 6MST produced higher values than did the 6MWT for HR at six minutes, percent predicted maximum HR, and leg fatigue at six minutes, as well as for systolic blood pressure at six minutes and at one minute of recovery.

Conclusions: The 6MST is valid and reproducible, producing greater cardiovascular stress than does the 6MWT. However, the 6MST is also characterized as a submaximal test for the assessment of exercise tolerance in individuals with OSA treated with CPAP.

Objetivo:: Avaliar a validade do constructo e a reprodutibilidade do teste de degrau de seis minutos (TD6) em indivíduos com apneia obstrutiva do sono (AOS) tratados com continuous positive airway pressure (CPAP, pressão positiva contínua nas vias aéreas).

Métodos:: Foram avaliados 48 voluntários com diagnóstico de AOS e tratados com CPAP há, no mínimo, dois meses. Os voluntários foram submetidos ao teste de caminhada de seis minutos (TC6) e ao TD6, em ordem aleatória e em dias diferentes, com um intervalo de, no máximo, sete dias entre os dois testes.

Resultados:: Foi observada uma correlação positiva moderada entre a distância percorrida no TC6 e o número de subidas no TD6, (r = 0,520; p < 0,001). Não foram encontradas diferenças significativas no número de subidas entre os dois TD6 (121,7 ± 27,1 vs. 123,6 ± 26,7 degraus). A reprodutibilidade para o desempenho no TD6 e para as variáveis cardiovasculares foi considerada excelente (coeficiente de correlação intraclasse > 0,8). Com relação às respostas cardiovasculares, quando comparado ao TC6, o TD6 apresentou maiores valores em relação a FC no sexto minuto, percentual do predito da FC máxima, fadiga de membros inferiores no sexto minuto e pressão arterial sistólica no sexto minuto e no primeiro minuto da fase de recuperação.

Conclusões:: O TD6 é válido, reprodutível e causa maior estresse cardiovascular quando comparado ao TC6. No entanto, o TD6 também se caracteriza como um teste submáximo para a avaliação da tolerância ao esforço em indivíduos com AOS tratados com CPAP.

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Figures

Figure 1
Figure 1. Correlation between the distance walked on the six-minute walk test (6MWD) and the number of steps climbed on the six-minute step test (S6MST).
Figure 2
Figure 2. Bland-Altman plot for the test and retest agreement between the six-minute step test (6MST), as measured by the number of steps climbed on the 6MST (S6MST). Mean error: 1.91 steps.
See this image and copyright information in PMC

References

    1. Beitler JR, Awad KM, Bakker JP, Edwards BA, DeYoung P, Djonlagic I. Obstructive sleep apnea is associated with impaired exercise capacity a cross-sectional study. J Clin Sleep Med. 2014;10(11):1199–1204. doi: 10.5664/jcsm.4200. - DOI - PMC - PubMed
    1. Maeder MT, Schoch OD, Rickli H. A clinical approach to obstructive sleep apnea as a risk factor for cardiovascular disease. Vasc Health Risk Manag. 2016;12:85–103. doi: 10.2147/VHRM.S74703. - DOI - PMC - PubMed
    1. Rotenberg BW, Vicini C, Pang EB, Pang KP. Reconsidering first-line treatment for obstructive sleep apnea a systematic review of the literature. J Otolaryngol Head Neck Surg. 2016;45:23–23. doi: 10.1186/s40463-016-0136-4. - DOI - PMC - PubMed
    1. Litvin AY, Sukmarova ZN, Elfimova EM, Aksenova AV, Galitsin PV, Rogoza AN. Effects of CPAP on "vascular" risk factors in patients with obstructive sleep apnea and arterial hypertension. Vasc Health Risk Manag. 2013;9:229–235. doi: 10.2147/VHRM.S40231. - DOI - PMC - PubMed
    1. Herdy AH, Ritt LE, Stein R, Araújo CG, Milani M, Meneghelo RS. Cardiopulmonary Exercise Test Background, Applicability and Interpretation. Arq Bras Cardiol. 2016;107(5):467–481. doi: 10.5935/abc.20160171. - DOI - PMC - PubMed

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