Pediatr Int. 2016 Jan 12. doi: 10.1111/ped.12919. [Epub ahead of print]

A comparison of the six-minute walk and incremental shuttle walk tests in CF.

Saglam M1, Vardar-Yagli N1, Savci S2, Inal-Ince D1, Aribas Z3, Bosnak-Guclu M3, Arikan H1, Calik-Kutukcu E1, Gunes-Yalcin E2,4.

• 1Hacettepe University, Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation, Ankara, Turkey.
• 2Dokuz Eylul University, School of Physiotherapy and Rehabilitation, Izmir, Turkey.
• 3Gazi University, Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation, Ankara, Turkey.
• 4Hacettepe University, Faculty of Medicine, Department of Pediatric Pulmonology, Ankara, Turkey.

Abstract

Although both self-paced and externally paced field tests are widely used in cystic fibrosis (CF), it is still unclear whether they induce clinically relevant and comparable cardiorespiratory responses. The aim of this study was to compare the incremental shuttle walk test (ISWT) and six-minute walk test (6MWT), and to determine the factors influencing exercise capacity in CF. Fifty clinically stable CF patients were included in the study. Pulmonary function, peripheral and respiratory muscle strength were assessed, anthropometric measurements were recorded, and patients performed the 6MWT and ISWT. The CF patients covered significantly more distance in the ISWT than 6MWT (p<0.001). Heart rate responses and dyspnea scores at the end of the tests and during the recovery phase were significantly higher in the ISWT compared to the 6MWT (p<0.05). The 6MWT and ISWT showed similar moderate-to-strong correlations with age, height, weight, pulmonary function, respiratory and peripheral muscle strength (p<0.05). Forty-nine percent of the variance in 6MWT distance was explained by age and FEV1 (R2 =0.49, F(2-48) =22.033, p<0.001). The variables contributing to ISWT distance were FEV1 , inspiratory muscle strength, and body mass index (R2 =0.596, F(3-44) =20.176, p<0.001).

CONCLUSIONS:

The ISWT is a better reflection of exercise tolerance in CF than the 6MWT. The ISWT is a preferable alternative assessment of exercise tolerance in terms of cardiorespiratory responses. What is Known:

• Exercise tests to evaluate exercise tolerance in CF patients are useful in predicting the prognosis, prescribing exercise programs, quantifying the effects of the disease on activities of daily life, and evaluation of interventions

What is New:

• ISWT was preferable to 6MWT in the assessment of symptom-limited exercise tolerance in patients with CF because it showed the cardiopulmonary responses better than 6MWT.

• Inspiratory muscle strength, lung function, and nutritional status affect walk/run performance, whereas age and lung function affect walk performance in CF.

KEYWORDS:

cardiorespiratory response; cystic fibrosis; exercise tolerance

PMID:

26756566