Chest
Volume 116, Issue 2, August 1999, Pages 363-368
Journal home page for Chest

Clinical Investigations
Exercise
Reproducibility of Maximal Exercise Ergometer Testing in Patients With Cystic Fibrosis

https://doi.org/10.1378/chest.116.2.363Get rights and content

Objectives

Exercise testing in patients with cystic fibrosis (CF) has become an important tool in assessing disease severity and predicting overall outcome. The reproducibility of maximal exercise testing was examined in adult subjects with stable CF.

Methods

Nine subjects with CF underwent a total of three maximal exercise tests carried out under identical circumstances over a 28-day period. Oxygen uptake (

o2), minute ventilation (
e), respiratory frequency (f), heart rate (HR), and arterial oxygen saturation (Sao2) were measured at rest, at end exercise, and at 40% and 70% of maximum workload.

Results

There were no significant differences in these measurements among the three tests. Reproducibility of exercise performance was assessed using the coefficient of variation. The mean within-subject coefficient of variation for test variables at end exercise are as follows:

o2, 6.9%;
e, 6.2%; f, 5.8%; HR, 3.0%; and Sao2, 1.1%. The mean within-subject coefficient of variation for test variables at 40% and 70% of maximal work rates are as follows:
o2, 5.2% and 4.6%; Sao2, 0.3% and 0.9%; HR, 4.0% and 3%;
e, 5.7% and 6.5%; and f, 5.8% and 7.2%, respectively.

Conclusions

Variables measured during clinical cycle ergometer exercise testing in adult patients with stable CF are reproducible. No learning effect was found on repeated testing.

Section snippets

Patients

Characteristics of our study population are outlined in Table 1. The subjects (six men and three women) were recruited from outpatients in the National Adult Cystic Fibrosis Unit, St. Vincent's University Hospital. All subjects had clinical, radiologic, and physiologic evidence of CF-related lung disease, and they all had CF diagnoses based on clinical features, abnormal sweat test (sweat sodium and chloride > 60 mmol/L), and genotyping. All subjects were clinically stable for a period of 2

Results

All subjects completed each exercise test without any complications, and no exercise test was terminated by the physician.

Discussion

As in previous studies1234567 of exercise in patients with CF, our patients showed reduced exercise tolerance with reduced maximal workload and

o2max. Our patients had increased ventilatory requirements with a high ventilation (
e), an elevated ventilatory equivalent for oxygen (
e/
o2) and an increased
e/MVV at end exercise. Two patients reached their predicted maximum HR. The three patients with the lowest FEV1 showed significant oxygen desaturation during exercise.

We looked at the

References (29)

  • FJ Cerny et al.

    Cardiorespiratory adaptations to exercise in cystic fibrosis

    Am Rev Respir Dis

    (1982)
  • LC Lands et al.

    Analysis of factors limiting maximal exercise performance in cystic fibrosis

    Clin Sci

    (1992)
  • PH Quanjer et al.

    Lung volumes and forced ventilatory flows: report Working Party Standardization of Lung Function Tests, European Community for Steel and Coal

    Eur Respir J Suppl

    (1993)
  • NL Jones

    Clinical exercise testing

    (1988)
  • Cited by (42)

    • Exercise Testing in CF, the What and How

      2015, Diet and Exercise in Cystic Fibrosis
    • Neuromuscular fatigue after maximal exercise in patients with cystic fibrosis

      2011, Journal of Electromyography and Kinesiology
      Citation Excerpt :

      In the present work, we tested the hypothesis that despite their ventilatory limitations, patients with CF would develop neuromuscular fatigue in exercising muscles following a maximal exercise test. As such, we used a maximal symptom limited test, widely validated and used in clinical and research settings in CF patients (Ehrman, 2009; McKone et al., 1999; Sexauer et al., 2003). All patients and healthy subjects achieved a peak respiratory exchange ratio ⩾ 1.09 and/or a maximum heart rate ⩾ 85% of predicted values, confirming that the test was near the maximal level.

    View all citing articles on Scopus

    Supported by the Cystic Fibrosis Research Trust and a researchfellowship grant from the Irish Lung Association (E.F.M.).

    View full text