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Longitudinal relationship between physical activity and lung health in patients with cystic fibrosis

Jane E. Schneiderman, Donna L. Wilkes, Eshetu G. Atenafu, Thanh Nguyen, Greg D. Wells, Nancy Alarie, Elizabeth Tullis, Larry C. Lands, Allan L. Coates, Mary Corey, Felix Ratjen
European Respiratory Journal 2014 43: 817-823; DOI: 10.1183/09031936.00055513
Jane E. Schneiderman
1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto
2Division of Respiratory Medicine, The Hospital for Sick Children, Toronto
3Faculty of Kinesiology and Physical Education, University of Toronto, Toronto
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Donna L. Wilkes
1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto
2Division of Respiratory Medicine, The Hospital for Sick Children, Toronto
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Eshetu G. Atenafu
4Biostatistics Dept, University Health Network, Toronto
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Thanh Nguyen
2Division of Respiratory Medicine, The Hospital for Sick Children, Toronto
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Greg D. Wells
1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto
3Faculty of Kinesiology and Physical Education, University of Toronto, Toronto
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Nancy Alarie
5Dept of Physical Therapy, Montreal Children’s Hospital, Montreal
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Elizabeth Tullis
6Division of Respirology, St Michael’s Hospital, Toronto
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Larry C. Lands
7Division of Respiratory Medicine, Montreal Children’s Hospital, Montreal
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Allan L. Coates
1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto
2Division of Respiratory Medicine, The Hospital for Sick Children, Toronto
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Mary Corey
8Child Health Evaluative Sciences, The Hospital for Sick Children, University of Toronto, Toronto, Canada
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Felix Ratjen
1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto
2Division of Respiratory Medicine, The Hospital for Sick Children, Toronto
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  • For correspondence: felix.ratjen@sickkids.ca
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Abstract

Exercise is beneficial for patients with cystic fibrosis (CF) but long-term effects of physical activity on lung function evolution are unknown. We evaluated the longitudinal relationship between changes in habitual physical activity (HPA) and rate of decline in lung function in patients with CF.

We tracked HPA using the Habitual Activity Estimation Scale, forced expiratory volume in 1 s (FEV1) and Stage I exercise tests in 212 patients with CF over a 9-year period.

Adjusting for sex, baseline age and FEV1, mucoid Pseudomonas aeruginosa and CF-related diabetes, mean±sd FEV1 % predicted decreased by 1.63±0.08% per year (p<0.0001) while mean±sd HPA increased by 0.28±0.03 h·day−1 per year (p<0.0001) over the study period. A greater increase in HPA was associated with a slower rate of decline in FEV1 (r=0.19, p<0.0069). Dividing subjects into “high” and “low” activity (above or below the mean rate of change of activity, respectively), a steeper rate of FEV1 decline was observed for low (-1.90% per year) compared to high (-1.39% per year) (p=0.002).

Increases in HPA are feasible despite progression of lung disease and are associated with a slower rate of decline in FEV1, highlighting the benefit of regular physical activity, and its positive impact on lung function in patients with CF.

Abstract

FEV1 declines at a lesser rate in patients with cystic fibrosis who increase their activity levels http://ow.ly/rETZc

Introduction

Advances in the treatment of cystic fibrosis (CF) have resulted in an increase in the median survival age for CF patients; however, the disease continues to be life limiting [1]. Nutritional status, pulmonary function, genotype, age at diagnosis and infection with Pseudomonas aeruginosa have been identified as predictors of mortality in patients with CF [2, 3]. A growing body of research has demonstrated that exercise training and physical activity contribute positively to outcome in patients with CF, with improvements in aerobic capacity, activity level, quality of life, weight gain, lung function and leg strength [4–6] and an association with a reduced rate of decline in lung function [7, 8].

While physical activity has well-documented benefits for healthy children [9], additional advantages for patients with CF include enhanced airway clearance [10] and improved ion channel function, possibly leading to better mucus hydration and enhanced mucus clearance [11]. Moreover, in patients with CF with severe lung disease, physical activity has been related to aerobic capacity [12], suggesting a direct relationship between aerobic capacity and survival.

Habitual physical activity (HPA) refers to activity that is incorporated into daily life, is less structured than traditional exercise training and can encompass a wide range of intensity levels. Thus far, reduced HPA has been reported to be related to lung function decline in females with CF over a short observation period [8] and adults with CF have been shown to accumulate less HPA than their non-CF peers [13]. While exercise training has been recommended for inclusion into CF routine therapy [14], issues such as the burden of disease [9] and inadequate adherence [15] have made it a challenge to incorporate into a treatment programme. Knowing that focusing patients and parents on the importance of regular activity could potentially change habitual levels over time, we sought to study prospectively the long-term relationship between changes in HPA levels and lung function in patients with CF.

Methods

Subject selection

Patients aged 7–17 years were recruited from the Hospital for Sick Children (Toronto, Canada) and Montreal Children’s Hospital (Montreal, Canada) CF clinics. For those who were unwell, displaying symptoms such as an increased cough and sputum production, malaise, fever and/or inability to participate in regular habitual physical activity, recruitment was postponed to a later visit when they were well. The research ethics boards of the Hospital for Sick Children (1000009000), Montreal Children’s Hospital (MCH003-28) and St Michael’s Hospital (Toronto; 05–06) (site of follow-up of patients aged >18 years) approved the study protocol and written informed consent was obtained from all participants.

Data collection

Data were collected for all study patients at each quarterly clinic visit over the 9-year study period. Similarly to the recruitment process, if a patient was not well enough to engage in their regular HPA, their data collection was postponed until a visit at which their typical HPA patterns had resumed, to control for potential losses in muscle force, and the documented reductions in HPA during exacerbation [16]. As a result, the number of data points varied among patients for the study period.

Anthropometric measures

Height (standard stadiometer with heel plate) and weight (Model 555; SR Instruments, Tonawanda, NY, USA) were measured, and a z-score for body mass index percentiles was calculated according to Centers for Disease Control and Prevention 2000 standards [17].

Pulmonary function testing

Spirometry was performed according to standard techniques [18] (VMax20 Pulmonary Spirometry Instrument; SensorMedics, Yorba Linda, CA, USA). Values were expressed as a percentage of the predicted value for height, sex and age for youths [19] and adults [20].

Habitual Activity Estimation Scale

At each quarterly clinic visit study patients completed the Habitual Activity Estimation Scale (HAES) [21] for a typical weekday of the previous 2 weeks, as outlined in an earlier validation study in this population [22]. Total activity (sum of “somewhat active” + “very active”) was calculated, as previously reported [8].

Aerobic cycle ergometer test

Patients performed an annual Stage I exercise test (incremental and maximal) on an electrically braked cycle ergometer (Rodby Electronik AB, Enhörna, Sweden), to determine peak oxygen consumption (V′O2peak) and work rate (WRpeak). 1-min work increments were chosen according to sex, height and physical activity level [23] and a maximal test was performed, as reported previously [7].

Data analysis

Descriptive statistics of means, medians, standard deviations and proportions were used to describe the variables measured. t-tests and/or Chi-squared tests were used to test for the difference between two independent means or proportions.

For the main analysis, weekday total activity (HPA) and pulmonary function (forced expiratory volume in 1 s (FEV1)) over time, mixed model analyses were used. To examine the association between activity level and pulmonary function, we obtained individualised slopes and intercepts, as well as the average slope and intercept, from the mixed model analyses of FEV1 and HPA over time. Correlation analysis was used for those individual slopes and intercepts to examine the association of FEV1 and HPA.

We then categorised individuals into those above (if the individualised estimate was above (“high”)) or below (if the individualised estimate was below (“low”)) the overall change in activity rate estimate. A mixed-model analysis was performed to evaluate the effect of activity level on the primary outcome FEV1, while controlling for the other potential confounders of baseline age and FEV1, sex, mucoid P. aeruginosa and CF-related diabetes (CFRD).

Finally, a mixed-model analysis was performed to evaluate any effect of WRpeak (% pred) and V′O2peak (mL·kg−1·min−1) on the primary outcome, FEV1, while controlling for baseline FEV1.

SAS (version 9.1; SAS Institute Inc., Cary, NC, USA) was used for all the analyses. p≤0.05 was considered statistically significant.

Results

212 patients with CF (aged 7–17 years at baseline, 108 (50.9%) females) were recruited over a 9-year period. Baseline characteristics for the study population are shown in table 1. Males had significantly higher pulmonary function, activity levels and V′O2peak values. Mean±sd HPA for the overall group at baseline was 5.47±2.78 h·day−1, with males engaging in greater activity than females (p=0.028).

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Table 1– Baseline characteristics

Length of follow-up is presented in table 2. The median (range) length of follow-up was 5.21 (0–9.7) years. A median (range) of nine (1–27) and 10 (1–29) measures were collected for HPA and FEV1, respectively, over the study period.

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Table 2– Number of patients by years of follow-up

Of 40 patients from Montreal Children’s Hospital, 16 (40%) moved to adult care during the study period; these patients were not followed in the study after the age of 18 years. Of 172 patients from the Hospital for Sick Children, 86 (50%) reached 18 years of age before the end of the study, of which 62 (72%) were followed after the age of 18 years.

As the majority of patients (n=166) were recruited in the first year, we compared the baseline characteristics of recruited patients to the overall eligible clinic population in the major recruitment centre (the Hospital for Sick Children). Patients participating in the study were younger (11.8±2.9 years versus 13.4±3.3 years, p<0.0005) and had higher lung function (FEV1 85.6±17.4% pred versus 67.2±23.0% pred, p<0.0001) than patients not participating in the study (n=67). There was no significant difference in baseline FEV1 (p=0.5048) or V′O2max (p=0.7126) between patients from the two paediatric centres (data not shown).

Adjusting for the potential confounders of sex, baseline age and FEV1, mucoid P. aeruginosa and CFRD, overall FEV1 decreased at a mean±sd rate of 1.63±0.08% per year (p<0.0001) and HPA increased at a mean±sd rate of 0.28±0.03 h·day−1 per year (p<0.0001) over the study period. There was a significant positive correlation between rates of change of activity level and change in FEV1 decline, indicating that an increase in activity was associated with a slower rate of decline in lung function over the study period (r=0.19, p<0.007).

Participants were divided into high (above the mean rate of change of activity) and low (below the mean rate of change of activity) groups. table 3 indicates that all evaluated potential confounder variables were evenly distributed between the two groups. The high group had a rate of increase in HPA of 0.59 h·day−1 per year, while the low group had a rate of decline of activity of 0.15 h·day−1 per year over the study period. Mixed model analysis results are presented in table 4 and indicate that FEV1 was significantly associated with baseline FEV1 (p=0.0001), CFRD (p=0.0452) and change in activity level over time, such that the rate of decline of FEV1 was less steep for the high group (-1.39% pred per year) compared to the low group (-1.90% pred per year) (p=0.0001).

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Table 3– Comparison of “high”- and “low”-activity groups at baseline
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Table 4– Mixed model analysis results for rate of decline of forced expiratory volume in 1 s (FEV1) on activity

189 patients performed Stage I exercise testing, with a total of 493 tests included for analysis (range 1–7 tests per patient). Adjusting for baseline FEV1, there was a positive relationship between FEV1 (% pred) and V′O2peak (p=0.0194) over the study period. Similarly, adjusting for baseline FEV1, there was a positive relationship between FEV1 (% pred) and WRpeak (% pred) (p=0.0004) over the study period. There was no significant association between V′O2peak and HPA (p=0.7457).

To confirm whether an increase in HPA was associated with a slower decline in FEV1, we performed the following additional analysis. Between T1 (baseline) and T2 (2.5 years) we classified the patients into either increasing or reducing HPA over time. We then used the data between T2 and T3 (6.6 yrs) to look at the rate of FEV1 decline for the two groups. The results showed that the rate of decline in FEV1 between T2 and T3 was significantly less steep for patients who incresed their HPA (-0.58% pred per year) compared to those with reduced HPA (-2.15% pred per year) (p=0.0231). Using the same method, we found no differences in change of V′O2peak between the two groups (p=0.7590).

Defining pulmonary exacerbation as hospitalisation for respiratory symptoms requiring antibiotics [24], 57 (32.2%) of our study patients had at least one exacerbation with a median (range) of three (1–16) over the study period. Hospital admissions were infrequent and there was no significant association between V′O2peak and hospital admissions per year (r= -0.07, p=0.35).

Discussion

In this prospective longitudinal study, after accounting for baseline characteristics known to affect clinical course, patients with CF with increasing activity levels had a reduced rate of decline of their FEV1 compared to those that did not become more active over the study period. If the goal in the treatment of CF is to preserve lung function for as long as possible thus potentially extending survival [25], these results would suggest that enhancing physical activity should be an integral part of the management of the disease.

We found a significant overall increase in physical activity of 0.28 h·day−1 per year over the study period, which translates into an increase of ∼17 min·day−1. This contrasts with earlier reports of declining levels of HPA for the majority of youth over a 5-year period of growth from childhood to adolescence, regardless of sex or weight status [26] and the trend of decreasing activity levels of children and youth in general [27]. It is possible that monitoring a patient’s activity level while participating in a study may be a sufficient stimulus to effectively maintain what would otherwise be a predictable pattern of decreasing activity level with age [28]. This highlights a valuable opportunity to have a positive impact on lung function decline, by promoting a physically active lifestyle throughout childhood, to encourage the maintenance of activity and enhance the carry-over into adulthood [29].

Previous reports of activity employing the HAES have indicated that children with CF engage in similar total amounts of HPA to their healthy peers [30]. Current values for HPA are similar to those reported in a small number of youths with CF [22] and somewhat lower than those reported by Ruf et al. [31] of 7.4 h·day−1 (females) and 6.0 h·day−1 (males) for patients with CF (aged 12–41 years). The latter may be explained by their inclusion of weekend activity, which was excluded in our analysis due to greater variability in preliminary analyses [8].

We investigated the relationship between lung function and HPA, as we were interested in documenting a “lifestyle” variable in patients with CF, one that did not require an “exercise prescription”, which is generally difficult to maintain once the research study resources have ended [4, 32]. HPA refers to the level of activity that is inherent in daily life, such as free play periods, climbing stairs, sporting activities, activities of daily living and activities of lower intensity such as walking. Therefore, changes in HPA represent a lifestyle modification that should result in longer lasting benefits. Enhancing HPA presents an interesting, widely feasible possibility for CF patients to improve their health and quality of life.

While multiple studies have highlighted factors that negatively affect the rate of decline of lung function, there are few that illustrate positive factors [25, 33]. Likewise, most interventions in CF have been assessed regarding their short-term efficacy in improving lung function rather than their long-term effect on lung function decline, as the latter requires a much longer observation period to demonstrate an effect. This is the first prospective, longitudinal study to illustrate that increasing habitual physical activity has a positive effect in attenuating the rate of decline of lung function in patients with CF, possibly affecting survival.

There is evidence to suggest that physical activity affects lung function even in the absence of lung disease. Berntsen et al. [34] reported that among a cross-sectional group of 2537 healthy children (aged 9–10 years), FEV1 was highest among those who were physically active four or more times per week, once adjusted for potential confounders (p=0.02). The results of this study would suggest that any intervention assessing pulmonary function decline as an outcome should adjust for activity level, as it is a significant factor in addition to the traditional potential confounders.

Our findings of a positive longitudinal relationship between the rate of decline of FEV1 and both V′O2peak and WRpeak agree with results of a 2-year follow-up of children with CF [35] and support earlier reports of a relationship between V′O2peak and survival [36, 37]. Thus, it would suggest that both HPA and maximal aerobic fitness positively influence the outcome of patients with CF, reinforcing the association between physical activity and V′O2peak in patients with CF [38].

There are some inherent limitations to this study. Participants enrolled in the study were younger and had a higher FEV1 than the remaining eligible clinic patients not recruited that year. Self-selection by those patients with mild disease is not uncommon in CF research studies [15], and in this case they would be healthier and less likely to have a chest exacerbation, and therefore eligible to participate in the activity study. Conversely, the included population represented the majority of patients followed in our CF centre and demonstrating a positive effect of physical activity on lung function decline in patients having less severe lung function abnormalities highlights the opportunity to utilise enhancing physical activity as an early intervention strategy.

Given that HPA is an important adjunct to treatment for patients with CF, future research is needed to determine the most efficacious strategies to help patients increase their HPA and build a lifestyle conducive to lifelong involvement in physical activity.

In summary, we demonstrate that patients with CF with increasing activity levels have a reduced FEV1 decline compared with those who did not become more active. This supports the hypothesis that even low-intensity activity, such as that reported by our adolescents, is able to preserve lung function. This study highlights the importance of incorporating, facilitating and encouraging long-term habitual physical activity in the clinical management of CF.

Footnotes

  • For editorial comments see page 675.

  • Support statement: This study was supported by Cystic Fibrosis Canada (2000–2003: #708; 2003–2006: #278; and 2006–2008: #990), The Irwin Foundation at the Hospital for Sick Children (G.D. Wells) and the Hospital for Sick Children Research Training Fellowship (J.E. Schneiderman).

  • Conflict of interest: Disclosures can be found alongside the online version of this article at www.erj.ersjournals.com

  • Received March 27, 2013.
  • Accepted September 4, 2013.
  • ©ERS 2014

References

  1. ↵
    Cystic Fibrosis Canada. Canadian Cystic Fibrosis Patient Data Registry Report 2010. www.cysticfibrosis.ca/assets/files/pdf/CPDR_ReportE.pdf Date last accessed: July 25, 2013. Date last updated: 2010.
  2. ↵
    1. Konstan MW,
    2. Morgan WJ,
    3. Butler SM,
    4. et al
    . Risk factors for rate of decline in forced expiratory volume in one second in children and adolescents with cystic fibrosis. J Pediatr 2007; 151: 134–139.
    OpenUrlCrossRefPubMedWeb of Science
  3. ↵
    1. Rosenfeld M,
    2. Davis R,
    3. FitzSimmons S,
    4. et al
    . Gender gap in cystic fibrosis mortality. Am J Epidemiol 1997; 145: 794–803.
    OpenUrlAbstract/FREE Full Text
  4. ↵
    1. Selvadurai HC,
    2. Blimkie CJ,
    3. Meyers N,
    4. et al
    . Randomized controlled study of in-hospital exercise training programs in children with cystic fibrosis. Pediatr Pulmonol 2002; 33: 194–200.
    OpenUrlCrossRefPubMedWeb of Science
    1. Selvadurai HC,
    2. Blimkie CJ,
    3. Cooper PJ,
    4. et al
    . Gender differences in habitual activity in children with cystic fibrosis. Arch Dis Child 2004; 89: 928–933.
    OpenUrlAbstract/FREE Full Text
  5. ↵
    1. Troosters T,
    2. Langer D,
    3. Vrijsen B,
    4. et al
    . Skeletal muscle weakness, exercise tolerance and physical activity in adults with cystic fibrosis. Eur Respir J 2009; 33: 99–106.
    OpenUrlAbstract/FREE Full Text
  6. ↵
    1. Schneiderman-Walker J,
    2. Pollock SL,
    3. Corey M,
    4. et al
    . A randomized controlled trial of a 3-year home exercise program in cystic fibrosis. J Pediatr 2000; 136: 304–310.
    OpenUrlCrossRefPubMedWeb of Science
  7. ↵
    1. Schneiderman-Walker J,
    2. Wilkes DL,
    3. Strug L,
    4. et al
    . Sex differences in habitual physical activity and lung function decline in children with cystic fibrosis. J Pediatr 2005; 147: 321–326.
    OpenUrlCrossRefPubMedWeb of Science
  8. ↵
    1. Wilkes DL,
    2. Schneiderman JE,
    3. Nguyen T,
    4. et al
    . Exercise and physical activity in children with cystic fibrosis. Paediatr Respir Rev 2009; 10: 105–109.
    OpenUrlCrossRefPubMed
  9. ↵
    1. McIlwaine M
    . Chest physical therapy, breathing techniques and exercise in children with CF. Paediatr Respir Rev 2007; 8: 8–16.
    OpenUrlCrossRefPubMedWeb of Science
  10. ↵
    1. Hebestreit A,
    2. Kersting U,
    3. Basler B,
    4. et al
    . Exercise inhibits epithelial sodium channels in patients with cystic fibrosis. Am J Respir Crit Care Med 2001; 164: 443–446.
    OpenUrlCrossRefPubMedWeb of Science
  11. ↵
    1. Nixon PA,
    2. Orenstein DM,
    3. Kelsey SF
    . Habitual physical activity in children and adolescents with cystic fibrosis. Med Sci Sport Exerc 2001; 33: 30–35.
    OpenUrlCrossRefPubMedWeb of Science
  12. ↵
    1. Rasekaba TM,
    2. Button BM,
    3. Wilson JW,
    4. et al
    . Reduced physical activity associated with work and transport in adults with cystic fibrosis. J Cyst Fibros 2013; 12: 229–233.
    OpenUrlCrossRefPubMed
  13. ↵
    1. Rand S,
    2. Prasad SA
    . Exercise as part of a cystic fibrosis therapeutic routine. Expert Rev Respir Med 2012; 6: 341–351.
    OpenUrlCrossRefPubMed
  14. ↵
    1. Paranjape SM,
    2. Barnes LA,
    3. Carson KA,
    4. et al
    . Exercise improves lung function and habitual activity in children with cystic fibrosis. J Cyst Fibros 2012; 11: 18–23.
    OpenUrlCrossRefPubMed
  15. ↵
    1. Burtin C,
    2. Van Remoortel H,
    3. Vrijsen B,
    4. et al
    . Impact of exacerbations of cystic fibrosis on muscle strength. Respir Res 2013; 14: 46–53.
    OpenUrlCrossRefPubMed
  16. ↵
    Centers for Disease Control and Prevention. CDC Growth Charts. www.cdc.gov/growthcharts/zscore.htm Date last updated: August 4, 2009. Date last accessed: October 10, 2010.
  17. ↵
    1. Miller MR,
    2. Hankinson J,
    3. Brusasco V,
    4. et al
    . Standardisation of spirometry. Eur Respir J 2005; 26: 319–338.
    OpenUrlAbstract/FREE Full Text
  18. ↵
    1. Wang X,
    2. Dockery DW,
    3. Wypij D,
    4. et al
    . Pulmonary function between 6 and 18 years of age. Pediatr Pulmonol 1993; 15: 75–88.
    OpenUrlCrossRefPubMedWeb of Science
  19. ↵
    1. Hankinson JL,
    2. Odencrantz JR,
    3. Fedan KB
    . Spirometric reference values from a sample of the general U.S. population. Am J Respir Crit Care Med 1999; 159: 179–187.
    OpenUrlCrossRefPubMedWeb of Science
  20. ↵
    1. Hay JA,
    2. Cairney J
    . Development of the habitual activity estimation scale for clinical research: a systematic approach. Pediatr Exerc Sci 2006; 18: 193–202.
    OpenUrl
  21. ↵
    1. Wells GD,
    2. Wilkes DL,
    3. Schneiderman-Walker J,
    4. et al
    . Reliability and validity of the habitual activity estimation scale (HAES) in patients with cystic fibrosis. Pediatr Pulmonol 2008; 43: 345–353.
    OpenUrlCrossRefPubMed
  22. ↵
    1. Godfrey S,
    2. Mearns M
    . Pulmonary function and response to exercise in cystic fibrosis. Arch Dis Child 1971; 46: 144–151.
    OpenUrlAbstract/FREE Full Text
  23. ↵
    1. Waters V,
    2. Stanojevic S,
    3. Atenafu EG,
    4. et al
    . Effect of pulmonary exacerbations on long-term lung function decline in cystic fibrosis. Eur Respir J 2012; 40: 61–66.
    OpenUrlAbstract/FREE Full Text
  24. ↵
    1. Konstan MW,
    2. Ratjen F
    . Effect of dornase alfa on inflammation and lung function: potential role in the early treatment of cystic fibrosis. J Cyst Fibros 2012; 11: 78–83.
    OpenUrlCrossRefPubMed
  25. ↵
    1. McMurray RG,
    2. Harrell JS,
    3. Creighton D,
    4. et al
    . Influence of physical activity on change in weight status as children become adolescents. Int J Pediatr Obes 2008; 3: 69–77.
    OpenUrlCrossRefPubMedWeb of Science
  26. ↵
    1. Katzmarzyk PT,
    2. Arden CI
    . Physical activity levels of Canadian children and youth: current issues and recommendations. Can J Diabetes 2004; 28: 67–78.
    OpenUrl
  27. ↵
    1. Bringolf-Isler B,
    2. Grize L,
    3. Mäder U,
    4. et al
    . Assessment of intensity, prevalence and duration of everyday activities in Swiss school children: a cross-sectional analysis of accelerometer and diary data. Int J Behav Nutr Phys Act 2009; 6: 50.
    OpenUrlCrossRefPubMed
  28. ↵
    1. Sallis JF,
    2. Simons-Morton BG,
    3. Stone EJ
    . Determinants of physical activity and interventions in youth. Med Sci Sport Exerc 1992; 24: Suppl. 6, S248–S257.
    OpenUrlPubMedWeb of Science
  29. ↵
    1. Boucher GP,
    2. Lands LC,
    3. Hay JA,
    4. et al
    . Activity levels and the relationship to lung function and nutritional status in children with cystic fibrosis. Am J Phys Med Rehabil 1997; 76: 311–315.
    OpenUrlCrossRefPubMedWeb of Science
  30. ↵
    1. Ruf KC,
    2. Fehn S,
    3. Bachmann M,
    4. et al
    . Validation of activity questionnaires in patients with cystic fibrosis by accelerometry and cycle ergometry. BMC Med Res Methodol 2012; 12: 43.
    OpenUrlCrossRefPubMed
  31. ↵
    1. Gulmans VA,
    2. de Meer K,
    3. Brackel HJ,
    4. et al
    . Outpatient exercise training in children with cystic fibrosis: physiological effects, perceived competence, and acceptability. Pediatr Pulmonol 1999; 28: 39–46.
    OpenUrlCrossRefPubMedWeb of Science
  32. ↵
    1. Konstan MW,
    2. Schluchter MD,
    3. Xue W,
    4. et al
    . Clinical use of ibuprofen is associated with slower FEV1 decline in children with cystic fibrosis. Am J Respir Crit Care Med 2007; 176: 1084–1089.
    OpenUrlCrossRefPubMedWeb of Science
  33. ↵
    1. Berntsen S,
    2. Wisløff T,
    3. Nafstad P,
    4. et al
    . Lung function increases with increasing level of physical activity in school children. Pediatr Exerc Sci 2008; 20: 402–410.
    OpenUrlPubMed
  34. ↵
    1. Klijn PH,
    2. van der Net J,
    3. Kimpen JL,
    4. et al
    . Longitudinal determinants of peak aerobic performance in children with cystic fibrosis. Chest 2003; 124: 2215–2219.
    OpenUrlCrossRefPubMedWeb of Science
  35. ↵
    1. Nixon PA,
    2. Orenstein DM,
    3. Kelsey SF,
    4. et al
    . The prognostic value of exercise testing in patients with cystic fibrosis. N Engl J Med 1992; 327: 1785–1788.
    OpenUrlCrossRefPubMedWeb of Science
  36. ↵
    1. Pianosi P,
    2. Leblanc J,
    3. Almudevar A
    . Peak oxygen uptake and mortality in children with cystic fibrosis. Thorax 2005; 60: 50–54.
    OpenUrlAbstract/FREE Full Text
  37. ↵
    1. Hebestreit H,
    2. Kieser S,
    3. Rüdiger S,
    4. et al
    . Physical activity is independently related to aerobic capacity in cystic fibrosis. Eur Respir J 2006; 28: 734–739.
    OpenUrlAbstract/FREE Full Text
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European Respiratory Journal: 43 (3)
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Longitudinal relationship between physical activity and lung health in patients with cystic fibrosis
Jane E. Schneiderman, Donna L. Wilkes, Eshetu G. Atenafu, Thanh Nguyen, Greg D. Wells, Nancy Alarie, Elizabeth Tullis, Larry C. Lands, Allan L. Coates, Mary Corey, Felix Ratjen
European Respiratory Journal Mar 2014, 43 (3) 817-823; DOI: 10.1183/09031936.00055513

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Longitudinal relationship between physical activity and lung health in patients with cystic fibrosis
Jane E. Schneiderman, Donna L. Wilkes, Eshetu G. Atenafu, Thanh Nguyen, Greg D. Wells, Nancy Alarie, Elizabeth Tullis, Larry C. Lands, Allan L. Coates, Mary Corey, Felix Ratjen
European Respiratory Journal Mar 2014, 43 (3) 817-823; DOI: 10.1183/09031936.00055513
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