Can Exercise Training Impact Outcomes in Patients with IPF?

Background

According to current guidelines, pulmonary rehabilitation programs are recommended therapy for the majority of patients with idiopathic pulmonary fibrosis (IPF),1 and exercise training (ET) is a mandatory component of such rehabilitation programs.2 Exercise tolerance and quality of life (QOL) are severely impaired in patients with IPF;3,4 therefore, ET may help maintain patients' function in daily living activity. Two randomized, controlled trials have demonstrated short-term improvements in functional exercise tolerance (6-min walking distance [6MWD]), dyspnea, and QOL after exercise-based rehabilitation in patients with IPF.5,6 In a separate study, a short-term effect was found for an ET-based pulmonary rehabilitation program on exercise tolerance, functional capacity, pulmonary function, dyspnea, and QOL in patients with IPF.7

What They Did

In the latest study, clinically stable patients with IPF (N=34) were randomized to either the ET group or a control group.7 Patients randomized to the ET group received twice-weekly 60 minute supervised group ET in addition to ongoing care in the outpatient pulmonary rehabilitation program, while the control group received regular medical care only. Thirty-two patients completed the study with baseline and post-12 week measurements. The primary outcomes included changes in 6MWD and oxygen consumption (VO2) peak. The secondary outcomes were changes in pulmonary function, ventilatory responses, dyspnea, 30-second chair stand test, and St. George's Respiratory Questionnaire (SGRQ).

What They Found

After 12 weeks, the primary and the secondary outcomes were achieved:7

  Control
(n=17)
ET
(n=15)
Mean Difference
(95% CI)
P Value
Δ6MWD, m –10.6 ± 35.4 70.4 ± 77 81 (38.7 to 123.5) <.001
ΔVO2 peak, ml/kg/min – 0.5 ± 2 2.1 ± 2.3 2.6 (1 to 4.1) .002
ΔFVC % predicted –3 ± 7.6 3 ± 8.4 6 (0.35 to 11.9) .038
ΔmMRC dyspnea scale (0-4) 0.35 ± 0.7 –0.73 ± 0.8 – 1.1 (–1.62 to –0.54) <.001
ΔSGRQ 2.8 ± 3.6 – 6.9 ± 6.5 – 9.7 (–13.4 to –5.9) <.001

FVC, forced vital capacity; mMRC, Modified Medical Research Council; VO2, oxygen consumption.

What It Means

The findings demonstrate that supervised group ET improves exercise tolerance, functional capacity, pulmonary function, ventilatory responses, dyspnea, and QOL in patients measured at 12 weeks, the end of the intervention.7 Of note, this is the first randomized controlled study of ET in patients with IPF to demonstrate significant improvements in VO2 peak. The findings were somewhat unexpected since pulmonary function and VO2 peak do not usually improve with exercise interventions in other respiratory diseases such as chronic obstructive pulmonary disease. These findings strengthen and expand the evidence for the role of an ET-based pulmonary rehabilitation program in patients with IPF. Given that 12-week supervised group ET can clinically improve several IPF manifestations in the short term, the authors suggest that ET be included as part of the standard comprehensive treatment of patients with IPF and that it may benefit from longer studies to measure longer-term effects.

Link to abstract: http://www.ncbi.nlm.nih.gov/pubmed/?term=25341682



References

  1. Raghu G, Rochwerg B, Zhang Y, et al. An Official ATS/ERS/JRS/ALAT clinical practice guideline: treatment of idiopathic pulmonary fibrosis. An update of the 2011 clinical practice guideline. Am J Respir Crit Care Med. 2015;192:e3-e19.
  2. Ries AL, Bauldoff GS, Carlin BW, et al. Pulmonary rehabilitation: joint ACCP/AACVPR evidence-based clinical practice guidelines. Chest. 2007;131:4S-42S.
  3. Jackson RM, Gomez-Marin OW, Ramos CF, et al. Exercise limitation in IPF patients: a randomized trial of pulmonary rehabilitation. Lung. 2014;192:367-376.
  4. Swigris JJ, Kuschner WG, Jacobs SS, Wilson SR, Gould MK. Health-related quality of life in patients with idiopathic pulmonary fibrosis: a systematic review. Thorax. 2005;60:588-594.
  5. Holland AE, Hill CJ, Conron M, Munro P, McDonald CF. Short term improvement in exercise capacity and symptoms following exercise training in interstitial lung disease. Thorax. 2008;63:549-554.
  6. Nishiyama O, Kondoh Y, Kimura T, et al. Effects of pulmonary rehabilitation in patients with idiopathic pulmonary fibrosis. Respirology. 2008;13:394-399.
  7. Vainshelboim B, Oliveira J, Yehoshua L, et al. Exercise training-based pulmonary rehabilitation program is clinically beneficial for idiopathic pulmonary fibrosis. Respiration. 2014;88:378-388.