Box 1.

Unanswered Questions Regarding Hyperinflation in COPD

What are the trajectories of hyperinflation in COPD?

Do patients with hyperinflation benefit to the same extent from exercise training as patients without hyperinflation?

What is the optimal exercise modality in patients with hyperinflation?

Is hyperinflation variable throughout the day?

Which patients do or do not benefit from LABDs, are there actually non-responders?

How do patients with hyperinflation respond to a combination of interventions?

Is treatment of hyperinflation useful and effective in patients with hyperinflation but without obstruction?

What is the association between reduction of hyperinflation and improvements in patient-related outcomes in individual patients?

Does reduction of hyperinflation lower cardiovascular risk?

Does reduction of hyperinflation improve mortality in COPD patients?