Dr. Christopher Ryerson is a leading expert in the study and treatment of patients with interstitial lung disease (ILD). His research aims to identify management strategies to improve symptoms and quality of life in patients with ILD, with a specific focus on idiopathic pulmonary fibrosis (IPF).
Why are you turning your research focus toward IPF?
IPF patients represent about one quarter of my practice. Almost all IPF patients develop disabling dyspnea (shortness of breath), which can really interfere with the amount of exercise they can do. We know that exercise is so important to improving quality of life for those living with this disease, in terms of lung capacity and muscle strength. People with IPF already have weaker muscles, and that gets worse when you don’t exercise. We want to find out why patients with pulmonary fibrosis get shortness of breath and try to identify ways it can be relieved during exercise.
Why is it important to study what happens to IPF patients when they exercise?
The studies that have been done on oxygen and how the body uses it during exercise almost exclusively focus on emphysema (COPD) patients. They don’t include IPF patients. We feel that the two are very different, and maybe IPF patients would do better with different amounts of oxygen supplementation at different times. The research so far suggests that pulmonary fibrosis patients might start out at the same oxygen level when walking but will drop much more quickly than COPD patients. We plan to study this. Providing more oxygen during pulmonary rehabilitation could allow patients to exercise at higher intensities, possibly leading to greater cardiovascular and muscular benefits.
What studies are you undertaking specific to IPF patients?
There are two related studies underway. The first is a dyspnea study looking at approximately 20 patients and is basically a pilot for a much larger study called the High Oxygen delivery to Preserve Exercise capacity in IPF patients (HOPE-IPF). In the pilot, patients come to the exercise lab on four separate occasions and we monitor them while they exercise. We want to see whether oxygen helps patients exercise at a higher intensity for longer duration with fewer symptoms.
What do you hope to learn from the dyspnea study?
The purpose is to show that there is benefit to oxygen in patients that don’t qualify by the standard criteria. The second part of the study is to determine the physiological mechanisms of that shortness of breath and the low oxygen levels. Early results in the first 15 patients show a dramatic improvement in the amount of exercise patients can do and how much shortness of breath they have during exercise.
What is the HOPE-IPF trial?
The HOPE-IPF study will be the largest and most comprehensive study of exercise physiology in IPF that’s ever been done. We currently have six patients in the study, with the goal to have a cohort of 88 patients nationally over the next three years. The study was designed to determine the benefits of breathing high amounts of supplemental oxygen during exercise training in patients with IPF that are receiving nintedanib (a medication used for the treatment of IPF).
How much do we know about the benefits of exercise for patients with IPF?
The theory is that, with the help of oxygen, patients can exercise at a higher intensity, pushing their heart and muscles to gain cardiac and muscular benefits. There have been a number of studies on dyspnea but fewer studies on exercise physiology. It’s something that is very difficult to study because it requires a lot of expensive equipment and a lot of patient buy-in. It’s very demanding on the patients. Our pilot study is larger than most previous studies, which included fewer than 10 patients. The good news is that the equipment has changed and improved over time as has our ability to monitor patients now that we have these new techniques and tools.
What are some of the implications for the HOPE-IPF trial?
The goal with IPF is to slow the progression as much as you can and make sure patients are feeling as well as they can. It’s all about quality of life. HOPE-IPF will lead to a comprehensive understanding of IPF exercise physiology. For patients, that means it might change their mindset as to how much more they could do with oxygen than without. Currently, all the criteria and the guideline recommendations for oxygen are derived from studies involving COPD patients. This study has the potential to change those criteria for IPF patients so that they can qualify for more oxygen earlier in their treatment.