April 12, 2012

Study examines sleep apnea’s role in lung diseases

Study examines sleep apnea’s role in lung diseases

Based on results from a 2009 pilot study that showed sleep apnea is more common in people who have idiopathic pulmonary fibrosis (IPF) than in the general population, Vanderbilt’s IPF research group is embarking on a larger study to determine its prevalence in people with other interstitial lung diseases (ILD).

Lisa Lancaster, M.D., associate professor of Medicine and clinical director of the IPF program and IPF Clinical Trials Center, said her group has been seeing more patients present with sleep disordered breathing such as sleep apnea.

Lisa Lancaster, M.D.

Lisa Lancaster, M.D.

“We started noticing that more of our patients were having sleep apnea, and it was a higher incidence than we see in the general public,” said Lancaster, who is trained as a sleep pulmonologist. “This raised a question for us.”

With funding from a VICTR grant, the research group studied 50 IPF patients in the Clinical Research Center to see if they had sleep apnea. The results, which were published in the medical journal Chest, indicated that 44 patients, or 88 percent, did have sleep apnea.

The prevalence of sleep apnea is thought to be 25 percent among the elderly patient population.

“That gave us good pilot information to be able to explore these findings further,” Lancaster said.

The IPF Clinical Trials Center is now recruiting patients with other interstitial lung diseases to see if treating sleep disordered breathing improves their quality of life or survival rates.

The study will last about seven months and involve a nocturnal polysomnography (sleep study) either at the Vanderbilt Sleep Center or at the Vanderbilt General Clinical Research Center. Patients diagnosed with sleep apnea will also be asked to have a continuous positive airway pressure (CPAP) titration study at the Vanderbilt Sleep Center.

“We’re interested in the relationship between sleep apnea and ILD because we know that untreated sleep apnea is pro-inflammatory, and it’s possible that there are inflammatory mediators that may be increased as a result of sleep-disordered breathing. These nocturnal dips in oxygen levels may aggravate ILD,” Lancaster said. “Treating it may help the underlying lung disease. “

The study runs through December. For more information, call 343-7068.
Co-investigators on the study are Wendi Mason, MSN, ACNP-BC, Jim Loyd, M.D., Beth Malow, M.D., and investigators Stephen Nathan and Oksana Schlobin at Inova Fairfax Hospital.