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October 3 , 2005
Pair of studies examines asthma triggers, treatments

By Tia McCollors

An Emory pulmonology researcher is recruiting patients for a pair of national, asthma-related studies: one to analyze how ozone levels in the environment affect a person’s innate nasal defenses and their ability to protect healthy lung function, and the other to determine whether treating acid reflux improves asthma symptoms.

“We know that high ozone levels can make asthma worse,” said principal investigator Sumita Khatri, assistant professor of pulmonary and critical care medicine, of the former. “We’re specifically looking to see whether the mechanism of this is due to decreased antioxidant defenses in the noses of asthmatics that render the asthmatics more susceptible to pulmonary symptoms than other individuals.”

Researchers are enrolling 44 asthmatics and 20 non-asthmatics between 18–75 years old to participate in the Serial Nasal Oxidant-Defense Testing (SNOT) in Asthma study. The study will evaluate their lung functions, as well as how nasal antioxidant activity may act as a biochemical filter for pollutants such as ozone, thereby decreasing airway inflammation.

Each participant will make two three-hour visits to Crawford Long Hospital’s Clinical Research Center, one during high ozone season (May to September) and one during low ozone season (October to April). Participants’ involvement in the study will include symptom questionnaires, medical and medication history, blood work, urine samples, breathing tests and nasal washing. Those who qualify and complete the study will receive $50 per visit for participation.

All participants must be non-smokers, cannot be pregnant, have emphysema, be on prednisone for asthma, or take daily vitamins C or E supplements equal to more than a multivitamin. Non-smoking asthmatics must currently have stable asthma symptoms, no lung disease, no family history of asthma or chronic sinus problems, and no history of seasonal or significant allergies.

“If we determine that asthmatics do worse during high ozone season due to depleted antioxidants, antioxidant supplements such as vitamin C and E given orally or even nasally may be a protective treatment,” Khatri said.

The acid reflux/asthma study is part of a national clinical trial; Emory is one of 20 sites in the American Lung Association-Asthma Clinical Research Centers (ACRC) network participating in the Study of Acid Reflux and Asthma (SARA). The SARA trial is designed to determine whether asthma is worsened by gastroesophageal reflux disease (GERD, or severe heartburn) and whether treatment of this condition using proton pump inhibitors improves asthma symptoms.

“It’s not well known why there appears to be more GERD in asthmatics than in the general population, or whether the presence of GERD actually worsens asthma,” Khatri said. “There are links experimentally between acid reflux and bronchial spasms related to asthma. In addition, bronchial spasms may increase reflux by altering pressures in the chest that may allow more acid to reflux into the esophagus. Asthma medications may also contribute to worsening GERD.”

Khatri is principal investigator of the SARA trial for the Emory site and co-principal investigator for the studies conducted through the ACRC, for which Emory pediatric pulmonologist Gerald Teague is the main principal investigator.

Patients with asthma who express some degree of continued asthma symptoms, and who also show signs of GERD, are being sought for enrollment. Nine visits to either the Emory Children’s Center or Crawford Long Hospital over a six-month period are required.

The national SARA trial will enroll 400 non-smoking asthmatics, ages 18–60, who have poor asthma control on inhaled steroids, defined on the basis of excessive bronchodilator use, nocturnal awakenings or frequent exacerbations.

Participants will be randomly assigned for treatment with either a proton pump inhibitor or matching placebo. The presence, severity and temporal relationship of GERD to asthma symptoms will be documented with a 24-hour ambulatory esophageal pH probe test of the participant’s esophagus to determine whether gastric acid washes back into the esophagus and causes symptoms. Interested participants who qualify and complete the study will receive between $600 and $650 for their time and effort.

For more information about either study, contact research coordinator Jeannie Peabody at Crawford Long at 404-686-1956. For more information about eligibility requirements and exclusion factors for the SARA trial, interested participants may also contact Rachna Patel at the Children’s Center at
404-712-1773.

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