Relationships between asthma, gastroesophageal reflux disease trend toward significance

Key takeaways:

• Patients often have asthma and gastroesophageal reflux disease.
• There was a negative correlation between DeMeester scores and the ratio between FEV1 and forced vital capacity.

WASHINGTON — A correlation between DeMeester scores and respiratory indicators approached statistical significance in patients with bronchodilator response and pathological gastroesophageal reflux disease.

“A lot of people have diagnoses of asthma and esophageal reflux disease on their history,” Richa Sheth, MD, second year resident, internal medicine program, University of California San Diego, told Healio at the American Thoracic Society International Conference.

Many patients are on asthma treatment as well as proton pump inhibitors (PPI), Sheth said, but they never had any pulmonary function testing (PFT) or esophageal pH testing.

“It’s hard to tell which one we are treating,” Sheth said, adding that when treatment start at the same time, it is difficult to tell which one worked.

“A lot of people are on both of these therapies without actually having any proof that these therapies are helping, or proof that they actually have this pathologic disease on any sort of testing,” she continued.

Further, she noted that providers should recognize patients who use PPI due to the risks associated with long-term use of this treatment.

“We should put a little more thought behind that besides starting it and keeping them on it for lifelong therapy,” Sheth said.

Sheth and her colleagues conducted a retrospective observational study of 73 patients (58 females) who had PFT including FEV₁, forced vital capacity (FVC), the ratio between FEV₁ and FVC and the presence of bronchodilator response as well as a clinical diagnosis of asthma between 2011 and 2022.

The researchers defined significant bronchodilator response as a 12% change in FEV₁ or FVC (n = 14), although they also assessed a subset of patients with a bronchodilator response of 6% or more for an additional subset (n = 34).

Also, the researchers assessed the DeMeester score of each patient, or the percent of time spent in reflux, and the presence of other pulmonary disease or hiatal hernia. Pathological GERD was defined as a DeMeester score of at least 14.7.

“That way we could look at objective measures of obstructive disease and objective measures of acid reflux and see if there was any connection between the two,” Sheth said. “That way we actually know if they have acid reflux and obstructive disease on testing.”

The researchers found negative correlation trends between DeMeester scores and FEV₁/FVC in the overall population (r = –0.073), in the subset of patients with a significant bronchodilator response (r = –0.353), and in those with a significant bronchodilator response at the lower threshold (r = –0.65).

“As the DeMeester score goes up, the ratio goes down, indicating a higher amount of obstructive disease,” Sheth said.

Similarly, there were negative correlation trends between DeMeester scores and FEV₁/FVC among the 46 patients with pathologic GERD in the full cohort (r = –0.185), the 21 patients with a significant bronchodilator response and pathologic GERD (r = –0.625) and the eight patients with a significant bronchodilator response at the lower threshold and pathologic GERD (r = –0.379).

“Patients with both pathologic GERD and bronchodilator response have some degree of reactive airway disease,” Sheth said. “An increase in the amount of acid reflux does have an increase in the amount of obstruction.”

However, the researchers said, not all of the patients who had pathologic GERD had symptoms that were associated with acid reflux.

The researchers considered 29 patients (39.7%) to be positive for symptom correlation via esophageal pH testing. Also, 29 (39.7%) had hiatal hernia, 14 (19.1%) had a diagnosis of sleep apnea and seven (9.5%) had an additional diagnosis of restrictive lung disease.

Overall, the researchers said, patients who had a significant bronchodilator response as well as pathologic GERD had an association between increases in physiologic measures of GERD and increases in degree of obstruction.

Next, the researchers plan on looking at a larger data set without limiting for the clinical diagnosis of asthma, including data collected at other clinics.

“We have about 380 patients in that data set now, and I’m working on the stats for that,” Sheth said.

The researchers want to look at esophageal pH testing and PFTs at approximately the same time as well, as patients in the cohort so far had these tests anywhere from a few months to a few years apart. Plus, Sheth noted, the pandemic led to scheduling problems too.

“Moving forward, if we do want to do a prospective study, we would get both studies done within a month of each other so that we could actually have more temporally accurate data,” Sheth said.

Further, Sheth noted that pulmonologists already are aware of how gastrointestinal issues may impact reactive airway disease or obstruction and look for them.

“One of the biggest things we think about when we think about chronic cough is acid reflux, because you can have microaspirations causing new coughing,” Sheth said.

Gastrointestinal specialists whose patients may be complaining about pulmonary issues with heartburn or hiatal hernia, she continued, may be good candidates for asthma therapy with exposure from their gastrointestinal tract.

Meanwhile, Sheth encourages providers to perform PFT with bronchodilator testing.

“I’ve seen a lot of PFTs without bronchodilator testing,” she said.