Acid Reflux Linked to Higher Risk of COPD Exacerbations, Review Suggests
People with chronic obstructive pulmonary disease (COPD) who also have gastroesophageal reflux disease (GERD) — commonly called acid reflux — have a higher risk of experiencing acute exacerbations, a systematic review suggested.
That review study, “A systematic review with meta-analysis of gastroesophageal reflux disease and exacerbations of chronic obstructive pulmonary disease,” was published in the journal BMC Pulmonary Medicine.
COPD exacerbations are acute episodes in which patients experience a sudden worsening of their symptoms, including extreme shortness of breath, persistent cough, increased mucus production, swelling of the feet and ankles, and extreme fatigue with confusion.
In most cases, exacerbations are triggered by an infection caused by bacteria, viruses, or irritating substances found in the environment, such as air pollutants. They also can be caused by severe allergies.
GERD is one of the most common conditions affecting the digestive system worldwide. It occurs when stomach acid flows back into the esophagus, called reflux, causing irritation and injury. This can lead to heartburn and regurgitation.
A number of studies have reported a connection between COPD and GERD. Some have found GERD to be more common in people with severe COPD, and to be associated with coughing and poor lung function. Bronchodilators — medications that widen lung airways, making it easier for patients to breathe, and are often prescribed for people with COPD — are thought to worsen reflux.
In recent research, GERD has been found to be associated with a higher rate of exacerbations, an increased risk of hospital admissions, and use of mechanical ventilation among COPD patients.
Now, researchers at the Shanghai Jiao Tong University School of Medicine, in China, sought to investigate the risks of COPD exacerbations among people with GERD in more detail. The team conducted a meta-analysis, or a systematic review of previous studies conducted worldwide that focused on comparing the risks of COPD exacerbations among those with and without reflux.
After an in-depth search in three medical databases — Embase, Medline, and the Cochrane Central Register of Controlled Trials, known as CENTRAL — the researchers identified more than 2,807 studies that had been published up until January 2019.
During screening, duplicated records, reviews, editorials, and conference abstracts were excluded, leaving 17 studies for detailed evaluation. From these, seven more were excluded for not comparing those with and without GERD, not assessing exacerbations, or for not include GERD among triggering factors leading to exacerbations.
Following the selection process, a total of 10 studies conducted in the U.S., Europe, and Asia, were included in the final meta-analysis. These studies involved a total 13,245 patients.
The analysis’ findings revealed that GERD significantly increased the risk of COPD exacerbations by more than five-fold, with an odds ratio of 5.37. An odds ratio above one indicates an increased risk.
When researchers analyzed data from studies comparing exacerbations in COPD patients with and without GERD, they found that those who had GERD had significantly more exacerbations per year. Still, they pointed out that there was a high degree of statistical variation between studies supporting this conclusion.
A more detailed analysis found a higher frequency of exacerbations in Asian COPD patients with GERD, which suggested that geographical differences might account for the statistical variation found in the overall data.
“In general, this meta-analysis of observational studies suggested GERD increased the risk of exacerbation of patients with COPD, and patients of COPD with GERD exhibited more exacerbations,” the researchers said.
“The recognition of the relationship may help physicians to better monitor and prevent GERD in patients with COPD exacerbations,” they said.