Weight-loss surgery may help obese patients breathe easier

Jan. 28 (UPI) -- Bariatric surgery may help some obese people breathe easier, according to a study published Tuesday.

Researchers found that people who underwent the procedure had measurable structural changes in their lungs and trachea, including less airway obstruction. The findings were published in the journal Radiology.

"For the first time, this study has demonstrated changes in the CT morphology of large and small airways that improve when individuals lose weight," co-author Dr. Susan J. Copley, a thoracic radiologist at Hammersmith Hospital in London, said in a statement. "These features correlate with an improvement in patient symptoms."

Obesity has become an epidemic in many parts of the world, and it has been linked with myriad other health problems, including increased risk for hypertension and stroke, diabetes and certain cancers.

It also places undue strain on the respiratory system, although the scope of these effects is not fully understood. What is known is that obesity overworks the heart and lungs, leading to reduced respiratory muscle strength, which may all contribute to limited pulmonary function.

For their study, Copley and her colleagues used computed tomography, or CT, an imaging technology capable of providing detailed pictures of the lungs and airways, to evaluate the effects of obesity on the lungs and the trachea in 51 obese patients who underwent bariatric surgery. They used CT to measure the size and shape of the trachea and assess "air trapping," a sign of lung obstruction in which excess air remains in the lungs after exhaling, resulting in a reduction in lung function.

Bariatric surgery is a widely used treatment for obese patients who haven't responded to other weight-loss approaches. The procedure effectively reduces the size of the stomach.

All of the study participants lost weight following surgery, with a mean body mass index decrease of 10.5 kg/m2 -- about 23 pounds. When the researchers compared results at baseline and six months after surgery, they found that surgery and weight loss were associated with structural changes to the lung and trachea.

In fact, post-surgery CT images showed reductions in air trapping and a lower incidence of tracheal collapse. Study participants with more significant changes in the extent of CT air trapping were more likely to experience less shortness of breath, the authors noted.

According to Copley, the results suggest that there may be a reversible element of small airway inflammation related to obesity and that reversal of this inflammation correlates with improvement in symptoms. The findings also point to CT as a potential way for measuring and assessing airway inflammation.

"CT is a useful [structural] marker to demonstrate subtle changes, which are not easily assessed by lung function alone," Copley said.