WEDNESDAY, Jan. 29, 2020 (HealthDay News) -- Countless Americans who struggle with extreme obesity turn to weight-loss surgery for help, and now new research shows the procedure can deliver an unexpected benefit: better breathing.
Until now, few studies have used CT scans to peer inside the body, to actually see obesity's effects on the respiratory system -- specifically, the lungs and trachea, or windpipe.
"This study gave an anatomical basis to what we see in practice," said Dr. Rodrick McKinlay, a Utah-based weight-loss surgeon who was not involved in the research.
In this new British study, doctors used such scans to observe changes in the respiratory systems of 51 obese individuals who underwent weight-loss (bariatric) surgery. They measured both the size and shape of the trachea and assessed air trapping, whereby excess air remains "trapped" in the lungs after exhaling, resulting in reduced lung function.
Comparing results before and six months after bariatric surgery, researchers noted postsurgical reductions in air trapping and a lower incidence of tracheal collapse.
"The take-home message for patients is that weight loss, as a result of bariatric surgery, improves the appearance of the lungs and airways on CT scans and this corresponds with an improvement in breathlessness and lung function," said study author Dr. Susan Copley, a thoracic radiologist at Hammersmith Hospital in London.
Six months after surgery, having lost an average of 10.5 body mass index (or BMI) points -- roughly equivalent to 60 or 65 pounds -- participants felt less breathless during daily activities.
The findings were published Jan. 28 in the journal Radiology.
Several factors make breathing difficult for people who are severely obese. The lungs are more "squashed" due to increased fat around them and in the abdomen, Copley explained. In addition, inflammatory substances in fat tissue are believed to cause airway inflammation. Further, increased airway resistance and reduced respiratory muscle strength make the respiratory system work harder.
It all translates into labored breathing.
That's often the driver behind patients seeking bariatric surgery, noted McKinlay, associate medical director of bariatric surgery for Intermountain Healthcare in Salt Lake City.
"They're saying: 'I'd really like to do the activities I like to do without getting winded,'" he explained. Whether it's keeping up with the kids or grandkids or having difficulty climbing stairs, these quality-of-life issues are typically what motivates patients to undergo this life-altering procedure.
Bariatric surgery leads to better nighttime breathing, too. Many patients who get the procedure report a reduction in labored breathing and increased daytime alertness just one or two months after surgery.
Sleep apnea and obesity are inextricably intertwined, McKinlay explained. With the accumulation of fatty tissue, the upper respiratory muscles narrow and the upper airway is obstructed to some degree, particularly while lying down.
The upshot? Sleep apnea results in repeated bouts of interrupted breathing during sleep. In the long run, this can trigger a host of health issues. In the short-term, sufferers struggle with excessive daytime fatigue due to the poor quality of nighttime sleep they're getting.
This study provides visible proof to support what doctors have heard anecdotally from patients all along, McKinlay said. "It's great to hear people say: 'Now I can keep up with my kids,'" he added.
More information
Learn more about bariatric surgery from the American Society for Metabolic and Bariatric Surgery.