Obese people who have weight loss surgeries like gastric bypass are much less likely than those who don't have surgery to develop gout, a painful type of arthritis, according to a Swedish study.
People who chose to get weight loss surgery are also less than half as likely to develop hyperuricemia, too much uric acid in urine, which can be a precursor to gout, the study team writes in the Annals of the Rheumatic Diseases.
Gout is an intensely painful condition involving tender joints and redness that is caused by a build-up of uric acid in joints.
Gout affects nearly 4 percent of people in the United States and is on the rise, according to the Centers for Disease Control and Prevention.
"Obesity is extremely common in western and developing countries and it comes with a burden of associated diseases, such as gout itself," said lead author Dr. Cristina Maglio of the University of Gothenburg in Sweden.
"Bariatric surgery is the only obesity treatment that is effective in reducing body weight up to many years after the surgery," Maglio said by email.
To explore the link between gastric surgeries and gout, the study team used data from a Swedish study on nearly 4,000 middle-aged, obese participants recruited between 1987 and 2001 from healthcare centers across Sweden.
Half of the patients chose to undergo bariatric surgeries including gastric bypass, gastric banding and stomach stapling, while the other half of patients received no surgery and acted as a comparison group.
None of the subjects had gout at the start of the study and both groups had follow-ups about 20 years into the study to check for gout and hyperuricemia.
Researchers found that people who received bariatric surgery were 40 percent less likely to develop gout, compared with people who did not have surgery.
The control group suffered 201 "gout events" during the study period, compared with 138 gout cases in the surgery group.
The differences translate into one case of gout prevented for every 32 people treated with bariatric surgery, the authors calculate.
Participants' body weight and other risk factors like having high blood pressure did not have an effect on how well surgery worked to reduce people's risk of gout.
At the follow up, the surgery group was 53 percent less likely than the comparison group to have high uric acid, and one case of hyperuricemia was prevented for every eight people treated with surgery, according to the report.
"Gout is a very common and somewhat debilitating problem," Dr. Phillip Schauer told Reuters Health. "While there is medication for gout, it's not always effective and patients can suffer quite severe pain from this problem."
Diet and exercise alone as a means to lose weight will likely not work well enough to lower the risk of gout, said Schauer, a professor of surgery at the Cleveland Clinic Lerner College of Medicine who was not involved with the study.
"For people who suffer gout and are obese and despite medical treatment are still suffering from gout attacks, they ought to think about surgery as an option," said Schauer. He noted that the surgery might also target other health conditions like diabetes and high blood pressure.
"People should be aware that bariatric surgery is effective not only in reducing body weight but also the risk of developing serious conditions that are commonly associated with obesity, such as gout," Maglio said.