Twenty-four of the 60 patients had serum urate above saturation concentrations (≥0.41 mmol/L) at baseline. Twelve of the 24 had been diagnosed with gout (five women), and 9 of the 12 were on urate-lowering therapy: The mean dose for eight patients was 237 mg daily of allopurinol. Five of the 12 patients with gout, and 21 of the 48 patients without gout were taking diuretics for hypertension.
After six months of nonsurgical weight loss efforts with dietary intervention, the mean weight loss was about 12.5 lbs., and there was no change in serum urate. All patients were then assigned laparoscopic sleeve gastrectomy and followed for one year. Mean weight loss was 75.3 lbs. at one year, and four of the 26 patients taking diuretics at the trial’s start were continuing that medication.
Serum urate significantly increased in the postoperative period and then started declining at three months after surgery, with the final mean at 0.30 mmol/L. According to the researchers, the data suggest that this temporary increase immediately after surgery may have occurred because of renal dysfunction associated with major surgery. They added that other contributing factors could have been fasting or rapid weight loss.
The investigators identified the factors associated with change in serum urate by the one-year follow-up: the baseline level, cessation of diuretic therapy, change in serum creatinine and female gender.
Implications of the Research
Robert Terkeltaub, MD, San Diego (Calif.) VA Medical Center rheumatology section chief and professor of medicine at University of California, San Diego, and also not involved in the study, says the research reinforces “our clinical impressions that it is hard to get people to lose weight, especially without bariatric surgery.”
The implications of the research, however, should be interpreted somewhat cautiously by physicians who do not treat a large number of Maori or Pacific Islanders, two ethnic groups that have high rates of gout and diabetes. Other caveats are that the BMI of patients was exceptionally high, only 12 patients with gout were in the study, and gout was not part of the inclusion criteria in the study, he says.
Some news reports about the study have suggested that bariatric surgery could be a new treatment for gout, but the trial was not designed to study the disease, he says. Dr. Terkeltaub, who was co-principal investigator and senior and corresponding author for the ACR 2012 gout guidelines, says the study “does not prove that bariatric surgery is a frontline procedure for treating people with gout. In fact, the patients with gout had not been treated prior to surgery with the maximum appropriate oral medication regimen, instead receiving a mean of only 237 mg of allopurinol daily. Patients with gout should be treated to uric acid target,” he says.
