High uric acid readings fell from 57% of patients to 2% two years after gastric bypass, in a 94‑person series

High uric acid is the chemistry behind gout, and it is common in people heavy enough to qualify for bariatric surgery. A single-center study following 94 adults through the first two years after Roux-en-Y gastric bypass found that levels dropped at every check, and that high readings went from more than half the group to about one in fifty.

The cohort study appeared in Obesity Surgery on September 15, 2026.

Levels fell at 6, 12 and 24 months, with no flattening out

Uric acid is a waste product that the body makes when it breaks down substances called purines. When blood levels run high, it can form sharp crystals in a joint, which is a gout attack, and it can form kidney stones.

The researchers measured serum uric acid before surgery and again at 6, 12 and 24 months in adults who had gastric bypass between 2015 and 2023. Mean levels went from 7.34 mg/dL before surgery to 6.13 at 6 months, 5.13 at 12 months, and 4.71 at 24 months. That is an average drop of 2.64 mg/dL, or about a third, and the authors report it as highly statistically significant.

The pattern matters as much as the endpoint. Levels were still falling between 12 and 24 months, well after most of the weight loss from a bypass has happened.

High readings went from 57.4% of patients to 2.2%

The study defined a high reading as above 7.0 mg/dL in men and above 6.0 mg/dL in women. Before surgery, 57.4% of the group met that definition. At 6 months it was 33.0%, at 12 months 9.8%, and at 24 months 2.2%.

Put the other way round, of the patients who started with a high reading, 96% were in the normal range two years later.

Men started about 1 mg/dL higher and stayed there

Men in the group, who made up 31.9% of the 94 patients, had uric acid levels averaging 0.97 mg/dL above women at every time point. The gap did not widen or narrow over the two years, which the authors confirm with a test for interaction between sex and time that came back at p equals 0.97.

In their regression analysis, two things independently predicted where a patient's uric acid landed at 24 months: how high it was to begin with, and being male. Mean starting BMI in the group was 54.1 kg/m2, which is high even by bariatric surgery standards, so these patients were not typical of everyone having the operation.

No comparison group, so the operation is not separated from the weight loss

This is the central limit, and it follows from the design rather than from anything the authors concede. Everyone in the study had surgery. There was no group that lost similar weight another way, and no untreated group.

Uric acid tends to fall when body weight falls, whatever the reason, and it also responds to changes in diet, alcohol intake and certain medicines. A bypass changes all of those at once. This design cannot tell you how much of the drop is the rerouted anatomy and how much is simply losing a large amount of weight, which is a question a reader weighing bypass against other options would want answered.

The study measured blood levels, not gout attacks

Lower uric acid in a blood test is a reasonable proxy for lower gout risk, but it is not the same thing as fewer attacks, and this study did not count attacks, emergency visits or kidney stones. Nor does the abstract say whether patients were taking urate-lowering medicines such as allopurinol, or whether those were stopped or started during follow-up, which would affect the readings directly.

Ninety-four patients at one center is a small base for the size of the claim in the title the authors chose. They call for larger prospective studies to confirm the findings and work out what they mean clinically, which is the right reading of their own data.

Anyone with gout who is considering or recovering from bariatric surgery should raise it with their surgical team and whoever manages the gout, since urate-lowering treatment and attack risk during rapid weight loss are both worth planning for rather than improvising.