Roux-en-Y Gastric Bypass Produces Sustained Uric Acid Reduction and Near-Elimination of Hyperuricemia at 24 Months - A Single-Center Longitudinal Cohort Study.

BACKGROUND

Obesity is a major and well-established risk factor for hyperuricemia and gout. Metabolic and bariatric surgery (MBS) is associated with marked and sustained improvements in metabolic health. The long-term trajectory of serum uric acid (UA) levels after Roux-en-Y gastric bypass (RYGB) is incompletely characterized. In this study, we sought to describe the evolution of serum UA concentrations during the first 24 months after RYGB.

METHODS

We performed a single-center longitudinal cohort study of adults undergoing RYGB between 2015 and 2023. Serum UA was measured preoperatively (baseline) and at 6, 12, and 24 months postoperatively. Temporal trends in UA were examined using linear mixed effects models. The prevalence of hyperuricemia (UA >7.0 mg/dL in men, UA >6.0 mg/dL in women) was compared across time points using paired McNemar tests. Multivariable regression analyses were conducted to identify independent predictors of UA levels at 24 months.

RESULTS

Ninety-four patients were analyzed (mean baseline BMI, 54.1 kg/m2; 31.9% male). Mean serum UA levels decreased from 7.34 mg/dL at baseline to 6.13, 5.13, and 4.71 mg/dL at 6, 12, and 24 months, respectively, which corresponds to a mean reduction of 2.64 mg/dL from baseline to 24 months (p < 0.001). Male sex was consistently associated with higher UA levels at all time points (mean difference, +0.97 mg/dL; p < 0.001) without evidence of a sex-by-time interaction (p = 0.97). The prevalence of hyperuricemia decreased from 57.4% preoperatively to 33.0%, 9.8%, and 2.2% at 6, 12, and 24 months, respectively. At 24 months postoperatively, 96% of subjects with baseline hyperuricemia had achieved normouricemia. In multivariable analyses, higher baseline serum UA (β = 0.176 per mg/dL; p < 0.001) and male sex (β = 0.848; p < 0.001) independently predicted 24-month serum UA concentrations.

CONCLUSIONS

RYGB was associated with substantial and sustained reductions in serum UA and marked resolution of hyperuricemia during 24 months of follow-up. Higher baseline UA concentrations and male sex were independently associated with higher UA levels at 24 months. Larger prospective studies are warranted to confirm these findings and evaluate their clinical implications.