Preoperative serum uric acid and metabolic and bariatric surgery outcomes

Metabolic and bariatric surgery (MBS) is effective in achieving substantial weight loss in patients with severe obesity and provides significant improvements in cardiometabolic health. Although serum uric acid (SUA) levels decrease after MBS, the association between preoperative SUA and postoperative weight-loss outcomes has been understudied. This retrospective study included 152 patients who underwent MBS at Päijät-Häme Central Hospital (Lahti, Finland) between 2013 and 2018. Data were obtained from electronic health records. Anthropometric measures, including preoperative and 12-month postoperative body weight, height, and body mass index (BMI), were recorded. Percentage of excess weight loss (%EWL) was calculated using an ideal BMI of 25 kg/m². Clinical data, including comorbidities, medications, lifestyle factors, type of surgery, and laboratory data, including SUA levels measured before and approximately one year after MBS, were collected. Multivariable analyses were adjusted for age, sex, diabetes status, non-HDL cholesterol, preoperative BMI, type of bariatric procedure (Roux-en-Y gastric bypass [RYGB] vs. sleeve gastrectomy [SG]), estimated glomerular filtration rate and diuretic use. Of the 152 patients, 56 (37%) had preoperative hyperuricemia (SUA ≥ 360 µmol/L). The cohort was predominantly female (80%), and most procedures were RYGB (90%). Higher preoperative SUA levels were associated with less favorable weight-loss outcomes, including lower %EWL and a lower likelihood of achieving %EWL ≥ 60%. Adjusted mean %EWL was 67% (95% CI: 60 to 74%) among patients with SUA < 300 µmol/L, compared with 65% (95% CI: 60 to 69%) among those with SUA 300–399 µmol/L and 61% (95% CI: 54 to 69%) among those with SUA ≥ 400 µmol/. The corresponding odds ratios for achieving %EWL ≥ 60% were 1.00 (reference), 0.55 (95% CI: 0.15 to 2.01), and 0.44 (95% CI: 0.09 to 2.09), respectively. Higher preoperative SUA levels were associated with less favorable postoperative weight-loss outcomes in this cohort, including lower %EWL and a lower likelihood of achieving %EWL ≥ 60%. However, these findings demonstrate an association rather than clinical predictive utility. Prospective studies are needed to determine whether preoperative SUA provides clinically useful prognostic information for postoperative weight-loss outcomes.