# Short-term dynamics of serum uric acid and its influencing factors in patients with obesity after laparoscopic sleeve gastrectomy

## TL;DR

This study examines how serum uric acid levels change in the first six months after weight-loss surgery in obese patients and identifies factors that influence these changes.

## Contribution

The study identifies specific predictors of short-term serum uric acid fluctuations after sleeve gastrectomy and provides actionable clinical monitoring thresholds.

## Key findings

- Δ₁ₘ-BMI is a key determinant of Δ₁ₘ-SUA, with patients having Δ₁ₘ-BMI ≥ 4.25 kg/m² needing weekly SUA monitoring.
- Males in the normal SUA group are at increased risk of SUA elevation at 6 months post-surgery.
- Baseline eGFR and TyG are significant predictors of SUA changes at both 1 and 6 months postoperatively.

## Abstract

The pathophysiological association between obesity and hyperuricemia (HUA) is well-established. Metabolic and bariatric surgery (MBS) has been shown to effectively manage severe obesity and lead to sustained reductions in serum uric acid (SUA) over the long term; however, the factors modulating short-term fluctuations in SUA (i.e., within 6 months postoperatively) and their underlying mechanisms remain poorly elucidated.

We performed a retrospective analysis of data from 184 patients with obesity who underwent laparoscopic sleeve gastrectomy (LSG). Clinical data were retrieved at baseline, on postoperative day 1, and at 1, 3, and 6 months postoperatively. Per established guidelines, patients were stratified into a normal SUA (NUA) group (n = 74) and an elevated SUA (EUA) group (n = 110).

Age, baseline estimated glomerular filtration rate (eGFR₀), baseline SUA (SUA₀), 1-month postoperative change in eGFR (Δ₁ₘ-eGFR), and 1-month postoperative change in BMI (Δ₁ₘ-BMI) were independent predictors of 1-month postoperative change in SUA (Δ₁ₘ-SUA).

Age, sex, SUA₀, baseline triglyceride-glucose index (TyG₀), eGFR₀, 6-month postoperative change in eGFR (Δ₆ₘ-eGFR), 6-month postoperative change in total protein (Δ₆ₘ-TP), and 6-month postoperative change in TyG (Δ₆ₘ-TyG) were independent predictors of 6-month postoperative SUA (SUA₆ₘ).

Process-mediated mediation analysis revealed that the effect of baseline BMI (BMI₀) on Δ₁ₘ-SUA was fully mediated by Δ₁ₘ-BMI; the effect of eGFR₀ on Δ₁ₘ-SUA was partially mediated by Δ₁ₘ-eGFR, while the effect of eGFR₀ on SUA₆ₘ was fully mediated by Δ₆ₘ-eGFR.

In the EUA group, 3-month postoperative SUA (SUA₃ₘ) was significantly lower than the baseline value. In the NUA group, SUA at 1, 3, and 6 months postoperatively (SUA₁ₘ/SUA₃ₘ/SUA₆ₘ) remained significantly higher than the baseline value, with a more pronounced increase in Δ₆ₘ-eGFR noted in males compared to females.

Δ₁ₘ-BMI is a key determinant of Δ₁ₘ-SUA. Patients with Δ₁ₘ-BMI ≥ 4.25 kg/m2 warrant weekly SUA monitoring during the first month postoperatively. Prompt clinical intervention is necessary when SUA exceeds 535.5 μmol/L, especially in patients with a history of gout. For patients with baseline impaired renal function (eGFR: 60–89 mL/min/1.73m2), preoperative optimization of renal reserve is recommended; those with renal hyperfiltration (eGFR > 125 mL/min/1.73m2) require intensified postoperative monitoring of eGFR and SUA. Males in the NUA group are at an increased risk of SUA elevation at 6 months postoperatively. Furthermore, age and SUA₀ are independent predictors of Δ₁ₘ-SUA, while age, sex, SUA₀, TyG₀, Δ₆ₘ-TP, and Δ₆ₘ-TyG are independent predictors of SUA₆ₘ.

The online version contains supplementary material available at 10.1186/s12893-025-03437-z.