Changes in Serum Uric Acid After Laparoscopic Sleeve Gastrectomy: Are They Associated with Baseline Renal Hyperfiltration?

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) provides durable, stable weight loss and ameliorates renal dysfunction, hyperuricemia (HUA), and other obesity-related metabolic disorders. Renal function is tightly linked to serum uric acid (SUA) metabolism, but conventional estimated glomerular filtration rate (eGFR) equations have well-documented substantial bias in individuals with obesity.

METHODS

We retrospectively collected clinical data from 202 patients who underwent LSG, with assessments performed at baseline and 1, 3, and 6 months postoperatively. Patients were stratified into the renal hyperfiltration (HF, 1n = 147) and normal filtration (NF, n = 55) groups using a baseline eGFR cutoff of 125 mL/min/1.73 m². 1:1 propensity score matching (PSM) was conducted using 7 covariates to balance baseline between-group heterogeneity.

RESULTS

The main effect of time on SUA levels was marginally significant pre-PSM (P = 0.054), but reached statistical significance post-PSM (P = 0.034). A significant main effect of group was observed at both stages (pre-PSM P = 0.008; post-PSM P = 0.037), with consistently higher SUA levels in the NF group. No significant time-by-group interaction effect was detected in either pre- or post-PSM analyses (both P > 0.05). Bonferroni-adjusted post hoc pairwise comparisons revealed significant SUA reductions at 3 and 6 months postoperatively relative to baseline in the pre-PSM HF group, with no significant temporal changes in the pre-PSM NF group; no significant pairwise differences across time points were seen in the matched cohort.

CONCLUSION

Temporal changes in SUA levels after LSG are not significantly associated with baseline renal filtration status.

KEY POINTS: • The time-by-group interaction effect was not significant in either pre- or post-PSM analyses, meaning the temporal trends of SUA levels after LSG did not differ significantly by baseline renal filtration status (HF vs. NF). • Both before and after PSM, SUA levels were consistently lower in the HF group than in the NF group; therefore, a longer duration of SUA monitoring may be necessary for the NF group.