Risk of nephrolithiasis, hyperoxaluria, and calcium oxalate supersaturation increased after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis

source extracted confidence: high 2026-04-09
#calcium-oxalate #controlled-clinical-trials-as-topic #female #gastric-bypass #humans

Risk of nephrolithiasis, hyperoxaluria, and calcium oxalate supersaturation increased after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis

Upala et al., 2016 | Surg Obes Relat Dis | Meta Analysis

Citation

Upala Sikarin, Jaruvongvanich Veeravich, Sanguankeo Anawin. Risk of nephrolithiasis, hyperoxaluria, and calcium oxalate supersaturation increased after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis. Surg Obes Relat Dis. 2016;12(8):1513-1521. doi:10.1016/j.soard.2016.04.004

Abstract

BACKGROUND: Earlier publications have shown renal stone complications after bariatric surgery. Multiple reports have also linked metabolic changes that alter the urinary chemistry profiles, especially hyperoxaluria, after bariatric surgery. However, evidence on change of other urine chemistry studies and type of bariatric surgery and risk of stone has been inconclusive so far. OBJECTIVES: To explore the association between bariatric surgery and postoperative urinary chemistry change and risk of stone formation SETTING: A systematic review and meta-analysis. METHODS: We comprehensively searched the databases of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from their dates of inception to January 2016. The inclusion criteria were published studies of association between bariatric surgery and postoperative renal stone formation or urine chemistry profiles. We used random-effects model meta-analysis and calculated the pooled risk of renal stone and difference in 24-hour urine chemistry profiles. RESULTS: Twelve observational studies were included in the meta-analysis. There was significantly higher risk of stone formation after Roux-en-Y gastric bypass surgery with pooled relative risk = 1.79 (95% CI: 1.54-2.10). In the analysis of urine chemistry profiles, there was significantly higher calcium oxalate supersaturation, lower citrate, and lower volume postoperatively compared with preoperatively. There was also higher urine oxalate in patients who had bariatric surgery compared with nonsurgery controls. CONCLUSIONS: Roux-en-Y gastric bypass surgery is associated with higher risk of renal stone and increased urine oxalate and calcium oxalate supersaturation.

Key Findings

Twelve observational studies were included in the meta-analysis. There was significantly higher risk of stone formation after Roux-en-Y gastric bypass surgery with pooled relative risk = 1.79 (95% CI: 1.54-2.10). In the analysis of urine chemistry profiles, there was significantly higher calcium oxalate supersaturation, lower citrate, and lower volume postoperatively compared with preoperatively. There was also higher urine oxalate in patients who had bariatric surgery compared with nonsurgery c

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size See abstract
Age Range See abstract
Condition See abstract

MeSH Terms

  • Calcium Oxalate
  • Controlled Clinical Trials as Topic
  • Female
  • Gastric Bypass
  • Humans
  • Hyperoxaluria
  • Kidney Calculi
  • Male
  • Obesity
  • Observational Studies as Topic
  • Postoperative Complications
  • Risk Factors

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Systematic Review
  • Vertical: calcium

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09