Abstract: FR-PO231
Enteric Hyperoxaluria: A 13-Year Retrospective Analysis of Urine Metabolic Risk Factors and Kidney Stone Events across Different Etiologies
Session Information
- Mineral Bone Disease: Transplant and Kidney Stones
October 25, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bone and Mineral Metabolism
- 502 Bone and Mineral Metabolism: Clinical
Authors
- Tatton, Ryan, Mayo Clinic, Phoenix, Arizona, United States
- O'Neill, Stephen Raul, Mayo Clinic, Phoenix, Arizona, United States
- Jordan, Deondre, Mayo Foundation for Medical Education and Research, Rochester, Minnesota, United States
- Vaughan, Lisa E., Mayo Foundation for Medical Education and Research, Rochester, Minnesota, United States
- Lieske, John C., Mayo Foundation for Medical Education and Research, Rochester, Minnesota, United States
- Keddis, Mira T., Mayo Clinic, Phoenix, Arizona, United States
Background
Enteric Hyperoxaluria (EH) increases the risk for calcium oxalate nephrolithiasis. This retrospective observational study compared baseline patient characteristics and subsequent nephrolithiasis rates by enteric etiology among EH patients.
Methods
Patients with a measured urine oxalate>40 mg/24hr between Jan1,2010, and Oct31,2023 with an enteric pathology consistent with EH and eGFR >30ml/min at the time of EH diagnosis were included. A stone event was defined as surgical management of kidney stones, stone composition analysis, or emergency department visit with a nephrolithiasis diagnosis. Patient characteristics and nephrolithiasis parameters were evaluated.
Results
Of 715 patients meeting inclusion criteria, the most common EH etiology was malabsorptive bariatric surgery(63%). Characteristics varied significantly by EH cause: non-bariatric surgically associated malabsorption(SAM) patients exhibited the greatest hyperoxaluria, profound hypocitraturia, and lowest eGFR, while Celiac patients had greater hypercalciuria and highest calcium oxalate supersaturation(Table 1). Over an average follow-up of 5.3(±3.9) years, the overall median (IQR) stone event rate was 0.6(0,1.54) per year. Exocrine pancreatic insufficiency, SAM, and Celiac groups had the highest stone burden (1.06,0.94, and 0.86 events per year, respectively).
Conclusion
This large EH cohort with comprehensive urine metabolic data reveals significant heterogeneity by enteric etiology. Malabsorptive bariatric surgery was the most common EH cause but had the lowest nephrolithiasis event rate. Other etiologies were less common but had more severe disease with higher stone events and different urine risk profiles, leading to higher overall SS. This study highlights the significant stone burden EH patients face (approximately 1 stone per year) and the need for a robust EH patient registry to define natural history, appropriate endpoints, and targets for tailored treatment across the heterogenous EH population.