Abstract
Background/Objectives: Patients with chronic kidney disease (CKD) frequently experience upper gastrointestinal (GI) symptoms such as epigastric discomfort, nausea, vomiting, and early satiety. These symptoms can contribute to malabsorption and intermittent dehydration, ultimately accelerating the decline of residual renal function. However, they are often attributed to electrolyte imbalances or fluid overload, and the possibility of underlying gastroparesis is frequently overlooked by both patients and caregivers. This study aimed to provide new insights into the relationship between CKD and gastroparesis through a dual, population-based retrospective analysis that incorporated both inpatient and outpatient data. Methods: From the National Inpatient Sample (NIS) database, 3,579,372 patients diagnosed with gastroparesis, with or without CKD, were identified. From the TriNetX database, 6,263,251 patients presenting to ambulatory clinics with a chief complaint of nausea and vomiting were included. In both datasets, gastroparesis was defined using ICD-10-CM codes. Results: In the inpatient cohort, the prevalence of gastroparesis increased in proportion to CKD severity, with the highest likelihood observed in advanced stages compared to patients without CKD. An increased risk of gastroparesis was also observed in the outpatient CKD cohort from an independent TriNetX database, while the severity-dependent phenotype was not consistent. However, after rigorous propensity score matching, advanced CKD remained significantly associated with higher odds of gastroparesis, with the greatest risk observed in patients with end-stage renal disease (ESRD). Conclusions: These findings, validated across two large and independent datasets representing both inpatient and outpatient populations, demonstrate a consistent association between CKD severity and gastroparesis. They highlight the importance of routine screening and early management of gastroparesis in patients with advanced CKD to improve outcomes and reduce disease burden for CKD patients with sign of early satiety or dyspepsia.