Endoscopic Anatomy of Hiatal Hernia and its Relationship with C-Reactive Protein Levels: A Case-Control Study

Objective: This study aimed to evaluate the relationship between endoscopically determined hiatal hernia and C-reactive protein (CRP) levels in patients.Methods: This retrospective case-control study was conducted among 166 patients who underwent upper gastrointestinal endoscopy at Giresun Training and Research Hospital between March 2024 and May 2025. Of these patients, 83 were with hiatal hernia (case group), and 83 were without hiatal hernia (control group), matched by age and gender in a 1:1 ratio. Hiatal hernia was diagnosed endoscopically when the distance between the Z-line and the gastroesophageal junction (GEJ) exceeded 2 cm. Demographic characteristics, endoscopic parameters such as GEJ level and Z-GEJ distance, concomitant endoscopic findings, and CRP levels were compared between the groups.Results: The groups were demographically homogeneous regarding age (66.72±13.70 vs 66.19±13.70 years, P>0.05) and gender distribution (P=1.00). GEJ level and Z-GEJ distance were significantly higher in the case group (P<0.001). CRP levels were significantly elevated in the hiatal hernia group compared to controls (9.29±25.45 vs 3.01±7.62 mg/L, P<0.001). The prevalence of gastritis and duodenitis was significantly higher in the case group (P<0.001). ROC analysis demonstrated an area under the curve of 0.696 (95% CI: 0.617-0.776) for CRP at a cut-off value of 2.215 mg/L, with 67.5% sensitivity, 63.9% specificity, and 65.7% accuracy. However, CRP was not found to be an independent predictor of hiatal hernia in multivariate logistic regression analysis, suggesting that its elevation may reflect a broader systemic inflammatory context.Conclusion: Patients with hiatal hernia showed elevated CRP levels on univariate analysis, suggesting a systemic inflammatory component. While CRP may serve as a supportive biomarker reflecting inflammatory burden, its independent predictive value was limited in multivariate analysis. Therefore, it cannot be used as a standalone diagnostic test and should complement endoscopic evaluation.