Is there an association between hiatal hernia and ineffective esophageal motility in patients with gastroesophageal reflux disease?

INTRODUCTION: The pathophysiology of gastroesophageal reflux disease is multifactorial, where esophageal motility is one of the factors implicated in its genesis. However, there is still no consensus on the existence of an association between esophageal dysmotility and hiatal hernia in patients with gastroesophageal reflux disease. The objective of this study was to establish the prevalence of esophageal dysmotility in patients with hiatal hernia and to determine if herniation is a factor related to esophageal dysmotility in patients with gastroesophageal reflux disease.
METHODS: The study included 356 patients with a clinical diagnosis of gastroesophageal reflux disease submitted to upper digestive endoscopy and esophageal functional diagnostics. Hiatal hernia was defined endoscopically by a distance equal to or greater than 2 cm between the diaphragmatic constriction and the squamocolumnar junction and esophageal dysmotility when the esophageal manometry identified the amplitude of the peristaltic waves in the distal esophagus as <30 mmHg and/or less than 80% of effective contractions. For univariate statistical analysis, the patients were divided into two groups: with and without hiatal hernia. Poisson regression models were used to estimate crude and adjusted prevalence ratios (PR) of esophageal dysmotility according to hiatal hernia.
RESULTS: Gastroesophageal reflux disease patients with hiatal hernia had a prevalence of esophageal dysmotility equal to 14.8% and those without hiatal hernia, a prevalence of 7.7% (p = 0.041). Patients with hiatal hernia also showed a higher frequency of erosive esophagitis (47.5% versus 24.2%, p < 0.001), lower low esophageal sphincter pressure (10.4 versus 13.10; p < 0.001), and higher frequency of individuals with abnormal pH-metry values (p < 0.001). The crude PR for esophageal dysmotility, according to the presence of hiatal hernia, was 1.92 (confidence interval (CI), 1.04-3.53; p = 0.037), but this association did not persist when controlled for age, esophagitis, altered pH-metry, and altered low esophageal sphincter (adjusted PR, 1.69; CI, 0.68-4.15; p = 0.257).
CONCLUSION: Despite the prevalence of esophageal dysmotility in the hiatal hernia group being higher than that in the group without hiatal hernia, the association between these variables in individuals with gastroesophageal reflux disease disappeared when controlling for age, esophagitis, altered pH-metry, and altered low esophageal sphincter, leading us to believe that in these patients, hiatal hernia is not an independent risk factor for dysmotility.