Association between reflux esophagitis and/or hiatus hernia and gastric mucosal atrophy level in Japan

Visceral fat obesity is the key risk factor for the development of reflux erosive esophagitis in 40-69-years subjects

BACKGROUND

Visceral fat obesity can be defined quantitatively by abdominal computed tomography, however, the usefulness of measuring visceral fat area to assess the etiology of gastrointestinal reflux disease has not been fully elucidated.

METHODS

A total of 433 healthy subjects aged 40-69 years (234 men, 199 women) were included in the study. The relationship between obesity-related factors (total fat area, visceral fat area, subcutaneous fat area, waist circumference, and body mass index) and the incidence of reflux erosive esophagitis was investigated. Lifestyle factors and stomach conditions relevant to the onset of erosive esophagitis were also analyzed.

RESULTS

The prevalence of reflux erosive esophagitis was 27.2% (118/433; 106 men, 12 women). Visceral fat area was higher in subjects with erosive esophagitis than in those without (116.6 cm² vs. 64.9 cm², respectively). The incidence of erosive esophagitis was higher in subjects with visceral fat obesity (visceral fat area ≥ 100 cm²) than in those without (61.2% vs. 12.8%, respectively). Visceral fat obesity had the highest odds ratio (OR) among obesity-related factors. Multivariate analysis showed that visceral fat area was associated with the incidence of erosive esophagitis (OR = 2.18), indicating that it is an independent risk factor for erosive esophagitis. In addition, daily alcohol intake (OR = 1.54), gastric atrophy open type (OR = 0.29), and never-smoking history (OR = 0.49) were also independently associated with the development of erosive esophagitis.

CONCLUSIONS

Visceral fat obesity is the key risk factor for the development of reflux erosive esophagitis in subjects aged 40-69 years.

Endoscopic diagnosis of hiatus hernia under deep inspiration is not consistent with esophageal manometric diagnosis

BACKGROUND

To investigate the relationship between endoscopic and esophageal manometric hiatus hernia (HH).

METHODS

Forty-six gastroesophageal reflux disease patients with endoscopic HH under maintenance therapy were recruited. Endoscopy was performed on all patients in a fully conscious state. Endoscopic HH was defined as apparent separation greater than 1 cm of the lower margin of the esophageal palisade vessels and the diaphragm hiatus on endoscopy under deep inspiration. Esophageal manometry was conducted using high-resolution manometry (HRM). The length between the lower margin of the lower esophageal sphincter and pulmonary inversion point was measured 10 times. The mean and maximum of the length was then calculated.

RESULTS

The mean HH length on HRM was 0 cm (0-0) [median (25th to 75th percentile)], 0 cm (0-0), 0.5 cm (0-1.1), and 2.2 cm (1.3-2.5) in the groups with endoscopic HH lengths of 1-2, 2-3, 3-4, and 4-5 cm, respectively. The maximum HH length on HRM was 0 cm (0-0), 0 cm (0-0), 0.8 cm (0-1.4), and 2.4 cm (1.5-2.9) in the 1-2, 2-3, 3-4, and 4-5 cm endoscopic HH groups, respectively. The mean and maximum HH lengths increased significantly in the group with an endoscopic HH length of 4-5 cm compared with the other groups, but did not differ significantly among the 1-2, 2-3, and 3-4 cm groups. Of patients with endoscopic HH less than 3 cm, few had esophageal manometric HH greater than 2 cm.

CONCLUSIONS

Endoscopic diagnosis of HH under deep inspiration is not consistent with esophageal manometric diagnosis, leading to overdiagnosis.

Association between Increased Gastric Juice Acidity and Sliding Hiatal Hernia Development in Humans

Objectives

Several clinical factors; overweight, male gender and increasing age, have been implicated as the etiology of hiatal hernia. Esophageal shortening due to acid perfusion in the lower esophagus has been suggested as the etiological mechanism. However, little is known about the correlation between gastric acidity and sliding hiatus hernia formation. This study examined whether increased gastric acid secretion is associated with an endoscopic diagnosis of hiatal hernia.

Methods

A total of 286 consecutive asymptomatic patients (64 were diagnosed as having a hiatal hernia) who underwent upper gastrointestinal endoscopy were studied. Clinical findings including fasting gastric juice pH as an indicator of acid secretion, age, sex, body mass index, and Helicobacter pylori infection status determined by both Helicobacter pylori serology and pepsinogen status, were evaluated to identify predictors in subjects with hiatal hernia.

Results

Male gender, obesity with a body mass index >25, and fasting gastric juice pH were significantly different between subjects with and without hiatal hernia. The cut-off point of fasting gastric juice pH determined by receiver operating curve analysis was 2.1. Multivariate regression analyses using these variables, and age, which is known to be associated with hiatal hernia, revealed that increased gastric acid secretion with fasting gastric juice pH <2.1 (OR = 2.60, 95% CI: 1.38–4.90) was independently associated with hiatal hernia. Moreover, previously reported risk factors including male gender (OR = 2.32, 95% CI: 1.23–4.35), body mass index >25 (OR = 3.49, 95% CI: 1.77–6.91) and age >65 years (OR = 1.86, 95% CI: 1.00–3.45), were also significantly associated with hiatal hernia.

Conclusions

This study suggests that increased gastric acid secretion independently induces the development of hiatal hernia in humans. These results are in accordance with the previously reported hypothesis that high gastric acid itself induces hiatal hernia development.

The role of excessive esophageal acid exposure in patients with gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD), especially reflux esophagitis (RE), is characterized by excessive esophageal acid exposure. Transient lower esophageal sphincter (LES) relaxation is the major mechanism of acid reflux episodes in both healthy subjects (HS) and patients with GERD. In the sitting position, where acid reflux episodes often occur, there is no difference in the frequency of transient LES relaxations between these two groups; however, in patients with GERD, at 5 cm above the LES, the proportion of acid reflux episodes during transient LES relaxations is significantly greater than in the HS group. This difference is considered to be one of the causes of excessive esophageal acid exposure in patients with GERD, but its cause is still unclear. A recent study, which investigated the proportion of acid reflux episodes during transient LES relaxations at 2 and 7 cm above the LES, showed that there was no difference at 2 cm above the LES between HS and patients with RE, but at 7 cm they were significantly greater in patients with RE than in HS. Evaluation of acid reflux at 2 cm above the LES is difficult to measure, but the proximal extent of refluxate could be one of the important factors of excessive acid esophageal exposure in patients with RE. Ineffective esophageal motility, found in patients with moderate to severe RE, impairs esophageal bolus clearance of acid, therefore both the proximal extent of refluxate and the delay of esophageal bolus clearance of acid could be major causes of excessive esophageal acid exposure. Hiatus hernia also causes acid reflux, due to its association with hypotensive LES, and also impairs esophageal bolus clearance of acid.

Epidemiology and clinical characteristics of GERD in the Japanese population

We reviewed articles on the epidemiology and clinical characteristics of gastroesophageal reflux disease (GERD) in Japan to clarify these features of GERD in this country. Although the definition of GERD depends on the individual study, the prevalence of GERD has been increasing since the end of the 1990s. The reasons for the increase in the prevalence of GERD may be due to increases in gastric acid secretion, a decrease in the Helicobacter pylori infection rate, more attention being paid to GERD, and advances in the concept of GERD. More than half of GERD patients had non-erosive reflux disease, and the majority (87%) of erosive esophagitis was mild type, such as Los Angeles classification grade A and grade B. There were several identified risk factors, such as older age, obesity, and hiatal hernia. In particular, mild gastric atrophy and absence of H. pylori infection influence the characteristics of GERD in the Japanese population. We also discuss GERD in the elderly; asymptomatic GERD; the natural history of GERD; and associations between GERD and peptic ulcer disease and H. pylori eradication. We examined the prevalence of GERD in patients with specific diseases, and found a higher prevalence of GERD, compared with that in the general population, in patients with diabetes mellitus, those with obstructive sleep apnea syndrome, and those with bronchial asthma. We provide a comprehensive review of GERD in the Japanese population and raise several clinical issues.

Mechanisms of excessive esophageal acid exposure in patients with reflux esophagitis

The pathophysiology of excessive esophageal acid exposure, including the way refluxed acid extends towards the proximal esophagus, in patients with reflux esophagitis (RE), is not yet clear. For 3 h after a meal, concurrent esophageal manometry and pH monitoring was carried out on 14 patients with severe RE, 15 patients with mild RE, and 15 healthy subjects. At 2 cm above the proximal margin of the lower esophageal sphincter (LES) there was no difference between the three groups in the total number of acid-reflux episodes, the rate of transient LES relaxations (TLESRs), or the rate of acid reflux during TLESRs. The rate of acid reflux at 7 cm above the proximal margin of the LES, during TLESRs, in patients with severe RE (50.9%, median) was, however, significantly higher than in patients with mild RE (35.7%) and healthy subjects (15.4%). In addition, the rate of acid reflux during TLESRs in patients with mild RE was significantly higher than in healthy subjects. Both the amplitude and the success rate of primary peristalsis in patients with severe RE were significantly lower than those of healthy subjects and patients with mild RE but there was no difference between healthy subjects and patients with mild RE. The cause of excessive acid exposure in patients with RE is the difference in the way refluxed acid extends towards the proximal esophagus and acid bolus clearance, not the number of acid-reflux episodes.

Gastroesophageal reflux disease: an Asian perspective

The prevalence of gastroesophageal reflux disease (GERD) ranges from 2.5% to 7.1% in most population-based studies in Asia. There is evidence that GERD and its complications are rising, coinciding with a decline in Helicobacter pylori (H. pylori) infection. Asian GERD patients share similar risk factors and pathophysiological mechanisms with their Western counterparts. Possible causes for the lower prevalence of GERD include less obesity and hiatus hernia, a lesser degree of esophageal dysmotility, a high prevalence of virulent strains of H. pylori, and low awareness. Owing to the lack of precise translation for 'heartburn' in most Asian languages, reflux symptoms are often overlooked or misinterpreted as dyspepsia or chest pain. Furthermore, a symptom-based diagnosis with a therapeutic trial of the proton pump inhibitor (PPI) may be hampered by the high prevalence of H. pylori-related disease. The risk stratification for prompt endoscopy, use of a locally-validated, diagnostic symptom questionnaire, and response to H. pylori'test and treat' help improve the accuracy of the PPI test for diagnoses. PPI remain the gold standard treatment, and 'on-demand' PPI have been shown to be a cost-effective, long-term treatment. The clinical course of GERD is benign in most patients in Asia. The risk of progression from non-erosive reflux disease to erosive esophagitis is low, and treatment response to a conventional dose of PPI is generally higher. Although H. pylori eradication may lead to more resilient GERD in a subset of patients, the benefits of H. pylori eradication outweigh the risks, especially in Asian populations with a high incidence of gastric cancer.