Sex, gonads, sex hormones and histamine-stimulated gastric acid and serum pepsinogen

No increase in gastric acid secretion in healthy Japanese over the past two decades

BACKGROUND

The prevalence of gastroesophageal reflux disease (GERD) has been increasing worldwide over recent decades. A previous study demonstrated that gastric acid secretion, thought to be an important factor in the increase in the rate of GERD, in Japanese individuals increased in the era from the 1970s to the 1990s. The aim of this study was to evaluate whether gastric acid secretion has altered over the past two decades with and without the influence of Helicobacter pylori infection in nonelderly and elderly Japanese.

METHODS

Gastric acid secretion, the concentrations of serum gastrin, pepsinogen I, and pepsinogen II, and H. pylori infection were determined in 78 healthy Japanese subjects. The findings were compared with data obtained in the 1990s.

RESULTS

Basal acid output (BAO) and maximal acid output (MAO) gradually decreased with age in H. pylori-negative subjects. In addition, those with H. pylori infection tended to show decreased gastric acid secretion as compared with those without infection, particularly in the elderly group. MAO decreased gradually with age in males, whereas it remained unchanged with age in females. MAO in H. pylori-negative subjects has not changed over the past two decades (17.7 mEq/h vs 17.6 mEq/h in nonelderly subjects, and 15.2 mEq/h vs 12.7 mEq/h in elderly subjects).

CONCLUSIONS

In contrast to the increased prevalence of GERD, gastric acid secretion has not increased over the past two decades in Japanese. However, secretion has decreased with age in males but not in females, which may partly explain the sex difference in the age-related GERD prevalence.

Clinical characteristics of Helicobacter pylori-negative drug-negative peptic ulcer bleeding

AIM: To investigate the clinical characteristics and outcomes of idiopathic Helicobacter pylori (H. pylori)-negative and drug-negative] peptic ulcer bleeding (PUB).

METHODS: A consecutive series of patients who experienced PUB between 2006 and 2012 was retrospectively analyzed. A total of 232 patients were enrolled in this study. The patients were divided into four groups according to the etiologies of PUB: idiopathic, H. pylori-associated, drug-induced and combined (H. pylori-associated and drug-induced) types. We compared the clinical characteristics and outcomes between the groups. When the silver stain or rapid urease tests were H. pylori-negative, we obtained an additional biopsy specimen by endoscopic re-examination and performed an H. pylori antibody test 6-8 wk after the initial endoscopic examination. For a diagnosis of idiopathic PUB, a negative result of an H. pylori antibody test was confirmed. In all cases, re-bleeding was confirmed by endoscopic examination. For the risk assessment, the Blatchford and the Rockall scores were calculated for all patients.

RESULTS: For PUB, the frequency of H. pylori infection was 59.5% (138/232), whereas the frequency of idiopathic cases was 8.6% (20/232). When idiopathic PUB was compared to H. pylori-associated PUB, the idiopathic PUB group showed a higher rate of re-bleeding after initial hemostasis during the hospital stay (30% vs 7.4%, P = 0.02). When idiopathic PUB was compared to drug-induced PUB, the patients in the idiopathic PUB group showed a higher rate of re-bleeding after initial hemostasis upon admission (30% vs 2.7%, P < 0.01). When drug-induced PUB was compared to H. pylori-associated PUB, the patients in the drug-induced PUB were older (68.49 ± 14.76 years vs 47.83 ± 15.15 years, P < 0.01) and showed a higher proportion of gastric ulcer (77% vs 49%, P < 0.01). However, the Blatchford and the Rockall scores were not significantly different between the two groups. Among the patients who experienced drug-induced PUB, no significant differences were found with respect to clinical characteristics, irrespective of H. pylori infection.

CONCLUSION: Idiopathic PUB has unique clinical characteristics such as re-bleeding after initial hemostasis upon admission. Therefore, these patients need to undergo close surveillance upon admission.