Clinical characteristics of gastroesophageal reflux disease in Japan.

BACKGROUND/AIMS: Little is known about the correlation between clinical symptoms in daily life and the endoscopic features of gastroesophageal reflux disease (GERD). The study aim is to evaluate the correlation between clinical symptoms in daily life and endoscopic findings in reflux esophagitis (RE), and endoscopically suspected esophageal metaplasia (ESEM) in a large number of Japanese non-clinical cases. METHODOLOGY: A total of 6504 subjects who underwent an endoscopy for their annual medical check-up at Miyagi cancer society were enrolled in this study. If esophagitis was present, it was graded according to the Los Angeles classification. ESEM describes endoscopic findings consistent with BE that await histological evaluation. It was also investigated the symptom of heartburn as a "typical symptom" of GERD, and dysphagia as an "atypical symptom" of GERD. RESULTS: The prevalence of heartburn and dysphagia significantly increased concomitantly with endoscopic the esophagitis grading. The prevalence of heartburn was significantly higher in subjects with long segment ESEM than those without it. CONCLUSION: The prevalence of heartburn and dysphagia were closely associated with RE grading. Long segment ESEM is strongly associated with the reflux symptom and RE. The more frequent the GERD symptoms, the greater the risk for the development of severe RE, and ESEM.

Simple quantification of lansoprazole and rabeprazole concentrations in human serum by liquid chromatography/tandem mass spectrometry.

A rapid, simple and highly sensitive method was developed for the quantitative determination of lansoprazole and rabeprazole concentrations in 20 microL of human serum using high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS). Analytes, along with an internal standard (lansoprazole deuterium derivatives), were separated using a mobile phase of acetonitrile/1mM ammonium formate (140/60, v/v) on a C18 analytical column and analyzed in the selected reaction-monitoring (SRM) mode. The lower limit of quantification was 0.25 ng/mL. A good linear response was observed for each analyte (from 0.25 ng to 2.5 microg/mL). This method was useful for therapeutic drug monitoring and pharmacokinetic studies.

Prevalence of gastroesophageal reflux symptoms in a large unselected general population in Japan.

AIM: To examine the prevalence of gastroesophageal reflux disease (GERD) symptoms in a large unselected general population in Japan. METHODS: In Japan, mature adults are offered regular check-ups for the prevention of gastric cancer. A notice was sent by mail to all inhabitants aged>40 years. A total of 160983 Japanese (60774 male, 100209 female; mean age 61.9 years) who underwent a stomach check up were enrolled in this study. In addition, from these 160983 subjects, we randomly selected a total of 82894 (34275 male, 48619 female; mean age 62.4 years) to evaluate the prevalence of abdominal pain. The respective subjects were prospectively asked to complete questionnaires concerning the symptoms of heartburn, dysphagia, and abdominal pain for a 1 mo period. RESULTS: The respective prevalences of the symptoms in males and females were: heartburn, 15.8% vs 20.7%; dysphagia, 5.4% vs 7.8%; and abdominal pain, 6.6% vs 9.6%. Among these symptoms, heartburn was significantly high compared with the other symptoms, and the prevalence of heartburn was significantly more frequent in females than in males in the 60-89-year age group. Dysphagia was also significantly more frequent in female patients. CONCLUSION: The prevalence of typical GERD symptoms (heartburn) was high, at about 20% of the Japan population, and the frequency was especially high in females in the 60-89 year age group.

Stronger inhibition of gastric acid secretion by lafutidine, a novel H2 receptor antagonist, than by the proton pump inhibitor lansoprazole.

AIM: To compare the antisecretory activity and plasma drug concentrations of a single oral dose of 10 mg lafutidine, a novel H2 receptor antagonist, with those of the proton pump inhibitor lansoprazole (LPZ) 30 mg. METHODS: Ten volunteers without H pylori infection participated in this crossover study comparing lafutidine 10 mg with LPZ 30 mg. Intragastric pH was monitored for 6 h in all participants, and blood samples were collected from four randomly selected individuals after single-dose administration of each drug. RESULTS: The median intragastric pH was significantly higher in individuals who received lafutidine 10 mg than in those who received LPZ 30 mg 2, 3, 4, 5, and 6 h after administration. Maximal plasma drug concentration was reached more promptly with lafutidine 10 mg than with LPZ 30 mg. CONCLUSION: In H pylori-negative individuals, gastric acid secretion is more markedly inhibited by lafutidine than by LPZ.

Tongue-like Barrett's esophagus is associated with gastroesophageal reflux disease.

AIM: To test this hypothesis of barrett esophagus (BE) classified into two types and to further determine if there was any correlation between the shape of endoscopically suspected esophageal metaplasia (ESEM), prevalence of reflux esophagitis (RE) and heartburn. METHODS: A total of 6504 Japanese who underwent endoscopy for their annual stomach check-up were enrolled in this study. BE was detected without histological confirmation that is ESEM. We originally classified cases of ESEM into 3 types based on its shape: Tongue-like (T type), Dome-like (D type) and Wave-like (W type) ESEM. The respective subjects were prospectively asked to complete questionnaires concerning the symptoms of heartburn, dysphagia, and abdominal pain for a one-month period. RESULTS: ESEM was observed in 10.3% of 6504 subjects (ESEM < 1 cm, 9.4%; 1 cm < or = ESEM < 3 cm, 1.7%; ESEM > or = 3 cm, 0.5%). The frequency of ESEM was significantly higher in males compared with female subjects. Statistical analysis showed that the prevalence of heartburn and RE were significantly higher in the T type ESEM than in the W type ESEM (P < 0.05). CONCLUSION: The T type ESEM was strongly asso-ciated with reflux symptoms and RE whereas the W type ESEM was not associated with GERD.

Early effects of Lansoprazole orally disintegrating tablets on intragastric pH in CYP2C19 extensive metabolizers.

AIM: To compare rabeprazole (RPZ; 10 mg) with Lansoprazole orally disintegrating tablets (LPZ; 30 mg OD) in terms of antisecretory activity and blood drug concentration after a single dose. METHODS: Eight H pylori -negative cytochrome P450 (CYP) 2C19 extensive metabolizers were assigned to receive a single oral dose of RPZ 10 mg or LPZ 30 mg OD. Twelve hour intragastric pH monitoring was performed on the day of treatment. Blood samples were also collected after the administration of each drug. RESULTS: LPZ 30 mg OD induced a significantly earlier rise in blood drug concentration than RPZ 10 mg; consequently, LPZ 30 mg OD induced a significantly earlier rise in median pH in the third and fourth hours of the study. CONCLUSION: In H pylori-negative CYP2C19 extensive metabolizers, LPZ 30 mg OD induced a significantly faster inhibition of gastric acid secretion than RPZ 10 mg.

Preservation of gastric acid secretion may be important for the development of gastroesophageal junction adenocarcinoma in Japanese people, irrespective of the H. pylori infection status.

BACKGROUND: We have previously reported that Helicobacter pylori infection prevents reflux esophagitis (RE) and Barrett's esophagus (BE) by decreasing gastric acid secretion. Gastroesophageal (GE) junction adenocarcinoma, including Barrett's adenocarcinoma, has been thought to be a complication of gastroesophageal reflux disease (GERD). However, the relationship between H. pylori infection, gastric acid secretion, and GE junction adenocarcinoma has not yet been investigated in Japan. The aim of this study was to evaluate this relationship in the Japanese population. METHODS: A total of 168 Japanese patients (RE alone: 80, short-segment BE (SSBE): 16, long-segment BE (LSBE): 20, GE junction adenocarcinoma: 12, distal early gastric cancer (EGC): 40; male/female = 106/62; mean age 61.5 yr) and 80 Japanese control subjects who had no localized lesions in the upper gastrointestinal tract (male/female = 43/37, mean age 58.1 yr) were enrolled for this study. The prevalence of H. pylori infection was determined by biopsy, the rapid urease test, and measurement of the serum H. pylori IgG antibody. Gastric acid secretion was assessed by the endoscopic gastrin test (EGT). RE was diagnosed according to the Los Angeles classification. RESULTS: The prevalence of H. pylori infection in the patients with RE alone (30%) was significantly lower than that in control subjects (71.2%). There was also a tendency for the prevalence of H. pylori infection to be lower in patients with BE (SSBE, 18.7%; LSBE, 0%) when compared to that in patients with RE alone. On the other hand, while the prevalence of H. pylori infection in patients with GE junction adenocarcinoma (58.3%) was significantly lower than that in patients with EGC (87.5%), it tended to be higher than that in patients with RE alone or BE. The mean EGT value in patients with RE alone (3.74 mEq/10 min) was significantly higher than that in control subjects (1.83). The mean EGT value in patients with BE (SSBE, 4.74; LSBE, 4.76) tended to be even higher than that in patients with RE alone. The mean EGT value in patients with GE junction adenocarcinoma (3.94) was significantly higher than that in control subjects and patients with EGC (0.67), but it was comparable to that independent of the H. pylori infection status in patients with RE alone or BE. CONCLUSION: Preservation of gastric acid secretion may be important for the development of GE junction adenocarcinoma in Japanese people, irrespective of the H. pylori infection status.