Decrease of serum level of gastrin in healthy Japanese adults by the change of Helicobacter pylori infection

Background and Aim In Japan, the prevalence of Helicobacter pylori infection is decreasing and the number of patients who receive eradication therapy is increasing. Although the serum level of gastrin is affected by H. pylori infection, the normal level has been unchanged for more than 20 years. The aim of this study was to study whether the present normal range for the serum gastrin level is appropriate for Japanese at present or in the near future. Methods We studied 810 adults (40–80 years old) who participated in a health survey in 2012. We measured H. pylori stool antigen, titer of serum antibody to H. pylori, and serum level of gastrin. The patient's H. pylori status was defined as positive or negative when the results of both stool antigen and serology were concordant. Subjects who were taking proton‐pump inhibitor and had a previous history of gastric surgery were excluded. Results Mean serum level of gastrin was 66.2 ± 49.6 pg/mL in 281 H. pylori‐negative subjects and 69.7 ± 42.2 pg/mL in 115 patients who had H. pylori eradicated at least 2 years ago. The level of gastrin was 134.4 ± 145.6 pg/mL in 224 patients with H. pylori infection and the level was significantly higher when compared with those in uninfected subjects and eradicated patients (P