Review article: historic changes of Helicobacter pylori-associated diseases.

BACKGROUND: The long-term time trends of multiple gastrointestinal diseases are characterised by a striking rise and fall. These temporal changes provide important clues about disease aetiology.

AIM: To highlight the importance of Helicobacter pylori infection in shaping the temporal trends of many common gastrointestinal diseases.

METHODS: Literature review of the time trends associated with common digestive diseases.

RESULTS: The general trends of gastric ulcer, duodenal ulcer, gastric cancer, colon cancer, rectum cancer have all been shaped by a similar underlying birth-cohort phenomenon. Mortality associated with these diagnoses increased in all generations born during the nineteenth century. It peaked among generations born shortly before the turn of the century and then decreased in all subsequent generations born throughout the twentieth century. These patterns can be observed in the incidence, hospitalisation and mortality data from many different countries. They reflect similar rising and falling trends of H. pylori infection in the general population. Diseases that are inversely associated with H. pylori, such as reflux disease, erosive oesophagitis, Barrett's oesophagus, and oesophageal adenocarcinoma, have seen a striking rise during the recent decline of H. pylori infection.

CONCLUSION: The temporal variations of H. pylori infection have affected the occurrence of gastroenterology's most common disorders.