Environmental factors in aetiology of chronic gastric ulcer: a case control study of exposure variables before the first symptoms.

The aim of the present study was to determine whether there is indication that either smoking, alcohol ingestion, or ingestion of analgesic or non-salicylate non-steroidal anti-inflammatory drugs plays any role in the development of chronic gastric ulcer disease. A group of 104 patients with gastric ulcer was compared with an age, sex and social grade matched community control population as regards exposure to the above factors during three time periods--the lifetime, five year and one year periods before the initial onset of the patients' ulcer symptoms. In all three study periods a statistically significant risk of gastric ulcer was found to be associated with smoking, and the daily use of aspirin, indomethacin and of other non-salicylate non-steroidal anti-inflammatory drugs as a group, but not with alcohol or daily use of paracetamol. As exposure to the environmental factors preceded the initial onset of ulcer symptoms, causal relationships are suggested. Assuming the association are causal, it can be calculated that possibly up to 80% of gastric ulcer disease is attributable to smoking and the daily ingestion of analgesic and anti-inflammatory drugs.