The factors affecting gastric and duodenal ulcers in Japanese factory workers. A case-control study.

Factors affecting gastric and duodenal ulcers in factory workers were examined by a case-control study of 74 male cases of active and inactive ulcers and in the same number of control subjects by the use of our past study materials. The cases were found by mass surveys for gastrointestinal disease over a period of four years at a plastics processing factory with 348 male workers; the controls were workers at the same factory in whom no ulcers were diagnosed in the surveys and were matched to each case by sex (all males), age (same 5-year span), type of work and job position. The results indicated that a) smoking was a major factor in gastric ulcers, and b) existence of ulcers in first or second degree relatives and eating at irregular intervals were two major factors for duodenal ulcers. Psychosocial factors such as frustration at work and in the family were not significantly associated with either gastric or duodenal ulcers. In the light of these findings, it was suggested that workers should be encouraged to refrain from smoking and to eat at regular intervals in order to prevent and recover from gastric and duodenal ulcers.