Aetiology of peptic ulcer: a prospective population study in Norway.

STUDY OBJECTIVE To analyse simultaneously the effect of several risk factors for peptic ulcer. DESIGN Cohort study where all patients with new or incident peptic ulcers in a well defined population were registered for a seven year period. The follow up started with a comprehensive health survey including a questionnaire on diet, lifestyle, psychological and social conditions, and health. Relative risks, both sex specific and separate, for gastric and duodenal ulcers were estimated from proportional hazard regression analysis. SETTING A population based survey conducted in the municipality of Tromsø, northern Norway. PARTICIPANTS In 1980, a total of 21,440 men and women, aged 20 to 54 years and 20 to 49 years respectively, were invited to participate. A total of 14,667 people attended and returned the questionnaire. MAIN RESULTS A total of 328 people had their first peptic ulcer in the follow up period. Age, cigarette smoking, first degree relatives with peptic ulcer, and low educational level were shared risk factors for peptic ulcer in both men and women. In men, frequent upper respiratory infections increased the risk of gastric ulcer and drinking a great deal of milk increased the risk of duodenal ulcer. None of the other dietary variables, including coffee and alcohol consumption, contributed significantly to the risk. Use of analgesics was not a risk factor, and none of the psychological indicators analysed carried any significant risk. CONCLUSIONS Age, inheritance, and cigarette smoking are all important risk factors for peptic ulcer. The increased risk associated with low educational background indicate that social strains, comprising lifestyle and diet habits, are part of the multifactorial aetiology of peptic ulcer. No support was found for the assumption that peptic ulcer disease is a psychosomatic disorder. This study did not support the view that duodenal and gastric ulcers have different aetiologies-rather it showed a similarity in risk patterns.