Intervention of smoking and eating habits in healthy men carrying high risk for coronary heart disease. The Oslo Study.

1232 healthy, normotensive, but coronary high risk men were selected for a 5-year randomized trial in order to show if lowering of serum lipids and cessation of smoking was followed by prevention of coronary heart disease. The men included in the trial had serum cholesterol between 7.5 mmol/l (290 mg/dl) and 9.8 mmol/l (380 mg/dl), coronary risk score (based on cholesterol, smoking and blood pressure) in the upper quartile of the distribution and systolic blood pressure less than 150 mm Hg. The men in the intervention group were recommended to stop smoking and to lower their blood lipids by dietary changes. On average, mean serum cholesterol concentration was 13 per cent lowered in the intervention group compared to the controls during the 5 years of the trial. Mean fasting serum triglycerides decreased by 20 per cent in the intervention group compared to the control group. Tobacco smoking was reduced about 50 per cent in the intervention group in relation to controls. (Eighty per cent of the men in both groups were daily cigarette smokers at the start of the study). Diagnoses of events of cardiovascular disease during the 5 years were made blindly by a diagnostic board not involved in the study, according to predefined criteria. At the end of the observation time the incidence of myocardial infarction (fatal and non-fatal) and sudden death was 47% lower in the intervention group than in the controls (p = 0.028, 2-sided test). It is concluded that in healthy, coronary high risk, middle-aged men, advice to change eating habits and to stop smoking, significantly reduces the incidence of a first event of myocardial infarction and sudden death.