Influence of serum triglyceride levels on the risk for myocardial infarction in 12 510 middle aged males: interaction with serum cholesterol

Objective: To study the influence of different levels of serum (s)-triglycerides in relation to s-cholesterol on the risk of myocardial infarction. Design and subjects: A 6–13 (mean 10) year follow-up of 12 510 middle-aged men. Fasting s-triglycerides and s-cholesterol were measured at the screening examination. Setting: Section of Preventive Medicine at the Department of Internal Medicine, Malmö General Hospital, an urban hospital for 240 000 inhabitants in southern Sweden. Intervention: In minor groups of patients there were interventions addressing high lipid levels, high alcohol consumption, hypertension and glucose intolerance. Main outcome measure: Myocardial infarction was used as an end-point. Results: 446 myocardial infarctions occurred. The cumulative incidence rates were for the lowest triglyceride quartile 1.2%, for the second 3.2%, for the third 4.1% and for the highest 5.6%. After adjustment for age, year of screening, body mass index, diabetes, smoking, hypertension and s-cholesterol there was a significant relationship between triglycerides and the relative risk for myocardial infarction ( P for trend=0.0087). For increasing levels of triglycerides, adjusted for the above factors except cholesterol, the impact of a certain cholesterol value for the occurrence of myocardial infarction was increased ( P for trend=0.0092). Conclusions: The present study emphasizes the interaction between cholesterol and triglyceride values for the risk of myocardial infarction. It is concluded that at triglyceride values above 1.0 mmol/l and cholesterol above 6.8 mmol/l there is an increasing interaction between cholesterol and triglyceride levels that might be of importance when evaluating the cardiovascular risk of middle aged men.