Objective: To study the association between alcohol consumption and death from coronary heart disease and to determine the extent to which the association can be explained by the high-density lipoprotein (HDL) cholesterol level.
Design: A cohort study involving men enrolled in the Multiple Risk Factor Intervention Trial (MRFIT).
Setting: Community-based study.
Participants: Men (n = 11,688) at high risk for developing coronary heart disease but without clinical evidence of it. More than 90% of the men were white, and the average age was 46 years. Five percent of the men abstained from alcohol during the trial, 81% consumed fewer than 21 alcoholic drinks per week, and 14% consumed more than 21 alcoholic drinks per week.
Measurements: Average alcohol intake over 7 years was calculated for MRFIT participants who were alive at the end of the trial and who had at least three follow-up records of alcohol consumption. Post-trial mortality during a 3.8-year period was assessed.
Results: The adjusted relative risk for death from coronary heart disease for each increase of 7 drinks per week was 0.89 (95% CI, 0.80 to 1.00), with an apparent dose-response relationship. The average HDL level was associated with the average alcohol intake in a least-squares regression model (beta = -0.0074; P less than 0.01). When the average HDL level was included in the proportional hazards model for mortality from coronary heart disease, the absolute value of the coefficient for average drinks per week declined 45%, yielding an adjusted relative risk for each additional 7 drinks per week of 0.94 (CI, 0.84 to 1.05).
Conclusion: In middle-aged men who are light to moderate drinkers, the inverse association between alcohol consumption and death from coronary heart disease can be explained, in large part, by the HDL cholesterol level, which increases with alcohol consumption. However, alcohol consumption cannot be recommended because of the known adverse effects of excess alcohol use.