Dilated cardiomyopathy and the level of alcohol consumption: a planned multicentre case-control study

The association between clinical or environmental factors and dilated cardiomyopathy (DCM) has been assessed in a planned case-control study. Patients and controls were men aged between 20 and 65 years, matched for age, profession and geographic location. DCM was defined by strict radiologic and angiographic criteria excluding multiple-vessel coronary disease. Controls were recruited from the surgical centres after excluding diseases usually linked with alcohol or tobacco consumption. Univariate and multivariate analyses were used to ensure adequate techniques for matched pairs. The prevalence of diabetes and hypertension and the exposure to toxic substances, drugs and tobacco was identical in both groups. Alcohol consumption before the onset of first symptoms was higher in patients than in controls (101 vs 64 ml day-1, P less than 0.001); the excess of consumption concerns all kinds of alcoholic beverage (wine, beer, etc.). The relative risk (RR), estimated from the odds ratio, increased only among heavy drinkers (greater than or equal to 110 ml day-1; RR: 7.6, P less than 0.001) with an independent contribution of both wine (RR: 4.7, P less than 0.001) and other alcoholic beverages (RR: 4.1, P less than 0.01). In conclusion, alcohol is a strong risk factor for DCM, but the excess of risk is limited to heavy drinkers and is independent of the type of beverage.