Alcohol increases circulatory disease mortality in Russia: acute and chronic effects or misattribution of cause?

BACKGROUND: There is a consensus that the large fluctuations in mortality seen in Russia in the past two decades can be attributed to trends in alcohol consumption. However, the precise mechanisms linking alcohol to mortality from circulatory disease remain unclear. It has recently been argued that a substantial number of such deaths currently ascribed to cardiovascular disorders are misclassified cases of acute alcohol poisoning. METHODS: Analysis of routine mortality data and of a case-control study of mortality among working-age (25-54 years) men occurring in the Russian city of Izhevsk, west of the Ural mountains, 2003-05. Interviews were carried out with proxy informants for both the dead cases (N = 1750) and the controls (N = 1750) selected at random from a population register. Mortality was analysed according to indicators of alcohol problems. RESULTS: Hazardous drinking was associated with an increased risk of death from circulatory diseases as a whole odds ratio (OR) = 4.14, 95% confidence interval (CI) 3.23, 5.31 adjusted for age, smoking and education. The association with alcoholic cardiomyopathy was particularly strong (OR = 15.7, 95% CI 9.5, 25.9). Although there was no association with deaths from myocardial infarction (MI; OR = 1.17, 95% CI 0.59, 2.32), there was a strong association with the aggregate of all other ischaemic heart disease (IHD; OR = 4.04, 95% CI 2.79, 5.84). Stronger associations for each of these causes (other than MI) were seen with whether or not the man had drunk very heavily in the previous week. However, associations also remained when analyses were restricted to subjects with no evidence of recent heavy drinking, suggesting that misclassification of acute alcohol poisonings is unlikely to explain these overall associations. CONCLUSION: Taken as a whole, the available evidence suggests that the positive association of alcohol with increased cardiovascular disease mortality may be best explained as being the result of a combination of chronic and acute alcohol consumption resulting in alcohol-related cardiac disorders, especially cardiomyopathy, rather than being due to misclassification of acute alcohol poisoning. Further work is required to understand the mechanisms underlying the link between heavy alcohol consumption and deaths classified as being due to IHD (other than MI).