Influence of pattern of drinking on cardiovascular disease and cardiovascular risk factors - a review

There is an established inverse relationship between the regular light cons umption of alcohol (5-10g/day) and the incidence of coronary artery disease (CAD). This association has several biologically plausible mechanisms with dose-dependent effects of alcohol to increase HDL cholesterol, lower plasm a fibrinogen and inhibit platelet aggregation. However, such a protective e ffect against atheroma cannot be considered in isolation from known adverse effects on blood pressure and triglycerides or possible detrimental effect s of episodic or binge drinking on several other cardiovascular end-points and risk factors. In subjects with pre-existing CAD, an alcoholic binge can increase both silent myocardial ischaemia and angina. During withdrawal fo llowing binge drinking, marked fluctuations in blood pressure together with heightened platelet activation and adverse changes in the balance of fibri nolytic factors, may offer an explanation for the reported association betw een episodic heavy drinking and ischaemic stroke. This has been seen partic ularly in young males and extends further to an increase in both subarachno id haemorrhage and intracerebral haemorrhage after binge drinking. Interven tion studies in man have shown acute increases in blood pressure in men who drink predominantly at weekends, compared to longer-term presser effects i n regular daily drinkers. We have been unable, however, to reproduce the fi nding of unfavourable effects of binge drinking on the lipid profile that h ave been reported in animal studies and man. Binge drinking may also induce cerebrovascular spasm or cause both ventricular and supraventricular arrhy thmias, especially atrial fibrillation. Alcohol-induced arrhythmia has been postulated as the basis for alcohol-related sudden coronary death in those subjects with pre-existing CAD. Hence, further exploration of any protecti ve association of alcohol against CAD needs to carefully consider the impli cations of pattern of drinking for the relationship. The modulating influen ces of co-timing of drinking with meals, cigarette smoking or illicit drug use also need to be evaluated. Without such vital information, public healt h advice on alcohol and CAD will be limited in its scope and potentially fl awed in its impact.