Current issues of ACP Journal Club are published in Annals of Internal Medicine


Etiology

Inverse association between alcohol intake and risk for ischemic heart disease depended on the LDL cholesterol level

ACP J Club. 1996 Sept-Oct;125:51. doi:10.7326/ACPJC-1996-125-2-051


Source Citation

Hein HO, Suadicani P, Gyntelberg F. Alcohol consumption, serum low density lipoprotein cholesterol concentration, and risk of ischaemic heart disease: six year follow up in the Copenhagen male study. BMJ. 1996 Mar 23;312:736-41.


Abstract

Objective

To examine the association between alcohol consumption, low-density lipoprotein (LDL) cholesterol levels, and risk for ischemic heart disease (IHD).

Design

Cohort analytic study with 6-year follow-up of participants in the Copenhagen male study.

Setting

Copenhagen, Denmark.

Participants

2826 men aged 53 to 74 years without a history of acute myocardial infarction, angina, stroke, or intermittent claudication.

Assessment of risk factors

Between 1985 and 1986, a baseline questionnaire and examination were done that included measurements of height, weight, and blood pressure; the recording of an electrocardiogram; and information on tobacco use, physical activity, and social class. Venous blood was taken after 12 hours of fasting for measurement of serum lipid levels. Weekly alcohol consumption was calculated from questionnaire items about average intake, with beer, wine, and spirits recorded separately.

Main outcome measure

Incidence of IHD.

Main results

172 men (6%) had a first ischemic event during follow-up; 42 were fatal. A strong inverse association existed between alcohol consumption and risk for IHD in the highest fifth of LDL cholesterol level. In men with a high LDL cholesterol level (≥ 5.25 mmol/L), the cumulative incidence rates of IHD were 16.4% for abstainers, 8.7% for those who drank 1 to 21 beverages/wk, and 4.4% for those who drank ≥ 22 beverages/wk. Compared with abstainers, men who drank ≥ 22 alcoholic beverages/wk had a relative risk (RR) for IHD of 0.2 (95% CI 0.1 to 0.8, P < 0.01) and men who drank 1 to 21 alcoholic beverages/wk had a RR of 0.4 (CI 0.2 to 1.0, P < 0.05). In the distributions of LDL cholesterol levels < 5.25 mmol/L, the inverse association between alcohol intake and IHD was not significant. All-cause mortality was independent of alcohol use.

Conclusions

In middle-aged and elderly men, a strong association existed between alcohol use, low-density lipoprotein cholesterol levels, and risk for ischemic heart disease. The inverse association between alcohol consumption and the risk for ischemic heart disease depended on low-density lipoprotein cholesterol levels.

Sources of funding: King Christian X's Foundation; Danish Medical Research Council; Danish Heart Foundation; Else and Mogens Wedell-Wedellsborg Foundation.

For article reprint: Dr. H.O. Hein, Copenhagen Male Study, Epidemiological Research Unit, 7122 Rigshospitalet, State University Hospital, DK-2200 Copenhagen N, Denmark.


Commentary

Review: Modest alcohol consumption lowers risk for coronary heart disease irrespective of the type of drink

Numerous studies over the past few decades have evaluated the association between alcohol consumption and mortality from CHD. Most studies have shown that there is a J-shaped association; that is, persons who drink moderately live longer than those who drink heavily and those who drink rarely or not at all. Increased mortality among abstainers was initially thought to be because of higher mortality among recovering alcoholics; however, well-designed studies have shown that this is not the case.

One of the most interesting and controversial questions about the benefits of moderate alcohol consumption is whether some types of alcohol are more beneficial than others. A perception exists among many, perhaps aided by the popular press, that wine, particularly red wine, is the drink responsible for all the benefit. As Rimm and colleagues document, this is far from clear. They systematically reviewed ecological, case-control, and cohort studies to determine the effect of consumption of beer, wine, and spirits. In ecological studies, the average alcohol intake per capita is compared with the mortality rate from CHD across many countries and regions. Because the results of these studies are based on population averages and not on individual measurements, they are subject to bias and are best used for generating hypotheses. Many ecological studies suggest that wine is most effective in reducing the risk for mortality from CHD, perhaps accounting for this popular view. The 10 prospective cohort studies showed quite different results—it is more likely that the benefit is caused by the alcohol and not by the individual type of liquor. Thus, at this point, there is no evidence that patients (and physicians) who drink beer or spirits should switch to wine.

Another important question is: What mechanism is responsible for the beneficial effect of moderate alcohol consumption? Approximately half the benefit is caused by the rise in high-density lipoprotein cholesterol levels produced by moderate alcohol consumption. Recent evidence has shown that moderate al-cohol consumption increases levels of tissue plasminogen activator, thereby decreasing the risk for thrombosis (1). LDL cholesterol levels are not considered to be an important factor in the decrease in mortality from moderate alcohol consumption.

Hein and colleagues followed nearly 3000 Danish men for 6 years. They found that the association between alcohol consumption and risk for CHD depended highly on LDL cholesterol levels. In multivariate analysis, an association between alcohol consumption and the rate of CHD was only present with higher LDL cholesterol levels (> 5.25 mmol/L). Hein and colleagues do not imply that alcohol intake decreases LDL cholesterol levels; rather, they conclude that the association between moderate alcohol consumption and decreased risk for ischemic heart disease occurs only among persons with higher LDL cholesterol levels. This is an important clinical distinction because it implies that persons with low LDL cholesterol levels will not benefit from moderate alcohol consumption. This needs to be confirmed in additional studies, particularly in different populations.

So, what can we tell our patients? We can advise them that moderate alcohol consumption (up to 1 to 2 drinks/d) lowers the rate of CHD and overall mortality and that the type of alcohol consumed does not matter. For each patient, we need to weigh his or her risk for heart disease with the risk for alcohol abuse. For women, we must also consider the risk for developing breast cancer, which increases with increased alcohol consumption (2).

Scott E. Sherman, MD, MPH
Department of Veterans Affairs Medical CenterSepulveda, California, USA


References

1. Ridker PM, Vaughan DE, Stampfer MJ, Glynn RJ, Hennekens CH. Association of moderate alcohol consumption and plasma concentration of endogenous tissue-type plasminogen activator. JAMA. 1994; 272: 929-33.

2. Willett WC, Stampfer, MJ, Colditz GA, et al. Moderate alcohol consumption and the risk of breast cancer. N Engl J Med. 1987;316:1174-80.