Alcohol intake and cardiovascular and gastrointestinal diseases: Do other factors matter?

    Research output: ThesisDoctoral Thesis

    Abstract

    Alcohol is used all over the world and in most Western societies,
    the average intake is high. Alcohol is associated with more
    than 60 diseases and globally, 4% of all deaths are attributable
    to alcohol.
    The aim of the present thesis is to study associations between
    alcohol intake and risk of coronary heart disease (CHD),
    atrial fibrillation, liver cirrhosis and pancreatitis, and more
    specifically, to review the data for differential effects of alcohol
    according to modifying factors on these diseases.
    The thesis is based on the results from 10 epidemiological
    studies, conducted in the Copenhagen City Heart Study, the
    Diet, Cancer and Health Study and the Pooling Project of Diet
    and Coronary Disease. In all study cohorts, a lower risk of CHD
    was observed in light and moderate alcohol drinkers. In the
    Copenhagen City Heart Study, we also found that increasing
    alcohol intake was associated with increasing HDL cholesterol
    and non-fasting triglycerides, higher systolic and diastolic
    blood pressure and decreasing fibrinogen. In contrast, ADH1B
    and ADH1C genotypes were not associated with risk of CHD or
    with any of the cardiovascular biomarkers, and there was no
    indication that associations between alcohol intake and CHD
    and between alcohol intake and biomarkers were modified by
    genotypes. The finding that ADH genotypes are not modifying
    the association between alcohol and CHD was confirmed in the
    Diet, Cancer and Health Study.
    In the Pooling Project of Diet and Coronary Disease, we
    found that the association between alcohol and relative risk of
    CHD was similar in young adults (39-50 years), middle-aged
    (50-60 years) and older individuals (60+ years). However,
    since the incidence of CHD is low in young adults, the incidence
    rate difference between nondrinkers and moderate
    drinkers was much smaller in young adults than in older individuals,
    hence, for young adults, the absolute beneficial effect
    of alcohol is small.
    Alcohol has differential effects on the risk of mortality and
    CHD according to drinking pattern. In the Diet, Cancer and
    Health Study, we found that for the same weekly amount of
    alcohol intake, a non-frequent intake implied a higher risk of
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    death than a frequent one. For CHD, drinking frequency may
    be the primary determinant of the inverse association between
    alcohol intake and CHD: The risk of CHD was lower
    among men who drank alcohol on more days of the week,
    compared to men who drank alcohol on fewer days of the
    week, independent of the total weekly amount of alcohol intake.
    The risk of atrial fibrillation according to alcohol intake
    seems to be threshold-shaped; In the Copenhagen City Heart
    Study, no increased risk was observed among light to moderate
    drinkers and an increased risk only among individuals
    drinking >35 drinks per week.
    Also in the Copenhagen City Heart Study, the risk of liver
    cirrhosis was strongly associated with increasing alcohol
    intake. Further, we found that increasing alcohol intake associated
    with biomarkers for liver damage (alanine aminotransferase,
    albumin, alkaline phosphatase, bilirubin, coagulation
    factors II, VII and X, -glutamyl transpeptidase and mean erythrocyte
    volume). In contrast, ADH1B and ADH1C genotypes
    were not associated with a risk of liver cirrhosis or with any of
    these biomarkers, and there was no indication that associations
    between alcohol intake and liver cirrhosis and between
    alcohol intake and biomarkers were modified by genotypes.
    Finally, we observed that alcohol intake was associated
    with an increased risk of pancreatitis. Smoking was also associated
    with an increased risk of pancreatitis, which was independent
    of alcohol and of gallstone disease; two risk factors
    suggested as being the main causes of pancreatitis.
    In conclusion, the results show that the association between
    alcohol and CHD is independent of genetic variation in
    alcohol-degrading enzymes. The alcohol drinking pattern is
    independently associated with risk of coronary heart disease
    and all-cause mortality. The beneficial effect of alcohol on CHD
    is observed among both young adults, middle-aged and elderly,
    but the magnitude of the absolute beneficial effect is least
    among the young adults. Both alcohol and smoking are associated
    with increased risk of pancreatitis. These results are
    important for future studies of the biological effects of alcohol
    on health and for public guidelines on alcohol.
    Original languageDanish
    Publisher
    Publication statusPublished - 2011

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