Alcohol consumption decreases with the development of disease
In a cross-sectional study from the 2004 and 2007 Australian National Drug Strategy Household (NDSH) surveys, respondents were questioned about their current and past drinking, the presence of formal diagnosis for specific diseases (heart disease, type 2 diabetes, hypertension, cancer, anxiety, depression) and self-perceived general health status. The sample sizes for the 2004 and 2007 NDSH surveys were 24,109 and 23,356, respectively.
The authors report that respondents with a diagnosis of diabetes, hypertension, or anxiety were more likely to have reduced or stopped alcohol consumption in the past 12 months. The likelihood of having reduced or ceased alcohol consumption in the past 12 months increased as perceived general health status declined from excellent to poor (although the authors do not point out that lifetime abstainers were more likely than moderate drinkers to report less than excellent health status).
The authors conclude that the experience of ill health is associated with subsequent reduction or cessation of alcohol consumption (“sick quitters), which is consistent with most prospective epidemiologic studies. The authors also conclude that this may at least partly underlie the observed ‘J-shaped’ function relating alcohol consumption to premature mortality. On the other hand, most modern epidemiologic studies are careful not to include “sick quitters” within the non-drinking category, and relate health effects of drinkers with those of lifetime abstainers. Further, prospective studies in which alcohol intake is assessed at different times (rather than having “changes” based only on recall at one point in time, as was done in this study) usually indicate that subjects who decrease their intake are more likely to subsequently develop adverse health outcomes, especially related to cardiovascular disease, than those who continue moderate drinking.
Source: Liang W, Chikritzhs T. Reduction in alcohol consumption and health status. Addiction 2010; in press (doi:10.1111/j.1360-0443.2010.03164.x).
The detailed critique of this study by the International Scientific Forum on Alcohol Research is available at www.bu.edu/alcohol-forum/critique-022-alcohol-consumption-decreases-with-the-development-of-disease-21-november-2010/
References from Forum Review:
1. Wellmann J, Heidrich J, Berger K, Döring A, Heuschmann PU, Keil U. Changes in alcohol intake and risk of CHD and all-cause mortality in the MONICA-Augsburg cohort 1987-1997. EJCPR 2004;11:48-55.
2. Valmadrid CT, Klein R, Moss SE, Klein BE, Cruickshanks KJ. Alcohol intake and the risk of coronary heart disease mortality in persons with older-onset diabetes mellitus. JAMA. 1999;21;282:239-246.
3. Solomon CG, Hu FB, Stampfer MJ, Colditz GA, Speizer FE, Rimm EB, Willett WC, Manson JE. Moderate alcohol consumption and risk of coronary heart disease among women with type 2 diabetes mellitus. Circulation 2000;102:494-949.
4.. Ajani UA, Gaziano JM, Lotufo PA, Liu S, Hennekens CH, Buring JE, Manson JE. Alcohol consumption and risk of coronary heart disease by diabetes status. Circulation. 2000;102:500-505.
Comments included in this critique by the International Scientific Forum on Alcohol Research were provided by the following:
Ross McCormick PhD, MSC, MBChB, Associate Dean, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
Creina Stockley, clinical pharmacology, Health and Regulatory Information Manager, Australian Wine Research Institute, Glen Osmond, South Australia, Australia.
Harvey Finkel, MD, Hematology/Oncology, Boston University Medical Center, Boston, MA, USA.
Pierre-Louis Teissedre, PhD, Faculty of Oenology – ISVV, University Victor Segalen Bordeaux 2, Bordeaux, France.
Erik Skovenborg, MD, Scandinavian Medical Alcohol Board, Practitioner, Aarhus, Denmark.
R. Curtis Ellison, MD, Section of Preventive Medicine & Epidemiology, Boston University School of Medicine, Boston, MA, USA.
Ulrich Keil, MD, PhD, Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany.
Dominique Lanzmann-Petithory,MD, PhD, Nutrition/Cardiology, Praticien Hospitalier Hôpital Emile Roux, Paris, France.
David Vauzour, PhD, Dept. of Food and Nutritional Sciences, The University of Reading, UK.
Comments by Gerry Shaper, Emeritus Professor of Clinical Epidemiology, University College Medical School, London
I have read with interest the AIM critique on the recent paper by Liang and Chikritzhs in Addiction and I venture to make some comment on it as it is an area of the alcohol story in which I have a longstanding interest through the British Regional Heart Study (BRHS) (www.ucl.ac.uk/primcare-popsci/brhs).
1. Sick Quitters. The term “sick quitters” is unfortunate in that it carries the unintended implication that the person who has quit drinking or reduced their alcohol intake, has done so for reasons associated with alcohol usage. Although ISFAR makes it clear that “sick quitters” need not be due to alcohol, most readers still believe this to be so. Any study of ex-drinkers or those who have markedly reduced their alcohol intake will show that it is only a small minority who have done so through an illness directly associated with the use of alcohol. Most ex-drinkers and most of those who make significant reductions in their intake usually do so as they age and because of physical or mental ill health, medication, economic factors or other changes in life-style that are conducive towards a reduction in alcohol consumption.
2. Lifelong abstainers. The critique remarks that “the authors do not point out that lifetime abstainers were more likely than moderate drinkers to report less than excellent health status”. This has been the finding in other studies as well and one of the problems with using lifetime abstainers as a baseline is that the reasons for being a lifetime abstainer differ in different communities and many who claim to be lifelong abstainers are often ex-drinkers of long duration. Lifelong abstainers are too unusual and usually too small a group to be used as a baseline..
3. Exclusion of ‘sick quitters’. Your critique states that “most modern epidemiological studies are careful not to include ‘sick quitters’ within the non-drinking category and relate (compare) health effects of drinkers with those of lifelong abstainers or with regular light drinkers”. The problem with this statement is that few studies use light regular drinkers as the baseline and different authors vary in their definition of “sick quitters”. Many make the assumption that I have referred to in my first paragraph above i.e that the illness is associated with previous excess alcohol intake (e.g having been a heavy drinkers). The comparison of groups of drinkers with lifelong abstainers has other problems and I have referred to this in my second paragraph above.
Liang and Chikritzhs have argued that the phenomenon of the ‘sick quitter’ may be viewed as similar to the loss of subjects to clinic trials. “Subjects who begin as ‘drinkers’ but who ultimately stop [or markedly reduce] drinking while participating in a cohort study are analogous to subjects in clinical trials who drop out of treatment for reasons which are related to the prognosis itself. In clinical trials, subject dropout potentially introduces a bias, because people who complete a particular treatment may, at the outset, be predisposed to have a better outcome In the same way, people who do not become ex-drinkers may be predisposed to have better health outcomes”. This is a powerful and sustainable argument and should be considered.
4. Characteristics of drinking categories. Essential to any understanding of the analysis of the outcome in various drinking categories is a full tabular display of the health and life-style characteristics of the subjects in each drinking category. Usually the table showing these features, if it is provided at all, is brief and highly selective and gives little indication or true measure of the factors that might be affecting outcome in these subjects. It is no exaggeration to say that remarkably few papers carry a comprehensive table of health characteristics sufficient to enable the reader to get the feel of what the various groups of subjects are like. In the end, it is this that matters and not whether or not a person has been a previous drinker at a particular level. Most studies which do show the characteristics of the drinking categories, reveal that non-drinkers do have greater morbidity, more medication and worse life style characteristics than other groups. This situation worsens as the subjects age.
5. Prospective studies. Your critique states that in prospective studies assesssing change in alcohol intake at several points in time over many years follow-up, “that subjects who decrease their intake are more likely to subsequently develop adverse health outcomes“. This could well be an example of thinking in terms of reverse causation (‘circular reasoning’), and some studies, including the British Regional Heart Study, have shown that subjects developing ill health and going on to medication will, as a consequence, either reduce their alcohol intake or give it up completely. Indeed, this is a major point in the paper under consideration.
6. Suitable baseline. If lifelong abstainers are not suitable as a baseline group, and the non-drinking category is beset with problems,- what should we use as a baseline? In the best epidemiological tradition, perhaps one should look at the category with the healthiest characteristics and the best outcomes in morbidity and mortality, and that is usually the light regular drinkers. The BRHS has in the past suggested that the ‘occasional/light drinking’ category i.e less than 15 drinks/week, provides a large and satisfactory baseline group for comparative purposes. However, the ‘occasional’ drinking group may have health characteristics that are less satisfactory than the light regular drinkers of 1-2 drinks/day and so further studies, particularly in prospective studies with repeated checks on intake levels, should be carried out to compare the occasional and the light regular categories over time.