HF: Alcohol Intake (2007)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To compare the prevalence and cardiac status of male and female alcoholics with symptomatic dilated cardiomyopathy. 
Inclusion Criteria:
  • Heart failure (HF) Class II to IV.
  • Alcoholic cardiomyopathy
  • Normal coronary angiogram.
Exclusion Criteria:
  • Hypertension, valvular heart disease, peripartum cardiomyopathy, coronary heart disease or diabetes mellitus
  • Aged less than 16 or over 65 years
  • Neoplasms, terminal diseases or human immunodeficiency virus infection.
Description of Study Protocol:
  • Recruitment: Patients who visited the alcohol unit of the hospital clinic from 1991 to 1995 and patients who were admitted to the Departments of Medicine and Cardiology of the hospital clinic through the emergency department
  • Design: Longitudinal
  • Blinding used: All examinations were performed by personnel who had no knowledge of the amount of alcohol consumed by th subjects 
  • Intervention: None.

Statistical Analysis

  • The central tendencies of the quantitative variables were determined using the Student's T-test
  • Non-parametric tests were performed when necessary
  • The relationships between quantitative variables were determined by chi-square test and Fisher's exact test
  • Multi-variate analysis was performed by the multiple stepwise regression analysis, considering the parameters of the left ventricle dysfunction as continuous dependent variables
  • To study the different sensitivities to alcohol-induced cardiac damage in women vs. men,  alcoholic men and women matched for left ventricular ejection fractions were selected from one or two male patients with alcoholic cardiomyopathy with similar ejection fractions (±2%) for each woman with alcoholic cardiomyopathy,  thus resulting in a group of 10 women and 17 men with similar left ventricular ejection fractions (36.2±9% for women and 35.6±8% for men, respectively)
  • All variables are expressed as mean ±SD analyzed with SPSS software.
Data Collection Summary:

Timing of Measurements

  • Within 24 and after 72 hours after admission to the hospital for the acute effects of alcohol on the heart for blood and urine tests and for cardiac examinations, respectively
  • Nutritional intake was recorded one month prior to admission.

Dependent Variables

  • Variable One: Blood was measured within 24 hours of admission to the study for hematocrit, hemoglobin, red blood, white and platelet cell counts, prothrombin time, glucose, creatinine, electrolytes, uric acid, total protein, albumin, preablumin, retinol-binding protein, transferrin, aspartate and alanine aminotransferases, lactic dehydrogenase, creatine kinase, cholesterol and triglycerides. 
  • Variable Two: Ethanol levels in the blood and urine were determined within 24 hours of admission to the study.
  • Cardiac examinations were performed about 72 hours after admission and included a chest X-ray with the measurement of the cardiothoracic ratio, conventional electrocardiography, bidimensional echocardiography with a Toshiba SS-10 instrument, coronary angiography and a technetium-99m radionuclide angiocardiography with evaluation of left ventricular ejection fraction. End-diastolic and end-systolic indexes, shortening fraction and mass index of the left ventricle were measured according to the recommended standards of the American Society of Echocardiography. 
  • Total number of calories eaten daily for a month before admission was recorded together with the proportion corresponding to ethanol, carbohydrates, lipids and proteins. 
  • Overall nutrition was assessed in terms of the proportion of the actual weight to the ideal weight. The lean body mass and muscular area of the arm was calculated from the circumference of the upper non-dominant arm and the thickness of the tricipital skinfold. The fatty areas of the arm was estimated from the thickness of the tricipital skinfold and was considered as an indication of total body fat.
  • Nutritional proteins were estimated according to the values for total leukocytes, lymphocytes, total protein, albumin, prealbumin, transferrin and retinol-binding protein. Patients were considered to have caloric malnutrition if their body weight was below 90% of their ideal weight or if the calculated fat-free body mass was more than 10% below the normal values. Patients were considered to have protein malnutrition when three or more of the nutritional protein parameters were significantly diminished. 

Independent Variables

  • History of lifetime ethanol consumption was determined by interview, using a minimum of five "anchor points" to help recollection. These included marriage, childbirth, military service and workposts
  • The total lifetime dose of ethanol (kg per kg body weight) was estimated by multiplying the daily consumption of ethanol, as adjusted for variations reported by the patients, by the number of years of alcoholism multiplied by 365, and adding the amounts ingested during the different periods.
Description of Actual Data Sample:

Initial N

  • Alcoholic groups: 10 females (three in the outpatient drug unit and seven admitted for heart failure); 26 males (six in the outpatient drug unit and 19 admitted for heart failure)
  • Control group: 20 females and 20 males.

Attrition (Final N)

Same as above.

Mean Age

  • Controls: Females, 44±10 years; males, 44±9 years
  • Alcoholics: Females, 47±10 years; males, 51±7 years.

Ethnicity

Caucasian of Spanish origin living in and around Barcelona.

Other Relevant Demographics

Four of the alcoholic women and 21 of the alcoholic men smoked. Two of the women and 12 of the men had alcoholic cirrhosis.

Location

Barcelona, Spain.

Summary of Results:
  • Women consumed a significantly lower daily dose of alcohol (124±58g per day vs. 194±56g per day; P=0.002) for a shorter period of time (23±7 years vs. 29±6 years; P=0.017) and consumed a lower total lifetime dose of ethanol than men (17±7kg per kg body weight vs. 30±7kg per kg body weight; P=0.001). 
  • Chronic alcoholic women with heart failure presented more frequently with NYHA Functional Class II than men (P=0.01) and chronic alcoholic men with HF presented more frequently with NYHA Functional Class IV than women (P=0.03). 
  • No electrolyte disturbances were observed in the patients and there was no difference in the laboratory analyses between the male and female alcoholics. None of the patients presented with caloric or protein malnutrition. The women had a lower hemoglobin level than the men (P=0.01). Blood and urine levels of ethanol determined the day after admission were negative in all subjects. 
  • Chronic alcoholic women had a significantly lower left ventricular mass index than men (P<0.01). There were no other statistically significant differences between the alcoholic men and women in the cardiac studies.   
  • Differences in the cardiac status in women, with respect to men, were related to the total lifetime dose of ethanol consumed (P<0.04; all variables), but not to gender (P>0.15; all variables), suggesting that at the same level of cardiac dysfunction, women had consumed a significantly smaller amount of ethanol than men. 

 

Author Conclusion:

After the consumption of lower doses of ethanol, alcoholic women had cardiac dysfunction similar to that of alcoholic men. Therefore, women seem to be more sensitive than men to the toxic effects of ethanol on cardiac function. 

Funding Source:
Government: Fondo de Investigaciones Sanitarias (Spain)
Reviewer Comments:
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? N/A
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? Yes
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes