Over-reports of recent alcohol consumption in a clinical population: A validity study

Decisions concerning appropriate treatment in alcoholism programs are often based on the self-reports of the clients. However, few programs have incorporated validation procedures (such as breath tests) since it is generally assumed that alcoholics will deny the extent of their drinking and their subsequent alcohol problems.The self-reports of recent alcohol consumption of sixty-five new entrants to an alcoholism treatment program were validated with breath tests. Five estimates of blood alcohol concentrations were derived by varying elimination rates. For all five estimates, over-reporters comprised a substantial proportion of the total sample (23%–57%) and exceeded the percentage of consistent reporters for those people who had a positive breath test. Correlations between self-reports and breath tests were not significant which indicates that the amount of alcohol consumed does not necessarily relate to reporting behavior.It is concluded that despite the widely held notion that alcoholics deny the extent of their drinking, errors in the direction of over-reporting should be taken seriously and examined more closely. On an individual level, overpresentation of a client's condition may be related to subsequent behavior in a treatment program; on an aggregate level, over-reports may bias the findings of evaluation studies by inflating success rates.     

Distribution and dose response of laboratory markers to alcohol consumption in a general population: results of the study of health in Pomerania (SHIP)

OBJECTIVE: Biomarker distributions must be well known for use as screening tools for hazardous alcohol consumption in general populations. The aim of this study was to investigate characteristics of carbohydrate-deficient transferrin (CDT) and to compare it with gamma-glutamyltransferase (GGT) and erythrocyte mean corpuscular volume (MCV) in regard to distribution in the general population; the dose response relationship between alcohol consumption and biomarkers; and the effect of gender, age, body mass index (BMI) and smoking. METHOD: In a cross-sectional health survey in northeast Germany (1997-2001), a sample of 7,008 men and women aged 20-79 years was drawn, following stratification by age and gender. Of this sample, 4,310 subjects (2,193 women) took part in the study. Alcohol consumption was evaluated by self-reports with a beverage specific quantity-frequency method. RESULTS: Biomarker distributions differ across age and gender. The distribution of drinkers and nondrinking subjects showed considerable overlap. The association of alcohol consumption to laboratory markers is weak in the general population: strongest for GGT, followed by CDT and MCV For CDT and MCV it is weaker in women than in men. We found increasing risk of all three elevated marker values with increasing alcohol consumption and significant effects of age, gender, smoking and body mass index on the alcohol-biomarker dose response curve. CONCLUSIONS: When biomarkers are used for screening, all confounding effects have to be taken into account and adjusted normal ranges must be used. CDT shows no overall advantage over GGT. Low correlation of biomarkers with alcohol consumption, their high variability and widely spread ranges in nondrinking subjects limit the usefulness of these markers in general population settings.     

Changes in Lp(a) lipoprotein levels during the treatment of hypercholesterolaemia with simvastatin

Summary Thirty-six patients with total serum cholesterol levels above 6.5 mmol/l and Lipoprotein(a) levels above 100 mg · 1^–1 were evaluated in a 24 week double-blind, placebo controlled, cross-over study to assess the possible changes in Lp(a) during treatment with the HMG CoA reductase inhibitor simvastatin.The median plasma Lp(a) increased from 359 to 464 mg·l^–1 during simvastin treatment as compared to placebo (not significant). Individual changes in Lp(a) varied. In a multivariate linear regression analysis the individual change in Lp(a) was correlated with the baseline Lp(a) (r = 0.64), the change in serum triglycerides (r = 0.48) and the baseline apolipoprotein B (r = 0.36). Differences between the Lp(a) phenotypes may explain some of the varied Lp(a) responses. It appears that the effect of simvastatin on the Lp(a) level in individuals is usually insignificant, but in patients with a high Lp(a) simvastatin may further increase it.     

Lipoprotein(a) concentrations and apolipoprotein(a) isoform distribution in a Zimbabwean population

OBJECTIVE: To determine serum lipoprotein(a)[Lp(a)] concentrations and apolipoprotein(a)[apo(a)] phenotypes in a Zimbabwean population. DESIGN: Cross sectional study. SETTING: Blood Transfusion Services, Harare, Zimbabwe. SUBJECTS: 84 black and 40 white blood donors. MAIN OUTCOME MEASURES: Lp(a) concentrations and apo(a) phenotypes. RESULTS: The mean and median values for Lp(a) concentrations were 506 and 350 mg/L for the black subjects and 278 and 142 mg/L for the white subjects (p < 0.005). The frequency distributions of Lp(a) concentrations for both populations were skewed to the right. The frequency distribution of apo(a) size, expressed as the number of kringle IV repeats, was determined. Comparison of the frequency distribution plots showed very similar isoform distributions between the two groups. The documented inverse relationship between apo(a) size and Lp(a) concentration was observed in the white population. CONCLUSION: The Lp(a) levels in the black population were two to three fold higher than in the white population whilst no differences in apo(a) phenotype distribution were noted. This suggests that environmental and metabolic factors may be responsible for the elevated Lp(a) levels observed in blacks. Thus different pathological thresholds may have to be established for elevated serum Lp(a) levels to be used as a risk marker for coronary heart disease in black populations.     

Social status and voluntary alcohol consumption in mice: interaction with stress

Dominant rats are found to consume less alcohol than their subordinate cage-mates. It is unclear whether the difference is due to dominant, aggressive animals consuming low levels of alcohol or whether social stress increases alcohol intake in subordinate animals. The present study investigated alcohol drinking patterns in aggressive alpha mice, their fight-stressed submissive cage-mates and non-fighting control mice before and after the establishment of social hierarchies. The results revealed that both moderately and severely fight-stressed submissive mice showed increased consumption of 5% alcohol, expressed as g/kg, but only severely wounded submissive mice showed increased alcohol preference over total fluid consumption, as compared with alpha mice. The difference in alcohol consumption was not seen prior to the establishment of submissive and alpha status, indicating that the submissive mice increased their alcohol consumption only after experiencing fight-stress. The amount of alcohol consumed did not differ between alpha and non-fighting control mice. To further investigate the possible connection between alcohol intake and aggressivity, the mice were studied in the resident-intruder test before group-housing. The results failed to show a consistent pattern of correlations between the time spent in aggression in this test and subsequent alcohol intake measures. The data indicate that severe fight-stress increases alcohol consumption in mice. Alcohol intake of aggressive, dominant alpha mice is not significantly altered, as compared with non-fighting animals. Furthermore, the level of aggressiveness prior to the establishment of social status does not directly affect alcohol consumption. These results suggest that aggression and dominance are not critical in determining alcohol intake patterns, whereas being a target of severe social and physical stress significantly elevates alcohol consumption in mice.     

Weekly recall and dairy estimates of alcohol consumption in a general population survey

Diary and weekly recall measures of alcohol consumption in a representative sample (N = 399) of the Dutch population are compared. The weekly recall method consisted of a personal interview with questions about actual alcohol consumption on the previous 7 days. The diary consisted of 14 daily self-reports of consumption and followed the interview. The diary method yields estimates of consumption that are on average 22% higher than those based on weekly recall measures, reducing total undercoverage by about 11%. The difference between the two methods cannot be attributed to a variation of consumption over weeks but seems to stem from a difference in accuracy of recall. There was an increase in glasses underreported at the upper levels of consumption, but underreporting did not seem to be of a nonlinear nature. Considering the large individual variation in consumption over weeks, the ranking of individuals according to their self-reports is relatively stable across method.