Carbohydrate-Deficient Transferrin as a Marker of Change in Alcohol Intake in Men Drinking 20 to 60 g of Alcohol Per Day

Predictive risk markers in alcoholism

The medical disorders of alcoholism rank among the leading public health problems worldwide and the need for predictive and prognostic risk markers for assessing alcohol use disorders (AUD) has been widely acknowledged. Early-phase detection of problem drinking and associated tissue toxicity are important prerequisites for timely initiations of appropriate treatments and improving patient's committing to the objective of reducing drinking. Recent advances in clinical chemistry have provided novel approaches for a specific detection of heavy drinking through assays of unique ethanol metabolites, phosphatidylethanol (PEth) or ethyl glucuronide (EtG). Carbohydrate-deficient transferrin (CDT) measurements can be used to indicate severe alcohol problems. Hazardous drinking frequently manifests as heavy episodic drinking or in combinations with other unfavorable lifestyle factors, such as smoking, physical inactivity, poor diet or adiposity, which aggravate the metabolic consequences of alcohol intake in a supra-additive manner. Such interactions are also reflected in multiple disease outcomes and distinct abnormalities in biomarkers of liver function, inflammation and oxidative stress. Use of predictive biomarkers either alone or as part of specifically designed biological algorithms helps to predict both hepatic and extrahepatic morbidity in individuals with such risk factors. Novel approaches for assessing progression of fibrosis, a major determinant of prognosis in AUD, have also been made available. Predictive algorithms based on the combined use of biomarkers and clinical observations may prove to have a major impact on clinical decisions to detect AUD in early pre-symptomatic stages, stratify patients according to their substantially different disease risks and predict individual responses to treatment.

Changes in Cognitive Measures in a Randomized Controlled Trial of a Health Promotion Program for Couples Targeting Diet and Physical Activity

Purpose.

To examine cognitive responses to a 4-month health promotion program targeting diet and physical activity in recently cohabiting couples.

Design.

A three-group randomized controlled trial: no intervention (Controls), interactive group sessions and mail-outs (Interactive), and one group session followed by mail-outs (Mail).

Setting.

Australian research studies unit.

Subjects.

Seventy-eight of 137 couples cohabiting for <2 years, recruited by advertising, completed the study.

Measures.

Stages of change; health beliefs; self-efficacy; and perceived barriers to change evaluated by questionnaires at baseline, postintervention, and 1-year follow-up. Data were analyzed using mixed models, factor analysis, and linear regression.

Results.

In the Mail group, the perceived importance of barriers to dietary change decreased by 19% at postintervention and 16% at 1-year follow-up; dietary self-efficacy increased by 9% and 3%, respectively. In the Interactive group, the perceived importance of barriers to dietary change decreased by 26% and 20%, and dietary self-efficacy increased by 14% and 12%, respectively. Similar trends for physical activity were not statistically significant. However, changes in self-efficacy and perceived barriers to change significantly predicted dietary and physical activity behaviors. A preponderance of higher socio-economic groups and the proportion of drop-out may have biased results.

Conclusions.

Health promotion using partners' support and targeting diet and physical activity improves associated cognitive variables in couples. Most improvements were greater and more sustained with interactive group sessions.

Biomarker-Based Approaches for Assessing Alcohol Use Disorders

Although alcohol use disorders rank among the leading public health problems worldwide, hazardous drinking practices and associated morbidity continue to remain underdiagnosed. It is postulated here that a more systematic use of biomarkers improves the detection of the specific role of alcohol abuse behind poor health. Interventions should be initiated by obtaining information on the actual amounts of recent alcohol consumption through questionnaires and measurements of ethanol and its specific metabolites, such as ethyl glucuronide. Carbohydrate-deficient transferrin is a valuable tool for assessing chronic heavy drinking. Activities of common liver enzymes can be used for screening ethanol-induced liver dysfunction and to provide information on the risk of co-morbidities including insulin resistance, metabolic syndrome and vascular diseases. Conventional biomarkers supplemented with indices of immune activation and fibrogenesis can help to assess the severity and prognosis of ethanol-induced tissue damage. Many ethanol-sensitive biomarkers respond to the status of oxidative stress, and their levels are modulated by factors of life style, including weight gain, physical exercise or coffee consumption in an age- and gender-dependent manner. Therefore, further attention should be paid to defining safe limits of ethanol intake in various demographic categories and establishing common reference intervals for biomarkers of alcohol use disorders.

The usefulness of biomarkers of alcohol abuse in hair and serum carbohydrate-deficient transferrin: a case report

The detection of carbohydrate-deficient transferrin (CDT) in serum is widely accepted to identify chronic alcohol consumption over the previous two weeks, but minor ethanol metabolites detected in hair often complete the information obtained. In particular, ethylglucuronide and cocaethylene (a marker of simultaneous intake of cocaine and alcohol) allow correct interpretation of data obtained in forensic cases. We refer to a negative CDT value obtained from a serum sample collected during hospitalization of a man admitted for cardiac arrest who died about 14 h later. Clinical analysis performed on admission showed a high ethanol level and a positive urinary screening for cocaine. The toxicological analyses of post-mortem samples found cocaine metabolites in his urine and blood. The negative CDT level suggested the ethanol concentration at admission to be an acute episode. Cocaine and cocaethylene well above the cut-off suggested by the literature were found in hair analyzed for the entire length (about 1 cm). Ethylglucuronide detected on the same hair sample confirmed chronic abuse of ethanol in the previous month, at least. The present report suggests caution in the interpretation of biomarkers of alcohol abuse, encouraging the detection of more than one marker to avoid misinterpretation.

How accurate are blood (or breath) tests for identifying self-reported heavy drinking among people with alcohol dependence?

AIMS

Managing patients with alcohol dependence includes assessment for heavy drinking, typically by asking patients. Some recommend biomarkers to detect heavy drinking but evidence of accuracy is limited.

METHODS

Among people with dependence, we assessed the performance of disialo-carbohydrate-deficient transferrin (%dCDT, ≥1.7%), gamma-glutamyltransferase (GGT, ≥66 U/l), either %dCDT or GGT positive, and breath alcohol (> 0) for identifying 3 self-reported heavy drinking levels: any heavy drinking (≥4 drinks/day or >7 drinks/week for women, ≥5 drinks/day or >14 drinks/week for men), recurrent (≥5 drinks/day on ≥5 days) and persistent heavy drinking (≥5 drinks/day on ≥7 consecutive days). Subjects (n = 402) with dependence and current heavy drinking were referred to primary care and assessed 6 months later with biomarkers and validated self-reported calendar method assessment of past 30-day alcohol use.

RESULTS

The self-reported prevalence of any, recurrent and persistent heavy drinking was 54, 34 and 17%. Sensitivity of %dCDT for detecting any, recurrent and persistent self-reported heavy drinking was 41, 53 and 66%. Specificity was 96, 90 and 84%, respectively. %dCDT had higher sensitivity than GGT and breath test for each alcohol use level but was not adequately sensitive to detect heavy drinking (missing 34-59% of the cases). Either %dCDT or GGT positive improved sensitivity but not to satisfactory levels, and specificity decreased. Neither a breath test nor GGT was sufficiently sensitive (both tests missed 70-80% of cases).

CONCLUSIONS

Although biomarkers may provide some useful information, their sensitivity is low the incremental value over self-report in clinical settings is questionable.

Biomarkers of alcohol consumption and related liver disease

Abstract Alcohol abuse is a major cause of abnormal liver function throughout the world. While measurements of liver enzyme activities (GGT, ALT, AST) are important screening tools for detecting liver disease, due to lack of ethanol-specificity and inconsistencies regarding the definitions of significant alcohol consumption, several other blood tests are usually needed to exclude competing and co-existing causes of abnormal liver function. Information on the specific role of ethanol consumption behind hepatotoxicity may be obtained through measurements of blood ethanol and its specific metabolites (ethyl glucuronide, phosphatidylethanol, protein-acetaldehyde condensates and associated autoimmune responses). Recent studies have indicated that being overweight is another increasingly common cause of abnormal liver enzyme levels and adiposity may also increase the impact of ethanol consumption on liver pathology. Interestingly, increased liver enzyme activities in circulation may reflect not only hepatic function but can also serve as indicators of general health and the status of oxidative stress in vivo. ALT and GGT activities predict insulin resistance, metabolic syndrome, mortality from coronary heart diseases and even mortality from all causes. If the upper reference limits for liver enzyme activities were defined based on the data obtained from normal weight abstainers, the clinical value of liver enzyme measurements as screening tools and in patient follow-up could be significantly improved.

NAFLD as a risk factor for the development of diabetes and the metabolic syndrome: an eleven-year follow-up study

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) uncommonly results in cirrhosis and liver-related death; however, its impact on the development of metabolic complications remains unclear. We sought to determine whether NAFLD with elevated aminotransaminase (ALT) levels was a risk factor for incident diabetes or the metabolic syndrome (MS) over an 11-year period.

METHODS

Adult residents of Busselton, Western Australia underwent assessment in 1994-1995 as part of the Busselton Health Survey. NAFLD was diagnosed on the basis of a raised ALT (>40 IU/l) after the exclusion of alcohol, viral, metabolic, and autoimmune liver disease. NAFLD and non-NAFLD subjects were reassessed in 2005 for liver complications, diabetes, and the MS.

RESULTS

A total of 358 subjects, 68% male (109 NAFLD, 249 non-NAFLD), mean age (s.d.) 59.9 (11.6) years, attended follow-up 11.1 years after the initial assessment. After excluding subjects with diabetes at baseline, those with NAFLD were more likely to have developed diabetes on follow-up (20/106, 18.9% vs. 15/246, 6.1%; P<0.001). After excluding subjects with MS at baseline, those with NAFLD were more likely to have developed MS at follow-up (27/81, 33.3% vs. 51/226, 22.6%; P=0.056). However, in multivariate logistic regression models, NAFLD was no longer a significant independent predictor of the development of diabetes or MS after adjusting for baseline waist circumference, hypertension, and insulin resistance. None of the subjects developed liver complications.

CONCLUSIONS

Subjects with NAFLD and elevated ALT levels are at an increased risk of developing diabetes and the MS. This may be because of the presence of associated metabolic risk factors.

Body mass index is a stronger predictor of alanine aminotransaminase levels than alcohol consumption

BACKGROUND AND AIMS

The relative effects of obesity compared to alcohol on liver injury are uncertain. We examined their effects on alanine aminotransferase (ALT) and gamma glutamyltransferase (GGT) levels in a population-based cohort.

METHODS

Adult residents (2610: 1326 males, 1284 females) from Busselton, Australia, participated in a cross-sectional survey determining alcohol intake as determined by a validated questionnaire, anthropometric measurements and serum analysis. Alcohol consumption was classified as never, light (<140 g/week), moderate (140-420 g/week) or heavy (>420 g/week).

RESULTS

The majority of subjects were either overweight (41%) or obese (17%). A minority of subjects were moderate (25%) or heavy drinkers (4%). Body mass index (BMI) and waist circumference were strongly associated with ALT and GGT (P < 0.0001 for all tests). Alcohol consumption was modestly associated with ALT in females (P = 0.01) but not in males (P = 0.9). In contrast, GGT was significantly associated with alcohol in both genders (P < 0.0005). The risk of an elevated ALT was seven-fold higher with obesity but only two-fold higher with moderate or heavy alcohol use. Obesity accounted for half of all elevated ALT levels in the cohort, whereas alcohol excess was responsible for less than 10%. No synergistic effect was observed between BMI or waist circumference and alcohol on ALT or GGT (P > 0.2 for all tests).

CONCLUSIONS

Excess weight is more common than excessive alcohol consumption in the community and confers a greater risk of elevated aminotransaminase levels.

Biomarkers in alcoholism

Alcoholism ranks as one of the main current threats to the health and safety of people in most Western countries. Therefore, a high priority should be given to aims at reducing its prevalence through more effective diagnosis and early intervention. The need for objective methods for revealing alcohol abuse in its early phase has also been widely acknowledged. It is postulated here that the diagnosis of alcohol use disorders could be markedly improved by a more systematic use of specific questionnaires and laboratory tests, including blood ethanol, serum gamma-glutamyltransferase (GGT), carbohydrate-deficient transferrin (CDT), and mean corpuscular volume of erythrocytes (MCV). Recent research has provided new insights into the relationships between ethanol intake, biomarkers, and factors affecting their diagnostic validation, including gender, age, and the effects of moderate drinking and obesity. It appears that the concept of reference intervals for several ethanol-sensitive parameters in laboratory medicine needs to be revisited. CDT is currently the most specific marker of alcohol abuse, and when combined with GGT using a mathematically formulated equation a high sensitivity is reached without loss of assay specificity. Possible new biomarkers include minor ethanol metabolites (protein-acetaldehyde condensates and associated autoimmune responses, ethylglucuronide, and phosphatidylethanolamine), 5-hydroxytryptophol, and genetic markers although so far their routine applications have been limited.

Cost-Benefit Analysis of a New Alcohol Biomarker, Carbohydrate Deficient Transferrin, in a Chronic Illness Primary Care Sample

BACKGROUND

Carbohydrate Deficient Transferrin (CDT) is a new alcohol biomarker recently approved by the Food and Drug Administration for alcohol screening. Limited information is available on the economic benefits of alcohol biomarkers. Our objective was to conduct a cost-benefit analysis (CBA) of the CDT test in a primary care sample of patients being treated for diabetes and hypertension.

METHODS

A decision tree was created using data from national surveys, published literature, and two brief intervention trials conducted in primary care settings. The decision tree was used to estimate the costs and benefits of CDT under different scenarios.

RESULTS

For the base case, utilizing CDT in addition to patient self-report resulted in an increase from 28 to 53 problem drinking cases identified out of 70 cases screened. With increased detection and subsequent intervention, the average medical and legal costs were far lower in the CDT arm of the study. When these avoided costs were incorporated into the model, an overall savings of $212.30 per patient was realized with CDT testing. Monte Carlo analysis also indicated a trend toward cost savings, with a mean cost savings of approximately $353 and a range of $1,619 in savings to $450 in costs for 1,000 simulations of the decision tree model.

CONCLUSION

This CBA suggests that the addition of routine CDT screening to patient self-report may provide positive net economic benefits in primary care settings.

Effects of HFE gene mutations and alcohol on iron status, liver biochemistry and morbidity

BACKGROUND AND AIMS

The aims of the present study were to determine: (i) whether alcohol consumption is greater in individuals with HFE mutations; and (ii) whether common HFE mutations modify the effects of alcohol on serum iron and liver biochemistry or morbidity.

METHODS

The residents of the town of Busselton in Western Australia were subject to cross-sectional health surveys between 1966 and 1983. In 1994/1995 all surviving participants of the earlier surveys were invited to take part in a follow-up survey. Logistic, linear and Poisson log-linear regression analyses were performed in 1490 men and 1452 women from the 1994/1995 survey to assess the relationships between HFE mutations, alcohol, iron levels, liver biochemistry and morbidity.

RESULTS

Heavy or moderate alcohol consumption was present in 7% or 36% of men and 0.5% or 12% of women, respectively. Alcohol consumption strongly influenced levels of serum ferritin and gamma glutamyl transpeptidase (GGT) and mean cell volume (MCV) in men and women but only alanine aminotransferase (ALT) levels in women. These effects were independent of HFE gene mutations. Hospital admission rates for respiratory disorders were higher in men with the C282Y mutation.

CONCLUSIONS

Alcohol consumption strongly influences serum ferritin and GGT levels and MCV in men and women but only ALT levels in women, and these effects are independent of HFE mutations. HFE gene mutations do not predispose to moderate or heavy alcohol consumption. The C282Y mutation is associated with increased respiratory admission rates in men.

A review of genetic, biological, pharmacological, and clinical factors that affect carbohydrate-deficient transferrin levels

BACKGROUND

Carbohydrate-deficient transferrin (CDT) is an alcohol biomarker recently approved by the U.S. Food and Drug Administration. This test is increasingly being used to detect and monitor alcohol use in a variety of health care, legal, and industrial settings. The goal of this study is to review the genetic, biological, pharmacological, and clinical factors that may affect CDT levels.

METHODS

A review of the literature identified 95 research articles that met the authors' criteria and reported potential interactions of a variety of factors on percent and total CDT levels. The review established 12 categories of variables that may affect CDT levels. These categories include (1) alcohol use, (2) genetic factors, (3) race, (4) gender, (5) age, (6) liver disease, (7) iron levels, (8) tobacco use, (9) medication such as estrogen and anticonvulsants, (10) metabolic factors such as body mass index and total body water, (11) chronic medical conditions such as rheumatoid arthritis, and (12) surgical patients.

RESULTS

There is evidence that %CDT levels are affected by alcohol use, end-stage liver disease, and genetic variants. In addition to these three factors, total CDT levels (CDTect) are also affected by factors that raise transferrin levels such as iron deficiency, chronic illnesses, and menopausal status. Other potential factors such as tobacco and age appear to be confounded by alcohol use. The roles of female gender, low body mass index, chronic inflammatory diseases, and medication on CDT levels require further study. False negatives are associated with female gender, episodic lower level alcohol use, and acute trauma with blood loss.

CONCLUSIONS

This review suggests that a number of factors are associated with false-positive CDTect and %CDT levels. CDT offers great promise to assist physicians in the care of patients to detect and monitor heavy alcohol use.

Carbohydrate-deficient transferrin (CDT)--a biomarker for long-term alcohol consumption

Carbohydrate-deficient transferrin (CDT) is a biomarker for chronic alcohol intake of more than 60 g ethanol/d. It has been reported to be superior to conventional markers like gamma-glutamyltransferase (GGT) and mean corpuscular volume MCV). This review covers theoretical and analytical aspects, with data from controlled drinking experiments and from different population subgroups such as subjects with different liver diseases or different drinking patterns. CDT determinations are particularly indicated in (1) cases of chronic alcohol consumption and relapses after withdrawal, (2) license reapplication after driving under alcohol influence, (3) differentiating patients with enzyme-inducing medication from those with alcohol abuse, 4) congenital disorders of glycosylation such as carbohydrate-deficient glycoprotein syndrome Ia (CDGS Ia), and (5) patients treated for galactosemia. The main advantage of CDT is its high specificity, as evidenced in combination with increased alcohol consumption. CDT values are not markedly influenced by medication except in immunosuppressed patients, who may show low CDT values. In general, CDT values appear less elevated after alcohol intake in women. The main disadvantage is the relatively low sensitivity. Hence, this parameter is not suitable for screening for subjects with alcohol abuse in the general population. As CDT, GGT, and MCV are connected with chronic alcohol consumption by different pathophysiological mechanisms, a combination of these parameters will further improve the diagnostic value.

Recommendations on Use of Biomarkers in Alcoholism Treatment Trials

BACKGROUND

Biochemical markers of heavy drinking are playing increasingly prominent roles in alcohol treatment efficacy studies, especially in those designed to evaluate medications. Among these roles are serving as inclusion or exclusion criteria for research participants, corroboration of self-report of drinking status, assessment of the safety of the agent being evaluated, and determination of treatment outcome.

METHODS

Recent alcohol medication development trials that included biomarker information were reviewed and critiqued from the perspectives of how biomarker measures were used and how findings on them were reported.

RESULTS

Although generally the application of biomarkers as inclusion criteria is not recommended, they may aid in exclusion of potential subjects (e.g., elevated liver function measures in trials of agents that could result in liver damage). Biomarkers are most commonly used as indicators of outcome, usually serving as secondary outcome variables. The relationship of outcome findings on biomarker and self-report measures is positive, but only moderate. As used to date, biomarkers of drinking tend to be less sensitive than well-standardized and properly administered self-report measures. Nevertheless, they do provide a useful, unique source of information on drinking status.

CONCLUSIONS

The contribution of biomarkers to alcoholism clinical research would be enhanced if certain design strategies were incorporated into their application and if critical information were included in the research publication. This article offers a series of recommendations to improve on their use in a research context.

Biomarkers as aids to identification of relapse in alcoholic patients

Since return to drinking is common in patients recovering from alcoholism, recognition of relapse should be an important component of treatment. Recurrent assessment with biochemical measures can provide clinicians with useful information on the drinking status of their patients. This chapter addresses issues surrounding the importance of early detection of relapse, describes biochemical markers that may assist in this, reviews relevant scientific investigations, and offers recommendations to researchers and clinicians.

Use of capillary zone electrophoresis for differentiating excessive from moderate alcohol consumption

BACKGROUND

The poorly sialylated transferrin isoforms in serum were analyzed by capillary zone electrophoresis (CZE) to differentiate moderate from heavy alcohol consumption.

METHODS

We enrolled 614 volunteers, classified after interviews, self-reported drinking habits, and AUDIT scores as alcohol abusers (consuming >50 g/day ethanol for the previous 3 months or longer; n = 413) or moderate drinkers (<30 g/day ethanol; n = 201). Serum transferrin isoforms were separated at 28 kV and monitored at 214 nm on a P/ACE 5500 CZE with use of fused-silica capillaries and the related CEofix CDT reagent set. Immunosubtraction by anti-human transferrin and electrophoretic migration times identified the isoforms. Previous markers of alcohol abuse and an assay combining anion-exchange minicolumn chromatography with immunoturbidimetry (%CDT) were included in the study. Sensitivities and specificities were compared by ROC analysis.

RESULTS

The asialylated isoform was missing in 95% of moderate drinkers but present in 92% of alcohol misusers. Disialotransferrin had a specificity and sensitivity of 0.75 at a cutoff of 0.7% of total transferrin, whereas the sum (asialo- + disialotransferrin) at a threshold of 1.2% had a sensitivity of 0.73 and a specificity of 0.92. Trisialotransferrin values did not distinguish between the two populations. Sensitivities and specificities of %CDT averaged 0.77 and 0.74, respectively, at a 2.6% cutoff; 0.67 and 0.83 at 2.8%; and 0.63 and 0.90 at 3%. CDT data were more sensitive and specific for males. Conventional biomarkers appeared less discriminating.

CONCLUSIONS

Asialotransferrin detected by CZE in sera of alcohol abusers offers the highest discrimination between excessive and moderate drinking.

Biochemical markers of alcohol use in pregnant women

OBJECTIVES

To describe the serious health consequences of alcohol (ethanol) use, especially as they relate to pregnancy and the development of fetal alcohol syndrome (FAS) and fetal alcohol effects (FAE). The classic markers of alcohol exposure, including blood/breath alcohol, gamma-glutamyl transferase (gammaGT), mean corpuscular volume (MCV), hemoglobin-associated acetaldehyde (HAA) and carbohydrate deficient transferrin (CDT), are valuable and their methods of analysis are reviewed.

CONCLUSIONS

Since both FAS and FAE represent two of the leading preventable causes of mental retardation and birth defects, identification of alcohol use early in pregnancy is important to avoid adverse fetal outcomes. Unfortunately, the diagnosis of FAS and FAE is usually made after birth, when alcohol damage has become irreversible and permanent. The clinical laboratory can help prevent this damage and make a valuable contribution in assessing prenatal alcohol use. The clinical utility of blood/breath alcohol, gammaGT, MCV, HAA and CDT in alcohol use identification, especially in pregnancy, is substantial. Although none of the markers singularly has adequate sensitivity and specificity for screening, their diagnostic utility increases when measured as a panel. This is especially true in detecting alcohol use in pregnancy where the presence of several positive markers was correlated with the presence of alcohol-related fetal effects.

Sensitivity and specificity of carbohydrate-deficient transferrin in drinking experiments and different patients

Information provided by patients about the amounts of alcohol they drink may often be too subjective and therefore unreliable. Because of the possible serious consequences of interactions between alcohol and medication, reliable laboratory test markers for alcohol consumption are needed. Carbohydrate-deficient transferrin (CDT) is at present the best available objective measure of drinking behavior. During a withdrawal trial, 92 alcohol-dependent patients who had been admitted to a hospital in an ethanol-intoxicated state were monitored over the following 28 days by using the percent carbohydrate-deficient transferrin (%CDT of total transferrin) (%CDT) method. At the time of admission, 63% showed elevated %CDT levels. After a subsequent period of abstinence, a decrease in %CDT levels was apparent in four different groups of patients, whereas in two groups, comprising the greatest number of patients, normal %CDT levels were evident after 14 days of abstinence. In patients whose CDT levels were very high at study initiation, it took at least 21 to 28 days--and sometimes longer--for CDT to decrease to the radioimmunoassay (RIA) %CDT test cutoff point of 2.5. In a further study of 56 male alcohol-dependent patients, we measured liver enzyme concentrations, mean corpuscular volume (MCV), and four CDT variants on the first day of evidence of withdrawal syndrome. We found a significant correlation between results on the Munich Alcoholism Test (MALT) and MCV levels; among gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels; and among all four CDT variants. A cluster analysis yielded three clusters: (1) GGT, AST, and ALT levels; (2) MCV levels and MALT results; and (3) all CDT measurement variants. We conclude that these three clusters measure different detriments to the patient and that all available CDT variants are commensurate.

Carbohydrate-deficient Transferrin as a Marker of Chronic Alcohol Abuse: A Critical Review of Preanalysis, Analysis, and Interpretation

Background: Carbohydrate-deficient transferrin (CDT) is used for diagnosis of chronic alcohol abuse. Some 200–300 reports on CDT have been published in impact factor-listed journals. The aims of this review were to condense the current knowledge and to resolve remaining issues on CDT.

Approach: The literature (1976–2000) was searched using MEDLINE and Knowledge Server with “alcohol and CDT” as the search items. The data were reviewed systematically, checked for redundancy, and organized in sequence based on the steps involved in CDT analysis.

Content: The review is divided into sections based on microheterogeneity of human serum transferrin (Tf), definition of CDT, structure of human serum CDT, pathomechanisms of ethanol-induced CDT increase, preanalysis, analysis, and medical interpretation (postanalysis). Test-specific cutoff values for serum CDT and causes of false positives and negatives for chronic alcohol abuse are discussed and summarized.

Summary: Asialo- and disialo-Fe2-Tf, which lack one or two complete N-glycans, and monosialo-Fe2-Tf (structure remains unclear) are collectively referred to as CDT. Diminished mRNA concentration and glycoprotein glycosyltransferase activities involved in Tf N-glycan synthesis and increased sialidase activity most likely account for alcohol-induced increases in CDT. Knowledge about in vivo and in vitro effects on serum CDT is poor. Reliable CDT and non-CDT fractionation is needed for CDT measurement. Analysis methods with different analytical specificities and recoveries decreased the comparability of values and statistical parameters of the diagnostic efficiency of CDT. CDT is the most specific marker of chronic alcohol abuse to date. Efforts should concentrate on the pathomechanisms (in vivo), preanalysis, and standardization of CDT analysis.

Mean corpuscular volume may be a useful index of risk for colorectal adenoma in middle-aged Japanese men

OBJECTIVE

It has been reported that alcohol intake and folate deficiency are associated with an increased risk of colorectal adenomas and carcinomas. Mean corpuscular volume (MCV) of red blood cells has been reported to be increased in these conditions. The purpose of this study was to assess the association between MCV and risk of colorectal adenoma.

METHODS

The subjects were 497 middle-aged (45-65 yr old) men who underwent both barium enema examination and total colonoscopy. The subjects answered a questionnaire regarding their alcohol consumption history, and their blood samples were analyzed. The subjects were divided into four groups three times: with or without alcoholism, and with or without adenoma according to alcohol intake, and according to the MCV value. Various variables were compared among the groups, and the odds ratios of adenoma were calculated.

RESULTS

The MCV was higher in the alcoholic group than in the nonalcoholic group (p < 0.01) and in patients with adenoma than in those without adenoma (p < 0.0001). When the subjects were stratified by alcohol intake, the MCV value had a higher significant difference than alcohol intake, between patients with adenoma and those without adenoma. As for the MCV value, the odds ratio (95% confidence interval) of adenoma was 1.00 (referent); (<92), 1.20 (0.71-1.69); (> or =92 but <95), 2.61 (2.07-3.15); (> or =95 but <98); and 3.62 (2.99-4.25); (> or =98).

CONCLUSION

A high MCV value may be used as a simple index of the risk of colorectal adenomas, regardless of alcohol consumption.