Association of self-reported diseases and health care use with commonly used laboratory markers for alcohol consumption

Phosphatidylethanol (B-PEth) and other direct and indirect biomarkers of alcohol consumption

When identifying, preventing and treating alcohol use disorder, a correct estimation of alcohol intake is essential. An objective marker is preferred as self-reported alcohol intake suffers from bias, and the use of alcohol biomarkers is increasing globally. An easy-to-use blood biomarker to correctly assess alcohol consumption is an invaluable asset in alcohol treatment strategies, as well as in alcohol research studies. The specific, cumulative, biomarker phosphatidylethanol, mirroring the past two weeks of consumption, has shown superiority over traditional biomarkers and is an attractive choice of proxy for alcohol intake.

Phenotypes, Risk Factors, and Mechanisms of Adult-Onset Asthma

Asthma is a heterogeneous disease with many phenotypes, and age at disease onset is an important factor in separating the phenotypes. Genetic factors, atopy, and early respiratory tract infections are well-recognized factors predisposing to childhood-onset asthma. Adult-onset asthma is more often associated with obesity, smoking, depression, or other life-style or environmental factors, even though genetic factors and respiratory tract infections may also play a role in adult-onset disease. Adult-onset asthma is characterized by absence of atopy and is often severe requiring treatment with high dose of inhaled and/or oral steroids. Variety of risk factors and nonatopic nature of adult-onset disease suggest that variety of mechanisms is involved in the disease pathogenesis and that these mechanisms differ from the pathobiology of childhood-onset asthma with prevailing Th2 airway inflammation. Recognition of the mechanisms and mediators that drive the adult-onset disease helps to develop novel strategies for the treatment. The aim of this review was to summarize the current knowledge on the pathogenesis of adult-onset asthma and to concentrate on the mechanisms and mediators involved in establishing adult-onset asthma in response to specific risk factors. We also discuss the involvement of these mechanisms in the currently recognized phenotypes of adult-onset asthma.

Alcohol screening and brief counseling in a primary care hypertensive population: a quality improvement intervention

AIMS

To determine the effect of an intervention to improve alcohol screening and brief counseling for hypertensive patients in primary care.

DESIGN

Two-year randomized, controlled trial.

SETTING/PARTICIPANTS

Twenty-one primary care practices across the United States with a common electronic medical record.

INTERVENTION

To promote alcohol screening and brief counseling. Intervention practices received site visits from study personnel and were invited to annual network meetings to review the progress of the project and share improvement strategies.

MEASUREMENTS

Main outcome measures included rates of documented alcohol screening in hypertensive patients and brief counseling administered in those diagnosed with high-risk drinking, alcohol abuse or alcohol dependence. Secondary outcomes included change in blood pressure among patients with these diagnoses.

FINDINGS

Hypertensive patients in intervention practices were significantly more likely to have been screened after 2 years than hypertensive patients in control practices [64.5% versus 23.5%; adjusted odds ratio (OR) = 8.1; 95% confidence interval (CI) 1.7-38.2; P < 0.0087]. Patients in intervention practices diagnosed with high-risk drinking, alcohol abuse or alcohol dependence were more likely than those in control practices to have had alcohol counseling documented (50.5% versus 29.6%; adjusted OR = 5.5, 95% CI 1.3-23.3). Systolic (adjusted mean decline = 4.2 mmHg, P = 0.036) and diastolic (adjusted mean decline = 3.3 mmHg, P = 0.006) blood pressure decreased significantly among hypertensive patients receiving alcohol counseling.

CONCLUSIONS

Primary care practices receiving an alcohol-focused intervention over 2 years improved rates of alcohol screening for their hypertensive population. Implementation of alcohol counseling for high-risk drinking, alcohol abuse or alcohol dependence also improved and led to changes in patient blood pressures.

Combinations of carbohydrate-deficient transferrin, mean corpuscular erythrocyte volume, gamma-glutamyltransferase, homocysteine and folate increase the significance of biological markers in alcohol dependent patients

AIMS

The traditionally used biological markers for alcoholism include a wide range of sensitivity and specificity as single tests. This study focuses on the combination of established laboratory parameters with new meaningful biomarkers to advance the significance regarding alcohol dependence.

DESIGN

We analyzed blood samples from alcohol-dependent patients (n=177) compared with a control group (n=181). In the statistical calculation we included carbohydrate-deficient transferrin (CDT), mean corpuscular erythrocyte volume (MCV), gamma-glutamyltransferase (GGT), total plasma homocysteine, and folate.

RESULTS

None of the examined biomarkers reached sensitivity above 90% while all markers showed a good specificity. Combinations of different markers led to a significant elevation in sensitivity. Best values for men were achieved by using a combination of MCV, CDT, GGT, homocysteine and folate in different weightings (sensitivity: 98.6%, specificity: 86.4%). For women, similar results were yielded by combining MCV and CDT (sensitivity: 94.1%, specificity: 96%). The addition of homocysteine and folate in different weightings did not result in further enhancement.

CONCLUSIONS

Gender-specific clusters including MCV, CDT, GGT, homocysteine and folate led to an increase in sensitivity compared to single laboratory markers. This is a reliable help to identify patients with regular heavy drinking in clinical practice which might prevent further complications.

Initial Steps Taken by Nine Primary Care Practices to Implement Alcohol Screening Guidelines with Hypertensive Patients

Many medical conditions are caused or exacerbated by heavy drinking, necessitating alcohol screening and discussion in primary care practices. This is particularly true of hypertension, the most common primary diagnosis in the United States, which has been linked to the regular consumption of 3 or more standard alcoholic beverages a day. The Accelerating Alcohol Screening-Translating Research into Practice (AA-TRIP) project was designed to improve detection and management of alcohol problems in primary care patients with hypertension. Medical providers are being trained using the Practice Partner Research Network's- Translating Research into Practice (PPRNet-TRIP) quality improvement model. This includes a multi-method intervention (electronic medical records, on-site academic detailing, practice feedback reports and annual network meetings) to help practices increase adherence to clinical guidelines. Qualitative analyses of initial steps taken by nine primary care practices toward the routine implementation of alcohol screening guidelines are presented. Organizational factors and provider and patient characteristics all influenced the method and consistency of alcohol screening and intervention. Perceived time constraints, patient sensitivity to questions about alcohol, and possible stigma associated with a diagnosis of alcoholism were also relevant barriers requiring problem solving.

Carbohydrate-deficient transferrin (CDT) as a marker of alcohol abuse: a critical review of the literature 2001-2005

The diagnosis of alcohol abuse based on objective data is a necessary requirement in both clinical and forensic environments. Among the different biomarkers of chronic alcohol abuse, carbohydrate-deficient transferrin (CDT) is world wide recognized as the most reliable indicator. However, several problems about the real meaning of CDT and the reliability of its use for the diagnosis of alcohol abuses are still open, as reported by numerous research articles and reviews. The present article presents a critical review of the literature on CDT appeared in the period from 2001 to 2005 (included). The article is organized in the following sections: (1) introduction, (2) definition and structure of human serum CDT, (3) pathomechanisms of the ethanol-induced CDT increase, (4) preanalysis, (5) analysis, (6) data interpretation, (7) review papers, (8) conclusions. As many as 127 papers appeared in the international literature and retrieved by the search engines PubMed and Scopus are quoted.

Alcohol Biomarker Screening in Medical and Surgical Settings

This article highlights the proceedings of a symposium presented at the 28th Annual Meeting of the Research Society on Alcoholism in Santa Barbara, CA, on June 28, 2005, organized and chaired by Peter Miller. The presentations included (1) Screening for Alcohol Use Disorders in Surgical and Trauma Patients, presented by Claudia Spies; (2) Are Serum Levels of %CDT and GGT Related to Severity of Liver Biopsy Inflammation, Fibrosis, and Steatohepatitis in Patients with Hepatitis C? by Martin Javors; (3) Biochemical Alcohol Screening in the Treatment of Hypertension, presented by Peter Miller; and (4) The Cost-Effectiveness of a New Biomarker, CDT, in a Primary Care Sample, by Michael Fleming. Presentations were discussed by Raymond Anton.

Excessive alcohol consumption and hypertension: clinical implications of current research

Substantial evidence demonstrates that: 1) heavy alcohol consumption (three or more standard drinks per day) is associated with and predictive of hypertension; 2) reduction in alcohol consumption is associated with a significant dose-dependent lowering of mean systolic and diastolic blood pressure; and 3) physician advice can reduce heavy drinking in hypertensive patients. These findings suggest that the routine evaluation of alcohol consumption in hypertensive patients is warranted. The Alcohol Use Disorders Identification Test-C (AUDIT-C), a brief, three-question screening test, is useful in this regard. Alcohol biomarkers can also play a role in detecting and monitoring heavy drinking in hypertensive patients whose self-reports on the AUDIT-C are suspect. Carbohydrate-deficient transferrin, a new alcohol biomarker with high specificity, can provide objective data for feedback and counseling. A routine search for excessive use of alcohol, along with brief interventions and monitoring, can have a major impact on reducing the prevalence of hypertension in the general population.

Genetic variants of transferrin in the diagnosis of protein hypoglycosylation

Human transferrin (Tf) shows genetic polymorphisms, which may interfere in the screening of congenital disorders of glycosylation (CDG). Isoelectric focusing followed by direct immunofixation was used for Tf analysis in controls and several groups of patients. Equivocal results in one case have been recognized as a rare Tf CD variant. A higher incidence of some genetic variants has been reported in connection with certain diseases; of the seven Tf phenotypes detected in our set of samples, an apparently higher frequency of Tf C1C2 variant found in some groups of patients was not significant.

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.

Biochemical alcohol screening in primary health care

Alcohol biomarkers such as carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GGT) have significant potential for enhancing the quality of medical treatment in primary health care settings. Recent studies demonstrate that these laboratory tests can help the general practitioner in several ways. First, CDT and GGT can detect current heavy drinking in primary care patients with a fair degree of sensitivity (approximately 60% to 70%), with CDT being more specific (approximately 90%). When combined with self-report tests, they can provide a clinically useful alcohol screening battery. Second, elevated CDT and GGT levels have been correlated with specific alcohol-sensitive diseases (e.g., hypertension) and, as such, can serve as risk indicators for those diseases. Third, alcohol biomarkers have proven to be useful in monitoring the effectiveness of brief alcohol interventions with medical patients. Unfortunately, preliminary findings indicate that physicians have little knowledge of current biomarker research as applied to primary health care. Translational studies are needed on methods to facilitate knowledge and use of alcohol biomarkers by general practitioners.

Use of biomarkers for alcohol use disorders in clinical practice

BACKGROUND

Biomedical markers may provide additive objective information in screening and confirmation of acute or recent consumption, intoxication, relapse, heavy drinking, hazardous/harmful use/abuse and dependence and alcohol use related organ dysfunction (alcohol use-related disorders: AUDs).

AIMS

To review the use of biomarkers in clinical practice to detect AUDs.

FINDINGS

About one-fifth of the patients seen in clinical practice have AUDs, which offer a variety of treatment options if diagnosed. The diagnosis of AUDs relies on clinical and alcohol-related history, physical examination, questionnaires and laboratory values. No clinical available laboratory test [e.g. for acute abuse: alcohol in blood or breath; for chronic alcohol abuse: gamma-glutamyl transferase (GGT), mean corpuscular volume (MCV), carbohydrate-deficient transferrin (CDT)] is reliable enough on its own to support a diagnosis of alcohol dependence, harmful use or abuse. Sensitivities, specificities and the predictive values may vary considerably according to patient and control group characteristics (e.g. gender, age or related comorbidity). In patient groups with limited cooperation markers may be helpful when considering treatment options.

CONCLUSIONS

More research is needed to determine the value of markers (single or combined, with questionnaires) in the context of clinical decision-making algorithms in defined settings and with defined dichotomous outcome variables.