Factors Affecting %CDT Status at Entry Into a Multisite Clinical Treatment Trial: Experience from the COMBINE Study

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.

Opioid and Dopamine Genes Interact to Predict Naltrexone Response in a Randomized Alcohol Use Disorder Clinical Trial

BACKGROUND

While the opiate antagonist, naltrexone, is approved for treating alcohol use disorder (AUD), not everyone who receives the medication benefits from it. This study evaluated whether the OPRM1 SNP rs1799971 interacts with the dopamine transporter gene DAT1/SLC6A3 VNTR rs28363170 or the catechol-O-methyltransferase (COMT) gene SNP rs4680 in predicting naltrexone response.

METHODS

Individuals who met DSM-IV alcohol dependence were randomly assigned to naltrexone (50 mg/d) or placebo based on their OPRM1 genotype (75 G-allele carriers and 77 A-allele homozygotes) and also genotyped for DAT1 VNTR (9 vs. 10 repeats) or COMT SNP (val/val vs. met carriers). Heavy drinking days (%HDD) were evaluated over 16 weeks and at the end of treatment. Effect sizes (d) for naltrexone response were calculated based on genotypes.

RESULTS

Naltrexone, relative to placebo, significantly reduced %HDD among OPRM1 G carriers who also had DAT1 10/10 (p = 0.021, d = 0.72) or COMT val/val genotypes (p = 0.05, d = 0.80), and to a lesser degree in those OPRM1 A homozygotes who were also DAT1 9-repeat carriers (p = 0.09, d = 0.70) or COMT met carriers (p = 0.03, d = 0.63). All other genotype combinations showed no differential response to naltrexone. Diarrhea/abdominal pain was more prominent in OPRM1 A homozygotes who were also DAT 9 or COMT met carriers.

CONCLUSIONS

These results suggest that individuals with AUD with a more opioid-responsive genotype (OPRM1 G carriers) respond better to naltrexone if they have genotypes indicating normal/less dopamine tone (DAT1 10,10 or COMT val,val), while those with a less responsive opioid-responsive genotype (OPRM1 A homozygotes) respond better to naltrexone if they have genotypes indicating greater dopamine tone (DAT1 9-repeat or COMT met carriers). These results could lead to more personalized AUD treatments.

Specific aspects of cognitive impulsivity are longitudinally associated with lower treatment retention and greater relapse in therapeutic community treatment

INTRODUCTION

Impulsivity has been consistently associated with poorer addiction treatment outcomes. However, impulsivity is a multifaceted construct and current evidence have failed to unravel which specific aspects explain this relationship. There is also limited research examining long-term outcomes. We aimed to examine the longitudinal association between baseline performance on a comprehensive battery of impulsivity measures and retention and relapse at the end of treatment.

METHODS

The sample comprised 68 participants with miscellaneous diagnoses of substance use disorders and polysubstance use patterns, enrolled in public residential therapeutic communities in Andalusia (Spain). At baseline, we applied measures of selective attention (Stroop), response inhibition (Affective Go/No Go), delay discounting (Monetary Choice Questionnaire; MCQ), and decision-making (Iowa Gambling Task; IGT). At the end of treatment (mean = 148.36 days, range = 22-289 days), we collected outcome measures of retention (coded by the clinical team as completion or dropout based on statewide practice guidelines) and relapse (defined as at least two separate alcohol/drug use episodes based on urine analyses).

RESULTS

Cox regression models showed that poorer decision-making in the IGT was associated with premature treatment dropout, whereas elevated commission errors in the Affective Go/No Go were associated with higher relapse rates. Selective attention and delay discounting were unrelated to outcomes.

CONCLUSION

Long-term based decision-making skills are important to commit to the complex and intensive treatment programs of therapeutic communities. The ability to withhold behavioural responses under positive affect is relevant to prevent relapse. Both skills should be assessed and potentially trained during therapeutic community treatment.

Drinking Risk Level Reductions Associated with Improvements in Physical Health and Quality of Life Among Individuals with Alcohol Use Disorder

BACKGROUND

Abstinence and no heavy drinking days are currently the only Food and Drug Administration-approved end points in clinical trials for alcohol use disorder (AUD). Many individuals who fail to meet these criteria may substantially reduce their drinking during treatment, and most individuals with AUD prefer drinking reduction goals. One- and two-level reductions in World Health Organization (WHO) drinking risk levels have been proposed as alternative end points that reflect reduced drinking and are associated with reductions in drinking consequences, improvements in mental health, and reduced risk of developing alcohol dependence. The current study examined the association between WHO drinking risk level reductions and improvements in physical health and quality of life in a sample of individuals with alcohol dependence.

METHODS

Secondary data analysis of individuals with alcohol dependence (n = 1,142) enrolled in the longitudinal, prospective COMBINE study, a multi site randomized placebo-controlled clinical trial, examining the association between reductions in WHO drinking risk levels and change in blood pressure, liver enzyme levels, and self-reported quality of life following treatment for alcohol dependence.

RESULTS

One- and two-level reductions in WHO drinking risk level during treatment were associated with significant reductions in systolic blood pressure (p < 0.001), improvements in liver enzyme levels (all p < 0.01), and significantly better quality of life (p < 0.001).

CONCLUSIONS

One- and two-level reductions in WHO drinking risk levels predicted significant improvements in markers of physical health and quality of life, suggesting that the WHO drinking risk level reduction could be a meaningful surrogate marker of improvements in how a person "feels and functions" following treatment for alcohol dependence. The WHO drinking risk levels could be useful in medical practice for identifying drinking reduction targets that correspond with clinically significant improvements in health and quality of life.

Nicotine-Use/Smoking Is Associated with the Efficacy of Naltrexone in the Treatment of Alcohol Dependence

BACKGROUND

The opioid antagonist naltrexone is not efficacious for every alcohol treatment seeker. However, various individual factors, such as genetic differences and nicotine-use/smoking status, have been suggested as predictors of naltrexone response. In a randomized clinical trial, we previously reported that nicotine-use/smoking status might be a stronger predictor of naltrexone efficacy than OPRM1 A118G single nucleotide polymorphism (SNP) genotype. In this report, we further characterize the nicotine-users in that trial, examine other drinking outcomes, examine the influence of smoking change on naltrexone effects on drinking, and validate the result in smokers with disialo carbohydrate-deficient transferrin (%dCDT) change as an independent biomarker of response.

METHODS

Individuals (n = 146) meeting DSM-IV criteria for alcohol dependence who were genotyped for the OPRM1 A118G SNP and who did, or did not, use nicotine/cigarettes were randomized, in a balanced fashion, to naltrexone (50 mg/d) or placebo and provided medical management (MM) over a 16-week clinical trial. Alcohol use and smoking during the trial were assessed and analyzed.

RESULTS

Nicotine-use/smoking status significantly interacted with medication in reducing percent heavy drinking days (PHDD) during the trial (p = 0.003), such that nicotine-users/smokers showed significantly lower PHDD on naltrexone versus placebo (p = 0.0001, Cohen's d = 0.89), while nonusers showed no significant difference between naltrexone and placebo (p = 0.95, Cohen's d = 0.02). Similar effects were shown for drinks per day and percent days drinking. The superiority of naltrexone over placebo on PHDD reduction in nicotine-users/smokers was confirmed with %dCDT (Cohen's d range 0.3 to 0.9 over the study). Naltrexone did not significantly change cigarette use in smokers, and change in use did not influence naltrexone's effect on PHDD.

CONCLUSIONS

These data confirm past findings that naltrexone is more efficacious in those who use nicotine/cigarettes. Compared to previous work on the OPRM1 A118G SNP, it appears that nicotine-use might be a more salient predictor of naltrexone treatment response. While naltrexone did not change cigarette use during the study, and smoking change was not related to alcohol reduction, it should be noted that participants were not seeking smoking cessation and MM did not address this issue.

Improved recovery of repeat intoxicated drivers using fingernails and blood spots to monitor alcohol and other substance abuse

OBJECTIVES

This study reports the results of a pilot program in Kenosha County that used a combination of direct biomarkers extracted from blood spots and nails to monitor repeat intoxicated drivers for their use of alcohol and drugs with a detection window spanning from 3 weeks to several months. The objectives were to test whether the direct biomarkers phosphatidylethanol (PEth), ethylglucuronide (EtG), and 5 drug metabolites would (1) help assessors obtain a more objective evaluation of repeat offenders during the assessment interview, (2) allow for timely identification of relapses and improve classification of drivers into risk categories, and (3) predict recidivism by identifying offenders most likely to obtain a subsequent operating while intoxicated (OWI) offense within 4 years of enrollment in the program.

METHODS

All (N = 261) repeat offenders were tested using PEth obtained from blood spots and EtG obtained from fingernails; 159 participants were also tested for a 5 drugs of abuse nail panel. Drivers were tested immediately after the assessment interview (baseline) and at 3, 6, 9, and 12 months after baseline. Based on biomarker results and self-reports of abstinence, offenders were classified into different risk categories and required to follow specific testing timelines based on the program's decision tree.

RESULTS

The baseline analysis shows that 60% of drivers tested positive for alcohol biomarkers (EtG, PEth, or both) at the assessment interview, with lower detection rates (0-11%) for the 5 drug metabolites. The comparison of biomarkers results to self-reports of abstinence identified 28% of all offenders as high risk and assigned them to more frequent testing and more intense monitoring. The longitudinal analysis shows that 56% (completers) of participants completed the program successfully and the remaining 44% (noncompliant) terminated prematurely. Two thirds (68%) of the completers were able to reduce or control their drinking and one third relapsed at least one time during their mandated monitoring periods. After a brief intervention by the assessors, 79% of relapsers tested negative for biomarkers in their repeat tests. The rearrest analysis showed that offenders classified in the noncompliant and relapsers groups were 7 times more likely to receive a new OWI 4 years after enrollment compared to drivers classified as abstainers or controllers. Refractory drivers were monitored the longest and reported no subsequent rearrests.

CONCLUSION

These findings demonstrate the benefits of more individualized interventions with repeat OWI offenders and calls for further development of multimodal approaches in traffic medicine including those that use direct alcohol biomarkers as evidence-based practices to reduce recidivism.

Ethylglucuronide in maternal hair as a biomarker of prenatal alcohol exposure

While direct ethanol metabolites, including ethylglucuronide (EtG), play an important role for the confirmation of prenatal alcohol exposure (PAE), their utility is often limited by their short half-lives in blood and urine. Maternal hair allows for a retrospective measure of PAE for up to several months. This study examined the validity of hair EtG (hEtG) relative to self-reporting and five other biomarkers in 85 pregnant women. Patients were recruited from a UNM prenatal clinic, which provides care to women with substance abuse and addiction disorders. The composite index, which was based on self-reported measures of alcohol use and allowed us to classify subjects into PAE (n = 42) and control (n = 43) groups, was the criterion measure used to estimate the sensitivity and specificity of hEtG. Proximal segments of hair were collected at enrollment (average 22.0 gestational weeks) and analyzed by LC-MS/MS. At the same visit, maternal blood and urine specimens were collected for analysis of GGT, %dCDT, PEth, uEtG, and uEtS. The study population included mostly opioid-dependent (80%) patients, a large proportion of ethnic minorities (75.3% Hispanic/Latina, 8.2% American Indian, 4.7% African-American), and patients with low education (48.2% < high school). The mean maternal age at enrollment was 26.7 ± 4.8 years. Hair EtG demonstrated 19% sensitivity and 86% specificity. The sensitivities of other biomarkers were comparable (5-20%) to hEtG but specificities were higher (98-100%). Hair EtG sensitivity improved when combined with other biomarkers, especially with GGT (32.5%) and PEth (27.5%). In addition, validity of hEtG improved in patients with less frequent shampooing and those who did not use hair dyes/chemical treatments. These data suggest that hEtG alone is not a sufficiently sensitive or specific biomarker to be used separately for the identification of PAE, but might be useful in a battery along with other maternal biomarkers.

The validity of phosphatidylethanol in dried blood spots of newborns for the identification of prenatal alcohol exposure

BACKGROUND

Accurate identification of prenatal alcohol exposure (PAE) in the newborn period offers an opportunity for early identification of children at risk of future neurocognitive problems and the implementation of interventional approaches earlier in life. PAE newborn screening by measuring phosphatidylethanol in dried blood spot (PEth-DBS) cards is feasible, logistically easier, and more cost-efficient compared with other biomarkers. However, the sensitivity and specificity of this method have yet to be established.

METHODS

This prospective cohort study examined validity of PEth-DBS among 28 infants with PAE and 32 controls relative to maternal self-report and other biomarkers. Pregnant women were recruited from a University of New Mexico clinic and followed to early postpartum period. The composite index, which was based on self-reported measures of alcohol use and allowed to classify subjects into PAE and control groups, was the criterion measure used to estimate sensitivity and specificity of PEth-DBS.

RESULTS

The study included large proportions of patients representing ethnic minorities (7.4% American Indian, 81.7% Hispanic/Latina), low education (54.2% <high school), and unplanned pregnancy (90.0%). No differences in sociodemographic characteristics, smoking or illicit drug use were observed among the study groups. The sensitivity of maternal biomarkers (gamma glutamyltranspeptidase [GGT], % carbohydrate-deficient transferrin [%CDT], urine ethyl glucuronide [UEtG], urine ethyl sulfate [UEtS]) was low (<15%) reflecting a moderate chronic or intermittent binge pattern of drinking in this cohort. PEth-DBS demonstrated 100% specificity and the highest sensitivity (32.1%) compared with other biomarkers. A battery consisting of maternal direct ethanol metabolites (UEtG, UEtS, PEth) and newborn PEth-DBS increased sensitivity to 50% without a substantial drop in specificity (93.8%).

CONCLUSIONS

Newborn PEth-DBS is a highly specific biomarker and can facilitate accurate detection of PAE in conjunction with other biomarkers. Minimal invasiveness, ease of storage and transportation of DBS cards, absence of postcollection synthesis, cost savings, and potential integration with routine newborn screening are all unique advantages of this method.

Ethyl glucuronide (EtG): better than breathalyser or self-reports to detect covert short-term relapses into drinking

AIMS

The assessment of relapses is widely used as an outcome measure of alcohol dependence treatment. However, the methods of assessing relapses range from questionnaires to biological markers of alcohol for different time spans. The aim of this study was to compare the relapse rates of weekend home stays during long-term alcohol dependence treatment, assessed by ethyl glucuronide (EtG), breath alcohol tests and self-reports.

METHODS

Two hundred and ninety-seven alcohol-dependent patients receiving a long-term inpatient treatment programme participated. After a weekend at home (Friday to Sunday) they were evaluated for relapse by personal interviews and with breath alcohol tests. A concomitantly collected urine sample was later assessed for EtG with liquid chromatography-tandem mass spectrometry (LC-MS/MS analysis).

RESULTS

Of the total, 37.7% of the patients were positive for EtG at least once. Breath alcohol tests had been positive in only 4.4% and in personal interviews only 5.7% of the patients had admitted relapse. 15.6% of EtG tests were positive, but breath alcohol tests were negative (Cohen's kappa = 0.056). Ninety-three per cent of the relapses were only detected by EtG.

CONCLUSION

In addition to breath alcohol tests and interviews, urinary EtG can clearly improve the verification of relapse in inpatient treatment programmes allowing for weekend stays at home. Without EtG testing, a high amount of relapses will stay undetected.

Does session attendance by a supportive significant other predict outcomes in individual treatment for alcohol use disorders?

BACKGROUND

A significant amount of research has supported the efficacy of couple versus individual treatment for alcohol use disorders, yet little is known about whether involving a significant other during the course of individual treatment can improve outcomes. Likewise, several barriers to couple treatment exist and a more flexible approach to significant other involvement may be warranted.

METHODS

This study constituted secondary analyses of the COMBINE data, a randomized clinical trial that combined pharmacotherapy and behavioral intervention for alcohol dependence. Data were drawn from the 16-week individual combined behavioral intervention (CBI), which had 776 participants, 31% of which were female, and 23% were non-white. The current study examined whether attendance by a supportive significant other (SSO) during CBI sessions would predict better outcomes. It was further hypothesized that active SSO involvement, defined by attendance during drink refusal or communication skills training sessions, would predict better outcomes.

RESULTS

SSOs attended at least 1 session for 26.9% of clients. Clients with SSOs who attended at least 1 session had significantly fewer drinking days and fewer drinking-related problems at the end of treatment. The presence of an SSO during a drink refusal training session predicted significantly better outcomes, as compared to SSO attendance at other sessions and drink refusal training without an SSO present. SSO attendance at a communication training session did not predict better outcomes.

CONCLUSIONS

These results suggest that specific types of active involvement may be important for SSO-involved treatment to have greater efficacy than individual treatment.

Clinical (nonforensic) application of ethyl glucuronide measurement: are we ready?

Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are minor metabolites of ethanol. Multiple studies have documented that, depending upon the amount of alcohol consumed, they can be measured in biological fluids for hours to days after the parent compound can no longer be detected. Testing for the presence of EtG, in a manner analogous to urinary drug abuse screening, has largely been restricted to forensic and law enforcement situations. Despite a real need for an objective and possibly quantitative marker of ethanol exposure for use in conjunction with outpatient clinical trials and treatment programs, measurement of these metabolites has seen only limited clinical application. The barriers to more extensive clinical use of EtG/EtS testing, particularly misleading assay results that can occur as a consequence of inadvertent exposure to nonbeverage ethanol-containing substances, are reviewed and put into perspective. Additional information needed to develop guidelines for optimal clinical utilization of EtG/EtS measurements is discussed.

Alcohol biomarkers in applied settings: recent advances and future research opportunities

During the past decade, advances have been made in the identification, development, and application of alcohol biomarkers. This is important because of the unique functions that alcohol biomarkers can serve in various applied settings. To carry out these functions, biomarkers must display several features including validity, reliability, adequacy of temporal window of assessment, reasonable cost, and transportability. During the past two decades, several traditional alcohol biomarkers have been studied in multiple human studies. Meanwhile, several new, promising biomarkers, including various alcohol metabolites and alcohol biosensors, are being explored in human studies. In addition, researchers have explored using biomarkers in combination and using biomarkers in combination with self-reports, resulting in increased sensitivity with little sacrifice in specificity. Despite these advances, more research is needed to validate biomarkers, especially the new ones, in humans. Moreover, recent advances in high-throughput technologies for genomics, proteomics, and metabolomics offer unique opportunities to discover novel biomarkers, while additional research is needed to perfect newly developed alcohol sensors. Development of more accurate biomarkers will help practicing clinicians to more effectively screen and monitor individuals who suffer from alcohol use disorders.

Comparison of ethyl glucuronide in hair with carbohydrate-deficient transferrin in serum as markers of chronic high levels of alcohol consumption

This study was designed with the aim to compare sensitivity and specificity of ethyl glucuronide in hair (HEtG) and carbohydrate-deficient transferrin (CDT) in serum as markers of heavy drinking. Eighty-six volunteers, including teetotalers, social, and heavy drinkers, were interviewed to evaluate their ethanol daily intake (EDI) during the last 2-week and 3-month periods. HEtG determination was performed by a fully validated LC-MS-MS procedure and ranged from <LOD (2 pg/mg) to 890.5 pg/mg. CDT was measured by immunonephelometry or by HPLC. Sensitivity and specificity of the two markers as indicators of an EDI higher than 60 g/day were calculated, with cut-off at 27 pg/mg (HEtG) and 2.5% (CDT). Considering the EDI of the last 2 weeks, HEtG showed equal selectivity (0.93 for both HEtG and CDT-immunonephelometry; 0.70 for both HEtG and CDT-HPLC) and 2 times the sensitivity of either of the two CDT methods (1.00 vs. 0.44 for CDT-immunonephelometry; 0.96 vs. 0.50 for CDT-HPLC). The same difference in performances but with higher absolute sensitivity and selectivity values for HEtG were observed considering the EDI of the last 3-months (selectivity: 1.00 for both HEtG and CDT-immunonephelometry, 0.89 and 0.78 for HEtG and CDT-HPLC, respectively; sensitivity: 1.00 vs. 0.47 for CDT-immunonephelometry; 0.98 vs. 0.51 for CDT-HPLC). Our results indicate that HEtG, as compared to CDT measured using different methods, is a selective marker of ethanol heavy chronic use providing considerably higher sensitivity.

Alcohol-use disorders

Alcohol dependence and alcohol abuse or harmful use cause substantial morbidity and mortality. Alcohol-use disorders are associated with depressive episodes, severe anxiety, insomnia, suicide, and abuse of other drugs. Continued heavy alcohol use also shortens the onset of heart disease, stroke, cancers, and liver cirrhosis, by affecting the cardiovascular, gastrointestinal, and immune systems. Heavy drinking can also cause mild anterograde amnesias, temporary cognitive deficits, sleep problems, and peripheral neuropathy; cause gastrointestinal problems; decrease bone density and production of blood cells; and cause fetal alcohol syndrome. Alcohol-use disorders complicate assessment and treatment of other medical and psychiatric problems. Standard criteria for alcohol dependence-the more severe disorder-can be used to reliably identify people for whom drinking causes major physiological consequences and persistent impairment of quality of life and ability to function. Clinicians should routinely screen for alcohol disorders, using clinical interviews, questionnaires, blood tests, or a combination of these methods. Causes include environmental factors and specific genes that affect the risk of alcohol-use disorders, including genes for enzymes that metabolise alcohol, such as alcohol dehydrogenase and aldehyde dehydrogenase; those associated with disinhibition; and those that confer a low sensitivity to alcohol. Treatment can include motivational interviewing to help people to evaluate their situations, brief interventions to facilitate more healthy behaviours, detoxification to address withdrawal symptoms, cognitive-behavioural therapies to avoid relapses, and judicious use of drugs to diminish cravings or discourage relapses.

Measuring carbohydrate-deficient transferrin by direct immunoassay: factors affecting diagnostic sensitivity for excessive alcohol intake

BACKGROUND

carbohydrate-deficient transferrin (CDT) is a marker of alcohol intake that is used for detecting or monitoring alcohol-use disorders. The introduction of a new direct immunoassay for CDT justifies reevaluation of test performance and reexamination of factors affecting test diagnostic sensitivity and specificity.

METHODS

individuals enrolled in twin/family studies of alcohol use and dependence provided blood samples and information on recent alcohol use. Serum CDT concentration was measured in 2 088 people with the N Latex CDT (Dade Behring) method, and CDT percentage (CDT%) was calculated as the proportion of the total transferrin concentration measured with Roche reagents.

RESULTS

diagnostic sensitivity was low, both for comparisons of men who reported an alcohol intake of >28 drinks/week vs those who consumed < or = 28 drinks/week (28% sensitivity) and for women who consumed >14 drinks/week vs those who consumed < or = 14 drinks/week (18% sensitivity), at cutoff values that yielded a 95% specificity. Body mass index, variables associated with metabolic syndrome, and smoking had notable effects on the probability of an abnormal CDT result with excessive alcohol use. Diagnostic sensitivity was greater in men of normal weight (43%) than in obese men (10%) and greater in male smokers (38%) than in male nonsmokers (21%). In women, diagnostic sensitivities were < or = 20%, even for those of normal weight and for smokers.

CONCLUSIONS

CDT is a poor marker of excessive alcohol intake in both women and men who are overweight or obese. It is also less useful in nonsmokers than in smokers. The diagnostic performance of the direct immunoassay and the effects of obesity and smoking are similar to those reported with previous anion-exchange immunoassay methods.