Equivalent Blood Alcohol Concentrations Research Articles

Change in brain asymmetry reflects level of acute alcohol intoxication and impacts on inhibitory control

Alcohol is one of the most commonly used substances and frequently abused, yet little is known about the neural underpinnings driving variability in inhibitory control performance after ingesting alcohol. This study was a single-blind, placebo-controlled, randomized design with participants (N = 48 healthy, social drinkers) completing three study visits. At each visit participants received one of three alcohol doses; namely, a placebo dose [equivalent Blood Alcohol Concentration (BAC) = 0.00%], a low dose of alcohol (target BAC = 0.04%), or a moderate dose of alcohol (target BAC = 0.08%). To measure inhibitory control, participants completed a Go/No-go task paradigm twice during each study visit, once immediately before dosing and once after, while their brain activity was measured with time-domain functional near-infrared spectroscopy (TD-fNIRS). BAC and subjective effects of alcohol were also assessed. We report decreased behavioral performance for the moderate dose of alcohol, but not the low or placebo doses. We observed right lateralized inhibitory prefrontal activity during go-no-go blocks, consistent with prior literature. Using standard and novel metrics of lateralization, we were able to significantly differentiate between all doses. Lastly, we demonstrate that these metrics are not only related to behavioral performance during inhibitory control, but also provide complementary information to the legal gold standard of intoxication (i.e. BAC).

A Disposable and Noncontact Paper Breathalyzer Based on Small Conjugated Molecules/Carbon Nanotubes Electrodes

Herein, N,N′‐di(decyl)‐3,4,9,10‐perylenebis(dicarboximide) (PDIC10) is first functionalized by hydrothermal synthesis method and processed onto single‐walled carbon nanotube (SWCN) electrodes and paper substrate. The PDC10/SWCN/paper device can be applied as a noncontact breathalyzer to detect and quantify ethanol alcohol and determine equivalent blood alcohol concentration (BAC). The sensing mechanism increases the electrical resistance upon ethanol alcohol (EtOH) exposition. This device allows the quantification of BAC values from 0.01% to 0.2%, with ΔR (%) of 2–25% in this range, with adequate stability operating in cycles.

Statistical comparisons of blood alcohol samples from 6-mL and 10-mL grey-top tubes.

Historically, blood alcohol concentration (BAC) studies utilized a 1% concentration of the preservative sodium fluoride (NaF), leaving an information gap supporting usage of lower concentrations of NaF to preserve ethanol. As many forensic laboratories utilize Becton, Dickinson and Company 6-mL gray-top tubes (0.25% NaF), statistical comparisons were conducted to determine whether significant differences exist between BAC values obtained from 6-mL tubes versus 10-mL tubes (1% NaF). Whole blood was spiked at three concentrations, (0.04, 0.08, and 0.15g/100mL) and aliquoted into tubes at "low," "medium," and "high" fill volumes. Tubes were split into refrigerated or ambient storage and analyzed after 1, 3, 5, 7, and 30days, using headspace gas chromatography. Each 6-mL and 10-mL tube pair, prepared, stored, and analyzed under identical conditions, was compared by t-test (95% confidence level). For refrigerated tubes, 32 of 45-tube pairs did not reject the null hypothesis (that 6-mL and 10-mL tubes yield equivalent BACs), and 31 of 45 ambient stored tube pairs did not reject the null hypothesis. Analysis of variance (ANOVA) found no significant differences between 6-mL and 10-mL gray-top tubes for 0.04 and 0.15g/100mL concentrations over 30days; significant differences were observed for 0.08g/100mL concentration tubes, which warrants further study. Paired t-tests of grouped samples found no significant differences between 6-mL and 10-mL tubes at any concentration.

Subjective and Neural Responses to Intravenous Alcohol in Young Adults with Light and Heavy Drinking Patterns

Heavy alcohol consumption during young adulthood is a risk factor for the development of serious alcohol use disorders. Research has shown that individual differences in subjective responses to alcohol may affect individuals' vulnerability to developing alcoholism. Studies comparing the subjective and objective response to alcohol between light and heavy drinkers (HDs), however, have yielded inconsistent results, and neural responses to alcohol in these groups have not been characterized. We performed a double-blind, placebo-controlled, randomized crossover alcohol challenge study comparing functional magnetic resonance imaging and subjective response to intravenously administered 6% v/v ethanol to a target blood alcohol concentration of 0.08% or placebo between HDs and social drinkers (SDs). During the imaging, we presented emotional cues in order to measure how emotion modulated the effects of alcohol on the brain's reward circuitry. We found that, at equivalent blood alcohol concentrations, HDs reported lower subjective alcohol effects than SDs. Alcohol significantly activated the nucleus accumbens in SDs, but not in HDs. Self-reported ratings of intoxication correlated with striatal activation, suggesting that activation may reflect subjective experience of intoxication. Fearful faces significantly activated the amygdala in the SDs only, and this activation was attenuated by alcohol. This study shows that HDs not only experience reduced subjective effects of alcohol, but also demonstrate a blunted response to alcohol in the brain's reward system. Our findings indicate that reduced subjective and neural response to alcohol in HDs may be suggestive of either the development of tolerance to alcohol, or of pre-existing decreased sensitivity to alcohol's effects.

Blood Alcohol Concentration Levels among Dui Arrestees: Are There Differences When Considering Race and Gender?

Many studies and treatment programmes associated with driving under the influence (DUI) of alcohol have focused on Caucasian males, either minimising or casually addressing minorities and females who historically may have not consumed alcohol and driven at equivalent BAC levels. The current study examines arrest report data in order to compare the mean blood alcohol concentration (BAC) levels for individuals arrested for DUI when considering race and gender. Examination of arrest data revealed that while females were less frequently arrested for driving under the influence of alcohol, female intoxication levels as measured by their blood alcohol concentration (BAC) at the time of their arrest were equivalent to their male counterparts ( t (242) = 1.214, p = 0.226). Further, when considering for arrestee's race there was no statistically significant difference between the mean BAC levels of Caucasians when compared with African Americans and other minorities ( F (2, 241) = 0.358, p = 0.700).

Associations of ALDH2 and ADH1B genotypes with response to alcohol in Asian Americans.

Individuals with alcohol dependence are less likely to possess variant alleles of the alcohol-metabolizing genes, aldehyde dehydrogenase (ALDH2*2) and alcohol dehydrogenase (ADH1B*2), than non-alcohol-dependent controls. It is hypothesized that the mechanism through which these alleles protect against alcohol dependence is by causing elevations in acetaldehyde, which in turn cause an increased response to alcohol. Previous research has shown that individuals with ALDH2*2 demonstrate enhanced reactions to alcohol compared with those without this genetic variant, but evidence that ADH1B*2 is associated with a greater alcohol response is mixed. This study was designed to determine whether the ADH1B genotype is associated with more intense reactions to alcohol after controlling for the ALDH2 genotype. Participants (N = 101) were Asian American college students. Each was evaluated using objective and subjective measures before and after ingestion of alcohol and placebo beverages. Participants with the ALDH2*1/*2 and ALDH2*2/*2 genotypes were more likely to experience vomiting following ingestion of the alcohol beverage than those with the ALDH2*1/*1 genotype. Participants with the ALDH2*1/*2 genotype also had greater pulse-rate increases, observed flushing ratings, and subjective feelings of intoxication 30 minutes after ingestion of alcohol than participants with the ALDH2*1/*1 genotype, despite equivalent blood alcohol concentration (BAC) measurements. Among participants with the ALDH2*1/*1 genotype, there were no additional effects of the ADH1B genotype on any measures of response to alcohol. Among participants with the ALDH2*1/*2 genotype, those with the ADH1B*2/*2 genotype were more likely to experience alcohol-induced vomiting and to report feeling less "great overall" 30 minutes after ingestion of alcohol than those with the ADH1B*1/*2 genotype. These findings are consistent with the hypothesis that there is an additional effect of ADH1B*2 on level of response to alcohol, but only among individuals with the ALDH2*1/*2 genotype.

Acute Effects of Alcohol on P300 in Asians with Different ALDH2 Genotypes

Asian men were genotyped for alleles of aldehyde dehydrogenase (ALDH2) and tested on two separate occasions following oral administration of placebo and 0.75 ml/kg alcohol. Sixty minutes after beverage ingestion, event-related potentials were elicited using an auditory oddball paradigm. Repeated measures ANOVA revealed that alcohol produced significant increases in P300 latency and significant decreases in P300 amplitude compared with placebo. Subjects with ALDH2*1/2*2 genotype (n = 14) demonstrated some significantly greater P300 effects after alcohol than subjects with ALDH2*1/2*1 genotype (n = 15), despite equivalent blood alcohol concentrations. These data suggest that neurocognitive functioning may be more impaired following alcohol in subjects with an ALDH2*2 allele. These findings further suggest that a genetically controlled factor (deficiency in ALDH enzyme activity) might contribute to a decreased likelihood of alcohol intake and protection from alcoholism, because of an enhanced sensitivity to alcohol.

Absorption, distribution and elimination of alcohol: highway safety aspects.

Key aspects of the pharmacokinetics of alcohol are highly relevant to highway safety. Of particular pertinence are the partition of alcohol between various body tissues and fluids and the resulting alcohol concentration ratios for blood: breath and other body fluids, as well as the irregularity and short-term fluctuations of the blood and breath alcohol curves. Most alcohol pharmacokinetics parameters are subject to wide intersubject variability, as exemplified by peak blood alcohol concentrations reached on ingestion of identical weight-adjusted doses, time to peak after end of drinking and the rate of alcohol elimination from the blood. This great biological intersubject variability, when combined with sex-, age- and time-related differences, makes the blood alcohol information in widely distributed alcohol consumption nomograms and tables based on mean data inappropriate as a guide for the drinking behavior of individuals. Although there is good statistical correlation between the alcohol concentration of different body tissues and fluids in the fully postabsorptive state, wide individual variations from the population mean alcohol partition values exist. It is often impossible to determine whether the postabsorptive state has been reached at any given time. Those factors make it impossible or infeasible to convert the alcohol concentration of breath or urine to the simultaneous blood alcohol concentration with forensically acceptable certainty, especially under per se or absolute alcohol concentration laws. Inclusion of breath alcohol concentrations in drinking-driving statutes, as definitions or per se offense elements, makes unnecessary the conversion of breath alcohol analysis results into equivalent blood alcohol concentrations. Urine alcohol concentrations are inadequately correlated with blood alcohol concentrations or with driver impairment, and analysis of bladder urine is, therefore, inappropriate in traffic law enforcement. Significantly large sex-related differences in pharmacokinetic parameters have been demonstrated (e.g., in peak blood alcohol concentrations for weight-adjusted doses). The effects of age and time of day have been less extensively studies and are less clear. Breath and blood alcohol time curves are subject to short-term fluctuations from the trend line and other irregularities, and often do not follow the typical Widmark pattern. From the existing information on pharmacokinetics of alcohol and the characteristics and variability of blood and breath alcohol versus time curves, the following conclusions can be reached.(ABSTRACT TRUNCATED AT 400 WORDS)

Blood Alcohol Concentration Determined from Urine Samples as a Practical Equivalent or Alternative to Blood and Breath Alcohol Tests

The value of urine tests for determining an equivalent blood alcohol concentration in driving under the influence (DUI) enforcement cases is reviewed from a historical, theoretical, and practical perspective. The limits of precision and accuracy that can be ascribed to urine alcohol results are demonstrated through an evaluation of actual case results wherein both a first void and a subsequent urine sample were analyzed and converted to an equivalent blood alcohol concentration (BAC) using a urine to blood conversion factor of 1.3:1.