Population pharmacokinetics and pharmacogenetics of alcohol in Chinese and Indians in Singapore

The Circassians and the Chechens in Jordan: results of a decade of epidemiological and genetic studies

Circassians and Chechens in Jordan, both with Caucasian ancestry, are genetically isolated due to high rate of endogamous marriages. Recent interest in these populations has led to studies on their genetic similarities, differences, and epidemiological differences in various diseases. Research has explored their predisposition to conditions like diabetes, hypertension, and cancer. Moreover, pharmacogenetic (PGx) studies have also investigated medication response variations within these populations, and forensic studies have further contributed to understanding these populations. In this review article, we first discuss the background of these minority groups. We then show the results of a principle component analysis (PCA) to investigate the genetic relationships between Circassian and Chechen populations living in Jordan. We here present a summary of the findings from the 10 years of research conducted on them. The review article provides a comprehensive summary of research findings that are truly valuable for understanding the unique genetic characteristics, diseases' prevalence, and medication responses among Circassians and Chechens living in Jordan. We believe that gaining deeper comprehension of the root causes of various diseases and developing effective treatment methods that benefit the society as a whole are imperative to engaging a wide range of ethnic groups in genetic research.

Analysis of Comprehensive Pharmacogenomic Profiling of VIP Variants Among the Genetically Isolated Chechen Subpopulation from Jordan

Background

Profiling rare variants in isolated populations can significantly clarify and understand the development of a clinically relevant process. Therefore, leading to a better identifying novel targeted treatment.

Objective

This study aimed to determine the allele frequencies of 56 single nucleotide polymorphisms (SNPs) within several important pharmacogenes.

Methods

This study consisted of 166 unrelated subjects from a genetically isolated group (Chechen) who were living in Jordan. In this study, the distribution of the variants among Chechen was compared to other ethnic groups available at two databases (Genome 1000 and (ExAC)). The frequency of genotypes and alleles was calculated and tested using the chi-square test and the Hardy–Weinberg equilibrium equation (HWE).

Results

Our results revealed that the distribution of allele frequencies within different pharmacogenes among Chechen showed different similarities with other populations. The CEU and TSI showed the highest resemblance with the Chechen population (75% similarity), in contrast to LWK which had the lowest similarity (30%).

Conclusion

This study sheds light on clinically relevant SNPs to enhance medical research and apply pharmacogenomics in clinical settings.

Genetic Polymorphisms of the Mitochondrial Aldehyde Dehydrogenase ALDH2 Gene in a Large Ethnic Hakka Population in Southern China

Background

Human mitochondrial aldehyde dehydrogenase 2 (ALDH2) plays a critical role in the detoxification of the ethanol metabolite acetaldehyde. The ALDH2*2 (rs671) gene variant is mainly absent among Europeans but is prevalent in populations in East Asia. The aim of this study was to investigate ALDH2*2 mutant alleles and genotype frequencies in the Hakka population of China.

Material/Methods

Between January 2016 and June 2017, 7,966 unrelated individuals were recruited into the study from the Hakka ethnic population residing in the Meizhou area of Guangdong Province, China, who provided venous blood samples. Genotyping of ALDH2 genotypes were determined using a gene chip platform and confirmed by DNA sequencing.

Results

In the 7,966 individuals from the Hakka population of China in this study, the frequencies of the ALDH2 genotypes *1/*1, *1/*2 and *2/*2 were 52.03%, 39.67%, and 8.30%, respectively; 47.97% of the individuals were found to carry the ALDH2*2 genotype, which was associated with a deficiency in the aldehyde dehydrogenase (ALDH2) enzyme activity. The frequency of the ALDH2*2 allele was lower than that previously reported in the Japanese population but higher than that reported in other Oriental populations.

Conclusions

The findings of this study have provided new information on the ALDH2 gene polymorphisms in the Hakka ethnic population residing in the Meizhou area of Guangdong Province, China, including an understanding of the origin of the atypical ALDH2*2 allele. Also, the study findings may be relevant to the primary care of patients in China.

Effect of alcohol dehydrogenase-1B and -7 polymorphisms on blood ethanol and acetaldehyde concentrations in healthy subjects with a history of moderate alcohol consumption

This study aims to evaluate the effect of ADH1B and ADH7 genotypes on blood acetaldehyde and ethanol levels after alcohol ingestion, and to measure the genotoxic effect of smoking and ethanol on the buccal cells, also controlling for ADH variants. We recruited healthy Italian subjects with at least a moderate history of alcohol consumption. All subjects were given an alcoholic drink of 0.4 g ethanol /kg of body weight. Blood venous samples were collected at baseline, and 30, 60, 90, and 120 minutes after ingestion. Buccal cells were collected before ethanol ingestion. Sixty subjects were enrolled in the study. Individuals with the ADH1B GG genotype had median ethanol levels of 5.0mM (IQR 3.4-7.2), and those with the ADH1B GT/TT genotype had 4.7mM (IQR 4.2-4.8). Corresponding acetaldehyde levels were 1.5μM (IQR 0.7-2.6) for ADH1B GG genotype and 1.6μM (IQR 1.5-1.7) for ADH1B CG/GG genotype. Individuals with the ADH7 CC genotype had median ethanol levels of 5.0mM (IQR 3.3-7.2), while 5.0mM (IQR 4.7-5.6) was in those with the ADH7 CG/GG genotype. Corresponding acetaldehyde levels were 1.5 μM (IQR 0.7-2.6) for ADH7 CC genotype and 1.5 μM (IQR 1.4-1.6) for ADH7 CG/GG genotypes. A non-significant increase in the frequency of karyolitic and pyknotic cells was found in the group of heavy drinkers and current smokers, when compared to the moderate drinkers and the non-smokers. Our study does not support the hypothesis that ADH1B and ADH7 genotypes affect blood ethanol and acetaldehyde concentration.

A Bayesian Approach for Population Pharmacokinetic Modeling of Alcohol in Japanese Individuals

Background

Blood alcohol concentration data that were previously obtained from 34 healthy Japanese subjects with limited sampling times were reanalyzed. Characteristics of the data were that the concentrations were obtained from only the early part of the time-concentration curve.

Objective

To explore significant covariates for the population pharmacokinetic analysis of alcohol by incorporating external data using a Bayesian method, and to estimate effects of the covariates.

Methods

The data were analyzed using a Markov chain Monte Carlo Bayesian estimation with NONMEM 7.3 (ICON Clinical Research LLC, North Wales, Pennsylvania). Informative priors were obtained from the external study.

Results

A 1-compartment model with Michaelis-Menten elimination was used. The typical value for the apparent volume of distribution was 49.3 L at the age of 29.4 years. Volume of distribution was estimated to be 20.4 L smaller in subjects with the ALDH2*1/*2 genotype than in subjects with the ALDH2*1/*1 genotype.

Conclusions

A population pharmacokinetic model for alcohol was updated. A Bayesian approach allowed interpretation of significant covariate relationships, even if the current dataset is not informative about all parameters. This is the first study reporting an estimate of the effect of the ALDH2 genotype in a PPK model.

Lipids and Oxidative Stress Associated with Ethanol-Induced Neurological Damage

The excessive intake of alcohol is a serious public health problem, especially given the severe damage provoked by chronic or prenatal exposure to alcohol that affects many physiological processes, such as memory, motor function, and cognitive abilities. This damage is related to the ethanol oxidation in the brain. The metabolism of ethanol to acetaldehyde and then to acetate is associated with the production of reactive oxygen species that accentuate the oxidative state of cells. This metabolism of ethanol can induce the oxidation of the fatty acids in phospholipids, and the bioactive aldehydes produced are known to be associated with neurotoxicity and neurodegeneration. As such, here we will review the role of lipids in the neuronal damage induced by ethanol-related oxidative stress and the role that lipids play in the related compensatory or defense mechanisms.

Ethanol pharmacokinetics in neonates and infants

Introduction

Ethanol has been used for years in neonatal and infant liquid medications, yet the pharmacokinetics, pharmacodynamics, and safety of ethanol in this vulnerable population have not been well characterized. The purpose of this review is to raise awareness of ethanol use as an excipient in neonatal and infant medications and to provide insight, based on the available evidence, into clearance rates of ethanol in babies. We also discuss ethanol pharmacokinetics in adults, theoretical pharmacokinetic changes in neonates and infants as it may apply to ethanol disposition, and case reports involving ethanol exposure in neonates and infants.

Materials and methods

This study was a narrative review in which relevant papers were selected using databases and scientific search engines such as PubMed with the key words ethanol, infant, and newborninfant.

Results

It remains unclear what ethanol exposure is safe for neonates and infants. The Food and Drug Administration and American Academy of Pediatrics have both taken action, by either setting limits of ethanol content in over-the-counter medications or by recommending restricted exposure to ethanol-containing pediatric formulations.

Conclusions

Until the short- and long-term health effects of chronic ethanol administration can be further characterized, ethanol-containing medications should be used with caution.