Sex and gender-related differences in alcohol use and its consequences: Contemporary knowledge and future research considerations

An investigation of broad-spectrum antibiotic-induced liver injury based on the FDA Adverse Event Reporting System and retrospective observational study

Tazobactam/piperacillin and meropenem are commonly used as an empiric treatment in patients with severe bacterial infections. However, few studies have investigated the cause of tazobactam/piperacillin- or meropenem-induced liver injury in them. Our objective was to evaluate the association between tazobactam/piperacillin or meropenem and liver injury in the intensive care unit patients. We evaluated the expression profiles of antibiotics-induced liver injury using the US Food and Drug Administration Adverse Event Reporting System (FAERS) database. Further, in the retrospective observational study, data of patients who initiated tazobactam/piperacillin or meropenem in the intensive care unit were extracted. In FAERS database, male, age, the fourth-generation cephalosporin, carbapenem, β-lactam and β-lactamase inhibitor combination, and complication of sepsis were associated with liver injury (p < 0.001). In the retrospective observational study, multivariate logistic regression analyses indicated that the risk factors for liver injury included male (p = 0.046), administration period ≥ 7 days (p < 0.001), and alanine aminotransferase (p = 0.031). Not only administration period but also sex and alanine aminotransferase should be considered when clinicians conduct the monitoring of liver function in the patients receiving tazobactam/piperacillin or meropenem.

Latent profiles of modifiable dementia risk factors in later midlife: relationships with incident dementia, cognition, and neuroimaging outcomes

In 2020, the Lancet Commission identified 12 modifiable factors that increase population-level dementia risk. It is unclear if these risk factors co-occur among individuals in a clinically meaningful way. Using latent class analysis, we identified profiles of modifiable dementia risk factors in dementia-free adults aged 60-64 years from the UK Biobank. We then estimated associations between these profiles with incident dementia, cognition, and neuroimaging outcomes, and explored the differences across profiles in the effects of a polygenic risk score for Alzheimer's disease on outcomes. In 55,333 males and 63,063 females, three sex-specific latent profiles were identified: cardiometabolic risk, substance use-related risk, and low risk. The cardiometabolic risk profile in both males and females was associated with greater incidence of all-cause dementia (male: OR [95% CI] = 2.33 [2.03, 2.66]; female: OR [95% CI] = 1.44 [1.24, 1.68]), poorer cognitive performance, greater brain atrophy, and greater white matter hyperintensity volume compared to the low risk profile. The substance use-related risk profile in males was associated with poorer cognitive performance and greater white matter hyperintensities compared to the low risk profile, but no difference in all-cause dementia incidence was observed (OR [95% CI] = 1.00 [0.95, 1.06]). In females, the substance use-related risk profile demonstrated increased dementia incidence (OR [95% CI] = 1.58 [1.57, 1.58]) and greater brain atrophy but smaller white matter hyperintensity volume compared to the low risk profile. The polygenic risk score had larger effects among females, and differentially influenced outcomes across profiles; for instance, there were larger effects of the polygenic risk score on atrophy in the cardiometabolic profile vs. the low risk profile among males, and larger effects of the polygenic risk score on loss of white matter integrity in the cardiometabolic profile vs. the low risk profile among females. These results reveal three modifiable dementia risk profiles, their unique cognitive/neuroimaging outcomes, and their interactions with genetic risk for Alzheimer's disease. These differences highlight the need to consider population heterogeneity in risk prediction tools and in planning personalized prevention strategies.

Age- and sex-driven alterations in alcohol consumption patterns: Role of brain ethanol metabolism and the opioidergic system in the nucleus accumbens

Alcohol consumption leads to significant neurochemical and neurobiological changes, contributing to the development of alcohol use disorders (AUDs), which exhibit sex- and age-dependent variations according to clinical data. However, preclinical studies often neglect these factors when investigating alcohol consumption patterns. In this study, we present data on male and female rats continuously exposed to a 20 % ethanol solution for one month. The animals were divided into two groups based on their age at the onset of drinking (8 and 12 weeks old). Interestingly, 12-week-old males consumed significantly less alcohol than both 12-week-old females and 8-week-old animals, indicating that alcohol consumption patterns vary with sex and age in our model. Additionally, to advance in the study of the neurobiological alterations induced by ethanol intake in the mesocorticolimbic system (MCLS) that may participate in its reinforcing properties and the maintenance of alcohol drinking behavior, we measured catalase activity-an enzyme involved in alcohol metabolism and related to ethanol reinforcement-in the nucleus accumbens (NAc) of these animals. Furthermore, we measured the levels of mu (MOR), kappa (KOR), delta (DOR), and nociceptin (NOP) opioid receptors in the NAc, as the endogenous opioidergic system plays a pivotal role in regulating the MCLS and alcohol reinforcement. MOR levels were lower in high alcohol-consuming groups (8-week-old males and all females). Both DOR and NOP levels decreased with age, whereas KOR levels remained unchanged. Our findings suggest that the age at onset of alcohol consumption critically influences alcohol intake, particularly in males. Additionally, females consistently showed higher alcohol intake regardless of age, highlighting inherent sex-specific differences. The dynamic changes in catalase activity and opioid receptor expression suggest the involvement of these factors in modulating alcohol consumption.

A longitudinal test of problematic alcohol use and binge eating among college women: The moderating role of shame

Problematic alcohol use and binge eating frequently co-occur. High levels of negative affect, negative urgency, and/or shame may increase the likelihood that problematic alcohol use and binge eating co-occur over time.

OBJECTIVE

Examine 1) the temporal relationship between problematic alcohol use and binge eating among college women, who are at high risk for both, and 2) the additive and moderating effects of shared, emotion-based risk factors in models involving both problematic alcohol use and binge eating.

METHOD

In n = 302 college women assessed at two time points across 8 months, we used hierarchical linear regression to invstigate our objectives.

RESULTS

Baseline problematic alcohol use and baseline shame independently predicted increases in follow-up binge eating, controlling for baseline binge eating. In addition, the interaction between problematic alcohol use and shame accounted for further variance in subsequent binge eating (the influence of baseline problematic alcohol use on follow-up binge eating was stronger at higher levels of baseline shame). The reciprocal relationship was not significant: baseline binge eating did not predict follow-up problematic alcohol use independently or in conjunction with risk factors. Neither negative affect nor negative urgency showed predictive effects beyond prior behavior and shame. Results support 1) problematic alcohol use as a prospective risk factor for binge eating, 2) shame as an additive predictor of binge eating, and 3) shame as a positive moderator of binge eating prediction from problem drinking.

CONCLUSION

Addressing shame and problematic alcohol use may be warranted in binge eating interventions for college women.

Youth participation in substance use prevention: A national profile, 2011-2019

PURPOSE

Prevention efforts are critical to avoid the negative consequences of substance use in adolescents. This study aimed to examine national trends and sociodemographic differences in adolescents' participation in school-based substance use prevention (SUP) education, community-based SUP programs, as well as family conversations about substance use.

METHODS

Publicly available data for adolescents aged 12-17 from the annual cross-sectional surveys of the National Survey on Drug Use and Health 2011-2019 were analyzed.

RESULTS

Across the survey years, up to 74.9%, 12.2%, and 58.1% of adolescents reported having participated in school-based SUP education, community-based SUP programs, and family conversations about the danger of substance use in the past-year, respectively. From 2011 to 2019, statistically significant decreases were observed in adolescents' participation in school-based SUP education (OR = 0.97, 95% CI: 0.96, 0.98, p < 0.001) and community-based SUP programs (OR = 0.98, 95% CI: 0.97, 0.99, p < 0.001). Meanwhile, no significant changes were observed in adolescents' participation in family conversations about the dangers of substance use. Overall, lower levels of participation in school-based and community-based SUP programs were found in adolescents aged 16-17. Adolescents living in rural areas showed lower levels of participation in school-based SUP programs and family conversations about SUP. Racial/ethnic minority adolescents overall were less likely to participate in conversations with parents about SUP than Whites.

CONCLUSIONS

Further development and implementation of developmentally appropriate, gender-specific, culturally sensitive, and contextually informed SUP programs at school, community, and family levels are needed.

Phosphoglycerate mutase 5 exacerbates alcoholic cardiomyopathy in male mice by inducing prohibitin-2 dephosphorylation and impairing mitochondrial quality control

BACKGROUND

The induction of mitochondrial quality control (MQC) mechanisms is essential for the re-establishment of mitochondrial homeostasis and cellular bioenergetics during periods of stress. Although MQC activation has cardioprotective effects in various cardiovascular diseases, its precise role and regulatory mechanisms in alcoholic cardiomyopathy (ACM) remain incompletely understood.

METHODS

We explored whether two mitochondria-related proteins, phosphoglycerate mutase 5 (Pgam5) and prohibitin 2 (Phb2), influence MQC in male mice during ACM.

RESULTS

Myocardial Pgam5 expression was upregulated in a male mouse model of ACM. Notably, following ACM induction, heart dysfunction was markedly reversed in male cardiomyocyte-specific Pgam5 knockout (Pgam5cKO) mice. Meanwhile, in alcohol-treated male mouse-derived neonatal cardiomyocytes, Pgam5 depletion preserved cell survival and restored mitochondrial dynamics, mitophagy, mitochondrial biogenesis and the mitochondrial unfolded protein response (mtUPR). We further found that in alcohol-treated cardiomyocyte, Pgam5 binds Phb2 and induces its dephosphorylation at Ser91. Alternative transduction of phospho-mimetic (Phb2S91D) and phospho-defective (Phb2S9A) Phb2 mutants attenuated and enhanced, respectively, alcohol-related mitochondrial dysfunction in cardiomyocytes. Moreover, transgenic male mice expressing Phb2S91D were resistant to alcohol-induced heart dysfunction.

CONCLUSIONS

We conclude that ACM-induced Pgam5 upregulation results in Pgam5-dependent Phb2S91 dephosphorylation, leading to MQC destabilisation and mitochondrial dysfunction in heart. Therefore, modulating the Pgam5/Phb2 interaction could potentially offer a novel therapeutic strategy for ACM in male mice.

HIGHLIGHTS

Pgam5 knockout attenuates alcohol-induced cardiac histopathology and heart dysfunction in male mice. Pgam5 KO reduces alcohol-induced myocardial inflammation, lipid peroxidation and metabolic dysfunction in male mice. Pgam5 depletion protects mitochondrial function in alcohol-exposed male mouse cardiomyocytes. Pgam5 depletion normalises MQC in ACM. EtOH impairs MQC through inducing Phb2 dephosphorylation at Ser91. Pgam5 interacts with Phb2 and induces Phb2 dephosphorylation. Transgenic mice expressing a Ser91 phospho-mimetic Phb2 mutant are resistant to ACM.

Cost of cardiovascular disease events in patients with and without type 2 diabetes and factors influencing cost: a retrospective cohort study

BACKGROUND

Cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) are non-communicable diseases that impose a significant economic burden on healthcare systems, particularly in low- and middle-income countries. The purpose of this study was to evaluate the hospital treatment cost for cardiovascular disease events (CVDEs) in patients with and without diabetes and identify factors influencing cost.

METHOD

We conducted a retrospective, cross-sectional study using administrative data from three public tertiary hospitals in Malaysia. Data for hospital admissions between 1 March 2019 and 1 March 2020 with International Classification of Diseases 10th Revision (ICD-10) codes for acute myocardial infarction (MI), ischaemic heart disease (IHD), hypertensive heart disease, stroke, heart failure, cardiomyopathy, and peripheral vascular disease (PVD) were retrieved from the Malaysian Disease Related Group (Malaysian DRG) Casemix System. Patients were stratified by T2DM status for analyses. Multivariate logistic regression was used to identify factors influencing treatment costs.

RESULTS

Of the 1,183 patients in our study cohort, approximately 60.4% had T2DM. The most common CVDE was acute MI (25.6%), followed by IHD (25.3%), hypertensive heart disease (18.9%), stroke (12.9%), heart failure (9.4%), cardiomyopathy (5.7%) and PVD (2.1%). Nearly two-thirds (62.4%) of the patients had at least one cardiovascular risk factor, with hypertension being the most prevalent (60.4%). The treatment cost for all CVDEs was RM 4.8 million and RM 3.7 million in the T2DM and non-T2DM group, respectively. IHD incurred the largest cost in both groups, constituting 30.0% and 50.0% of the total CVDE treatment cost for patients with and without T2DM, respectively. Predictors of high treatment cost included male gender, non-minority ethnicity, IHD diagnosis and moderate-to-high severity level.

CONCLUSION

This study provides real-world cost estimates for CVDE hospitalisation and quantifies the combined burden of two major non-communicable disease categories at the public health provider level. Our results confirm that CVDs are associated with substantial health utilisation in both T2DM and non-T2DM patients.

Sex and sobriety: Human brain structure and function in AUD abstinence

Women are drinking alcohol as much as men for the first time in history. Women experience more health-related consequences from alcohol use disorder (AUD), like increased prevalence of alcohol-related cancers, faster progression of alcohol-related liver disease, and greater risk for relapse compared to men. Thus, sex differences in chronic alcohol use pose a substantial public health problem. Despite these evident sex differences, our understanding of how these differences present during alcohol abstinence is limited. Investigations of brain structure and function are therefore critical for disentangling factors that lead to sex differences in AUD abstinence. This review will discuss current human neuroimaging data on sex differences in alcohol abstinence, focusing on structural and functional brain measures. Current structural imaging literature reveals that abstinent men have smaller gray and white matter volume and weaker structural connectivity compared to control men. Interestingly, abstinent women do not show differences in brain structure when compared to controls; instead, abstinent women show a relation between alcohol use and decreased measures of brain structure. Current functional brain studies reveal that abstinent men exhibit greater brain activation and stronger task-based functional connectivity to aversive stimuli than control men, while abstinent women exhibit lesser brain activation and weaker task-based functional connectivity than control women. Together, the current literature suggests that sex differences persist well into alcohol abstinence and impact brain structure and function differently. Understanding how men and women differ during alcohol abstinence can improve our understanding of sex-specific effects of alcohol, which will be critical to augment treatment methods to better serve women.

Benefits of exercise on cognitive impairment in alcohol use disorder following alcohol withdrawal

Although most cognitive impairments induced by prolonged alcohol consumption tend to improve within the initial months of abstinence, there is evidence suggesting certain cognitive deficits may persist. This study aimed to investigate the impact of aerobic exercise on learning and memory in alcohol use disorder (AUD) mice following a period of abstinence from alcohol. We also sought to assess the levels of monoamine neurotransmitters in the hippocampus. To this end, we established an AUD mouse model through a two-bottle choice (sucrose fading mode and normal mode) and chronic intermittent alcohol vapor (combined with intraperitoneal injection) and randomly allocated mice into exercise groups to undergo treadmill training. Learning and memory abilities were assessed through the Morris water maze test and spontaneous activity was evaluated using the open field test. The levels of dopamine, norepinephrine, serotonin, and brain-derived neurotrophic factor in the hippocampus were quantified using enzyme-linked immunoassay (ELISA) kits. The findings reveal that after cessation of alcohol consumption, learning and memory abilities in AUD mice did not completely return to normal levels. The observed enhancement of cognitive functions in AUD mice through aerobic exercise may be attributed to restoring levels of monoamine neurotransmitters in the hippocampus, boosting brain-derived neurotrophic factor (BDNF) concentrations, and facilitating an increase in hippocampal mass. These results offer empirical evidence to support aerobic exercise as a viable therapeutic strategy to alleviate cognitive deficits associated with AUD.

Sex Differences in Mouse Models of Voluntary Alcohol Drinking and Abstinence-Induced Negative Emotion

Alcohol Use Disorder (AUD) is a growing problem worldwide, causing an incredible burden on health and the economy. Though AUD impacts people of all backgrounds and demographics, increasing evidence has suggested robust sex differences in alcohol drinking patterns and AUD-induced negative emotionality or hyperkatifeia. Rates of problematic drinking have significantly risen among women, and women face more severe negative emotional consequences in abstinence such as increased risk of comorbidity with an anxiety or mood disorder and more severe symptoms of depression. As such, a bevy of preclinical literature using contingent methods of alcohol (ethanol) consumption has amassed in recent years to better understand sex as a biological variable in alcohol drinking and abstinence-induced negative emotionality. Mice are widely used to model alcohol drinking, as they are conducive to genetic manipulation strategies, and many strains will voluntarily consume alcohol. Sex-specific results from these mouse studies, however, have been inconsistent. Therefore, this review aims to summarize the current knowledge on sex differences in AUD-related contingent ethanol drinking and abstinence-induced negative emotionality in mice. Various contingent mouse drinking models and negative emotional-based behavioral paradigms are introduced and subsequently discussed in the context of sex differences to show increasing indications of sex specificity in mouse preclinical studies of AUD. With this review, we hope to inform future research on potential sex differences in preclinical mouse models of AUD and provide mounting evidence supporting the need for more widespread inclusion of preclinical female subjects in future studies.

Cognitive impairment among alcohol treatment service users in South Wales: an exploratory examination of typologies of behaviour, impairment, and service attendance

Introduction

Alcohol dependence is a global issue with many negative consequences, including alcohol-related brain damage (ARBD). Assessment of the sociodemographic and cognitive characteristics of individuals with confirmed or suspected ARBD presenting to alcohol services warrants further investigation.

Methods

This study retrospectively examined rates of cognitive impairment using Montreal Cognitive Assessment (MoCA) data from 300 adults who visited three alcohol support services. We demonstrate that 55.3% of the sample had significant levels of cognitive impairment. Females' cognitive performance was disproportionately negatively affected by historical alcohol use relative to males.

Results

The analysis identified four categories of participants, and the majority had a long history (+10 years) of alcohol use and were still actively drinking. Those taking part in active treatment for ARBD or practising abstinence demonstrated lower levels of cognitive impairment. Additionally, prior access to specialised ARBD care was associated with higher MoCA scores.

Discussion

This research has identified a range of key service engagement, sociodemographic and cognitive characteristics that could be used to optimise support for those with alcohol dependence, whilst also highlighting some critical questions to be addressed in future research.

Prevalence of alcohol use by gender and HIV status in rural Uganda

BACKGROUND

Alcohol use is a major contributor to mortality and morbidity worldwide. Uganda has a high level of alcohol use per capita. Compared to men, women are less likely to consume alcohol globally; however, women who drink have increased risks for co-occurring conditions, including depression, intimate partner violence, and HIV. This study assessed the prevalence of alcohol use and correlates of harmful alcohol use by gender and HIV status in rural Uganda.

METHODS

We used cross-sectional data from a study among women and men aged 15-59 residing in rural, central Uganda and accepting home-based HIV testing (Nov 2017 to Dec 2020). We estimated the prevalence of levels of alcohol use (categorized as no alcohol use (score 0), low (score 1-3 for men; 1-2 for women), medium (score 4-5 for men; 3-5 for women), high (score 6-7), and very-high (score 8-12) use with the AUDIT-C), stratified by gender and HIV status. We assessed correlates of harmful alcohol use using multivariable logistic regression models for women and men.

RESULTS

Among 18,460 participants, 67% (95% CI: 66-67%) reported no alcohol use, 16% (95% CI: 16-17%) reported low, 5% (95% CI: 4.8-5%) reported medium, 5% (95% CI: 4-5%) reported high, and 3% (95% CI: 2.8-3) reported very high alcohol use. Compared to women, men were more likely to report alcohol use (Chi-squared p-value<0.0001). People diagnosed with HIV (both newly diagnosed and previously aware of their status prior to home-based HIV testing) were more likely to report low, medium, high, and very high alcohol use compared to those who were HIV negative (Chi-squared p-value<0.0001). Among women, those who were newly diagnosed were more likely report alcohol use, compared to those who were HIV negative. In multivariable models, being newly diagnosed with HIV (compared to HIV negative) increased the odds of harmful alcohol use among women, but not men.

CONCLUSION

While alcohol use was higher among men and people living with HIV, being newly diagnosed with HIV had a stronger relationship with harmful alcohol use among women than men. More research is needed to understand how alcohol use may increase the risks of HIV acquisition among women and to identify gender-responsive services to address harmful alcohol use and increase access to HIV testing and linkage to care for women who use harmful levels of alcohol.

Sex- and estrous-related response patterns for alcohol depend critically on the level of compulsion-like challenge

Alcohol use disorder is a substantial social and economic burden. During the last years, the number of women with drinking problems has been increasing, and one main concern is that they are particularly more vulnerable to negative consequences of alcohol. However, little is known about female-specific response patterns for alcohol, and potential underlying differences in brain mechanisms, including for compulsion-like alcohol drinking (when intake persists despite adverse consequences). We used lickometry to assess behavioral microstructure in adult Wistar male and female rats (n = 28-30) during alcohol-only drinking or moderate- or higher-challenge alcohol compulsion (10 or 60 mg/l quinine in alcohol, respectively). Estrous stages were determined and related to drinking levels and patterns of responding to alcohol, as was ovariectomy. Our findings showed that females (where we didn't determine estrus stage) had similar total licks in a session as males, but significantly longer licking bouts under alcohol-only and moderate-challenge, suggesting greater persistence. Further, greater intake under alcohol-only and moderate-challenge was related to faster licking in males, while female consumption was not related to licking speed. Thus, females could have increased persistence without greater vigor, unlike males. However, under higher-challenge, faster licking did predict higher intake in females, similar to males. To better understand female higher-challenge responding, we examined drinking in relation to phases of the estrous cycle. Higher-challenge had longer bouts only in late diestrus. In addition, ovariectomy led to longer bouts only under higher-challenge, suggesting that conditions with reduced hormone levels could increase female persistence for alcohol under higher-challenge. However, ovariectomy also reduced alcohol-only and moderate-challenge drinking but did not reduce bout length. Thus, intake level and response strategy could be regulated somewhat differently by ovarian hormones. Finally, moderate-challenge licking speed was less variable during early diestrus, and we previously showed more stereotyped responding specifically under moderate-challenge in males. By combining behavioral microstructure and sex- and estrus-related changes in drinking patterns, our results suggest that females have greater persistence for alcohol under lower-challenge drinking, while late diestrus and ovariectomy unmasked greater persistence under higher-challenge. Together, our novel insights could help develop more effective and personalized treatments for problematic alcohol use.

Development and Validation of the Maternal Drinking Motives Scale (M-DMS)

BACKGROUND

Alcohol use is a gendered behavior and motherhood is a life stage which may influence drinking motives. However, there are no drinking motive scales uniquely tailored to maternal populations. This work developed a new maternal drinking motives scale (M-DMS) and determined associations between the M-DMS and alcohol-related behavior.

METHODS

An online observational survey (n = 534) and online test-retest survey (n = 164) were conducted with adult, UK mothers. From the observational study, data on drinking motives was extracted to determine M-DMS items and factor loading. This was split into two data sets for exploratory and confirmatory factor analyses. Alcohol Use Disorders Identification Test (AUDIT) and Timeline Follow back data, taken from both surveys, were combined to determine the M-DMS's predictive validity.

RESULTS

Following a parallel analysis and exploratory factor analysis, a two-factor model (positive reinforcement motives, negative reinforcement motives) was deemed the best fit. Probability functional analysis identified items with problematic responses. These were removed before confirmatory factor analysis (on the second dataset) demonstrated a good fit for the two-factor model. All factor loadings were significant and positive (βs > 0.56). Reliability of the two subscales was excellent: negative reinforcement (ωT = 0.95), positive reinforcement (ωT = 0.89). Test-retest reliability was good for both negative (ICC = 0.84, 95%CI = 0.80-0.88) and positive (ICC = 0.77, 95% CI = 0.71-0.82) subscales. Both subscales predicted AUDIT and quantity of alcohol consumption (ps < 0.001).

CONCLUSION

The first tailored Maternal Drinking Motives Scale (M-DMS) provides a more valid research tool for assessing psychological mechanisms of alcohol use in mothers.

Alcohol and Atrial Fibrillation: An Update and New Perspectives

In the Western world, sales of alcoholic beverages are skyrocketing1,2. While consumed for its transient euphoric effects, the consumption of alcohol (ethanol) is also a risk factor for the development of heart disease. Here, we review the possible association between alcohol consumption and atrial fibrillation. Using a familiar analogy, we propose that atrial fibrillation is the mere tip of an iceberg (alcohol associated heart disease). Our concern is that the many research studies on the effects of ethanol on the heart have produced inconsistent results. These include studies of individuals drinking only moderate amounts of alcoholic beverages (aka The French Paradox) on the one hand, and paroxysmal atrial fibrillation after binge drinking (the Holiday Heart Syndrome) on the other hand. The evidence available in the literature suggests that hypertension, structured heart disease of any form, neurohumoral stress, and cardiometabolic disorders all favor the development of atrial fibrillation triggered by alcohol. We also suggest that alcohol should be classified as a modifiable risk factor for atrial fibrillation, and also for heart disease in general.

The risk relationships between alcohol consumption, alcohol use disorder and alcohol use disorder mortality: A systematic review and meta-analysis

BACKGROUND AND AIMS

Increasing levels of alcohol use are associated with a risk of developing an alcohol use disorder (AUD), which, in turn, is associated with considerable burden. Our aim was to estimate the risk relationships between alcohol consumption and AUD incidence and mortality.

METHOD

A systematic literature search was conducted, using Medline, Embase, PsycINFO and Web of Science for case-control or cohort studies published between 1 January 2000 and 8 July 2022. These were required to report alcohol consumption, AUD incidence and/or AUD mortality (including 100% alcohol-attributable deaths). The protocol was registered with PROSPERO (CRD42022343201). Dose-response and random-effects meta-analyses were used to determine the risk relationships between alcohol consumption and AUD incidence and mortality and mortality rates in AUD patients, respectively.

RESULTS

Of the 5904 reports identified, seven and three studies from high-income countries and Brazil met the inclusion criteria for quantitative and qualitative syntheses, respectively. In addition, two primary US data sources were analyzed. Higher levels of alcohol consumption increased the risk of developing or dying from an AUD exponentially. At an average consumption of four standard drinks (assuming 10 g of pure alcohol/standard drink) per day, the risk of developing an AUD was increased sevenfold [relative risk (RR) = 7.14, 95% confidence interval (CI) = 5.13-9.93] and the risk of dying fourfold (RR = 3.94, 95% CI = 3.53-4.40) compared with current non-drinkers. The mortality rate in AUD patients was 3.13 (95% CI = 1.07-9.13) per 1000 person-years.

CONCLUSIONS

There are exponential positive risk relationships between alcohol use and both alcohol use disorder incidence and mortality. Even at an average consumption of 20 g/day (about one large beer), the risk of developing an alcohol use disorder (AUD) is nearly threefold that of current non-drinkers and the risk of dying from an AUD is approximately double that of current non-drinkers.

Mediational pathways between aggregate genetic liability and nonfatal suicide attempt: A Swedish population-based cohort

Despite recent progress in the genetics of suicidal behavior, the pathway by which genetic liability increases suicide attempt risk is unclear. We investigated the mediational pathways from family/genetic risk for suicide attempt (FGRSSA) to suicide attempt by considering the roles of psychiatric illnesses. In a Swedish cohort, we evaluated time to suicide attempt as a function of FGRSSA and the mediational effects of alcohol use disorder, drug use disorder, attention-deficit/hyperactivity disorder, major depression, anxiety disorder, bipolar disorder, and non-affective psychosis. Analyses were conducted by sex in three age periods: 15-25 years (Nfemales = 850,278 and Nmales = 899,366), 26-35 years (Nfemales = 800,189 and Nmales = 861,774), and 36-45 years (Nfemales = 498,285 and Nmales = 535,831). The association between FGRSSA and suicide attempt was mediated via psychiatric disorders. The highest mediation effects were observed for alcohol use disorder in males (15-25 years, HRtotal = 1.60 [1.59; 1.62], mediation = 14.4%), drug use disorder in females (25-36 years, HRtotal = 1.46 [1.44; 1.49], mediation = 11.2%), and major depression (25-36 years) in females (HRtotal = 1.46 [1.44; 1.49], mediation = 7%) and males (HRtotal = 1.50 [1.47;1.52], mediation = 4.7%). While the direct effect of FGRSSA was higher at ages of 15-25, the mediation via psychiatric disorders was more prominent in later adulthood. Our study informs about the psychiatric illnesses via which genetic liability operates to impact suicide attempt risk, with distinct contributions according to age and sex.

The Interaction between Education and Sex with Alcohol Consumption during the COVID-19 Pandemic: A Cross-Sectional Analysis of Two Brazilian Cities

This cross-sectional study, carried out between October and December 2020 in two Brazilian cities, aimed to evaluate the joint association of education and sex with habitual and episodic excessive alcohol consumption during the COVID-19 pandemic. Habitual alcohol consumption was defined as drinking any quantity of alcohol at least once per week. Excessive episodic alcohol consumption was defined as the consumption of five or more drinks by men or four or more drinks by women at least once in the last 30 days. Adjusted multivariate logistic regression models were used to analyze associations of education and sex with alcohol consumption. Education was not associated with habitual alcohol consumption and excessive episodic alcohol consumption. However, when evaluating the joint effect between education and sex, it can be seen that men with low education were more likely to habitually consume (OR: 5.85; CI95:2.74-14.84) and abuse alcohol (OR: 4.45; IC95:1.54-12.82) and women with high education were more likely to have habitual (OR: 2.16; IC95:1.18-3.95) and abusive alcohol consumption (OR: 2.00; IC95:1.16-3.43). These findings highlight the modifying effect of sex on the relationship between education and alcohol consumption, such that education influenced alcohol consumption differently between sexes during the pandemic.

Greater inhibition of female rat binge alcohol intake by adrenergic receptor blockers using a novel Two-Shot rat binge drinking model

Binge drinking (BD) contributes strongly to the harms of alcohol use disorder. Most rodent models do not result in binge-level blood alcohol concentrations (BACs), and to better understand individual and sex differences in neurobiological mechanisms related to BD, the use of outbred rat strains would be valuable. Here, we developed a novel BD model where after 3+ months of intermittent access to 20% alcohol Wistar rats drank, twice a week, with two 5-min intake (what we called Two-shot) separated by a 10-min break. Our findings showed during Two-Shot that most animals reached ≥ 80 mg% BAC levels (when briefly food-restricted). However, when increasing alcohol concentrations from 20 to 30%, 40%, or 50%, rats titrated to similar intake levels, suggesting rapid sensing of alcohol effects even when front-loading. Two-Shot drinking was reduced in both sexes by naltrexone (1 mg/kg), validating intake suppression by a clinical therapeutic agent for human problem drinking. Further, both propranolol (β-adrenergic receptor antagonist) and prazosin (α1-adrenergic receptor antagonist) reduced female but not male BD at the lower dose. Thus, our results provide a novel model for BD in outbred rats and suggest that female binging is more sensitive to adrenergic modulation than males, perhaps providing a novel sex-related therapy.

Alcohol abuse may increase the risk of autoimmune connective tissue disease: a nationwide population-based cohort study

Objectives

Altered immune and inflammatory responses resulting from alcohol abuse have been implicated in increasing the risk of autoimmune connective tissue disease (ACTD). However, limited research has been conducted on this topic in the Asian population. Therefore, this study was undertaken to investigate and address this knowledge gap.

Methods

Using data from Taiwan's National Health Insurance Research Database, we identified all patients with alcohol abuse between 2000 and 2017. We selected a comparison cohort without alcohol abuse, matching them in terms of age, sex, and index date at a 3:1 ratio. We collected information on common underlying comorbidities for analysis. Both cohorts were followed up until the diagnosis of ACTD or the end of 2018.

Results

A total of 57,154 patients with alcohol abuse and 171,462 patients without alcohol abuse were included in the study. The age and sex distributions were similar in both cohorts, with men accounting for 89.8% of the total. After adjusting for underlying comorbidities, patients with alcohol abuse had a higher risk of developing ACTD [adjusted hazard ratio (AHR): 1.12, 95% confidence interval (CI): 1.01-1.25]. The stratified analysis revealed that this increased risk was specific to the male population. Additionally, besides alcohol abuse, liver disease, renal disease, coronary artery disease, and chronic obstructive pulmonary disease were identified as independent predictors for ACTD.

Conclusion

This study demonstrates that alcohol abuse increases the risk of developing ACTD in the Asian population, particularly among men. Therefore, it is important to implement alcohol cessation, especially in individuals with liver disease, renal disease, coronary artery disease, and chronic obstructive pulmonary disease.

Mesocorticolimbic system reactivity to alcohol use-related visual cues as a function of alcohol sensitivity phenotype: A pilot fMRI study

Low sensitivity (LS) to alcohol is a risk factor for alcohol use disorder (AUD). Compared to peers with high sensitivity (HS), LS individuals drink more, report more problems, and exhibit potentiated alcohol cue reactivity (ACR). Heightened ACR suggests LS confers AUD risk via incentive sensitization, which is thought to take place in the mesocorticolimbic system. This study examined neural ACR in LS and HS individuals. Young adults (N = 32, M age=20.3) were recruited based on the Alcohol Sensitivity Questionnaire (HS: n = 16; LS: n = 16; 9 females/group). Participants completed an event-related fMRI ACR task. Group LS had higher ACR in left ventrolateral prefrontal cortex than group HS. In group LS, ACR in left caudomedial orbitofrontal cortex or left putamen was low at low alcohol use levels and high at heavier or more problematic alcohol use levels, whereas the opposite was true in group HS. Alcohol use level also was associated with the level of ACR in left substantia nigra among males in group LS. Taken together, results suggest elevated mesocorticolimbic ACR among LS individuals, especially those using alcohol at hazardous levels. Future studies with larger samples are warranted to determine the neurobiological loci underlying LS-based amplified ACR and AUD risk.

Moderate Alcohol Consumption Increases the Risk of Clinical Relapse in Male Depressed Patients Treated with Serotonin-Norepinephrine Reuptake Inhibitors

BACKGROUND

While depression can be associated with multiple comorbidities, the association between depression and liver injury significantly increases the mortality risk. The aim of this study was to evaluate if moderate alcohol intake affects the rate of clinical relapses in patients treated with antidepressants as monotherapy.

METHODS

We assessed, over a period of 30 months, the clinical records of 254 patients with depressive disorder, of either gender, without additional pathologies, receiving monotherapy treatment with antidepressants. Thirty-three patients with alcohol abuse, alcoholism or significant cognitive impairment were excluded. The medical and psychiatric history, medication and liver enzyme values were collected and analyzed.

RESULTS

Out of the 221 patients who met the inclusion criteria, 78 experienced relapses of depression. The rate of relapse did not correlate with the levels of liver enzymes. Alcohol consumption, as objectified based on GGT levels and the AST/ALT ratio, suggested that men had higher alcohol intake compared to women. Patients treated with serotonin-norepinephrine reuptake inhibitors (SNRIs) with elevated AST levels were approximately 9 times more likely to relapse, while the ones with elevated GGT had a 5.34 times higher risk. While GGT levels remained a marker for relapse in men with elevated GGT, ALT and not AST proved to be a better risk indicator for relapses in male patients.

CONCLUSION

The use of SNRIs in depressed male patients with moderate alcohol intake should be carefully considered, as they might be susceptible to higher risks of relapse compared to alternative antidepressant therapies.

Sex differences in clinical risk factors in obese ischemic stroke patients with a history of smoking

Clinical risk factors associated obesity and smoking, as well as their combined effect, are not fully understood. This study aims to determine sex differences in risk factors in a population of acute ischemic stroke (AIS) patients who are obese and with a history of previous or current smoking.

METHODS

A retrospective analysis of risk factors in male and female AIS patients with baseline data of obesity and current or previous history of smoking, smoking, and obesity alone was determined. The primary predictor and outcome are risk factors associated with male and female AIS patients. Baseline risk factors were analyzed using a multivariate regression analysis to determine specific risk factors linked with the combined effect of obesity and current or previous history of smoking''.

RESULTS

Male obese AIS patients who are current or previous smokers were more likely to be older patients(OR = 1.024, 95% CI, 1.022-1.047, P = 0.033) that present with coronary artery disease (OR = 1.806, 95% CI, 1.028-3.174, P = 0.040), a history of alcohol use (OR = 2.873, 95% CI, 1.349-6.166, P = 0.006), elevated serum creatinine (OR = 4.724, 95% CI, 2.171-10.281, P < 0.001) and systolic blood pressure (OR = 1.029, 95% CI, 1.011-1.047, P < 0.002). Females were more associated with depression (OR = 0.432, 95% CI, 0.244-0.764, P = 0.004), previous TIA (OR = 0.319, 95% CI, 0.142-0.714, P < 0.005), and higher levels of HDL (OR = 0.938, 95% CI, 0.915-0.962, P < 0.001).

CONCLUSION

Our results reveal sex differences in risk factors in obese AIS patients with a current or past history of smoking. This finding emphasizes the need to develop management strategies to improve the care of obese AIS patients who are either current or former smokers.

Greater inhibition of female rat binge alcohol intake by adrenergic receptor blockers using a novel Two-Shot rat binge drinking model

Binge drinking (BD) contributes strongly to the harms of alcohol use disorder. Most rodent models do not result in binge-level blood alcohol concentrations (BACs), and to better understand individual and sex differences in neurobiological mechanisms related to BD, the use of outbred rat strains would be valuable. Here, we developed a novel BD model where after 3+ months of intermittent access to 20% alcohol Wistar rats drank, twice a week, with two 5-minute intake (what we called Two-shot) separated by a 10-minute break. Our findings showed during Two-Shot that most animals reached ≥ 80mg% BAC levels (when briefly food-restricted). However, when increasing alcohol concentrations from 20% to 30%, 40%, or 50%, rats titrated to similar intake levels, suggesting rapid sensing of alcohol effects even when front-loading. Two-Shot drinking was reduced in both sexes by naltrexone (1mg/kg), validating intake suppression by a clinical therapeutic agent. Further, both propranolol (β adrenergic receptor antagonist) and prazosin (α1 adrenergic receptor antagonist) reduced female but not male BD at the lower dose. Thus, our results provide a novel model for BD in outbred rats and suggest that female binging is more sensitive to adrenergic modulation than males, perhaps providing a novel sex-related therapy.

Alcohol Consumption Is a Coping Mechanism for Male Patients with Severe Anxiety Disorders Treated with Antidepressants Monotherapy

Background: Anxiety disorders are prevalent mental health conditions often accompanied by various comorbidities. The association between anxiety and liver disease, as well as fluctuations in blood sugar levels, highlights the importance of carefully evaluating patients with anxiety undergoing antidepressant therapy. The aim of this study was to conduct a comparative assessment of liver function and blood glucose levels in patients diagnosed with anxiety disorders while considering potential gender-specific differences. Methods: An analysis was conducted over a 24-month period. This study included 88 patients diagnosed with anxiety disorders, with symptoms severe enough to require hospitalization, aged 18 or older, undergoing antidepressant monotherapy, without any additional pathologies. Liver enzymes (AST, ALT, GGT), AST/ALT ratio, and blood glucose levels were measured and compared. Results: While no significant differences were found between antidepressant classes, increased GGT levels were observed in men older than 40 years compared to women of the same age, suggesting that alcohol consumption may be a coping mechanism for anxiety. This gender difference was not observed among young patients. Conclusions: Early detection of alcohol consumption is essential in patients with anxiety disorders in order to prevent alcohol-related liver damage and to adjust the management of both conditions accordingly.

A systematic meta-epidemiologic review on nonabstinence-inclusive interventions for substance use: inclusion of race/ethnicity and sex assigned at birth/gender

Background: Minoritized racial/ethnic and sex assigned at birth/gender groups experience disproportionate substance-related harm. Focusing on reducing substance-related harm without requiring abstinence is a promising approach.Objectives: The purpose of this meta-epidemiologic systematic review was to examine inclusion of racial/ethnic and sex assigned at birth/gender in published studies of nonabstinence-inclusive interventions for substance use.Methods: We systematically searched databases (PubMed and PsycINFO) on May 26, 2022 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Articles were eligible for inclusion if they: 1) reported in English language, 2) had a primary goal of investigating a nonabstinence-inclusive intervention to address substance use, 3) used human subjects, and 4) only included adults aged 18 or older. Two coders screened initial articles and assessed eligibility criteria of full text articles. A third consensus rater reviewed all coding discrepancies. For the remaining full-length articles, an independent rater extracted information relevant to study goalsResults: The search strategy yielded 5,759 records. 235 included articles remained. Only 73 articles (31.1%) fully reported on both racial/ethnic and sex assigned at birth/gender, and only seven articles (3.0%) reported subgroup analyses examining treatment efficacy across minoritized groups. Nine articles (3.8%) mentioned inclusion and diversity regarding both racial/ethnic and sex assigned at birth/gender in their discussion and four articles (1.7%) broadly mentioned a lack of diversity in their limitationsConclusion: Findings highlight that little is known about nonabstinence-inclusive interventions to address substance use for individuals from minoritized racial/ethnic and sex assigned at birth/gender groups.

Associations of Menstrual Cycle and Progesterone-to-Estradiol Ratio With Alcohol Consumption in Alcohol Use Disorder: A Sex-Separated Multicenter Longitudinal Study

OBJECTIVE

Alcohol use disorder (AUD) constitutes a critical public health issue and has sex-specific characteristics. Initial evidence suggests that progesterone and estradiol might reduce or increase alcohol intake, respectively. However, there is a need for a better understanding of how the menstrual cycle in females and the ratio of progesterone to estradiol in females and males influence alcohol use patterns in individuals with AUD.

METHODS

In this sex-separated multicenter longitudinal study, the authors analyzed 12-month data on real-life alcohol use (from 21,460 smartphone entries), menstrual cycle, and serum progesterone-to-estradiol ratios (from 667 blood samples at four individual study visits) in 74 naturally cycling females and 278 males with AUD between 2020 and 2022, using generalized and general linear mixed modeling.

RESULTS

Menstrual cycle phases were significantly associated with binge drinking and progesterone-to-estradiol ratio. During the late luteal phase, females showed a lower predicted binge drinking probability of 13% and a higher predicted marginal mean of progesterone-to-estradiol ratio of 95 compared with during the menstrual, follicular, and ovulatory phases (binge drinking probability and odds ratios vs. late luteal phase, respectively: 17%, odds ratio=1.340, 95% CI=1.031, 1.742; 19%, odds ratio=1.523, 95% CI=1.190, 1.949; and 20%, odds ratio=1.683, 95% CI=1.285, 2.206; difference in progesterone-to-estradiol ratios, respectively: -61, 95% CI=-105.492, -16.095; -78, 95% CI=-119.322, -37.039; and -71, 95% CI=-114.568, -27.534). In males, a higher progesterone-to-estradiol ratio was related to lower probabilities of binge drinking and of any alcohol use, with a 10-unit increase in the hormone ratio resulting in odds ratios of 0.918 (95% CI=0.843, 0.999) and 0.914 (95% CI=0.845, 0.988), respectively.

CONCLUSIONS

These ecologically valid findings suggest that high progesterone-to-estradiol ratios can have a protective effect against problematic alcohol use in females and males with AUD, highlighting the progesterone-to-estradiol ratio as a promising treatment target. Moreover, the results indicate that females with AUD may benefit from menstrual cycle phase-tailored treatments.

Global, regional, and national burden of pancreatitis in older adults, 1990-2019: A systematic analysis for the global burden of disease study 2019

Background

To describe the past, present and future burden of pancreatitis in older adults, and to explore cross-national inequalities across socio-demographic index (SDI).

Methods

Data on pancreatitis in older adults, including mortality and disability-adjusted life years (DALYs) rates, were collected from the Global Burden of Disease (GBD) 2019 study. Temporal trends were measured using joinpoint analyses and predicted using a Bayesian age-period-cohort model. Additionally, the unequal distribution of the burden of pancreatitis in older adults was quantified.

Results

From 1990 to 2019, the number of deaths and DALYs due to pancreatitis in older adults has been increasing annually. However, in most regions of the world, age-standardized death rates (ASDR) and age-standardized DALYs rates have been declining. The burden of pancreatitis in older adults was highest in low SDI region, primarily affecting the population aged 65-74, with a greater burden on males than females. Furthermore, from 1990 to 2019, absolute and relative cross-national inequalities in pancreatitis among older adults have remained largely unchanged. It is projected that in the next 11 years, the number of deaths in older adults due to pancreatitis will continue to increase, but the ASDR is expected to decline.

Conclusion

Over the past 30 years, the ASDR and age-standardized DALYs rate of pancreatitis in older adults have shown a decline globally, but the absolute burden continues to increase. Cross-national health inequalities persist. Therefore, it is necessary to develop targeted intervention measures and enhance awareness among this vulnerable population regarding the risk factors associated with pancreatitis.

Sex and gender in alcohol use disorder and alcohol-associated liver disease in the United States: A narrative review

Over the last 20 years, there has been an alarming increase in alcohol use and AUD prevalence among women, narrowing the historical gender gap. Concurrently, there has also been a significant rise in alcohol-associated liver disease (ALD) prevalence, severity, and mortality among women. Despite this, there are no recent reviews that have sought to evaluate both sex and gender differences at the intersection of AUD and ALD. In this narrative review, we address the escalating rates of ALD and AUD in the United States, with a specific focus on the disproportionate impact on women. Sex and gender play an important and well-known role in the pathogenesis and epidemiology of ALD. However, sex and gender are also implicated in the development and prevalence of AUD, as well as in the treatment of AUD, all of which have important consequences on the approach to the treatment of patients with ALD and AUD. A better understanding of sex and gender differences in AUD, ALD, and the intersection of the 2 is essential to enhance prevention, diagnosis, and management strategies. These data underscore the urgent need for awareness and preventive efforts to mitigate the potential long-term health consequences.

Digital alcohol marketing and gender: A narrative synthesis

ISSUES

Alcohol marketing on social media platforms is pervasive and effective, reaching wide audiences and allowing interaction with users. We know little about the gendered nature of digital alcohol marketing, including how women and men are portrayed, how different genders respond and implications for gender relations. This review aimed to identify how males, females and other genders are targeted and represented in digital alcohol marketing, and how they are encouraged to engage with digital alcohol marketing content.

APPROACH

A narrative synthesis approach was employed. Academic literature and research reports were searched for studies on digital alcohol marketing published within the previous 10 years with a range of methods and designs. We reviewed the studies, extracted data relevant to gender and synthesised findings thematically.

KEY FINDINGS

The review included 17 articles and 7 reports with a range of designs and methods, including content analyses of digital material, interviews, focus groups and surveys. Our analysis identified three conceptual themes that captured many of the gendered results, namely: (i) leveraging a diversity of idealised femininities; (ii) amplifying hegemonic masculinity; and (iii) infiltrating everyday gendered life.

IMPLICATIONS AND CONCLUSION

Alcohol marketing on social media is highly gendered and is designed to embed itself into everyday life in agile ways that reinforce traditional and evolving gendered stereotypes, activities, lifestyles and roles. Gendered engagement strategies are widely used to link alcohol to everyday gendered activities and identities to encourage alcohol purchase and consumption. This marketing normalises alcohol consumption and reproduces harmful gender norms and stereotypes.

Prevention of alcohol exposed pregnancies in Europe: the FAR SEAS guidelines

INTRODUCTION

Drinking during pregnancy is the leading cause of birth defects and child developmental disorders in Europe. The adverse effects of drinking during pregnancy may include physical, behavioural and cognitive problems, known collectively as fetal alcohol spectrum disorders (FASD). Evidence-based comprehensive recommendations at the European level on how to implement preventive and treatment policies to reduce alcohol-exposed pregnancies are needed. FAR SEAS, a tendered service contract (number 20,187,106) awarded by the European Commission, aimed at developing guidelines to respond to this knowledge gap.

METHODS

FAR SEAS recommendations were built on (1) a two-phase review of interventions, (2) an international expert consultation, and (3) a pilot study on prevention of FASD conducted in the Mazovia region of Poland. The review of interventions included nineteen electronic open access databases, several repositories of grey literature and a key informant consultation covering most European Union (EU) countries and an additional guidelines search. After triangulating sources, 94 records were collected. Experts contributed in the design of the research questions, addressing the gaps in the literature and reviewing the recommendations formulated. The Polish pilot added nuances from real world practice to the formulated recommendations, resulting in the final set of guidelines for dissemination.

RESULTS

The FAR SEAS Guidelines comprise 23 recommendations grouped into different topics areas of policies, communication strategies, screening, brief intervention and referral to treatment, treatment and social services. The recommendations highlight the need to respect women's autonomy and avoid discrimination and stigmatization; using universal screening for women of childbearing age, including detection of other psychosocial risks (such as domestic violence); and individualized, comprehensive and multidisciplinary supportive interventions for those who require it, such as those with alcohol use disorders, including women's partners. Policies to prevent FASD should be multicomponent, and public health communication should combine information about the risks together with self-efficacy messages to promote changes.

CONCLUSIONS

The FAR SEAS guidelines are a tool to support policy-makers and service managers in implementing effective programmes to reduce prenatal alcohol exposure among general and at-risk population groups. FASD prevention has to involve comprehensive and multi-level evidence-based policies and practice, with services and activities tailored to the needs of women at differing levels of risk, and with due attention to reducing stigma.

Sensitivity to the initial rewarding effects of alcohol: Influence of age, sex, and β-endorphin

BACKGROUND

Alcohol use disorders (AUDs) are widespread, devastating and complex. About 20% of people who consume alcohol develop problem use, accounting for over 5% of worldwide deaths. While numerous animal models have facilitated understanding of the consequences of excessive drinking, translational models allow for experimental manipulation of factors thought to contribute to AUD liability.

METHODS

We employ a single-exposure conditioned place preference assay (SE-CPP) to investigate the influence of age, sex and the opioid peptide β-endorphin (bE) on the initial rewarding effects of ethanol, a strong predictor of AUDs. Adolescent (PND28-35) and adult (PND70-90) male and female, control C57BL/6J and bE-deficient mice were tested following a single injection of 1.5 g/kg of ethanol. Following the SE-CPP test, animals were deeply anesthetized, sacrificed, and perfused, and the brains were subsequently sectioned at 40 microns and processed for immunohistochemical localization of c-fos. One-sample, two-tailed t-tests were used to assess drug preference or aversion and the locomotor effects of alcohol.

RESULTS

In general, adults were more sensitive to the effects of alcohol than adolescents, and outcomes depended on sex and bE. For example, among females, adolescents were stimulated by the drug, but insensitive to locomotor effects as adults, while among males, adolescents were insensitive and adults sedated. Wild-type adolescents of both sexes failed to evince initial subjective reward from the drug, but bE-deficient adolescents, and all adult subjects, preferred a context once associated with ethanol over one that had been paired with saline. c-fos immunoreactivity in multiple brain regions was attenuated in bE-deficient animals, though influences of both sex and bE grew stronger with age.

CONCLUSIONS

This study demonstrates the utility of the SE-CPP paradigm for elucidating factors that contribute to the liability for AUDs, and supports the growing body of research that shows that sensitivity to the rewarding effects of alcohol changes during the course of development. Our results also suggest that developmental contributions are sex-dependent, and may also depend on the influence of endogenous opioid signaling.

Traumatic stress-enhanced alcohol drinking: Sex differences and animal model perspectives

Purpose of review

Stress is associated with alcohol drinking, and epidemiological studies document the comorbidity of alcohol use disorder (AUD) and post-traumatic stress disorder (PTSD), with higher comorbid prevalence in females than in males. The aim of this paper is to highlight information related to sex differences in stress-enhanced alcohol drinking from clinical studies and from preclinical studies utilizing an animal model of traumatic stress.

Recent findings

Stress is associated with alcohol drinking and relapse in males and females, but there are sex differences in the alcohol-related adaptation of stress pathways and in the association of different prefrontal regions with stress-induced anxiety. The predator stress model of traumatic stress produced enhanced alcohol drinking in a subgroup of stress-sensitive male and female animals, which could be associated with sex and subgroup differences in stress axis responsivity, behavioral responses to predator odors, and epigenetic mechanisms engaged by traumatic experiences.

Summary

While additional studies in females are necessary, existing clinical and preclinical evidence suggests that biological mechanisms underlying stress-enhanced drinking likely differ between males and females. Thus, effective treatment strategies may differ between the sexes.

Physiological acetic acid concentrations from ethanol metabolism stimulate accumbens shell medium spiny neurons via NMDAR activation in a sex-dependent manner

Recent studies have implicated the ethanol metabolite, acetic acid, as neuroactive, perhaps even more so than ethanol itself. In this study, we investigated sex-specific metabolism of ethanol (1, 2, and 4 g/kg) to acetic acid in vivo to guide electrophysiology experiments in the accumbens shell (NAcSh), a key node in the mammalian reward circuit. There was a sex-dependent difference in serum acetate production, quantified via ion chromatography only at the lowest dose of ethanol (males > females). Ex vivo electrophysiology recordings of NAcSh medium spiny neurons (MSN) in brain slices demonstrated that physiological concentrations of acetic acid (2 mM and 4 mM) increased NAcSh MSN excitability in both sexes. N-methyl-D-aspartate receptor (NMDAR) antagonists, AP5 and memantine, robustly attenuated the acetic acid-induced increase in excitability. Acetic acid-induced NMDAR-dependent inward currents were greater in females compared to males and were not estrous cycle dependent. These findings suggest a novel NMDAR-dependent mechanism by which the ethanol metabolite, acetic acid, may influence neurophysiological effects in a key reward circuit in the brain from ethanol consumption. Furthermore, these findings also highlight a specific sex-dependent sensitivity in females to acetic acid-NMDAR interactions. This may underlie their more rapid advancement to alcohol use disorder and increased risk of alcohol related neurodegeneration compared to males.

Effects of chronic alcohol intoxication on aerobic exercise-induced adaptations in female mice

Chronic alcohol intoxication decreases muscle strength/function and causes mitochondrial dysfunction. Aerobic exercise training improves mitochondrial oxidative capacity and increases muscle mass and strength. Presently, the impact of chronic alcohol on aerobic exercise-induced adaptations was investigated. Female C57BL/6Hsd mice were randomly assigned to one of four groups: control sedentary (CON SED; n = 26), alcohol sedentary (ETOH SED; n = 27), control exercise (CON EX; n = 28), and alcohol exercise (ETOH EX; n = 25). Exercise mice had running wheel access for 2 h a day, 7 days a week. All mice were fed either control or an alcohol-containing liquid diet. Grip strength testing and EchoMRI were performed before and after the interventions. After 6 wk, hindlimb muscles were collected for molecular analyses. A subset of mice performed a treadmill run to fatigue (RTF), then abstained from alcohol for 2 wk and repeated the RTF. Alcohol decreased lean mass and forelimb grip strength compared with control-fed mice. Alcohol blunted the exercise-induced increase in muscle mass (plantaris and soleus), type IIa fiber percentage in the plantaris, and run time to fatigue. Mitochondrial markers (Citrate synthase activity and Complex I-IV, COXIV and Cytochrome C protein expression) were increased with exercise regardless of ETOH in the gastrocnemius but not tibialis anterior muscle. Two weeks of alcohol abstinence improved RTF time in ETOH EX but not in ETOH SED. These data suggest that alcohol impairs some exercise-induced adaptations in skeletal muscle, but not all were negatively affected, indicating that exercise may be a beneficial behavior even while consuming alcohol.NEW & NOTEWORTHY Alcohol consumption during an aerobic exercise training period prevented training-induced increases in run to fatigue time and grip strength. Cessation of alcohol allowed for recovery of endurance performance within 2 wk. The worsened exercise performance after alcohol was unrelated to impairments in markers of mitochondrial health. Therefore, some adaptations to exercise training are impaired with alcohol use (endurance performance, muscle growth, and strength), while others remain mostly unaffected (mitochondrial health).

The association between night shift work and osteoporosis risk in adults: A cross-sectional analysis using NHANES

Purpose

Through this study, we assess whether night shift work increases the risk of osteoporosis, and explore the effects of age, gender, or lifestyle differences.

Methods

This cross-sectional study included the collection of data from a sample of the US adults who participated in the National Health and Nutrition Examination Survey (NHANES) over a 7.3-year period (2007-2008, 2009-2010, 2017-March2020), including 4408 participants (2351[52.8%] men and 2057[47.2%] women), with an age range of 20-80 years. The primary variables, health status, nutrition, harmful lifestyle habits, and bone mineral density (BMD), were segregated, and analyzed according to different work schedules. Linear regression models were conducted to evaluate correlations of night shift work and T-scores. Associations between night shift work and osteoporosis were examined using logistic regression analyses. All regression models were stratified by gender and age ≥50 years. Osteoporosis was defined as BMD at the femoral neck or total spine equal to or less than 2.5 standard deviations below the mean for youthful people of the same gender. All data were obtained using questionnaires and examinations collected in mobile examination center (MEC) from NHANES.

Results

After multivariate adjustment, night shift work was related to statistically significant decreases of the total spine in T-scores of females aged ≥50 years. Furthermore, night shift work of the overall population (OR = 2.31 [95% CI, 1.03-5.18]; P = 0.043) and females aged ≥50 years (OR = 4.6 [95% CI, 1.21-17.54]; P = 0.025) was related to an increased prevalence of osteoporosis.

Conclusion

Night shift work correlates with a higher risk of osteoporosis in the population of the US adults, with the combined effect of age, gender, and harmful lifestyle.

Impact of evolution on lifestyle in microbiome

This chapter analyses the interaction between microbiota and humans from an evolutionary point of view. Long-term interactions between gut microbiota and host have been generated as a result of dietary choices through coevolutionary processes, where mutuality of advantage is essential. Likewise, the characteristics of the intestinal environment have made it possible to describe different intrahost evolutionary mechanisms affecting microbiota. For its part, the intestinal microbiota has been of great importance in the evolution of mammals, allowing the diversification of dietary niches, phenotypic plasticity and the selection of host phenotypes. Although the origin of the human intestinal microbial community is still not known with certainty, mother-offspring transmission plays a key role, and it seems that transmissibility between individuals in adulthood also has important implications. Finally, it should be noted that certain aspects inherent to modern lifestyle, including refined diets, antibiotic intake, exposure to air pollutants, microplastics, and stress, could negatively affect the diversity and composition of our gut microbiota. This chapter aims to combine current knowledge to provide a comprehensive view of the interaction between microbiota and humans throughout evolution.

Cracking the code: unveiling the nexus between atopic dermatitis and addictive behavior: a cross-sectional exploration of risk factors

Atopic dermatitis (AD) stands as a prevalent chronic inflammatory skin disorder with a global reach. Beyond its cutaneous manifestations, AD is accompanied by comorbidities and psychological issues, significantly compromising the overall quality of life for individuals who suffer from AD. Previous research has evidenced a heightened prevalence of addictive disorders among dermatological patients when compared to the general population. Considering these findings, this study endeavors to examine the prevalence of addictive disorders among AD patients and, furthermore, to discern potential risk factors associated with this comorbidity. Therefore, a cross-sectional study was conducted involving patients with AD diagnosed by dermatologists within a large university hospital in Munich, South Germany, between January 2016 and December 2019. Patients received an anonymous paper-based questionnaire comprising standardized and reliable assessment tools concerning disease severity, quality of life, sexual dysfunction, well-being, and anxiety disorder as well as screening tools for various addictive disorders (compulsive internet use, drug abuse, pathological alcohol consumption, and smoking). Data were analyzed descriptively, and a multivariate logistic regression model was conducted. A total of 208 patients participated in the study, comprising 38% males and 62% females with a mean age of 44.8 ± standard deviation:17.9 years. Females showed a higher mean POEM (Patient-Oriented Eczema Measure) score compared to males (female 14.6 ± 7.8; male 12.5 ± 7.7), as well as a higher DLQI (Dermatology Life Quality Index) (female 8.5 ± 6; male 6.5 ± 6.5). Positive addictions were found in 14.9% for daily smoking, 15.4% for critical alcohol consumption, 16.8% for compulsive internet use, and 5.8% for drug abuse. Younger patients were more likely to be affected by one or multiple addictions than older patients. Patients with at least one addiction showed significantly impaired well-being and increased severe anxiety symptoms. Given the notable prevalence of addictive disorders among individuals with AD, it could be useful to implement systematic screening for such conditions as part of patient-centered care, especially focusing on young AD patients or those displaying concurrent indications of depression or anxiety.

Gender-specific genetic and epigenetic signatures in cardiovascular disease

Cardiac sex differences represent a pertinent focus in pursuit of the long-awaited goal of personalized medicine. Despite evident disparities in the onset and progression of cardiac pathology between sexes, historical oversight has led to the neglect of gender-specific considerations in the treatment of patients. This oversight is attributed to a predominant focus on male samples and a lack of sex-based segregation in patient studies. Recognizing these sex differences is not only relevant to the treatment of cisgender individuals; it also holds paramount importance in addressing the healthcare needs of transgender patients, a demographic that is increasingly prominent in contemporary society. In response to these challenges, various agencies, including the National Institutes of Health, have actively directed their efforts toward advancing our comprehension of this phenomenon. Epigenetics has proven to play a crucial role in understanding sex differences in both healthy and disease states within the heart. This review presents a comprehensive overview of the physiological distinctions between males and females during the development of various cardiac pathologies, specifically focusing on unraveling the genetic and epigenetic mechanisms at play. Current findings related to distinct sex-chromosome compositions, the emergence of gender-biased genetic variations, and variations in hormonal profiles between sexes are highlighted. Additionally, the roles of DNA methylation, histone marks, and chromatin structure in mediating pathological sex differences are explored. To inspire further investigation into this crucial subject, we have conducted global analyses of various epigenetic features, leveraging data previously generated by the ENCODE project.

Sex Differences in Treatment Response to Nucleos(t)ide Therapy in Chronic Hepatitis B: A Multicenter Longitudinal Study

BACKGROUND & AIMS

It is unclear if there may be sex differences in response to nucleos(t)ide analogs including virologic response (VR), biochemical response (BR), complete response (CR), and hepatocellular carcinoma (HCC) incidence among hepatitis B patients. We compared nucleos(t)ide analog treatment outcomes by sex.

METHODS

We performed a retrospective cohort study of 3388 treatment-naïve adult hepatitis B patients (1250 female, 2138 male) from the Real-World Evidence from the Global Alliance for the Study of Hepatitis B Virus consortium who initiated therapy with either entecavir or tenofovir from 22 sites (Argentina, Korea, Japan, Taiwan, and the United States). We used propensity-score matching to balance background characteristics of the male and female groups and competing-risks analysis to estimate the incidence and subdistribution hazard ratios (SHRs) of VR, BR, CR, and HCC.

RESULTS

Females (vs males) were older (52.0 vs 48.6 y); less likely to be overweight/obese (49.3% vs 65.7%), diabetic (9.9% vs 13.1%), or cirrhotic (27.9% vs 33.0%); and had a lower HBV DNA level (5.9 vs 6.0 log10 IU/mL) and alanine aminotransferase level (91 vs 102 IU/L) (all P < .01). However, after propensity-score matching, relevant background characteristics were balanced between the 2 groups. Females (vs males) had similar 5-year cumulative VR (91.3% vs 90.3%; P = .40) and HCC incidence rates (5.1% vs 4.4%; P = .64), but lower BR (84.0% vs 90.9%; P < .001) and CR (78.8% vs 83.4%; P = .016). Males were more likely to achieve BR (SHR, 1.31; 95% CI, 1.17-1.46; P < .001) and CR (SHR, 1.16; 95% CI, 1.03-1.31; P = .016), but VR and HCC risks were similar.

CONCLUSIONS

Sex differences exist for treatment outcomes among hepatitis B patients. Male sex was associated with a 16% higher likelihood of clinical remission and a 31% higher likelihood of biochemical response than females, while virologic response and HCC incidence were similar between the 2 groups.

Chronic alcohol-induced long-lasting working memory deficits are associated with altered histone H3K9 dimethylation in the prefrontal cortex

Introduction

Epigenetic modifications have emerged as key contributors to the enduring behavioral, molecular and epigenetic neuroadaptations during withdrawal from chronic alcohol exposure. The present study investigated the long-term consequences of chronic alcohol exposure on spatial working memory (WM) and associated changes of transcriptionally repressive histone H3 lysine 9 dimethylation (H3K9me2) in the prefrontal cortex (PFC).

Methods

Male C57BL/6 mice were allowed free access to either 12% (v/v) ethanol for 5 months followed by a 3-week abstinence period or water. Spatial WM was assessed through the spontaneous alternation T-maze test. Alcoholic and water mice received daily injections of GABAB agonist baclofen or saline during alcohol fading and early withdrawal. Global levels of histone modifications were determined by immunohistochemistry.

Results

Withdrawal mice displayed WM impairments along with reduced prefrontal H3K9me2 levels, compared to water-drinking mice. The withdrawal-induced decrease of H3K9me2 occurred concomitantly with increased level of permissive H3K9 acetylation (H3K9ac) in the PFC. Baclofen treatment rescued withdrawal-related WM deficits and fully restored prefrontal H3K9me2 and H3K9ac. Alcohol withdrawal induced brain region-specific changes of H3K9me2 and H3K9ac after testing, with significant decreases of both histone marks in the dorsal hippocampus and no changes in the amygdala and dorsal striatum. Furthermore, the magnitude of H3K9me2 in the PFC, but not the hippocampus, significantly and positively correlated with individual WM performances. No correlation was observed between H3K9ac and behavioral performance. Results also indicate that pre-testing intraperitoneal injection of UNC0642, a selective inhibitor of histone methyltransferase G9a responsible for H3K9me2, led to WM impairments in water-drinking and withdrawal-baclofen mice. Collectively, our results demonstrate that alcohol withdrawal induced brain-region specific alterations of H3K9me2 and H3K9ac, an effect that persisted for at least three weeks after cessation of chronic alcohol intake.

Conclusion

The findings suggest a role for long-lasting decreased H3K9me2 specifically in the PFC in the persistent WM impairments related to alcohol withdrawal.

MANdatory - why men need (and are needed for) gender equality progress

While much progress has been made towards gender equality, diversity and inclusion in the workplace, education and society, recent years have also revealed continuing challenges that slow or halt this progress. To date, the majority of gender equality action has tended to approach gender equality from one side: being focused on the need to remove barriers for girls and women. We argue that this is only half the battle, and that a focus on men is MANdatory, highlighting three key areas: First, we review men's privileged status as being potentially threatened by progress in gender equality, and the effects of these threats for how men engage in gender-equality progress. Second, we highlight how men themselves are victims of restrictive gender roles, and the consequences of this for men's physical and mental health, and for their engagement at work and at home. Third, we review the role of men as allies in the fight for gender equality, and on the factors that impede and may aid in increasing men's involvement. We end with recommendations for work organizations, educational institutions and society at large to reach and involve men as positive agents of social change.

Examining the role of posttraumatic stress disorder symptoms in intimate partner violence among couples with alcohol use disorder

Separate literatures indicate that both alcohol use disorder (AUD) and posttraumatic stress disorder (PTSD) are robust risk factors for using intimate partner violence (IPV). Despite the strength of these relative literatures, and the common co-occurrence of AUD and PTSD, their combined effects on IPV have rarely been examined. This study begins to address this gap by exploring the moderating effects of provisional PTSD diagnosis on the relation between heavy alcohol consumption and physical IPV using a multilevel modeling approach. Participants were adult romantic couples (N = 100) with current AUD and a history of physical IPV in their relationship. Results from the between-couple comparison indicate that couples who reported more heavy drinking days also experienced more physical IPV when at least one partner had probable PTSD. However, the within-couple comparison indicated that among partners without a provisional PTSD diagnosis, those with fewer heavy drinking days compared to their partner also reported more physical IPV perpetration. These preliminary and exploratory findings require replication and extension but provide new and important information regarding the complex intersection of heavy drinking, PTSD, and IPV among couples with AUD.

Subjective stress and any drinking during alcohol treatment: Disentangling within and between person autoregressive effects

Alcohol use has been shown to increase stress, and there is some evidence that stress predicts subsequent alcohol use during treatment for alcohol use disorder (AUD), particularly among females who are more likely to report coping-motivated drinking. Gaining a better understanding of the processes by which stress and alcohol use are linked during treatment could potentially inform AUD treatment planning. The current study aimed to characterize the association between stress and drinking during the course of AUD treatment and whether there were sex differences in these associations. Secondary data analyses of the COMBINE study (N = 1375; 69% male, 76.3% non-Hispanic and white, average age of 44.4 years) were conducted to examine self-reported perceived stress and alcohol consumption across 16 weeks of treatment for AUD using a Bayesian random-intercept cross-lagged panel model. There was stronger evidence for any alcohol use predicting greater than typical stress in subsequent weeks and less strong evidence for stress increasing the subsequent probability of alcohol use, particularly among males. For females, greater stress predicted subsequent drinking earlier in the treatment period, and a lower probability of subsequent drinking in the last week of treatment. Interventions might specifically focus on targeting reductions in stress following drinking occasions.

Brain-specific serine/threonine-protein kinase 1 is a substrate of protein kinase C epsilon involved in sex-specific ethanol and anxiety phenotypes

Protein kinase C epsilon (PKCε) regulates behavioural responses to ethanol and plays a role in anxiety-like behaviour, but knowledge is limited on downstream substrates of PKCε that contribute to these behaviours. We recently identified brain-specific serine/threonine-protein kinase 1 (BRSK1) as a substrate of PKCε. Here, we test the hypothesis that BRSK1 mediates responses to ethanol and anxiety-like behaviours that are also PKCε dependent. We used in vitro kinase assays to further validate BRSK1 as a substrate of PKCε and used Brsk1-/- mice to assess the role of BRSK1 in ethanol- and anxiety-related behaviours and in physiological responses to ethanol. We found that BRSK1 is phosphorylated by PKCε at a residue identified in a chemical genetic screen of PKCε substrates in mouse brain. Like Prkce-/- mice, male and female Brsk1-/- mice were more sensitive than wild-type to the acute sedative-hypnotic effect of alcohol. Unlike Prkce-/- mice, Brsk1-/- mice responded like wild-type to ataxic doses of ethanol. Although in Prkce-/- mice ethanol consumption and reward are reduced in both sexes, they were reduced only in female Brsk1-/- mice. Ex vivo slice electrophysiology revealed that ethanol-induced facilitation of GABA release in the central amygdala was absent in male Brsk1-/- mice similar to findings in male Prkce-/- mice. Collectively, these results indicate that BRSK1 is a target of PKCε that mediates some PKCε-dependent responses to ethanol in a sex-specific manner and plays a role distinct from PKCε in anxiety-like behaviour.

Engagement for alcohol escalates in the 5-choice serial reaction time task after intermittent access

Excessive intake plays a significant role in the development of alcohol use disorder and impacts 15 million Americans annually, with approximately 88 000 dying from alcohol related deaths. Several facets we contribute to alcohol use disorder include impulsivity, motivation, and attention. Previous studies have used the 5-Choice Serial Reaction Time Task (5-Choice) to analyze these types of behaviors using sugar, but recently we have published using 10% alcohol as the reward. This study analyzed 48 mice that were trained to respond for alcohol in the 5-Choice. All mice distributed and analyzed first by alcohol preference and then by consumption. Here, we became interested in a new classification called "engagement". High-engaged and low-engaged mice were determined by the number of correct responses during final Late-Stage training sessions. Interestingly, during Early-Stage training, the mice began to separate themselves into two groups based on their interaction with the task. Throughout both training stages, high-engaged mice displayed a greater number of trials and correct responses, as well as a lower percentage of omissions compared to low-engaged mice. Following three weeks of intermittent access homecage drinking, low-engaged mice showed greater increase in perseverative responding relative to high-engaged. Additionally, low-engaged mice decreased their reward and correct latencies compared to high-engaged mice suggesting an increase in motivation for alcohol. Overall, engagement analysis presents two clearly different groups, with only one being motivated to work for alcohol. These two distinct phenotypes in the 5-Choice could be used to model alcohol motivated behavior, which could help us further understand alcohol use disorder.

"When a man drinks alcohol it's cool but when a woman drinks she is a hoe": A qualitative exploration of alcohol, gender, stigma, and sexual assault in Moshi, Tanzania

Alcohol's ever-increasing global use poses a distinct threat to human well-being, with intake and associated burdens rising especially quickly in low- and middle-income countries like Tanzania. Prior research has shown alcohol use and related consequences differ by gender in Moshi, Tanzania, with important implications for both clinical care and future alcohol-reduction interventions. This study builds upon this knowledge by providing a deeper understanding of how gender differences affect alcohol-related stigma and sexual assault among Emergency Department (ED) and Reproductive Health Center (RHC) patients at Kilimanjaro Christian Medical Center (KCMC) in Moshi. In-depth interviews were conducted among ED and RHC KCMC patients (n = 19) selected for participation via purposive sampling. A mix of inductive and deductive coding schemes was used to identify themes and subthemes. All data were analyzed through a grounded theory approach. Gender roles that linked men with financial responsibilities and women with child caretaking led to different expectations on alcohol intake, with alcohol use encouraged for men but vilified for women. Women who drank, for example, were deemed poor mothers and undesirable spouses. Patients likewise emphasized that both alcohol-related stigma and sexual violence disproportionately impacted women, the latter fueled through alcohol use, with serious and lasting acts of discrimination and isolation from community members seen among women alcohol users but not for men. Women alcohol users in Moshi are subject to severe social consequences, facing disproportionate stigma and sexual violence as compared to men. Alcohol-related treatment for women should be mindful of the disproportionate burdens present in this context while treatment for men should be cognizant of the social pressures to drink. Strategies to address and/or mitigate these factors should be incorporated in subsequent care and interventions.

Genetic correlations of alcohol consumption and alcohol use disorder with sex hormone levels in females and males

Background

Alcohol consumption behaviors and alcohol use disorder risk and presentation differ by sex, and these complex traits are associated with blood concentrations of the steroid sex hormones, testosterone and estradiol, and their regulatory binding proteins, sex hormone binding globulin (SHBG) and albumin. Genetic variation is associated with alcohol consumption and alcohol use disorder, as well as levels of steroid sex hormones and their binding proteins.

Methods

To assess the contribution of genetic factors to previously described phenotypic associations between alcohol-use traits and sex-hormone levels, we estimated genetic correlations (rg) using summary statistics from prior published, large sample size genome-wide association studies (GWAS) of alcohol consumption, alcohol dependence, testosterone, estradiol, SHBG, and albumin.

Results

For alcohol consumption, we observed positive genetic correlation (i.e. genetic effects in the same direction) with total testosterone in males (rg = 0.084, p = 0.007) and trends toward positive genetic correlation with bioavailable testosterone (rg = 0.060, p = 0.084) and SHBG in males (rg = 0.056, p = 0.086) and with albumin in a sex-combined cohort (rg = 0.082, p = 0.015); however in females, we observed positive genetic correlation with SHBG (rg = 0.089, p = 0.004) and a trend toward negative genetic correlation (i.e. genetic effects in opposite directions) with bioavailable testosterone (rg = -0.064, p = 0.032). For alcohol dependence, we observed a trend toward negative genetic correlation with total testosterone in females (rg = -0.106, p = 0.024) and positive genetic correlation with BMI-adjusted SHBG in males (rg = 0.119, p = 0.017). Several of these genetic correlations differed between females and males and were not in the same direction as the corresponding phenotypic associations.

Conclusions

Findings suggest that shared genetic effects may contribute to positive associations of alcohol consumption with albumin in both sexes, as well as positive associations between alcohol consumption and bioavailable testosterone and between alcohol dependence and SHBG in males. However, relative contributions of heritable and environmental factors to associations between alcohol-use traits and sex-hormone levels may differ by sex, with genetic factors contributing more in males and environmental factors contributing more in females.

Different mechanisms underlie compulsive alcohol self-administration in male and female rats

BACKGROUND

Sex is an important factor in the progression and treatment of alcohol addiction, and therapeutic approaches may have to be tailored to potential sex differences. This highlights the importance of understanding sex differences in behaviors that reflect key elements of clinical alcohol addiction, such as continued use despite negative consequences ("compulsive use"). Studies in experimental animals can help provide an understanding of the role sex plays to influence these behaviors.

METHODS

Large populations of genetically heterogeneous male and female Wistar rats were tested in an established model of compulsive alcohol self-administration, operationalized as alcohol responding despite contingent foot shock punishment. We also tested baseline (fixed ratio, unpunished) operant alcohol self-administration, motivation to self-administer alcohol (progressive ratio), and temporal discounting for alcohol reward. In search of predictors of compulsivity, animals were screened for novelty-induced place preference, anxiety-like behavior, pain sensitivity and corticosterone levels. The estrous cycle was monitored throughout the study.

RESULTS

Unpunished self-administration of alcohol did not differ between males and females when alcohol intake was corrected for body weight. Overall, females showed higher levels of compulsive responding for alcohol. Compulsive response rates showed bimodal distributions in male but not in female rats when intermediate shock intensities were used (0.2 and 0.25 mA); at higher shock intensities, responding was uniformly suppressed in both males and females. We also found less steep discounting in females when alcohol was devalued by delaying its delivery. Males exhibited a stronger motivation to obtain alcohol under unpunished conditions, while females showed higher corticosterone levels at baseline. Factor analysis showed that an underlying dimension related to stress and pain predicted compulsivity in females, while compulsivity in males was predicted by a reward factor. We did not find differences in alcohol-related behaviors throughout the various stages of the estrous cycle.

CONCLUSIONS

Our results suggest that mechanisms promoting compulsivity, a key feature of alcohol addiction, likely differ between males and females. This underscores the importance of considering sex as a biological variable in both preclinical and clinical research, and has potential treatment implications in alcohol addiction.