The relationship between alcohol- and sleep-related traits: Results from polygenic risk score and Mendelian randomization analyses

The effectiveness of reduction in alcohol consumption achieved by the provision of non-alcoholic beverages associates with Alcohol Use Disorders Identification Test scores: a secondary analysis of a randomized controlled trial

BACKGROUND

The Alcohol Use Disorders Identification Test (AUDIT) is commonly used in clinical settings to assess the severity of alcohol-related problems, with the effectiveness of alcohol reduction interventions varying across this spectrum. In a recent study, we demonstrated that a 12-week intervention involving the provision of free non-alcoholic beverages reduced alcohol consumption among heavy drinkers for up to 8 weeks post-intervention. However, it remains unclear whether this effect was consistent across different AUDIT score ranges. Therefore, this secondary analysis aimed to examine whether the severity of alcohol-related problems, as indicated by AUDIT scores, influences the effectiveness of non-alcoholic beverage provision in reducing alcohol consumption.

METHODS

This was a single-center, open-label, randomized, parallel-group study. Participants were Japanese individuals who frequently consumed large quantities of alcohol (at least 40 g/day for men and 20 g/day for women) but were not diagnosed with alcohol dependence. Participants were randomly assigned to either an intervention or control group. The intervention group received free non-alcoholic beverages once every 4 weeks over a 12-week period (24 bottles of 350 mL per case, up to three cases per session, for a total of three sessions). Alcohol and non-alcoholic beverage consumption over the previous 4 weeks was tracked using a drinking diary. For this secondary analysis, participants were categorized into four groups based on their AUDIT scores (group 1: ≤ 7 points, group 2: 8-11 points, group 3: 12-14 points, and group 4: ≥ 15 points), and changes in alcohol consumption were compared across these groups in both the intervention and control participants.

RESULTS

The provision of non-alcoholic beverages significantly increased non-alcoholic beverage consumption in all groups. However, alcohol consumption was significantly reduced in the intervention groups compared to controls only in groups 1-3. The reduction in alcohol consumption was less pronounced in groups 3 and 4 compared to group 1 (both, p < 0.05). Importantly, the provision of non-alcoholic beverages did not lead to an increase in alcohol consumption, even among individuals with higher AUDIT scores.

CONCLUSIONS

These findings suggest that individuals with higher AUDIT scores may experience a reduced benefit from a 12-week non-alcoholic beverage intervention in terms of alcohol consumption reduction. Nevertheless, this intervention appears to be a safe and effective strategy for reducing alcohol consumption in heavy drinkers who do not have alcohol dependence.

TRIAL REGISTRATION

UMIN UMIN000047949. Registered 4 June 2022.

Melatonin Regulates Neuronal Synaptic Plasticity in the Supramammillary Nucleus and Attenuates Methamphetamine-Induced Conditioned Place Preference and Sensitization in Mice

Methamphetamine (METH) is an addictive drug that threatens human health. The supramammillary nucleus (SuM) and its neural circuits play key roles in the regulation of spatial memory retrieval, and hippocampal contextual or social memory. Melatonin (MLT), a pineal hormone, can regulate hypothalamic-neurohypophysial activity. Our previous study showed that MLT attenuates METH-induced locomotor sensitization. However, whether MLT regulates SuM function and participates in METH-induced contextual memory retrieval remains unclear. Using a mouse model of METH-conditioned place preference (CPP) and sensitization, we found that METH activated c-Fos expression and elevated calcium (Ca²⁺) levels in SuM neurons. Chemogenetic inhibition of SuM attenuates CPP and sensitization. Pretreatment with MLT decreased c-Fos expression and Ca2+ levels in the SuM and reversed METH-induced addictive behavior, effects that were blocked with the selective MT2 receptors antagonist 4P-PDOT and the MT1 receptors antagonist S26131. Furthermore, MLT reduced SuM synaptic plasticity, glutamate (Glu) release, and neuronal oscillations caused by METH, which were blocked by 4P-PDOT. In conclusion, our data revealed that MLT regulates neuronal synaptic plasticity in the SuM, likely through the MLT receptors (MTs), and plays a role in modulating METH-addictive behavior.

Reductions in World Health Organization risk drinking level are associated with improvements in sleep problems among individuals with alcohol use disorder

AIMS

Among individuals with alcohol use disorder (AUD), sleep disturbances are pervasive and contribute to the etiology and maintenance of AUD. However, despite increased attention toward the relationship between alcohol use and sleep, limited empirical research has systematically examined whether reductions in drinking during treatment for AUD are associated with improvements in sleep problems.

METHODS

We used data from a multisite, randomized, controlled trial that compared 6 months of treatment with gabapentin enacarbil extended-release with placebo for adults with moderate-to-severe AUD (N = 346). The Timeline Follow-back was used to assess WHO risk drinking level reductions and the Pittsburgh Sleep Quality Index was used to assess sleep quality over the prior month at baseline and the end of treatment.

RESULTS

Sleep problem scores in the active medication and placebo groups improved equally. Fewer sleep problems were noted among individuals who achieved at least a 1-level reduction (B = -0.99, 95% confidence interval (CI) [-1.77, -0.20], P = .014) or at least a 2-level reduction (B = -0.80, 95% CI [-1.47, -0.14], P = .018) in WHO risk drinking levels at the end of treatment. Reductions in drinking, with abstainers excluded from the analysis, also predicted fewer sleep problems at the end of treatment (1-level: B = -1.01, 95% CI [-1.83, -0.20], P = .015; 2-level: B = -0.90, 95% CI [-1.59, -0.22], P = .010).

CONCLUSIONS

Drinking reductions, including those short of abstinence, are associated with improvements in sleep problems during treatment for AUD. Additional assessment of the causal relationships between harm-reduction approaches to AUD and improvements in sleep is warranted.

Association between alcohol consumption and sleep traits: observational and mendelian randomization studies in the UK biobank

Previous studies have shown that excessive alcohol consumption is associated with poor sleep. However, the health risks of light-to-moderate alcohol consumption in relation to sleep traits (e.g., insomnia, snoring, sleep duration and chronotype) remain undefined, and their causality is still unclear in the general population. To identify the association between alcohol consumption and multiple sleep traits using an observational and Mendelian randomization (MR) design. Observational analyses and one-sample MR (linear and nonlinear) were performed using clinical and individual-level genetic data from the UK Biobank (UKB). Two-sample MR was assessed using summary data from genome-wide association studies from the UKB and other external consortia. Phenotype analyses were externally validated using data from the National Health and Nutrition Examination Survey (2017-2018). Data analysis was conducted from January 2022 to October 2022. The association between alcohol consumption and six self-reported sleep traits (short sleep duration, long sleep duration, chronotype, snoring, waking up in the morning, and insomnia) were analysed. This study included 383,357 UKB participants (mean [SD] age, 57.0 [8.0] years; 46% male) who consumed a mean (SD) of 9.0 (10.0) standard drinks (one standard drink equivalent to 14 g of alcohol) per week. In the observational analyses, alcohol consumption was significantly associated with all sleep traits. Light-moderate-heavy alcohol consumption was linearly linked to snoring and the evening chronotype but nonlinearly associated with insomnia, sleep duration, and napping. In linear MR analyses, a 1-SD (14 g) increase in genetically predicted alcohol consumption was associated with a 1.14-fold (95% CI, 1.07-1.22) higher risk of snoring (P < 0.001), a 1.28-fold (95% CI, 1.20-1.37) higher risk of evening chronotype (P < 0.001) and a 1.24-fold (95% CI, 1.13-1.36) higher risk of difficulty waking up in the morning (P < 0.001). Nonlinear MR analyses did not reveal significant results after Bonferroni adjustment. The results of the two-sample MR analyses were consistent with those of the one-sample MR analyses, but with a slightly attenuated overall estimate. Our findings suggest that even low levels of alcohol consumption may affect sleep health, particularly by increasing the risk of snoring and evening chronotypes. The negative effects of alcohol consumption on sleep should be made clear to the public in order to promote public health.