Exenatide Adjunct to Nicotine Patch Facilitates Smoking Cessation and May Reduce Post-Cessation Weight Gain: A Pilot Randomized Controlled Trial

Once-Weekly Semaglutide in Adults With Alcohol Use Disorder: A Randomized Clinical Trial

Importance

Preclinical, observational, and pharmacoepidemiology evidence indicates that glucagon-like peptide 1 receptor agonists (GLP-1RAs) may reduce alcohol intake. Randomized trials are needed to determine the clinical significance of these findings.

Objective

To evaluate the effects of once-weekly subcutaneous semaglutide on alcohol consumption and craving in adults with alcohol use disorder (AUD).

Design, Setting, and Participants

This was a phase 2, double-blind, randomized, parallel-arm trial involving 9 weeks of outpatient treatment. Enrollment occurred at an academic medical center in the US from September 2022 to February 2024. Of 504 potential participants assessed, 48 non-treatment-seeking participants with AUD were randomized.

Intervention

Participants received semaglutide (0.25 mg/week for 4 weeks, 0.5 mg/week for 4 weeks, and 1.0 mg for 1 week) or placebo at weekly clinic visits.

Main Outcomes and Measures

The primary outcome was laboratory alcohol self-administration, measured at pretreatment and posttreatment (0.5 mg/week). Secondary and exploratory outcomes, including prospective changes in alcohol consumption and craving, were assessed at outpatient visits.

Results

Forty-eight participants (34 [71%] female; mean [SD] age, 39.9 [10.6] years) were randomized. Low-dose semaglutide reduced the amount of alcohol consumed during a posttreatment laboratory self-administration task, with evidence of medium to large effect sizes for grams of alcohol consumed (β, -0.48; 95% CI, -0.85 to -0.11; P = .01) and peak breath alcohol concentration (β, -0.46; 95% CI, -0.87 to -0.06; P = .03). Semaglutide treatment did not affect average drinks per calendar day or number of drinking days, but significantly reduced drinks per drinking day (β, -0.41; 95% CI, -0.73 to -0.09; P = .04) and weekly alcohol craving (β, -0.39; 95% CI, -0.73 to -0.06; P = .01), also predicting greater reductions in heavy drinking over time relative to placebo (β, 0.84; 95% CI, 0.71 to 0.99; P = .04). A significant treatment-by-time interaction indicated that semaglutide treatment predicted greater relative reductions in cigarettes per day in a subsample of individuals with current cigarette use (β, -0.10; 95% CI, -0.16 to -0.03; P = .005).

Conclusions and Relevance

These findings provide initial prospective evidence that low-dose semaglutide can reduce craving and some drinking outcomes, justifying larger clinical trials to evaluate GLP-1RAs for alcohol use disorder.

Trial Registration

ClinicalTrials.gov Identifier: NCT05520775.

Connecting the dots: Understanding and addressing the metabolic impact of antipsychotic and antidepressant medications

Serious mental disorders such as schizophrenia and major depression are associated with considerable morbidity and mortality, resulting in much shorter life expectancies in those affected. The discovery of antipsychotic medications ushered in improved health outcomes for people with serious mental disorders but also brought about increased morbidity due to their metabolic side effects, including obesity and diabetes mellitus. Antidepressant medications have a more favorable metabolic side effect profile, but some can still cause weight gain and hyperglycemia. In this narrative review, we discuss antipsychotic and antidepressant medications' mechanisms of action, their respective effectiveness in treating psychosis and depression, and their metabolic side effects. In addition, we present therapeutic strategies for minimizing cardiometabolic health risks in patients treated with these medications by applying a comprehensive, biopsychosocial approach.

Association of GLP1R locus with mental ill-health endophenotypes and cardiometabolic traits: A trans-ancestry study in UK Biobank

AIMS

Glucagon-like peptide 1 receptor agonists (GLP1RA), used to treat type 2 diabetes and obesity, have been associated with off-target behavioural effects. We systematically assessed genetic variation in the GLP1R locus for impact on mental ill-health (MIH) and cardiometabolic phenotypes across diverse populations within UK Biobank.

MATERIALS AND METHODS

All genetic variants with minor allele frequency >1% in the GLP1R locus were investigated for associations with MIH phenotypes and cardiometabolic phenotypes. Linear or Logistic regression analyses (adjusted for age, sex, population structure and genotyping chip) were conducted separately in unrelated individuals of self-reported white British (N = 408 774), white European (N = 50 314), South Asian (N = 7667), multiple-ancestry groups (N = 10 437) or African-Caribbean (N = 7641) subsets. All ancestries were subsequently combined in an inverse variance-weighted fixed effects meta-analysis. Bonferroni correction for multiple testing was applied (for number of independent genetic variants).

RESULTS

Associations were identified between GLP1R variants and body mass index (BMI), blood pressure and type 2 diabetes in all ancestries. All ancestries except South Asian had significant MIH associations (mood instability: rs111265626-G, odds ratio [OR] 0.851 [confidence interval, CI 0.79-0.92], risk-taking behaviour: rs75408972-T, OR 1.05 [CI 1.03-1.08] or chronic pain: rs9296280-C, OR 0.645 [CI 0.54-0.78]). The trans-ancestry meta-analysis showed mainly consistent effect sizes and directions for metabolic traits, but discordant directions MIH associations. Only signals for chronic pain, stroke and BMI influenced expression of GLP1R.

CONCLUSIONS

GLP1R variants have consistent cardiometabolic effects across ancestries, but effects on MIH phenotypes are more varied. Any observed behavioural changes with GLP1RA are likely not acting directly through GLP1R.

Use of glucagon-like peptide-1 receptor agonists in people with history of acute pancreatitis: TriNetX analysis

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are used in subjects with type 2 diabetes (T2D) and obesity. However, concerns over their association with acute pancreatitis (AP) have emerged. Our aim was to evaluate the risk of recurrence of AP in subjects on GLP-1RAs with a history of AP.

METHODS

This retrospective study deployed the TriNetX platform. We identified adult cohorts of subjects with a history of AP and analyzed the impact of individual medications (GLP-1RAs, SGLT2i, or DPP4i) on the risk of recurrence of AP. To adjust for baseline differences, propensity score matching was done in cohorts with and without risk factors for AP.

RESULTS

Our analysis of 672,069 patients with a history of AP and T2D revealed significant risk reductions associated with GLP-1RAs compared to other treatments. Over one to five years, GLP-1RAs consistently showed a lower risk of AP recurrence compared to SGLT2i and DPP-4i. Specifically, over a one-year period, GLP-1RAs users had a risk reduction of -0.071 (95 % CI:0.085 to -0.057) (p < 0.001) compared to SGLT2i, and -0.064 (95 % CI:0.080 to -0.048) (p< 0.001) compared to DPP-4i. These trends persisted, with the risk differences further widening by the fifth year to -0.086 and -0.094, respectively.

CONCLUSION

Based on our findings, we conclude that GLP-1RAs may be safely used in subjects with a history of acute pancreatitis. While our analysis showed that there was a significantly lower risk of AP recurrence in subjects on GLP-1compared to DPP-IV inhibitors and SGLT2 inhibitors, as this is a retrospective analysis we suggest that these findings need to be confirmed in prospective studies.

Priors and decision thresholds in phase 2 and phase 3 randomized controlled trials evaluating drug efficacy using Bayesian methods: a systematic review

OBJECTIVES

To describe the priors and decision thresholds in phase 2 and 3 randomized controlled trials (RCTs) evaluating drug efficacy using Bayesian methods.

STUDY DESIGN AND SETTING

A systematic review of phase 2 and 3 RCTs evaluating drug efficacy through Bayesian inference was conducted across the MEDLINE, EMBASE, and Cochrane databases, with no date restrictions until September 2022. The type of prior used for the analysis of the primary endpoint and its characteristics (type and parameters of the distribution, justification, and sensitivity analysis), the use of a posterior probability decision threshold defined a priori, and its value, were extracted.

RESULTS

From 1161 articles screened, 69 articles were ultimately included, encompassing a total of 91 comparisons, as some trials assessed multiple primary endpoints or treatments. The prior was assigned to treatment effect in 51% of the cases (n = 46) to each arm in 37% (n = 34) and was not explicitly defined in 12% (n = 11). Prior distribution was described (with its parameters) in 59% of cases (n = 54). A decision threshold was set a priori in 68% of the results (n = 62), and its value ranged from 70% to 99% (median 95%).

CONCLUSION

The inconsistent description of priors, along with the wide variation and occasional absence of decision thresholds, underscore the need for clear guidelines on the use and reporting of Bayesian methods.

PLAIN LANGUAGE SUMMARY

Bayesian methods are being used more frequently in clinical trials to assess drug's efficacy. These methods offer flexibility by incorporating prior knowledge into the analysis. However, the use of Bayesian approaches is still not widespread, and there are challenges with how results are interpreted, partly due to a lack of clear standards. We conducted a systematic review to describe how Bayesian methods were used and reported in phase 2 and 3 clinical trials assessing drug efficacy. We looked at the types of prior information used in the analyses and how decisions about efficacy were made based on the results. Out of 1161 studies reviewed, 69 were included in the analysis, covering 91 drug comparisons. The priors in Bayesian drug trials were assigned to treatment effects or each arm, often justified but variably describe. Similarly, decision thresholds for determining drug efficacy were preset in most studies, but with heterogeneity in the thresholds used to conclude. Our findings highlight the need for clearer guidelines on using Bayesian methods in clinical trials to improve transparency and consistency in how results are reported.

Weight loss therapy and addiction: Increased risk after bariatric surgery but reduced risk with GLP-1 receptor agonists

BACKGROUND

Obesity is an increasing public health problem because of its high prevalence and associated morbidity and mortality. Two weight-loss strategies are currently used, either bariatric surgery or pharmacological therapy with glucagon-like peptide-1 receptor agonists (GLP-1RAs). Preclinical studies in rodents suggested an increased risk of additive disorders after bariatric surgery contrasting with a reduced risk with GLP-1RAs.

METHODS

An extensive literature search to detect clinical studies that investigated the prevalence of addictive disorders (food addiction, alcohol abuse, smoking, cannabis, cocaine, opioid use) following bariatric surgery or GLP-1RA therapy in obese patients.

RESULTS

In observational cohort studies, the prevalence of alcohol use disorder was twofold higher after > 2 years following surgery (eleven studies, mainly with gastric bypass) whereas it was reduced roughly by half with GLP-1RA therapy (five studies, mainly with semaglutide). Similar findings were reported with other addictive disorders. An addiction transfer from food addiction to other addictive disorders is hypothesized to explain the increased risk after bariatric surgery. Several mechanisms are proposed to explain the favorable findings reported with GLP-1RAs, i.e. effects on the dopamine reward pathway, central GABA (gamma-aminobutyric acid) release, negative emotional stress associated with food/drug restriction and/or neuronal inflammation.

CONCLUSION

Available data from observational cohort studies confirm an increased risk of addictive disorders following bariatric surgery, contrasting with a reduced risk with GLP-1RA therapy. Both physicians and patients should be informed of the higher risk post-surgery whereas available promising results with GLP-1RAs should be confirmed in ongoing dedicated randomized controlled trials before any official indication.

Effects of GLP-1 Receptor Agonists in Alcohol Use Disorder

In the search for novel treatment strategies for alcohol use disorder (AUD), glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) approved for treating Type 2 diabetes and obesity have caught much attention. GLP-1 is a naturally occurring peptide produced in the small intestines and the brain, regulating plasma glucose levels and satiety. This focused review will report on the preclinical studies, case stories, register-based cohort studies, brain-imaging data and secondary analysis of clinical data supporting the role of GLP-1RAs as a novel treatment of AUD. Several clinical trials are ongoing, examining the potential effects of the GLP-1RA semaglutide in AUD.

Effect of acute treatment with the glucagon-like peptide-1 receptor agonist, liraglutide, and estrus phase on cue- and drug-induced fentanyl seeking in female rats

Opioid use disorder (OUD) is a crisis in the USA. Despite advances with medications for OUD, overdose deaths have continued to rise and are largely driven by fentanyl. We have previously found that male rats readily self-administer fentanyl, with evident individual differences in fentanyl taking, seeking, and reinstatement behaviors. We also have shown that acute treatment with the glucagon-like peptide-1 receptor (GLP-1R) agonist, liraglutide, can reduce fentanyl seeking behavior in male rats. However, given that females are significantly more vulnerable to drug-related cues, drug cravings, and to the development of OUD compared to males, it is imperative that we investigate the biological risk factors on fentanyl use disorder. Further, preclinical models report that females in estrus have increased fentanyl intake, more rapid development of OUD, and enhanced relapse vulnerability compared to those in a non-estrus phase. Thus, we aimed here to understand the effect of estrus phase on our model of OUD and on the effectiveness of acute liraglutide treatment. Herein, we show that female rats readily self-administer fentanyl (1.85 μg/infusion) intravenously, with marked individual differences in fentanyl taking behavior. Additionally, rats in the estrus phase exhibited greater fentanyl intake compared with those in a non-estrus phase, greater cue-induced fentanyl seeking, and greater drug-induced reinstatement of fentanyl seeking. Finally, acute liraglutide treatment (0.3 mg/kg s.c.) reduced cue-induced fentanyl seeking and blocked drug-induced reinstatement of fentanyl seeking, particularly when tested in estrus. Overall, these data support the broad effectiveness of acute GLP-1R agonists as a promising non-opioid treatment for OUD.

Exploring Predictors of Treatment Response to GLP-1 Receptor Agonists for Smoking Cessation

INTRODUCTION

Understanding predictors of smoking cessation medication efficacy facilitates the ability to enhance treatment effectiveness. In our pilot trial, exenatide, a glucagon-like peptide-1 receptor agonist, adjunct to nicotine patch improved smoking abstinence compared to nicotine patch alone. This secondary analysis explores potential baseline characteristics associated with differential treatment response to exenatide.

METHODS

The parent trial randomized (1:1) 84 smokers with prediabetes and/or overweight to once-weekly placebo or exenatide, 2 mg, subcutaneously. All participants received nicotine patch (21 mg) and brief smoking cessation counseling, with biologically confirmed 7-day point prevalence abstinence at week 6 (end-of-treatment) deemed the primary outcome. Bayesian generalized linear modeling explored differential response to treatment as a function of baseline patient characteristics, including demographic, psychosocial, clinical, smoking related, and genetic factors. Posterior probability (PP)≥75% that an effect exists was taken as a minimum threshold of evidence in favor of model effects.

RESULTS

Exenatide showed stronger benefit versus placebo in participants that smoked >20 cigarettes per day (PP=81.7%) and in those without prediabetes (PP=76.0%) or obesity (PP=94.4%). Exenatide's efficacy was observed only in individuals with no/minimal depression symptoms but not in those with symptoms (PP=91.2%). Finally, exenatide was more efficacious than placebo only in those with the CHRNA rs16969968 GG genotype (PP=88.6%).

CONCLUSIONS

The effect of exenatide on abstinence may be moderated by the number of cigarettes smoked daily, metabolic, psychological, and genetic factors. Larger prospective investigations are needed to confirm and extend these findings.

IMPLICATIONS

Understanding predictors of smoking cessation medication efficacy enhances the ability to improve treatment effectiveness. In our pilot trial, extended-release exenatide, a GLP-1 receptor agonist, adjunct to nicotine patch, improved smoking abstinence in smokers with prediabetes and/or overweight. The current post-hoc analysis found that the effect of exenatide on smoking abstinence may be moderated by the number of cigarettes smoked daily, metabolic, psychological, and genetic factors. Larger investigations are needed to confirm and extend these findings.

Effect of the glucagon-like peptide-1 (GLP-1) receptor agonist semaglutide on alcohol consumption in alcohol-preferring male vervet monkeys

RATIONALE

Glucagon-like peptide-1 (GLP-1) receptor agonists reduce alcohol consumption in rodents and non-human primates. Semaglutide is a new long-acting GLP-1 receptor agonist, widely used in the clinic against type 2 diabetes and obesity. It is also reported to reduce alcohol intake in rodents.

OBJECTIVES

This study investigates the possible inhibitory effect of semaglutide on alcohol intake in alcohol-preferring African green monkeys.

METHODS

We performed a vehicle-controlled study on male monkeys that had demonstrated a preference for alcohol. In the monkeys selected for voluntary alcohol drinking, alcohol consumption was measured for ten days at baseline (Monday to Friday for two weeks). During this period, the monkeys had access to alcohol 4 h per day and free access to water 24 h per day. After two weeks of baseline measurements, the monkeys were randomized to semaglutide or vehicle. Each group consisted of ten monkeys, and the two groups were balanced with respect to baseline alcohol intake. Following the baseline period, the monkeys were treated with escalating doses of semaglutide (up to 0.05 mg/kg) or vehicle subcutaneously twice weekly for two weeks during which period alcohol was not available. After uptitration, the monkeys had access to alcohol 4 h daily for 20 days (Monday to Friday for 4 weeks), and alcohol consumption was measured. During this alcohol exposure period, treatment with semaglutide (0.05 mg/kg twice weekly) or vehicle continued for three weeks followed by a one-week washout period.

RESULTS

Compared to the vehicle, semaglutide significantly reduced alcohol intake. There were no signs of emetic events or changes in water intake.

CONCLUSIONS

These data demonstrate for the first time the potent effect of semaglutide in reducing voluntary alcohol intake in non-human primates and further substantiate the need for clinical trials investigating the effect of semaglutide in patients with alcohol-use disorder.

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) as treatment for nicotine cessation in psychiatric populations: a systematic review

BACKGROUND

Nicotine use and nicotine use disorder (NUD) are the leading causes of preventable death in the United States. Persons with mental disorders  (e.g., bipolar disorder) are differentially susceptible to nicotine use. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are indicated for type 2 diabetes mellitus (T2DM) and obesity and show preliminary evidence of efficacy in addiction-related behaviours. Herein, we synthesize extant preclinical and clinical evidence evaluating the effect of GLP-1RAs on neurobiological systems and behaviours salient to nicotine consumption and cessation.

METHODS

Online databases (MedLine, Embase, AMED, PsychINFO, JBI EBP Database, PubMed, Web of Science, Google Scholar) were searched from inception to May 21, 2024. Relevant studies were also extracted from the reference lists of the obtained articles. All articles were screened against inclusion and exclusion criteria.

RESULTS

Administration of GLP-1RAs reduced nicotine self-administration and nicotine-seeking behaviour in animal models that, in some cases, is sustained beyond exposure to the agent. GLP-1RAs also mitigated post-nicotine cessation weight gain, craving, withdrawal, and hyperphagia. The preceding effects are attributable to modulation of reward-related brain regions (e.g., mesolimbic dopamine system), resulting in nicotine aversion. GLP-1RAs were also efficacious as adjunctive therapies [e.g., in combination with nicotine replacement therapies (NRTs)].

CONCLUSION

The multi-effect characteristics in NUD paradigms provide a compelling rationale for large, adequately powered, long-term, randomized controlled trials of GLP-1RAs in the treatment and prevention of NUD. The replicated effect on mitigating post-nicotine cessation weight gain is a differentiating feature of GLP-1RAs from extant proven therapies for NUD.

Potential role of glucagon-like peptide-1 (GLP-1) receptor agonists in substance use disorder: A systematic review of randomized trials

BACKGROUND

Increasing evidence suggests that GLP-1 receptor agonists (GLP-1RA) have a potential use in addiction treatment. Few studies have assessed the impact of GLP-1RA on substance use disorder (SUD), particularly in humans. The study aimed to do systematic review of clinical trials to assess GLP-1RA's effect on reducing SUD in patients.

METHODS

The scientific literature was reviewed using the MEDLINE, Scopus and Cochrane Library databases, following PRISMA guidelines. Studies including patients with a diagnosis of SU who were treated with GLP-1RA were selected. The primary outcome was GLP-1RA's therapeutic effect on SUD, and the secondary outcomes were therapeutic effects of GLP-1RA on weight, BMI and HbA1c.

RESULTS

1218 studies were retrieved, resulting in 507 papers after title and abstract screening. Following full-text review, only 5 articles met inclusion criteria. We incorporated a total of 630 participants utilizing Exenatide (n=3) and Dulaglutide (n=2) as GLP-1RAs. Therapeutic effect of GLP-1RA on SUD was assessed in 5 studies, with 3 demonstrating a significant decrease in SUD (alcohol and nicotine). GLP-1RA's impact on body weight, BMI, and HbA1c, was reported in 3 studies. These revealed a notable reduction in these parameters among the GLP-1RA treated group.

CONCLUSION

This review will give an overview of current new findings in human studies; we suggest that the effects of GLP-1RA in SUD is a possible new option of therapy in addiction medicine.

Efficacy and Safety of GLP-1 Medicines for Type 2 Diabetes and Obesity

The development of glucagon-like peptide 1 receptor agonists (GLP-1RA) for type 2 diabetes and obesity was followed by data establishing the cardiorenal benefits of GLP-1RA in select patient populations. In ongoing trials investigators are interrogating the efficacy of these agents for new indications, including metabolic liver disease, peripheral artery disease, Parkinson disease, and Alzheimer disease. The success of GLP-1-based medicines has spurred the development of new molecular entities and combinations with unique pharmacokinetic and pharmacodynamic profiles, exemplified by tirzepatide, a GIP-GLP-1 receptor coagonist. Simultaneously, investigational molecules such as maritide block the GIP and activate the GLP-1 receptor, whereas retatrutide and survodutide enable simultaneous activation of the glucagon and GLP-1 receptors. Here I highlight evidence establishing the efficacy of GLP-1-based medicines, while discussing data that inform safety, focusing on muscle strength, bone density and fractures, exercise capacity, gastrointestinal motility, retained gastric contents and anesthesia, pancreatic and biliary tract disorders, and the risk of cancer. Rapid progress in development of highly efficacious GLP-1 medicines, and anticipated differentiation of newer agents in subsets of metabolic disorders, will provide greater opportunities for use of personalized medicine approaches to improve the health of people living with cardiometabolic disorders.

Semaglutide and smoking cessation in individuals with type 2 diabetes mellitus: there is no smoke without fire!

Tobacco use represents the leading preventable risk factor for premature deaths worldwide. A meta-analysis of 74 epidemiological studies, including 3.2 million individuals with type 2 diabetes mellitus (T2DM) from 33 countries, reported a pooled prevalence of smoking of 20.8% among individuals with T2DM. Cigarette smoking further aggravates existing deleterious vascular effects of T2DM. Namely, chronic hyperglycemia and exposure to cigarette smoke cause additive injurious effect on the endothelium, leading to an acceleration of vascular complications seen in persons with T2DM and tobacco use disorders (TUD). In a recent study, Wang and colleagues found that semaglutide use was associated with a significantly lower risk for medical encounters for TUD, when compared to other antidiabetic drug classes; indeed, this effect was strongest compared with insulins and weakest compared with other glucagon-like peptide-1 receptor agonists. Semaglutide was associated with reduced smoking cessation medication prescriptions and counseling. Similar findings were observed irrespective of the presence of obesity. Therefore, semaglutide use might be useful in terms of smoking cessation among individuals with T2DM, thus offering an additional benefit for this constantly growing population. However, those interesting findings should be confirmed through dedicated, large-scale randomized controlled trials.

Gut Hormones: Possible Mediators of Addictive Disorders?

BACKGROUND

Alcohol and drug dependence are major health and economic burdens to society. One of the major challenges to reducing this burden will be to develop more effective and better tolerated medications that target alternative mechanisms in the brain. While the dopamine system has been well characterized for mediating the reward value of drugs, there is evidence that the endocrine system also conveys signals to the same neural systems using gut hormones.

SUMMARY

These gut hormones, produced in the stomach and intestine and that regulate food intake, have also been shown to control the use of other substances, such as alcohol and drugs of abuse. Examples of such hormones are ghrelin and glucagon-like peptide-1, which exert their effects on dopamine transmission in parts of the brain known to be involved in some of the core features of addiction, such as reward sensitivity.

KEY MESSAGES

This raises the possibility that gut hormone systems may play a pivotal role in addictive disorders. This review will briefly outline emerging evidence that the ghrelin and glucagon-like peptide-1 hormones are contrasting mediators of alcohol and drug use and may present a promising alternative target for treatment intervention in addictive disorders.

Glucagon-like peptide 1 agonist and effects on reward behaviour: A systematic review

INTRODUCTION

The roles of metabolic signals, including Glucagon-like peptide 1 (GLP-1), have been implicated in multiple domains outside metabolic regulation. There is a growing interest in repurposing Glucagon-like peptide 1 receptor agonists (GLP-1RAs) as therapeutics for motivation and reward-related behavioural disturbances. Herein, we aim to systematically review the extant evidence on the potential effects of GLP-1RAs on the reward system.

METHODS

The study followed PRISMA guidelines using databases such as OVID, PubMed, Scopus, and Google Scholar. The search focused on "Reward Behavior" and "Glucagon Like Peptide 1 Receptor Agonists" and was restricted to human studies. Quality assessment achieved by the NIH's Quality Assessment of Controlled Intervention Studies RESULTS: GLP-1RAs consistently reduced energy intake and influenced reward-related behaviour. These agents have been associated with decreased neurocortical activation in response to higher rewards and food cues, particularly high-calorie foods, and lowered caloric intake and hunger levels.

DISCUSSION

GLP-1RAs show promise in addressing reward dysfunction linked to food stimuli, obesity, and T2DM. They normalize insulin resistance, and might also modulate dopaminergic signalling and reduce anhedonia. Their effects on glycemic variability and cravings suggest potential applications in addiction disorders.

IUPHAR review - Glucagon-like peptide-1 (GLP-1) and substance use disorders: An emerging pharmacotherapeutic target

Addiction is a chronic relapsing disease with high morbidity and mortality. Treatments for addiction include pharmacological and psychosocial interventions; however, currently available medications are limited in number and efficacy. The glucagon-like-peptide-1 (GLP-1) system is emerging as a potential novel pharmacotherapeutic target for alcohol and other substance use disorders (ASUDs). In this review, we summarize and discuss the wealth of available evidence from testing GLP-1 receptor (GLP-1R) agonist medications in preclinical models and humans with ASUDs, possible mechanisms underlying the impact of GLP-1R agonists on alcohol/substance use, gaps in knowledge, and future directions. Most of the research with GLP-1R agonists has been conducted in relation to alcohol use; psychostimulants, opioids, and nicotine have also been investigated. Preclinical evidence suggests that GLP-1R agonists reduce alcohol/substance use and other related outcomes. The main proposed mechanisms are related to reward processing, stress, and cognitive function, as well as broader mechanisms related to satiety, changes in gastric motility, and glucose homeostasis. More in-depth mechanistic studies are warranted. Clinical studies have been limited and their findings have been less conclusive; however, most support the safety and potential efficacy of GLP-1R agonists in ASUD treatment. Identifying preferred compounds, as well as possible subgroups who are most responsive to GLP-1R agonists are some of the key research questions to translate the promising preclinical data into clinical settings. Several clinical trials are underway to test GLP-1R agonists in people with ASUDs.

Effects of the glucagon-like peptide-1 receptor agonist dulaglutide on sexuality in healthy men: a randomised, double-blind, placebo-controlled crossover study

BACKGROUND

The reward-regulatory properties of GLP-1 are attracting increasing interest. Animal studies show that GLP-1 receptor agonists not only reduce consumption of addictive substances, but also influence sexual behaviour. We aimed to investigate the effect of dulaglutide versus placebo on sexual desire in humans.

METHODS

In this randomised, double-blind, placebo-controlled crossover trial, healthy eugonadal men of normal weight, aged 18-50 years with active and satisfactory sex lifes were (1:1) randomly allocated to dulaglutide or placebo for four weeks. We assessed sexual desire (Massachusetts General Hospital-Sexual Functioning Questionnaire [MGH-SFQ]), hormones of the hypothalamic-pituitary-gonadal axis (total testosterone, follicle-stimulating hormone [FSH], luteinizing hormone [LH]) and sperm parameters. Changes in these parameters were compared under dulaglutide versus placebo using paired t-tests.

FINDINGS

24 out of 26 randomised participants completed the study (13 participants randomised to dulaglutide first and 13 to placebo first). No change in the MGH-SFQ was observed after four weeks of dulaglutide versus placebo (estimated difference 0.58 [95% CI -0.83 to 2.00], p-value = 0.402). Hormones of the hypothalamic-pituitary-gonadal axis (estimated differences: total testosterone (nmol/l) 0.9 [95% CI -1.5 to 3.3], FSH (IU/l) -0.2 [95% CI -0.3 to 0.0] and LH (IU/l) -0.8 [95% CI -1.5 to 0.0]) as well as sperm parameters all remained in the normal range without significant differences between the treatments. No severe adverse events occurred.

INTERPRETATION

In this study of healthy men, we found no evidence of negative impacts of a four-week treatment with the widely used GLP-1 receptor agonist dulaglutide on sexual desire, hypothalamic-pituitary-gonadal axis hormones or sperm parameters.

FUNDING

Swiss National Science Foundation (PZ00P3_193206), Gottfried and Julia Bangerter-Rhyner Foundation, Goldschmidt-Jacobson Foundation, Swiss Academy of Medical Sciences.

The Efficacy of GLP-1 Agonists in Treating Substance Use Disorder in Patients: A Scoping Review

ABSTRACT

Substance use disorder (SUD) continues to be a leading cause of morbidity and mortality with limited treatments. There is interest in expanding the use of GLP-1 agonists in treating SUD. However, evidence for safety and efficacy in humans is limited. This review aims to bridge the existing knowledge gap by establishing a baseline of literature in this area to inform future trials and clinical practice. Our inclusion criteria were English peer-reviewed manuscripts reporting on use of GLP-1, GIP, and/or glucagon receptor agonists in treatment of SUDs, excluding case studies. The literature search was performed in accordance to PRISMA guidelines. Five studies were included in this review examining the use of this medication in tobacco use disorder, alcohol use disorder, and cocaine use disorder. No studies regarding substance withdrawal syndrome were identified. The included studies varied widely in terms of patient selection, dose/formulation of GLP-1 agonists, and follow-up. The results of this scoping review are mixed, with 3 studies demonstrating positive results and 2 studies finding no efficacy of this medication on SUD outcomes. It is premature to prescribe this medication off-label to patients. Further research is needed to determine the efficacy of GLP-1 agonists in treating SUD.

Metabolic Changes Following Smoking Cessation in Patients with Type 2 Diabetes Mellitus

BACKGROUND

Smoking cessation is crucial for reducing complications of type 2 diabetes mellitus (T2DM), but associated weight gain can worsen glycemic control, discouraging quitting attempts. Varenicline, a partial agonist of α4β2 nicotinic receptors, aids smoking cessation. This study examines the effects of varenicline on body weight and metabolic parameters in patients with T2DM and prediabetes.

METHODS

Fifty-three patients were enrolled, of which 32 successfully quit smoking after a three-month course of varenicline and were examined after an additional month with no medication. Measurements taken at baseline, 2.5 months, and 4 months included body weight, blood pressure, resting metabolic rate (RMR), glycated hemoglobin (HbA1c), fasting glucose, blood lipids, C-reactive protein (CRP), appetite-related hormones, and physical activity.

RESULTS

Post-treatment, there were no significant changes in body weight, blood pressure, RMR, or glycemic control. Total (CHOL) and low-density lipoprotein (LDL-C) cholesterol decreased significantly at 4 months of the study (from 168 to 156 mg/dL, p = 0.013, and from 96 to 83 mg/dL, p = 0.013, respectively). Leptin levels increased (from 11 to 13.8 ng/dL, p = 0.004), as did glucagon-like peptide-1 (GLP-1) levels (from 39.6 to 45.8 pM, p = 0.016) at 4 months of follow-up. The percentage of participants who reported moderate-intensity activity increased from 28% to 56%, while those reporting high-intensity activity increased from 19% to 22%, respectively (p = 0.039).

CONCLUSIONS

Our study showed that smoking cessation with varenicline in smokers with T2DM and prediabetes led to significant improvements in lipid profile, significant increase in plasma leptin and GLP-1 levels, and increased physical activity, without significant weight gain. Thus, smoking cessation without weight gain or deteriorated glycemic control is feasible for these smokers, with added benefits to lipid profiles, GLP-1 regulation, and physical activity.

Association of Semaglutide With Tobacco Use Disorder in Patients With Type 2 Diabetes : Target Trial Emulation Using Real-World Data

BACKGROUND

Reports of reduced desire to smoke in patients treated with semaglutide, a glucagon-like peptide receptor agonist (GLP-1RA) medication for type 2 diabetes mellitus (T2DM) and obesity, have raised interest about its potential benefit for tobacco use disorders (TUDs).

OBJECTIVE

To examine the association of semaglutide with TUD-related health care measures in patients with comorbid T2DM and TUD.

DESIGN

Emulation target trial based on a nationwide population-based database of patient electronic health records.

SETTING

United States, 1 December 2017 to 31 March 2023.

PARTICIPANTS

Seven target trials were emulated among eligible patients with comorbid T2DM and TUD by comparing the new use of semaglutide versus 7 other antidiabetes medications (insulins, metformin, dipeptidyl-peptidase-4 inhibitors, sodium-glucose cotransporter-2 inhibitors, sulfonylureas, thiazolidinediones, and other GLP-1RAs).

MEASUREMENTS

The TUD-related health care measures (medical encounter for diagnosis of TUD, smoking cessation medication prescriptions, and smoking cessation counseling) that occurred within a 12-month follow-up were examined using Cox proportional hazards and Kaplan-Meier survival analyses.

RESULTS

The study compared 222 942 new users of antidiabetes medications including 5967 of semaglutide. Semaglutide was associated with a significantly lower risk for medical encounters for TUD diagnosis compared with other antidiabetes medications, and was strongest compared with insulins (hazard ratio [HR], 0.68 [95% CI, 0.63 to 0.74]) and weakest but statistically significant compared with other GLP-1RAs (HR, 0.88 [CI, 0.81 to 0.96]). Semaglutide was associated with reduced smoking cessation medication prescriptions and counseling. Similar findings were observed in patients with and without a diagnosis of obesity. For most of the group comparisons, the differences occurred within 30 days of prescription initiation.

LIMITATION

Documentation bias, residual confounding, missing data on current smoking behavior, body mass index, and medication adherence.

CONCLUSION

Semaglutide was associated with lower risks for TUD-related health care measures in patients with comorbid T2DM and TUD compared with other antidiabetes medications including other GLP-1Ras, primarily within 30 days of prescription. These findings suggest the need for clinical trials to evaluate semaglutide's potential for TUD treatment.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Ecological momentary assessment and cue-elicited drug craving as primary endpoints: study protocol for a randomized, double-blind, placebo-controlled clinical trial testing the efficacy of a GLP-1 receptor agonist in opioid use disorder

BACKGROUND

Despite continuing advancements in treatments for opioid use disorder (OUD), continued high rates of relapse indicate the need for more effective approaches, including novel pharmacological interventions. Glucagon-like peptide 1 receptor agonists (GLP-1RA) provide a promising avenue as a non-opioid medication for the treatment of OUD. Whereas GLP-1RAs have shown promise as a treatment for alcohol and nicotine use disorders, to date, no controlled clinical trials have been conducted to determine if a GLP-1RA can reduce craving in individuals with OUD. The purpose of the current protocol was to evaluate the potential for a GLP-1RA, liraglutide, to safely and effectively reduce craving in an OUD population in residential treatment.

METHOD

This preliminary study was a randomized, double-blinded, placebo-controlled clinical trial designed to test the safety and efficacy of the GLP-1RA, liraglutide, in 40 participants in residential treatment for OUD. Along with taking a range of safety measures, efficacy for cue-induced craving was evaluated prior to (Day 1) and following (Day 19) treatment using a Visual Analogue Scale (VAS) in response to a cue reactivity task during functional near-infrared spectroscopy (fNIRS) and for craving. Efficacy of treatment for ambient craving was assessed using Ecological Momentary Assessment (EMA) prior to (Study Day 1), across (Study Days 2-19), and following (Study Days 20-21) residential treatment.

DISCUSSION

This manuscript describes a protocol to collect clinical data on the safety and efficacy of a GLP-1RA, liraglutide, during residential treatment of persons with OUD, laying the groundwork for further evaluation in a larger, outpatient OUD population. Improved understanding of innovative, non-opioid based treatments for OUD will have the potential to inform community-based interventions and health policy, assist physicians and health care professionals in the treatment of persons with OUD, and to support individuals with OUD in their effort to live a healthy life.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04199728. Registered 16 December 2019, https://clinicaltrials.gov/study/NCT04199728?term=NCT04199728 .

PROTOCOL VERSION

10 May 2023.

Targeting GLP-1 receptors to reduce nicotine use disorder: Preclinical and clinical evidence

Nicotine use disorder (NUD) remains a leading cause of preventable death in the U.S. Unfortunately, current FDA-approved pharmacotherapies for smoking cessation have limited efficacy and are associated with high rates of relapse. One major barrier to long-term smoking abstinence is body weight gain during withdrawal. Nicotine withdrawal-induced body weight gain can also lead to development of chronic disease states like obesity and type II diabetes mellitus. Therefore, it is critical to identify novel pharmacotherapies for NUD that decrease relapse and nicotine withdrawal symptoms including body weight gain. Recent studies demonstrate that glucagon-like peptide-1 receptor (GLP-1R) agonists attenuate voluntary nicotine taking and seeking and prevent withdrawal-induced hyperphagia and body weight gain. Emerging evidence also suggests that GLP-1R agonists improve cognitive deficits, as well as depressive- and anxiety-like behaviors, which contribute to smoking relapse during withdrawal. While further studies are necessary to fully characterize the effects of GLP-1R agonists on NUD and understand the mechanisms by which GLP-1R agonists decrease nicotine withdrawal-mediated behaviors, the current literature supports GLP-1R-based approaches to treating NUD.

Reconsidering the role of depression and common psychiatric disorders as partners in the type 2 diabetes epidemic

Common psychiatric disorders (CPDs) and depression contribute significantly to the global epidemic of type 2 diabetes (T2D). We postulated a possible pathophysiological mechanism that through Bridge-Symptoms present in depression and CPDs, promotes the establishment of emotional eating, activation of the reward system, onset of overweight and obesity and, ultimately the increased risk of developing T2D. The plausibility of the proposed pathophysiological mechanism is supported by the mechanism of action of drugs such as naltrexone-bupropion currently approved for the treatment of both obesity/overweight with T2D and as separate active pharmaceutical ingredients in drug addiction, but also from initial evidence that is emerging regarding glucagon-like peptide 1 receptor agonists that appear to be effective in the treatment of drug addiction. We hope that our hypothesis may be useful in interpreting the higher prevalence of CPDs and depression in patients with T2D compared with the general population and may help refine the integrated psychiatric-diabetic therapy approach to improve the treatment and or remission of T2D.

"Healthier health in more ways than one": Perspectives on a program for changing both smoking and obesity-related health behaviors

INTRODUCTION

Individuals with obesity who smoke cigarettes have increased risk of morbidity and mortality. The goal of the current study was to inform the development of a multiple health behavior change intervention designed to facilitate smoking cessation while also targeting weight gain.

METHODS

Four qualitative focus groups were conducted with individuals who smoked cigarettes and had overweight or obesity (n = 16) to explore the combined effects of smoking and obesity, past attempts to quit smoking or lose weight, and preferences for a combined health intervention.

RESULTS

Focus groups converged on five themes including: the interactive effects of weight and smoking; lack of experience with evidence-based weight loss approaches; a desire and expectation to lose weight quickly; rapid weight gain during past attempts at smoking cessation; and interest in a multiple health behavior change intervention with weight management preceding smoking cessation and an emphasis on planning for the future and receiving encouragement and support.

CONCLUSIONS

Groups provided insight into key topics to highlight in a combined intervention and key issues that have interfered with success in both domains.

Effect of dulaglutide in promoting abstinence during smoking cessation: 12-month follow-up of a single-centre, randomised, double-blind, placebo-controlled, parallel group trial

Background

Smoking cessation is challenging, despite making use of established smoking cessation therapies. Preclinical studies and one clinical pilot study suggest the antidiabetic drug glucagon-like peptide-1 (GLP-1) analogue to modulate addictive behaviours and nicotine craving. Previously, we reported the short-term results of a randomised, double-blind, placebo-controlled trial. Herein we report long-term abstinence rates and weight developments after 24 and 52 weeks.

Methods

This single-centre, randomised, double-blind, placebo-controlled, parallel group trial was done at the University Hospital Basel in Switzerland. We randomly assigned (1:1) individuals with at least a moderate nicotine dependence willing to quit smoking to either a 12-week treatment with dulaglutide 1.5 mg or placebo subcutaneously once weekly in addition to standard of care smoking cessation therapy (varenicline 2 mg/day and behavioural counselling). After 12 weeks, dulaglutide or placebo injections were discontinued and the participants were followed up at week 24 and 52. The primary outcome of self-reported and biochemically confirmed point prevalence abstinence rate, and secondary outcome of secondary outcome of weight change were assessed at weeks 24 and 52. All participants who received one dose of the study drug were included in the intention to treat set and participants who received at least 10/12 doses of the study drug formed the per protocol set. The trial was registered at ClinicalTrials.gov, NCT03204396.

Findings

Of the 255 participants who were randomly assigned between June 22, 2017 and December 3, 2020, 63% (80/127) (dulaglutide group) and 65% (83/128) (placebo group) were abstinent after 12 weeks. These abstinence rates declined to 43% (54/127) and 41% (52/128), respectively, after 24 weeks and to 32% (41/127) and 32% (41/128), respectively, after 52 weeks. Post-cessation weight gain was prevented in the dulaglutide group (-1.0 kg, standard deviation [SD] 2.7) as opposed to the placebo group (+1.9 kg, SD 2.4) after 12 weeks. However, at week 24, increases in weight from baseline were observed in both groups (median, interquartile range [IQR]: dulaglutide: +1.5 kg, [-0.4, 4.1], placebo: +3.0 kg, [0.6, 4.6], baseline-adjusted difference in weight change -1.0 kg (97.5% CI [-2.16, 0.16])), and at week 52 the groups showed similar weight gain (median, IQR: dulaglutide: +2.8 kg [-0.4, 4.7], placebo: +3.1 kg [-0.4, 6.0], baseline-adjusted difference in weight change: -0.35 kg (95% CI [-1.72, 1.01])). In the follow-up period (week 12 to week 52) 51 (51%) and 48 (48%) treatment-unrelated adverse events were recorded in the dulaglutide and the placebo group, respectively. No treatment-related serious adverse events or deaths occurred.

Interpretation

Dulaglutide does not improve long-term smoking abstinence, but has potential to counteract weight gain after quitting. However, 3 months of treatment did not have a sustained beneficial effect on weight at 1 year. As post-cessation weight gain is highest in the first year after quitting smoking, future studies should consider a longer treatment duration with a GLP-1 analogue in abstinent individuals.

Funding

Swiss National Science Foundation, the Gottfried and Julia Bangerter-Rhyner Foundation, the Goldschmidt-Jacobson Foundation, the Hemmi-Foundation, the University of Basel, the Swiss Academy of Medical Sciences.

Gender differences in weight gain during attempted and successful smoking cessation on dulaglutide treatment: a predefined secondary analysis of a randomised trial

Background

Women seem to have more difficulty quitting smoking than men. This is particularly concerning as smoking puts women at a higher risk of developing smoking-associated diseases. Greater concerns about postcessation weight gain in women have been postulated as a possible explanation.

Methods

Predefined secondary analysis of a placebo-controlled, double-blind, parallel-group, superiority randomised trial including 255 adults who smoke daily (155 women, 100 men). Participants received weekly dulaglutide (1.5 mg) or placebo (0.9% sodium chloride) in addition to standardised smoking cessation care (varenicline 2 mg/day plus behavioural counselling) over 12 weeks. We aimed to investigate gender differences in weight change after dulaglutide-assisted smoking cessation. Weight change between baseline and week 12 was analysed as absolute and revative weight change and as substantial weight gain (defined as >6% increase).

Results

No gender differences were observed in absolute or relative weight change neither on dulaglutide nor placebo treatment. However, substantial weight gain (defined as >6% increase) in the placebo group was almost five times more frequent in females than males (24% vs 5%). Female patients were less likely to have substantial weight gain on dulaglutide compared with placebo (1% (n=1/83) vs 24% (n=17/72); p<0.001), while this dulaglutide effect was less pronounced in males (0% (n=0/44) vs 5% (n=3/56); p=0.333).

Conclusion

Dulaglutide reduced postcessation weight gain in both genders and was very effective in preventing substantial weight gain, which seems to be a specific observation in females.

Trial registration number

NCT03204396.

Is There a Risk for Semaglutide Misuse? Focus on the Food and Drug Administration's FDA Adverse Events Reporting System (FAERS) Pharmacovigilance Dataset

Recent media reports commented about a possible issue of the misuse of antidiabetics related to molecules promoted as a weight-loss treatment in non-obese people. We evaluated here available pharmacovigilance misuse/abuse signals related to semaglutide, a glucagon-like peptide-1 (GLP-1) analogue, in comparison to other GLP-1 receptor agonists (albiglutide, dulaglutide, exenatide, liraglutide, lixisenatide, and tirzepatide) and the phentermine-topiramate combination. To acheieve that aim, we analyzed the Food and Drug Administration's FDA Adverse Events Reporting System (FAERS) dataset, performing a descriptive analysis of adverse event reports (AERs) and calculating related pharmacovigilance measures, including the reporting odds ratio (ROR) and the proportional reporting ratio (PRR). During January 2018-December 2022, a total of 31,542 AERs involving the selected molecules were submitted to FAERS; most involved dulaglutide (n = 11,858; 37.6%) and semaglutide (n = 8249; 26.1%). In comparing semaglutide vs. the remaining molecules, the respective PRR values of the AERs 'drug abuse', 'drug withdrawal syndrome', 'prescription drug used without a prescription', and 'intentional product use issue' were 4.05, 4.05, 3.60, and 1.80 (all < 0.01). The same comparisons of semaglutide vs. the phentermine-topiramate combination were not associated with any significant differences. To the best of our knowledge, this is the first study documenting the misuse/abuse potential of semaglutide in comparison with other GLP1 analogues and the phentermine-topiramate combination. The current findings will need to be confirmed by further empirical investigations to fully understand the safety profile of those molecules.

Exenatide as an adjunct to nicotine patch for smoking cessation and prevention of postcessation weight gain among treatment-seeking smokers with pre-diabetes and/or overweight: study protocol for a randomised, placebo-controlled clinical trial

INTRODUCTION

Obesity and smoking are the two leading causes of preventable death in the USA. Unfortunately, most smokers gain weight after quitting. Postcessation weight gain (PCWG) is frequently cited as one of the primary barriers to a quit attempt and a common cause of relapse. Further, excessive PCWG may contribute to the onset or progression of metabolic conditions, such as hyperglycaemia and obesity. The efficacy of the current treatments for smoking cessation is modest, and these treatments have no clinically meaningful impact on mitigating PCWG. Here, we outline a novel approach using glucagon-like peptide 1 receptor agonists (GLP-1RA), which have demonstrated efficacy in reducing both food and nicotine intake. This report describes the design of a double-blind, placebo-controlled, randomised clinical trial that evaluates the effects of the GLP-1RA exenatide as an adjunct to nicotine patches on smoking abstinence and PCWG.

METHODS AND ANALYSIS

The study will be conducted at two university-affiliated research sites in Houston, Texas, the UTHealth Center for Neurobehavioral Research on Addiction and Baylor College of Medicine Michael E. DeBakey VA Medical Centre. The sample will consist of 216 treatment-seeking smokers with pre-diabetes (haemoglobin A1c of 5.7%-6.4%) and/or overweight (body mass index of 25 kg/m² or above). Participants will be randomised (1:1) to receive subcutaneous injections of placebo or 2 mg exenatide, once weekly for 14 weeks. All participants will receive transdermal nicotine replacement therapy and brief smoking cessation counselling for 14 weeks. The primary outcomes are 4-week continuous abstinence and changes in body weight at the end of treatment. The secondary outcomes are (1) abstinence and changes in body weight at 12 weeks post end of treatment and (2) changes in neuroaffective responses to cigarette-related and food-related cues as measured by electroencephalogram.

ETHICS AND DISSEMINATION

The study has been approved by the UTHealth Committee for the Protection of Human Subjects (HSC-MS-21-0639) and Baylor College of Medicine Institutional Review Board (H-50543). All participants will sign informed consent. The study results will be disseminated via peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05610800.

Liraglutide attenuates nicotine self-administration as well as nicotine seeking and hyperphagia during withdrawal in male and female rats

RATIONALE

Nicotine cessation is associated with increased consumption of highly palatable foods and body weight gain in most smokers. Concerns about body weight gain are a major barrier to maintaining long-term smoking abstinence, and current treatments for nicotine use disorder (NUD) delay, but do not prevent, body weight gain during abstinence. Glucagon-like peptide-1 receptor (GLP-1R) agonists reduce food intake and are FDA-approved for treating obesity. However, the effects of GLP-1R agonist monotherapy on nicotine seeking and withdrawal-induced hyperphagia are unknown.

OBJECTIVES

We screened the efficacy of the long-lasting GLP-1R agonist liraglutide to reduce nicotine-mediated behaviors including voluntary nicotine taking, as well as nicotine seeking and hyperphagia during withdrawal.

METHODS

Male and female rats self-administered intravenous nicotine (0.03 mg/kg/inf) for ~21 days. Daily liraglutide administration (25 μg/kg, i.p.) started on the last self-administration day and continued throughout the extinction and reinstatement phases of the experiment. Once nicotine taking was extinguished, the reinstatement of nicotine-seeking behavior was assessed after an acute priming injection of nicotine (0.2 mg/kg, s.c.) and re-exposure to conditioned light cues. Using a novel model of nicotine withdrawal-induced hyperphagia, intake of a high fat diet (HFD) was measured during home cage abstinence in male and female rats with a history of nicotine self-administration.

RESULTS

Liraglutide attenuated nicotine self-administration and reinstatement in male and female rats. Repeated liraglutide attenuated withdrawal-induced hyperphagia and body weight gain in male and female rats at a dose that was not associated with malaise-like effects.

CONCLUSIONS

These findings support further studies investigating the translational potential of GLP-1R agonists to treat NUD.

Glucagon-like peptide-1 analogues: a new way to quit smoking? (SKIP)-a structured summary of a study protocol for a randomized controlled study

BACKGROUND

Cigarette smoking is the leading preventable cause of premature death. Despite dedicated programmes, quit rates remain low due to barriers such as nicotine withdrawal syndrome or post-cessation weight gain. Glucagon-like peptide-1 (GLP-1) analogues reduce energy intake and body weight and seem to modulate addictive behaviour. These GLP-1 properties are of major interest in the context of smoking cessation. The aim of this study is to evaluate the GLP-1 analogue dulaglutide as a new therapy for smoking cessation.

METHODS

This is a placebo-controlled, double-blind, parallel group, superiority, single-centre randomized study including 255 patients. The intervention consists of a 12-week dulaglutide treatment phase with 1.5 mg once weekly or placebo subcutaneously, in addition to standard of care (behavioural counselling and pharmacotherapy with varenicline). A 40-week non-treatment phase follows. The primary outcome is the point prevalence abstinence rate at week 12. Smoking status is self-reported and biochemically confirmed by end-expiratory exhaled carbon monoxide measurement. Further endpoints include post-cessational weight gain, nicotine craving analysis, glucose homeostasis and long-term nicotine abstinence. Two separate substudies assess behavioural, functional and structural changes by functional magnetic resonance imaging and measures of energy metabolism (i.e. resting energy expenditure, body composition).

DISCUSSION

Combining behavioural counselling and medical therapy, e.g. with varenicline, improves abstinence rates and is considered the standard of care. We expect a further increase in quit rates by adding a second component of medical therapy and assume a dual effect of dulaglutide treatment (blunting nicotine withdrawal symptoms and reducing post-cessational weight gain). This project is of high relevance as it explores novel treatment options aimed at preventing the disastrous consequences of nicotine consumption and obesity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03204396 . Registered on June 26, 2017.

Effect of dulaglutide in promoting abstinence during smoking cessation: a single-centre, randomized, double-blind, placebo-controlled, parallel group trial

BACKGROUND

Quitting smoking is difficult due to barriers such as craving for cigarettes and post-cessation weight gain. Recent experimental data suggest a role of glucagon-like peptide-1 (GLP-1) in the pathophysiology of addiction in addition to appetite regulation and weight control. We hypothesized that a pharmacological intervention with the GLP-1 analogue dulaglutide during smoking cessation may improve abstinence rates and reduce post-cessation weight gain.

METHODS

This is a single-centre, randomized, double-blind, placebo-controlled, parallel group, superiority study conducted in the University Hospital Basel in Switzerland. We included adult smokers with at least moderate cigarette dependence who wanted to quit. Participants were randomly assigned to a 12-week treatment with dulaglutide 1.5 mg once weekly or placebo subcutaneously in addition to standard of care including behavioural counselling and oral varenicline pharmacotherapy of 2 mg/day. The primary outcome was self-reported and biochemically confirmed point prevalence abstinence rate at week 12. Secondary outcomes included post-cessation weight, glucose metabolism, and craving for smoking. All participants who received one dose of study drug were included in the primary and safety analyses. The trial was registered on ClinicalTrials.gov (NCT03204396).

FINDINGS

Between June 22, 2017, and December 3, 2020, 255 participants were enrolled and randomly assigned to each group (127 in the dulaglutide group and 128 in the placebo group). After 12 weeks, 63% (80/127) participants on dulaglutide and 65% (83/128) on placebo treatment were abstinent (difference in proportions -1.9% [95% Confidence interval (CI) -10.7, 14.4], p-value (p) = 0.859). Dulaglutide decreased post-cessation weight (-1 kg [standard deviation (SD) 2.7]), while weight increased on placebo (+1.9 kg [SD 2.4]). The baseline-adjusted difference in weight change between groups was -2.9 kg (95% CI -3.59, -2.3, p < 0.001). Haemoglobin A1c (HbA1c) level declined on dulaglutide treatment (baseline-adjusted median difference in HbA1c between groups -0.25% [interquartile range (IQR) -0.36, -0.14], p < 0.001). Craving for smoking declined during treatment without any difference between the groups. Treatment-emergent gastrointestinal symptoms were very common in both groups: 90% (114/127) of participants on dulaglutide and 81% (81/128) on placebo).

INTERPRETATION

Dulaglutide had no effect on abstinence rates but prevented post-cessation weight gain and decreased HbA1c levels. GLP-1 analogues may play a role in future cessation therapy targeting metabolic parameters such as weight and glucose metabolism.

FUNDING

Swiss National Science Foundation, the Gottfried Julia Bangerter-Rhyner Foundation, the Goldschmidt-Jacobson Foundation, the Hemmi-Foundation, the University of Basel, the Swiss Academy of Medical Sciences.

The Effect of Smoking Cessation on Body Weight and Other Metabolic Parameters with Focus on People with Type 2 Diabetes Mellitus

Smokers with diabetes mellitus substantially lower their risks of microvascular and macrovascular diabetic complications, in particular cardiovascular disease, by quitting smoking. However, subsequent post-smoking-cessation weight gain may attenuate some of the beneficial effects of smoking cessation and discourage attempts to quit. Weight gain can temporarily exacerbate diabetes and deteriorate glycemic control and metabolic profile. The molecular mechanisms by which quitting smoking leads to weight gain are largely associated with the removal of nicotine's effects on the central nervous system. This review addresses mechanisms of post-smoking-cessation weight gain, by reviewing the effects of nicotine on appetite, food intake, eating behaviour, energy expenditure, fat oxidation and appetite-regulating peptides. We also highlight correlations between post-cessation weight gain and risk of type 2 diabetes, consequences of weight gain in people with type 2 diabetes and the role of pharmacotherapies, which combine treatment of nicotine addiction and promotion of weight control.

Exenatide once weekly for alcohol use disorder investigated in a randomized, placebo-controlled clinical trial

BackgroundAlcohol use disorder (AUD) is a chronic, relapsing brain disorder that accounts for 5% of deaths annually, and there is an urgent need to develop new targets for therapeutic intervention. The glucagon-like peptide-1 (GLP-1) receptor agonist exenatide reduces alcohol consumption in rodents and nonhuman primates, but its efficacy in patients with AUD is unknown.MethodsIn a randomized, double-blinded, placebo-controlled clinical trial, treatment-seeking AUD patients were assigned to receive exenatide (2 mg subcutaneously) or placebo once weekly for 26 weeks, in addition to standard cognitive-behavioral therapy. The primary outcome was reduction in number of heavy drinking days. A subgroup also completed functional MRI (fMRI) and single-photon emission CT (SPECT) brain scans.ResultsA total of 127 patients were enrolled. Our data revealed that although exenatide did not significantly reduce the number of heavy drinking days compared with placebo, it significantly attenuated fMRI alcohol cue reactivity in the ventral striatum and septal area, which are crucial brain areas for drug reward and addiction. In addition, dopamine transporter availability was lower in the exenatide group compared with the placebo group. Exploratory analyses revealed that exenatide significantly reduced heavy drinking days and total alcohol intake in a subgroup of obese patients (BMI > 30 kg/m2). Adverse events were mainly gastrointestinal.ConclusionThis randomized controlled trial on the effects of a GLP-1 receptor agonist in AUD patients provides new important knowledge on the effects of GLP-1 receptor agonists as a novel treatment target in addiction.Trial registrationEudraCT: 2016-003343-11. ClinicalTrials.gov (NCT03232112).FundingNovavi Foundation; Research Foundation, Mental Health Services, Capital Region of Denmark; Research Foundation, Capital Region of Denmark; Ivan Nielsen Foundation; A.P. Moeller Foundation; Augustinus Foundation; Woerzner Foundation; Grosserer L.F. Foghts Foundation; Hartmann Foundation; Aase and Ejnar Danielsen Foundation; P.A. Messerschmidt and Wife Foundation; and Lundbeck Foundation.

Varenicline and Lorcaserin for Smoking Cessation and Weight Gain Prevention: A Randomized Clinical Trial

Objective

To evaluate the safety and effectiveness of combination varenicline with lorcaserin in preventing post-cessation weight gain.

Participants and Methods

We conducted a randomized (varenicline for 12 weeks + lorcaserin for 24 weeks vs varenicline for 12 weeks + placebo for 24 weeks) phase II clinical study to obtain preliminary data on the safety and effectiveness of combination varenicline and lorcaserin in preventing post-cessation weight gain in overweight and obese smokers. Eighty-four overweight and obese (body mass index [BMI], 27-40 kg/m²) cigarette smokers were randomized before study termination (lorcaserin: n=40; placebo: n=44). The primary outcomes were weight and waist circumference (WC) changes at 12 and 24 weeks in smokers meeting criteria for prolonged smoking abstinence.

Results

Thirty-nine participants met criteria for prolonged smoking abstinence at 12 weeks (46%) and 21 at 24 weeks (25%). No significant treatment effect was observed at 12 weeks with lorcaserin compared with placebo (weight difference, −0.7 kg; 90% CI, −2.6 to 1.1 kg; P=.51; WC difference, −1.9 cm; 90% CI, −4.2 to 0.5 cm; P=.18; or BMI difference, −0.4 kg/m²; 90% CI, −1.1 to 0.3 kg/m²; P=.33). No significant treatment effect was observed between lorcaserin at 24 weeks compared with placebo (weight, 1.4 kg; 90% CI, −3.8 to 6.7 kg; P=.65; WC, −0.9 cm; 90% CI, −5.8 to 4.0 cm; P=.75; or BMI 0.29 kg/m²; 90% CI, −1.5 to 2.12 kg/m²; P=.79).

Conclusion

Weight gain and WC increases after prolonged smoking abstinence were not reduced using combination varenicline and lorcaserin. The results do not support further research in the obese and weight-concerned smoking population using lorcaserin or similar drugs.

Trial Registration

clinicaltrials.gov Identifier: NCT02412631

Acute treatment with the glucagon-like peptide-1 receptor agonist, liraglutide, reduces cue- and drug-induced fentanyl seeking in rats

Opioid Use Disorder (OUD) is a chronic relapsing disorder that has severe negative impacts on the individual, the family, and the community at large. In 2021, opioids contributed to nearly 70% of all drug overdose deaths in the United States. This rise in opioid related deaths coincides with a significant rise in the use of fentanyl, a synthetic opioid that is 150 times more potent than morphine. Furthermore, this overdose trend has spared no demographic and costs the nation an estimated $51.2 billion annually. Thus, it is imperative to better understand the underlying mechanisms of OUD in an effort to identify new treatment targets. Using animal models, studies have shown that rats readily self-administer heroin and increase seeking following exposure to cues for drug, the drug itself, or stress. We have shown that treatment with the glucagon-like peptide-1 receptor (GLP-1R) agonist, liraglutide, can reduce heroin taking and seeking behavior in rats. Therefore, using our rodent model, we established a fentanyl self-administration paradigm to test whether acute treatment with the GLP-1R agonist also can reduce fentanyl seeking in fentanyl experienced rats. The results showed that rats readily self-administer fentanyl (2.5 ug/kg) intravenously, with marked individual differences in drug taking behavior. As with other drugs of abuse tested, rats exhibited high seeking behavior when challenged with a drug-related cue or, after a period of extinction, the drug itself. Here, acute treatment with the GLP-1R agonist, liraglutide (0.3mg/kg s.c.), was found to attenuate both cue-induced fentanyl seeking and drug-induced reinstatement of fentanyl seeking with the same efficacy as the currently approved partial opioid agonist, buprenorphine. Taken together, these data suggest that a known satiety signal, GLP-1, may serve as an effective non-opioid alternative for the treatment of OUD.

Lithium increases cortical and subcortical volumes in subjects with bipolar disorder

Bipolar disorder (BD) is a highly variable and burdensome disease for patients and caregivers. A BD diagnosis almost triples the likelihood of developing dementia as the disease progresses. Neurocognitive reserve appears to be one of the most important influences on lifelong functional outcomes and quality of life in BD. Though several prior studies have assessed the effects of lithium on regional gray and white matter volumes in this population, representative cohorts are typically middle-aged, have a more severe pathology, and are not as commonly assessed in the depressive phase (which represents the majority of most patients' lifespans outside of remission). Here we have shown that positive adaptations with lithium can be observed throughout the brain after only six weeks of monotherapy at low-therapeutic serum levels. Importantly, these results remove some confounders seen in prior studies (patients were treatment free at time of enrollment and mostly treatment naïve). This cohort also includes underrepresented demographics in the literature (young adult patients, mostly bipolar II, and exclusively in the depressed phase). These findings bolster the extensive body of evidence in support of long-term lithium therapy in BD, furthering the possibility of its expanded use to wider demographics.

GLP-1 mediates the neuroprotective action of crocin against cigarette smoking-induced cognitive disorders via suppressing HMGB1-RAGE/TLR4-NF-κB pathway

Cigarette smoking (CS) has been associated with an increased risk of cognitive disorders. Although HMGB1 has been connected to various neurological ailments, its role in the pathogenesis of CS-induced cognitive impairments is undefined. With the ability of GLP-1 to lower HMGB1 expression and improve learning and memory performance, we sought to assess the potential neuroprotective efficacy of Crocin (Cro) as a GLP-1 stimulator against CS-induced cognitive impairments, with a focus on the HMGB1-RAGE/TLR4-NF-κB pathway. Fifty adult rats were specified into: Control; Cro (30 mg/kg); CS; Cro then CS and CS concurrently with Cro. Cognitive functions were assessed by MWM, EMP, and passive avoidance tests. Hippocampal levels of GLP-1, HMGB1, pro-inflammatory cytokines, and apoptotic markers were detected using ELISA, western blotting, and immunohistochemistry. Hippocampal oxidant/antioxidant status was evaluated via colorimetric determination of MDA and TAC. The results revealed that Cro either before or along with CS produced a significant improvement in learning and memory. Cro markedly hindered HMGB1-RAGE/TLR4-NF-κB pathway through enhancing GLP-1 level and expression, which in turn suppressed TNF-α and IL-1β levels and alleviated CS-induced neuroinflammation. Cro significantly counteracted CS-triggered oxidative stress as evidenced by reducing MDA level and raising TAC. Histopathologically, Cro lessened neuronal apoptosis by lowering Bax/Bcl-2 ratio at hippocampal CA2 region. These findings confirmed a GLP-1-dependent neuroprotective action of Cro against CS-induced cognitive disorders via suppressing HMGB1-RAGE/TLR4-NF-κB axis.

Tobacco and nicotine use

Tobacco smoking is a major determinant of preventable morbidity and mortality worldwide. More than a billion people smoke, and without major increases in cessation, at least half will die prematurely from tobacco-related complications. In addition, people who smoke have a significant reduction in their quality of life. Neurobiological findings have identified the mechanisms by which nicotine in tobacco affects the brain reward system and causes addiction. These brain changes contribute to the maintenance of nicotine or tobacco use despite knowledge of its negative consequences, a hallmark of addiction. Effective approaches to screen, prevent and treat tobacco use can be widely implemented to limit tobacco's effect on individuals and society. The effectiveness of psychosocial and pharmacological interventions in helping people quit smoking has been demonstrated. As the majority of people who smoke ultimately relapse, it is important to enhance the reach of available interventions and to continue to develop novel interventions. These efforts associated with innovative policy regulations (aimed at reducing nicotine content or eliminating tobacco products) have the potential to reduce the prevalence of tobacco and nicotine use and their enormous adverse impact on population health.

A mouse model of weight gain after nicotine withdrawal

Smoking cessation increases body weight. The underlying mechanisms, however, have not been fully understood. We here report an establishment of a mouse model that exhibits an augmented body weight gain after nicotine withdrawal. High fat diet-fed mice were infused with nicotine for two weeks, and then with vehicle for another two weeks using osmotic minipumps. Body weight increased immediately after nicotine cessation and was significantly higher than that of mice continued on nicotine. Mice switched to vehicle consumed more food than nicotine-continued mice during the first week of cessation, while oxygen consumption was comparable. Elevated expression of orexigenic agouti-related peptide was observed in the hypothalamic appetite center. Pair-feeding experiment revealed that the accelerated weight gain after nicotine withdrawal is explained by enhanced energy intake. As a showcase of an efficacy of pharmacologic intervention, exendin-4 was administered and showed a potent suppression of energy intake and weight gain in mice withdrawn from nicotine. Our current model provides a unique platform for the investigation of the changes of energy regulation after smoking cessation.

The role of glucagon-like peptide 1 (GLP-1) in addictive disorders

Drug-, alcohol- and tobacco use disorders are a global burden affecting millions of people. Despite decades of research, treatment options are sparse or missing, and relapse rates are high. Glucagon-like peptide-1 (GLP-1) is released in the small intestines, promotes blood glucose homeostasis, slows gastric emptying, and reduces appetite. GLP-1 receptor agonists approved for treating type 2 diabetes mellitus and obesity, have received attention as a potential anti-addiction treatment. Studies in rodents and non-human primates have demonstrated a reduction in intake of alcohol and drugs of abuse, and clinical trials have been initiated to investigate whether the preclinical findings can be translated to patients. This review will give an overview of current findings and discuss the possible mechanisms of action. We suggest that effects of GLP-1 in alcohol- and substance use disorder is mediated centrally, at least partly through dopamine signalling, but precise mechanisms are still to be uncovered.