Browsing by Author "Ramchandani, Vijay A."
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Item Binge and High-Intensity Drinking – Associations with Intravenous Alcohol Self-Administration and Underlying Risk Factors(Wiley, 2022) Plawecki, Martin H.; Boes, Julian; Wetherill, Leah; Kosobud, Ann E.K.; Stangl, Bethany L.; Ramchandani, Vijay A.; Zimmermann, Ulrich S.; Nurnberger, John I., Jr.; Schuckit, Marc; Edenberg, Howard J.; Pandey, Gayathri; Kamarajan, Chella; Porjesz, Bernice; Foroud, Tatiana; O’Connor, Sean; Psychiatry, School of MedicineSome styles of alcohol consumption are riskier than others. How the level and rate of alcohol exposure contribute to the increased risk of alcohol use disorder is unclear, but likely depends on the alcohol concentration time course. We hypothesized that the brain is sensitive to the alcohol concentration rate of change and that people at greater risk would self-administer faster. We developed a novel intravenous alcohol self-administration paradigm to allow participants direct and reproducible control over how quickly their breath alcohol concentration changes. We used drinking intensity and the density of biological family history of alcohol dependence as proxies for risk. Thirty-five alcohol drinking participants aged 21-28 years provided analytical data from a single, intravenous alcohol self-administration session using our computer-assisted alcohol infusion system rate control paradigm. A shorter time to reach 80 mg/dl was associated with increasing multiples of the binge drinking definition (p = 0.004), which was in turn related to higher density of family history of alcoholism (FHD, p = 0.04). Rate-dependent changes in subjective response (intoxication and stimulation) were also associated with FHD (each p = 0.001). Subsequently, given the limited sample size and FHD range, associations between multiples of the binge drinking definition and FHD were replicated and extended in analyses of the Collaborative Study on the Genetics of Alcoholism database. The rate control paradigm models binge and high-intensity drinking in the laboratory and provides a novel way to examine the relationship between the pharmacokinetics and pharmacodynamics of alcohol and potentially the risk for the development of alcohol use disorders.Item Fat-free mass accounts for most of the variance in alcohol elimination rate in women(Wiley, 2023) Seyedsadjadi, Neda; Ramchandani, Vijay A.; Plawecki, Martin H.; Kosobud, Ann E. K.; O'Connor, Sean; Rowitz, Blair; Pepino, Marta Yanina; Psychiatry, School of MedicineBackground: Understanding how blood alcohol concentrations (BAC) achieved after drinking are determined is critical to predicting alcohol exposure to the brain and other organs and alcohol's effects. However, predicting end-organ exposures is challenging, as there is wide variation in BAC achieved after drinking a specified volume of alcohol. This variation is partly due to differences in body composition and alcohol elimination rates (AER), but there are limited data on how obesity affects AER. Here, we assess associations between obesity, fat-free mass (FFM), and AER in women and examine whether bariatric surgeries, which are linked to an increased risk of alcohol misuse, affect these associations. Methods: We analyzed data from three studies that used similar intravenous alcohol clamping procedures to estimate AER in 143 women (21 to 64 years old) with a wide range of body mass index (BMI; 18.5 to 48.4 kg/m2 ). Body composition was measured in a subgroup using dual-energy X-ray absorptiometry (n = 42) or Bioimpedance (n = 60), and 19 of the women underwent bariatric surgery 2.1 ± 0.3 years before participation. We analyzed data using multiple linear regression analyses. Results: Obesity and older age were associated with a faster AER (BMI: rs = 0.70 and age: rs = 0.61, both p < 0.001). Compared to women with normal weight, AER was 52% faster (95% Confidence Interval: 42% to 61%) in women with obesity. However, BMI lost predictive value when adding fat-free mass (FFM) to the regression model. Age, FFM, and its interaction explained 72% of individual variance in AER (F (4, 97) = 64.3, p < 0.001). AER was faster in women with higher FFM, particularly women in the top tertile of age. After controlling for FFM and age, bariatric surgery was not associated with differences in AER (p = 0.74). Conclusions: Obesity is associated with a faster AER, but this association is mediated by an obesity-related increase in FFM, particularly in older women. Previous findings of a reduced alcohol clearance following bariatric surgery compared with prior to surgery are likely explained by a reduction in FFM post-surgery.Item Genome wide association studies of the Self-Rating of Effects of Ethanol (SRE)(Wiley, 2020-03) Lai, Dongbing; Wetherill, Leah; Kapoor, Manav; Johnson, Emma C.; Schwandt, Melanie; Ramchandani, Vijay A.; Goldman, David; Joslyn, Geoff; Rao, Xi; Liu, Yunlong; Farris, Sean; Mayfield, R. Dayne; Dick, Danielle; Hesselbrock, Victor; Kramer, John; McCutcheon, Vivia V.; Nurnberger, John; Tischfield, Jay; Goate, Alison; Edenberg, Howard J.; Porjesz, Bernice; Agrawal, Arpana; Foroud, Tatiana; Schuckit, Marc; Medical and Molecular Genetics, School of MedicineThe level of response (LR) to alcohol as measured with the Self-Report of the Effects of Alcohol Retrospective Questionnaire (SRE) evaluates the number of standard drinks usually required for up to four effects. The need for a higher number of drinks for effects is genetically influenced and predicts higher risks for heavy drinking and alcohol problems. We conducted genome-wide association study (GWAS) in the African-American (COGA-AA, N = 1527 from 309 families) and European-American (COGA-EA, N = 4723 from 956 families) subsamples of the Collaborative Studies on the Genetics of Alcoholism (COGA) for two SRE scores: SRE-T (average of first five times of drinking, the period of heaviest drinking, and the most recent 3 months of consumption) and SRE-5 (the first five times of drinking). We then meta-analyzed the two COGA subsamples (COGA-AA + EA). Both SRE-T and SRE-5 were modestly heritable (h2 : 21%-31%) and genetically correlated with alcohol dependence (AD) and DSM-IV AD criterion count (rg : 0.35-0.76). Genome-wide significant associations were observed (SRE-T: chromosomes 6, rs140154945, COGA-EA P = 3.30E-08 and 11, rs10647170, COGA-AA+EA P = 3.53E-09; SRE-5: chromosome13, rs4770359, COGA-AA P = 2.92E-08). Chromosome 11 was replicated in an EA dataset from the National Institute on Alcohol Abuse and Alcoholism intramural program. In silico functional analyses and RNA expression analyses suggest that the chromosome 6 locus is an eQTL for KIF25. Polygenic risk scores derived using the COGA SRE-T and SRE-5 GWAS predicted 0.47% to 2.48% of variances in AD and DSM-IV AD criterion count in independent datasets. This study highlights the genetic contribution of alcohol response phenotypes to the etiology of alcohol use disorders.Item Genome-wide admixture mapping of DSM-IV alcohol dependence, criterion count, and the self-rating of the effects of ethanol in African American populations(Wiley, 2021-04) Lai, Dongbing; Kapoor, Manav; Wetherill, Leah; Schwandt, Melanie; Ramchandani, Vijay A.; Goldman, David; Chao, Michael; Almasy, Laura; Bucholz, Kathleen; Hart, Ronald P.; Kamarajan, Chella; Meyers, Jacquelyn L.; Nurnberger, John I., Jr.; Tischfield, Jay; Edenberg, Howard J.; Schuckit, Marc; Goate, Alison; Scott, Denise M.; Porjesz, Bernice; Agrawal, Arpana; Foroud, Tatiana; Medical and Molecular Genetics, School of MedicineAfrican Americans (AA) have lower prevalence of alcohol dependence and higher subjective response to alcohol than European Americans. Genome-wide association studies (GWAS) have identified genes/variants associated with alcohol dependence specifically in AA; however, the sample sizes are still not large enough to detect variants with small effects. Admixture mapping is an alternative way to identify alcohol dependence genes/variants that may be unique to AA. In this study, we performed the first admixture mapping of DSM-IV alcohol dependence diagnosis, DSM-IV alcohol dependence criterion count, and two scores from the self-rating of effects of ethanol (SRE) as measures of response to alcohol: the first five times of using alcohol (SRE-5) and average of SRE across three times (SRE-T). Findings revealed a region on chromosome 4 that was genome-wide significant for SRE-5 (p value = 4.18E-05). Fine mapping did not identify a single causal variant to be associated with SRE-5; instead, conditional analysis concluded that multiple variants collectively explained the admixture mapping signal. PPARGC1A, a gene that has been linked to alcohol consumption in previous studies, is located in this region. Our finding suggests that admixture mapping is a useful tool to identify genes/variants that may have been missed by current GWAS approaches in admixed populations.Item Response to commentary on: "Fat-free mass accounts for most of the variance in alcohol elimination rate in women"(Wiley, 2023) Seyedsadjadi, Neda; Ramchandani, Vijay A.; Plawecki, Martin H.; Kosobud, Ann E. K.; O’Connor, Sean; Rowitz, Blair; Pepino, Marta Yanina; Psychiatry, School of MedicineItem Site of Alcohol First-Pass Metabolism Among Women(American Medical Association, 2022-03-01) Seyedsadjadi, Neda; Acevedo, M. Belen; Alfaro, Raul; Ramchandani, Vijay A.; Plawecki, Martin H.; Rowitz, Blair; Pepino, Marta Yanina; Psychiatry, School of MedicineThis cross-sectional study compares alcohol pharmacokinetics in patients who underwent sleeve gastrectomy with control participants who did not undergo surgery.Item Stress Vulnerability And Alcohol Use And Consequences: From Human Laboratory Studies To Clinical Outcomes(Elsevier, 2018) Ramchandani, Vijay A.; Stangl, Bethany L.; Blaine, Sara K.; Plawecki, Martin H.; Schwandt, Melanie L.; Kwako, Laura E.; Sinha, Rajita; Cyders, Melissa A.; O'Connor, Sean; Zakhari, Samir; Psychiatry, School of MedicineIt is well known that vulnerability to stress is a risk factor for alcohol use disorder (AUD). Chronic alcohol use can result in neuroadaptations in cortico-striatal pathways and hypothalamic pituitary adrenal (HPA) axis function that are manifested in altered behavioral and cognitive control functions contributing to alcohol craving, compulsive motivation, consumption and consequences. This symposium brings together studies utilizing novel approaches to help improve our understanding of stress – past, acute and chronic - on alcohol seeking and consumption and related outcomes using a combination of human laboratory models, neuroimaging and clinical measures. Examining factors that determine vulnerability as well as resilience to stress are of particular interest in the study of AUD because, in addition to increasing our understanding of the risk factors for AUD, such knowledge can be used to develop more effective treatments. Dr. Stangl presented a novel human experimental model that demonstrates, for the first time, stress-induced increases in alcohol self-administration in binge drinkers using a guided imagery paradigm combined with intravenous alcohol self-administration (IV-ASA). Dr. Blaine presented data demonstrating that glucocorticoid response to stress drives compulsive alcohol motivation and intake in binge/heavy drinkers. Dr. Plawecki presented data examining sex differences in the effect of two distinct stress paradigms – mood induction and abstinence – on IV-ASA in moderate drinkers. Dr. Schwandt presented clinical data providing a new perspective on the relationship between childhood trauma and AUD by suggesting possible underlying mechanisms that confer resilience, rather than vulnerability, to severe early life stress exposure.Item The Motivation for Alcohol Reward: Predictors of Progressive-Ratio Intravenous Alcohol Self-Administration in Humans(JoVE, 2022-04-28) Stangl, Bethany L.; Byrd, Nia D.; Soundararajan, Soundarya; Plawecki, Martin H.; O'Connor, Sean; Ramchandani, Vijay A.; Psychiatry, School of MedicineThe Progressive Ratio (PR) self-administration paradigm is a common pre-clinical method used to examine the motivation for a drug attributed to a craving, reward, or the relief of negative affect. The Computer-assisted Alcohol Infusion System (CAIS) enables intravenous alcohol self-administration behavior in humans. This system provides the investigator with control over the trajectory of each incremental breath alcohol concentration (BrAC) reward and the maximum BrAC allowed in a session. This paradigm allows participants to earn these alcohol rewards using a sequence of button presses specified by the investigator. The system employs a physiologically-based pharmacokinetic model-based algorithm to achieve the same incremental BrAC exposure in every participant. Participants (n = 11) took part in two identical sessions to examine test-retest reliability, and an additional group (n = 73) completed a single session. Sessions began with a 25 min priming phase: participants were instructed to press a button an increasing number of times per reward, accumulating four standardized incremental BrAC trajectories. The second phase comprised an ad-lib, PR paradigm lasting 125 min. Each reward required an increasing number of button presses. Measures of self-administration included: average and peak BrAC, total rewards earned, total grams of ethanol consumed per unit of total body water, the total number of button presses, and the average rate of button pressing. Self-administration measures were highly correlated both between and within sessions, demonstrating test-retest reliability and internal consistency. Recent drinking history was strongly associated with self-administration measures; heavier drinkers chose greater alcohol self-administration. These results indicate the reliability and sensitivity of this progressive-ratio intravenous alcohol self-administration method for assessing the motivational properties of alcohol, with the potential for improved testing of the efficacy of new medications thought to reduce consumption of alcohol. This method can be used to understand the genetic and environmental determinants of alcohol self-administration in humans.Item To Infuse or Ingest in Human Laboratory Alcohol Research(Wiley, 2020-04) Cyders, Melissa A.; Plawecki, Martin H.; Corbin, William; King, Andrea; McCarthy, Denis M.; Ramchandani, Vijay A.; Weafer, Jessica; O’Connor, Sean J.; Psychology, School of ScienceHuman alcohol laboratory studies use two routes of alcohol administration: ingestion and infusion. The goal of this paper is to compare and contrast these alcohol administration methods. The work summarized in this report was the basis of a 2019 Research Society on Alcoholism Roundtable, “To Ingest or Infuse: A Comparison of Oral and Intravenous Alcohol Administration Methods for Human Alcohol Laboratory Designs.” We review the methodological approaches of each and highlight strengths and weaknesses pertaining to different research questions. We summarize methodological considerations to aid researchers in choosing the most appropriate method for their inquiry, considering exposure variability, alcohol expectancy effects, safety, bandwidth, technical skills, documentation of alcohol exposure, experimental variety, ecological validity, and cost. Ingestion of alcohol remains a common, and often a preferable, methodological practice in alcohol research. Nonetheless, the main problem with ingestion is that even the most careful calculation of dose and control of dosing procedures yields substantial and uncontrollable variability in the participants’ brain exposures to alcohol. Infusion methodologies provide precise exposure control but are technically complex and may be limited in ecological validity. We suggest that alcohol ingestion research may not be the same thing as alcohol exposure research; investigators should be aware of the advantages and disadvantages that the choice between ingestion and infusion of alcohol invokes.