Mapping Brain Glutamate in Humans: Sex Differences in Cigarette Smokers

• Sponsor: University of California, Los Angeles (Other)
• Overall Status: Recruiting
• CT.gov ID: NCT05279053
• Collaborator: (none)
• Enrollment: 60
• Location: 1
• Anticipated Duration (Months): 24
• Patients Per Site Per Month: 2.5

Study Details

Study Description

Brief Summary

The proposed study will evaluate sex differences in whole-brain glutamate (Glu), with a focus on the dorsal anterior cingulate cortex (dACC), anterior insula, and thalamus, as well as how it is influenced by sex (males vs. females), smoking state (overnight abstinent vs. sated), and circulating ovarian hormones (estrogen and progesterone) in women. Glu will be measured in almost the entire brain, with special focus on the dorsal anterior cingulate cortex (dACC), anterior insula, and thalamus, all of which have been implicated in behavioral states linked to tobacco withdrawal, using an echo-planar spectroscopic imaging (EPSI) variant of magnetic resonance spectroscopy (MRS). Serum ovarian hormones (estrogen and progesterone) will be measured for female participants to determine relationships between brain Glu and this hormone. Whole-brain Glu will be measured in 60 smokers (30 men, 30 women) twice, after overnight (~12 h) abstinence and after participants smoke the first cigarette of the day.

Condition or Disease	Intervention/Treatment	Phase
Cigarette Smoking; Tobacco Dependence; Sex

Study Design

• Study Type: Observational
• Anticipated Enrollment: 60 participants
• Observational Model: Other
• Time Perspective: Prospective
• Official Title: Mapping Brain Glutamate in Humans: Sex Differences in Cigarette Smokers
• Actual Study Start Date: Apr 1, 2021
• Anticipated Primary Completion Date: Mar 31, 2023
• Anticipated Study Completion Date: Mar 31, 2023

Arms and Interventions

Arm	Intervention/Treatment
Male
Female

Outcome Measures

Primary Outcome Measures

1. Circulating Ovarian Hormone: Estrogen - in overnight abstinent smokers [Measured before and after smoking a cigarette across a period of 2 hours]

   Estrogen assayed via a blood sample

2. Circulating Ovarian Hormone: Progesterone - in overnight abstinent smokers [Measured before and after smoking a cigarette across a period of 2 hours]

   Estrogen assayed via a blood sample

3. Whole Brain Glutamate [Measured before and after smoking a cigarette across a period of 2 hours]

   Measured by EPSI acquisition in overnight abstinent smokers

4. Nicotine Metabolite Ratio [Measured before smoking a cigarette at a single timepoint]

   Measured by blood sample

Secondary Outcome Measures

1. Urge to Smoke Scale (UTS) [Measured before and after smoking a cigarette across a period of 2 hours]

   This is a 10-item self-reporting questionnaire that measures cigarette craving

2. Shiffman-Jarvik Withdrawal Scale (SJWS) [Measured before and after smoking a cigarette across a period of 2 hours]

   This is a 25-item self-reporting questionnaire that measures psychological withdrawal

3. Positive and Negative Affect Schedule (PANAS) [Measured before and after smoking a cigarette across a period of 2 hours]

   This is a 20-item self-reporting questionnaire that measures positive and negative affect

4. Spielberger State-Trait Anxiety (STAI) [Measured before and after smoking a cigarette across a period of 2 hours]

   This is a 20-item self-reporting questionnaire that measures anxiety

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 45 Years
• Sexes Eligible for Study: All

Inclusion Criteria:

1. Self-identified as only male or female

2. Age 18-45 years (children <18 years will be excluded due to low prevalence of conventional cigarette smoking; female participants >45 years of age will be excluded to avoid effects of perimenopause and menopause in women; male participants >45 years of age will be excluded as well to ensure that male and female groups are matched on age

3. English fluency demonstrated by verbal skills sufficient to participate in a conversation, including the ability to ask and answer questions at a level that assures adequate understanding of the study (a comprehension quiz will be given)

4. Right handedness (evaluated using the Edinburgh Inventory)

5. Generally in good health without cardiovascular, hepatic, renal, or autoimmune diseases, diabetes, or cancer

6. Must have smoked for ≥1 year

7. Must endorse inhaling while smoking

8. Must smoke ≥10 cigarettes per day

9. Must have expired CO >10 ppm and urinary cotinine ≥100 ng/ml at screening/intake

10. Fulfillment of DSM-5 criteria for Tobacco Use Disorder

Exclusion Criteria:

1. Seeking treatment for nicotine dependence within 3 months of screening

2. Medical condition that may compromise safety (based on history, physical exam)

3. Neurological disorder that would compromise compliance and/or informed consent

4. Major psychiatric disorder (e.g., Major Depression, Schizophrenia, Bipolar Disorder) per DSM-5 MINI

5. Current drug use disorders other than Tobacco Use Disorder (as defined in DSM-5)

6. Recent use of cocaine, opiates, benzodiazepines, or amphetamines as shown by urine test at the screening or testing sessions

7. Smoke marijuana >3X/week (self-report) or positive marijuana urine test on a scan day (positive at screening allowed)

8. Use of tobacco in forms other than cigarettes (e.g., snuff, chewing tobacco, e-cigarettes) >10 days in the month before screening

9. Preference for menthol cigarettes, given sex differences in the effect of menthol on the rate of nicotine entry into the brain

10. Pregnancy or nursing

11. Presence in the body of metal that would compromise safety during MRI

12. Claustrophobia

13. Any other condition that would compromise safety

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	UCLA Semel Institute	Los Angeles	California	United States	90095

Sponsors and Collaborators

• University of California, Los Angeles

Investigators

• Principal Investigator: Edythe London, PhD, University of California, Los Angeles

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Edythe London, Professor In Residence, University of California, Los Angeles
• ClinicalTrials.gov Identifier: NCT05279053
• Other Study ID Numbers: 17-000387
• First Posted: Mar 15, 2022
• Last Update Posted: Mar 25, 2022
• Last Verified: Mar 1, 2022

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No
• Additional relevant MeSH terms: Tobacco Use Disorder

Study Results

No Results Posted as of Mar 25, 2022