E-cigarette UseEarly Phase 1NCT06159608
Sex Differences in the Vascular Effects of E-cigarette Use
A Early Phase 1 study testing Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor) and Chronic estrogen exposure in people with E-cigarette Use, run by Anna Stanhewicz, PhD at 1 site in United States.
Trial summary
The use of electronic nicotine delivery systems, or e-cigarettes - colloquially referred to as "vaping" - in the United States has increased exponentially since their introduction to the US market in 2007. Read more about this study
- Who is it for?
- Ages 18 to 24 yearsHealthy volunteers can take part
- Conditions the study is for
- E-cigarette Use
- What is being tested?
- Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor) and Chronic estrogen exposure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 1 siteUnited States
- Study dates
- 2 Dec 2023to Dec 2026
- Phase
- Early Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 24 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 18-24 years old
- one of the following:
- have no history of e-cigarette use
- be a current e-cigarette user who has been using e-cigarettes for 6 months or longer
Who cannot join
- history of cardiovascular, metabolic, and/or skin diseases
- body mass index >30 kg/m2
- blood pressure ≥140 systolic and/or ≥ 90 diastolic
- current or history of tobacco cigarette use
- current antihypertensive or cholesterol-lowering medication
- current use of cannabis, marijuana, and/or other illegal substances
Show all 11Show fewer
- current use of stimulant drugs
- currently pregnant or breastfeeding
- allergy to materials used during the experiment (e.g. latex),
- known allergy to study drugs
- healthy control subjects will also be excluded if they have ever used e-cigarettes in the past
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Iowa
Iowa City, Iowa, 52242
Anna Stanhewicz, 319-467-1732, anna-stanhewicz@uiowa.edu
About this study
The use of electronic nicotine delivery systems, or e-cigarettes - colloquially referred to as "vaping" - in the United States has increased exponentially since their introduction to the US market in 2007. Prevalence of ever and current e-cigarette use is highest among teenagers and young adults with 16-28% of this population having reported vaping. While the majority of e-cigarette users are current tobacco smokers, 32.5% of current e-cigarette users are never- or former-smokers, representing a growing population of young adults who exclusively vape. While e-cigarettes have been marketed as a safer alternative to tobacco cigarettes, clinical studies examining these claims are limited. Cardiovascular disease (CVD) is the primary cause of premature death among tobacco cigarette smokers and reductions in vascular endothelial function, a significant predictor of future CVD, are detectible in otherwise healthy young adults who smoke. Despite the explosion in e-cigarette use among young adults, the health effects - especially the effects on mechanisms of vascular function - of these devices remain relatively unexplored.
In this study, we use the blood vessels in the skin as a representative vascular bed for examining mechanisms of microvascular dysfunction in humans. Using a minimally invasive technique (intradermal microdialysis for the local delivery of pharmaceutical agents) we examine the blood vessels in a dime-sized area of the skin in otherwise healthy young (18-24yrs) chronic e-cigarette users. Local heating of the skin at the microdialysis sites is used to explore differences in mechanisms governing microvascular control. As a compliment to these measurements, we also draw blood from the subjects to measure circulating factors that may contribute to cardiovascular health and examine markers of inflammatory activation. We will also collect urine from female participants to measure estradiol.
- Conditions
- E-cigarette Use
- Being tested
- Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor), Chronic estrogen exposure
- Medical subject headings
- Vaping
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor)Drug
Differences in endothelium- and nitric oxide (NO)-dependent dilation between groups
Chronic estrogen exposureOther
differences in urine estrogen levels across the menstrual cycle between women groups only
| Study group | Role | What they receive |
|---|---|---|
| Healthy Young Women | Other | Young women who do not use e-cigarettes Receives: Drug: Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor); Other: Chronic estrogen exposure |
| Healthy Young Men | Other | Young men who do not use e-cigarettes Receives: Drug: Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor) |
| Young Women using E-cigarettes | Other | Young women chronically use e-cigarettes Receives: Drug: Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor); Other: Chronic estrogen exposure |
| Young Men using E-cigarettes | Other | Young men chronically use e-cigarettes Receives: Drug: Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in microvascular endothelium-dependent dilation response measured by laser-Doppler flowmetry
cutaneous vascular vasodilator responses to local heating over a microdialysis fiber receiving lactated Ringer's solution, followed by L-NAME infusion to quantify NO-dependent response
Measured: at the study visit, an average of 4 hours
monthly estrogen exposure
daily estradiol levels will be measured in all women for 1 month/menstrual cycle
Measured: 1 month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Dec 2023
- Study start2 Dec 2023
- Primary completionDec 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for E-cigarette UseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Anna Stanhewicz, PhD
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Anna Stanhewicz, PhD, University of Iowa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06159608
- Sponsor's protocol ID
- 202308025
- Status last verified
- Dec 2025
- First submitted
- 27 Nov 2023
- Last updated
- 15 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Sex Differences in the Vascular Effects of E-cigarette Use
- ClinicalTrials.gov ID
- NCT06159608
- Acronym / sponsor ID
- 202308025
- Conditions
- E-cigarette Use
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- Anna Stanhewicz, PhDUniversity, hospital or other
- Study start
- 2 Dec 2023 (actual)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 7 Dec 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The use of electronic nicotine delivery systems, or e-cigarettes - colloquially referred to as "vaping" - in the United States has increased exponentially since their introduction to the US market in 2007. Prevalence of ever and current e-cigarette use is highest among teenagers and young adults with 16-28% of this population having reported vaping. While the majority of e-cigarette users are current tobacco smokers, 32.5% of current e-cigarette users are never- or former-smokers, representing a growing population of young adults who exclusively vape. While e-cigarettes have been marketed as a safer alternative to tobacco cigarettes, clinical studies examining these claims are limited. Cardiovascular disease (CVD) is the primary cause of premature death among tobacco cigarette smokers and reductions in vascular endothelial function, a significant predictor of future CVD, are detectible in otherwise healthy young adults who smoke. Despite the explosion in e-cigarette use among young adults, the health effects - especially the effects on mechanisms of vascular function - of these devices remain relatively unexplored.
In this study, we use the blood vessels in the skin as a representative vascular bed for examining mechanisms of microvascular dysfunction in humans. Using a minimally invasive technique (intradermal microdialysis for the local delivery of pharmaceutical agents) we examine the blood vessels in a dime-sized area of the skin in otherwise healthy young (18-24yrs) chronic e-cigarette users. Local heating of the skin at the microdialysis sites is used to explore differences in mechanisms governing microvascular control. As a compliment to these measurements, we also draw blood from the subjects to measure circulating factors that may contribute to cardiovascular health and examine markers of inflammatory activation. We will also collect urine from female participants to measure estradiol.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Healthy Young Women | Other | Drug: Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor), Other: Chronic estrogen exposureYoung women who do not use e-cigarettes |
| Healthy Young Men | Other | Drug: Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor)Young men who do not use e-cigarettes |
| Young Women using E-cigarettes | Other | Drug: Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor), Other: Chronic estrogen exposureYoung women chronically use e-cigarettes |
| Young Men using E-cigarettes | Other | Drug: Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor)Young men chronically use e-cigarettes |
Who may qualify
- Ages
- 18 to 24 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- 18-24 years old
- one of the following:
Key exclusion criteria (11 listed)
- history of cardiovascular, metabolic, and/or skin diseases
- body mass index >30 kg/m2
- blood pressure ≥140 systolic and/or ≥ 90 diastolic
- current or history of tobacco cigarette use
- current antihypertensive or cholesterol-lowering medication
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor)Differences in endothelium- and nitric oxide (NO)-dependent dilation between groups | Drug | Healthy Young Men, Healthy Young Women, Young Men using E-cigarettes, Young Women using E-cigarettes |
| Chronic estrogen exposuredifferences in urine estrogen levels across the menstrual cycle between women groups only | Other | Healthy Young Women, Young Women using E-cigarettes |
Primary outcome
Change in microvascular endothelium-dependent dilation response measured by laser-Doppler flowmetry
Time frame: at the study visit, an average of 4 hours
cutaneous vascular vasodilator responses to local heating over a microdialysis fiber receiving lactated Ringer's solution, followed by L-NAME infusion to quantify NO-dependent response
monthly estrogen exposure
Time frame: 1 month
daily estradiol levels will be measured in all women for 1 month/menstrual cycle
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Dec 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Local heating + L-NAME (NG-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor) and Chronic estrogen exposure in people with E-cigarette Use, run by Anna Stanhewicz, PhD at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Anna Reid-Stanhewicz, PHD (319-467-1732, anna-stanhewicz@uiowa.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in microvascular endothelium-dependent dilation response measured by laser-Doppler flowmetry (time frame: at the study visit, an average of 4 hours). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Dec 2025.