AzTrials
AzTrials

Cardiovascular Risk FactorTCORS-2NCT04449510

Short-Term Cardiovascular Effects of E-Cigarettes: Influence of E-Liquid pH

A study testing Electronic Cigarette in people with Cardiovascular Risk Factor and Nicotine Dependence, run by University of California, San Francisco at 2 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

This study will examine the short-term cardiovascular (CV) effects of e-liquid pH in a randomized, crossover clinical and behavioral pharmacology study of experienced adult e-cigarette users (N=21). Read more about this study

Who is it for?
Ages 21 to 70 yearsHealthy volunteers can take part
What is being tested?
Electronic Cigarette
Could I receive a placebo?
No, everyone receives an active treatment
How many people
14 participants
Where
2 sitesUnited States
Study dates
4 Jan 2021to 31 Jul 2024
Phase
Interventional
Are there results?
None posted in the registry

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 21 to 70 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Heart rate < 105 beats per minute (BPM)*
  • Systolic Blood pressure <160 and > 90*
  • Diastolic Blood Pressure <100 and > 50*
  • Body Mass Index (BMI) < 38.0 (at investigator's discretion for higher BMI if no other concurrent health issues)
  • considered out of range if both machine and manual readings are above/below these thresholds
  • Use e-cigarettes on at least 15 days in the past 30 for at least 3 months
Show all 12Show fewer
  • Smoke 10 or fewer cigarettes/tobacco products per day in the last 30 days
  • Willing to use mod e-cigarette
  • Willing to abstain from tobacco product use for night before study
  • Age: > 21 years old and < 70 years old
  • Using e-liquid > 0mg/ml nicotine
  • Saliva cotinine of ≥ 30 ng/ml or NicAlert=6 (in cases where lab turn around time will delay study procedure)

Who cannot join

  • Seizures
  • Cancer
  • Hepatitis B or C or Liver Disease
  • Oral Thrush
  • Heart disease
  • Glaucoma
Show all 42Show fewer
  • Kidney disease or urinary retention
  • Diabetes
  • High Blood Pressure (taking sympatholytic medications such as alpha and beta blockers)
  • History of stroke
  • An ulcer in the past year
  • Thyroid disease (okay if controlled with medication)
  • Active use of an inhaler for asthma or Chronic Obstructive Pulmonary Disease (COPD)
  • Psychiatric conditions
  • Current or past schizophrenia, and/or current or past bipolar disorder
  • Major depression, current or within the past year
  • Major personality disorder
  • Participants with current or past minor or moderate depression and/or anxiety disorders will be reviewed by the study physician and considered for inclusion.
  • History of psychiatric hospitalizations are not exclusionary, but study participation will be determined as per study physician's approval
  • Recent onset or change in cough, fever and/or abdominal symptoms (vomiting or pain) in the past two weeks. (If yes, participant can re-screen when symptoms resolve).
  • Drug/Alcohol Dependence
  • Alcohol or illicit drug dependence within the past 12 months with the exception of those who have recently completed an alcohol/drug treatment program
  • Positive toxicology test at the screening visit (THC \& prescribed medications okay)
  • Opioid replacement therapy (including methadone, buprenorphine, or other)
  • Positive urine cannabis is not exclusionary but participant must report use of cannabis and agree to abstain from cannabis use for the duration of the study
  • Psychiatric medications
  • Current regular use of any psychiatric medications with the exception of Selective Serotonin Reuptake Inhibitor (SSRI) and serotonin-norepinephrine reuptake Inhibitor (SNRIs) and current evaluation by the study physician that the participant is otherwise healthy, stable, and able to participate.
  • Medications
  • Use of medications that are inducers of nicotine metabolizing enzyme CYP2A4 (Example: rifampicin, carbamazepine, phenobarbital, and other anticonvulsant drugs).
  • Concurrent use of nicotine-containing medications
  • Any stimulant medications (example: Adderall) generally given for Attention deficit hyperactivity disorder (ADHD) treatment
  • Use of sympatholytic medications that affect cardiovascular conditions including hypertension, (Example: beta and alpha-blockers)
  • Other/Misc. Chronic Health Conditions
  • Fainting (within the last 30 days)
  • Other "life threatening illnesses" as per study physician's discretion
  • Pregnancy
  • Pregnancy (self-reported and urine pregnancy test)
  • Breastfeeding (determined by self-report)
  • Concurrent participation in another clinical trial
  • Inability to communicate in English
  • Planning to quit vaping within the next 60 days
  • Uncomfortable with getting blood drawn

Trial locations and contacts

2 sites in 1 country.

United States2 sites

  • Zuckerberg San Francisco General Hospital

    San Francisco, California, 94110

  • University of California, San Francisco

    San Francisco, California, 94143

Other trials in United States

About this study

This study will examine the short-term cardiovascular (CV) effects of e-liquid pH in a randomized, crossover clinical and behavioral pharmacology study of experienced adult e-cigarette users (N=21). The specific aim is to determine the impact of e-cigarette pH levels on nicotine pharmacology, systemic exposure to toxic volatile organic compounds (VOCs), and short-term cardiovascular effects.

Read the detailed description

This is a single-site, randomized, crossover study of experienced adult e-cigarette users to assess nicotine exposure, toxicant exposure, and the short-term CV effects of e-liquid pH. Three e-liquid pH conditions will be assessed on all participants: 5, 7, and 9.

Hypothesis 2a: The rate of systemic nicotine absorption is inversely related to e-liquid pH and results in lower peak blood nicotine levels at higher pH.

Hypothesis 2b: Heart rate acceleration will decrease and subjective measures of sensation in the throat, reward, and satisfaction will increase with increasing e-liquid pH.

Being tested
Electronic Cigarette
Keywords
E-Cigarettes, Vaping, E-Cig Mods
Medical subject headings
Tobacco Use Disorder, Vaping

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Electronic CigaretteOther

    E-cigarette Device: The delivery device will be a variable wattage all-in-one device with operating wattage of 7.0 - 75.0 W. The device will be set at 10 watts for the study visits.

Study groups in NCT04449510
Study groupRoleWhat they receive
E-liquid pH 5, 7, or 9OtherUsing an electronic cigarette, the participant will complete a standardized vaping session using 1 of 3 assigned e-liquid pH.
Receives: Other: Electronic Cigarette
1 of the other 2 remaining e-liquid pHOtherUsing an electronic cigarette, the participant will complete a standardized vaping session using 1 of the other 2 assigned e-liquid pH.
Receives: Other: Electronic Cigarette
Remaining e-liquid pHOtherUsing an electronic cigarette, the participant will complete a standardized vaping session using the remaining assigned e-liquid pH.
Receives: Other: Electronic Cigarette

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Mean Blood Nicotine Level

    Concentration of plasma nicotine (ng/ml) will be used to assess differences across the three e-liquid pH levels.

    Measured: Day 1 of each Arm

  2. Mean Saliva pH

    Participant saliva pH will be measured before and during outpatient stay.

    Measured: Day 1 of each Arm

  3. Mean Heart Rate

    Participant heart rate will be measured in beats per minute throughout the outpatient stay.

    Measured: Day 1 of each Arm

  4. Mean Skin Blood Flow

    Participant skin blood flow will be measured by product of average blood cell velocity and concentration in mL/min during outpatient stay.

    Measured: Day 1 of each Arm

  5. Mean scores on the Minnesota Nicotine Withdrawal Scale (MNWS)

    The investigators will compile a score for the subjective effect of withdrawal using the sum of points scored on the Minnesota Nicotine Withdrawal Scale (MNWS), where a higher score (score range from 0 points to 60 points) indicates a higher intensity of the indicated subjective effect.

    Measured: Day 1 of each Arm

  6. Mean scores on the Questionnaire of Smoking Urges (QSU-Brief)

    The investigators will compile a score for the subjective effect of craving using the sum of points scored in the two subscales (intention and desire to engage in smoking behavior that is anticipated as pleasant, and anticipation of relief from negative affect through smoking) of the Questionnaire of Smoking Urges (QSU-Brief), where a higher score (score range from 10 points to 70 points) indicates a higher intensity of the indicated subjective effect.

    Measured: Day 1 of each Arm

  7. Mean scores on the Cigarette Evaluation Scale (mCES)

    The investigators will compile a score for the subjective effect of reward using the sum of points scored in the five subscales (Smoking Satisfaction - score range from 1 point to 7 points; Psychological Reward - score range from 5 points to 35 points; Aversion - score range from 2 points to 14 points; Enjoyment of Respiratory Tract Sensations - score range from 2 points to 14 points; and Craving Reduction - score range from 1 point to 7 points) of the modified Cigarette Evaluation Scale (mCES), where a higher score indicates a higher intensity of the indicated subjective effect.

    Measured: Day 1 of each Arm

Secondary outcomes (3)

  1. Mean puffs per minute

    Vaping topography measures will be obtained from frame by frame analysis of high definition videos during the ad libitum sessions and measured as puffs per minute.

    Measured: Day 1 of each Arm

  2. Mean seconds per puff

    Vaping topography measures will be obtained from frame by frame analysis of high definition videos during the ad libitum sessions and measured as seconds per puff.

    Measured: Day 1 of each Arm

  3. Mean time between puffs

    Vaping topography measures will be obtained from frame by frame analysis of high definition videos during the ad libitum sessions and measured as seconds/minutes between puffs.

    Measured: Day 1 of each Arm

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted26 Jun 2020
  2. Study start4 Jan 2021
  3. Primary completion31 Jul 2024
  4. Study completion31 Jul 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Masking
None (open label)
Enrolment
14 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04449510
Sponsor's protocol ID
20-30597
Other IDs
5U54HL147127-09
Acronym
TCORS-2
Status last verified
Jul 2025
First submitted
24 Jun 2020
Last updated
15 Jul 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: De-identified data may be shared with research collaborators during the course of the study.

Questions about this trial

What is this clinical trial studying?

A study testing Electronic Cigarette in people with Cardiovascular Risk Factor and Nicotine Dependence, run by University of California, San Francisco at 2 sites 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 12 inclusion and 42 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: finished, as of the sponsor's last update on 15 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites 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.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Mean Blood Nicotine Level (time frame: Day 1 of each Arm). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04449510.

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 Jul 2025.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in