Trial Outcomes & Findings for E-Cigarette Effects on Markers of Cardiovascular and Pulmonary Disease (NCT NCT03863509)

NCT ID: NCT03863509

Last Updated: 2023-08-21

Results Overview

Visit 2 was scheduled up to 4 weeks from enrollment visit. Participants attended fasting and refraining from nicotine products for at least 8 hours prior. All visits were in the morning. Pre-challenge brachial artery diameter imaged with ultrasound after resting supine for 10 minutes before and repeated 15-20 minutes after smoking/vaping challenge ended. or in the case of controls after a 10 minute break.

• Recruitment status: COMPLETED
• Target enrollment: 450 participants
• Primary outcome timeframe: before and after smoking/vaping challenge during Visit 2 (up to 4 weeks from enrollment)
• Results posted on: 2023-08-21

Participant Flow

March 5 2019 started enrollment, ended last visit March 9th 2022. Studies were conducted at the University of Wisconsin Hospital and Clinics and the Center for Tobacco Research and Intervention (CTRI) in Madison, WI and for a short period we also at CTRI location in Milwaukee,WI.

Participants tested for Exhaled CO and urinary nicotine to determine if they qualified for either arm of the study. E-cigarette vapers exclusively (exhaled CO less than 5 ppm and nicotine in urine), cigarettes exclusively (CO more or equal 5 ppm, positive urine nicotine), and controls (CO less than 5 ppm, and negative nicotine in urine). NOTE: one participant was enrolled twice completing all study visits. Later, when this was noticed, we amended procedures, only his initial data was used.

Participant milestones

Measure	Exclusive Smokers Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime
Overall Study STARTED	139	192	119
Overall Study COMPLETED	117	164	114
Overall Study NOT COMPLETED	22	28	5

Reasons for withdrawal

Measure	Exclusive Smokers Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime
Overall Study COVID-19 shutdown period	0	4	0
Overall Study Missed V2 visit- outside protocol window	4	3	1
Overall Study Lost to Follow-up	8	0	2
Overall Study Did not qualify due to comorbidities, positive COVID-9, high CO, Low CO, Negative nicotine in urine	10	20	2
Overall Study While cleaning datasets, we realized one participant was enrolled twice.	0	1	0

Baseline Characteristics

E-Cigarette Effects on Markers of Cardiovascular and Pulmonary Disease

Baseline characteristics by cohort

Measure	Exclusive Smokers n=117 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=164 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Total n=395 Participants Total of all reporting groups
Age, Continuous	42.8 years STANDARD_DEVIATION 13.8 • n=5 Participants	27.4 years STANDARD_DEVIATION 10.6 • n=7 Participants	30.8 years STANDARD_DEVIATION 11.9 • n=5 Participants	32.9 years STANDARD_DEVIATION 13.6 • n=4 Participants
Sex: Female, Male Female	52 Participants n=5 Participants	64 Participants n=7 Participants	57 Participants n=5 Participants	173 Participants n=4 Participants
Sex: Female, Male Male	65 Participants n=5 Participants	100 Participants n=7 Participants	57 Participants n=5 Participants	222 Participants n=4 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants	5 Participants n=7 Participants	6 Participants n=5 Participants	12 Participants n=4 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	115 Participants n=5 Participants	159 Participants n=7 Participants	108 Participants n=5 Participants	382 Participants n=4 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	2 Participants n=4 Participants
Race (NIH/OMB) Asian	7 Participants n=5 Participants	9 Participants n=7 Participants	21 Participants n=5 Participants	37 Participants n=4 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants
Race (NIH/OMB) Black or African American	38 Participants n=5 Participants	4 Participants n=7 Participants	5 Participants n=5 Participants	47 Participants n=4 Participants
Race (NIH/OMB) White	65 Participants n=5 Participants	141 Participants n=7 Participants	79 Participants n=5 Participants	285 Participants n=4 Participants
Race (NIH/OMB) More than one race	5 Participants n=5 Participants	9 Participants n=7 Participants	9 Participants n=5 Participants	23 Participants n=4 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants
Region of Enrollment United States	117 participants n=5 Participants	164 participants n=7 Participants	114 participants n=5 Participants	395 participants n=4 Participants
Exhaled CO	16.11 ppm STANDARD_DEVIATION 13.7 • n=5 Participants	2.96 ppm STANDARD_DEVIATION 1.89 • n=7 Participants	2.79 ppm STANDARD_DEVIATION 1.73 • n=5 Participants	6.8 ppm STANDARD_DEVIATION 9.7 • n=4 Participants
Serum Nicotine (ng/ml)	4.48 ng/ml STANDARD_DEVIATION 4.54 • n=5 Participants	2.95 ng/ml STANDARD_DEVIATION 2.58 • n=7 Participants	1.99 ng/ml STANDARD_DEVIATION 0.00 • n=5 Participants	3.07 ng/ml STANDARD_DEVIATION 3.07 • n=4 Participants
Serum Cotinine (ng/ml)	231.3 ng/ml STANDARD_DEVIATION 127.7 • n=5 Participants	193.5 ng/ml STANDARD_DEVIATION 111.7 • n=7 Participants	2.99 ng/ml STANDARD_DEVIATION 8.88 • n=5 Participants	140.4 ng/ml STANDARD_DEVIATION 141.0 • n=4 Participants

PRIMARY outcome

Timeframe: V2 up to 4 weeks from enrollment visit, fasting

Population: % FMD pre-challenge after 8 hours refraining from nicotine exposure. A higher % dilation is an indication of better endothelial function.

Brachial Artery Flow-Mediated Dilation is a primary cardiovascular biomarker and a measure of endothelial function that will be assessed before and after an acute exposure challenge. These are pre-challenge values.

Ultrasound based changes in brachial artery diameter after a forearm cuff occlusion (250mmHg) for 5 minutes. FMD is the percent change in brachial diameter measured 60 to 90 seconds post cuff release compared to its resting diameter. A higher % dilation is an indication of better endothelial function.

Outcome measures

Measure	Exclusive Smokers n=113 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=164 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Brachial Artery Flow-Mediated Dilation (FMD)- Pre Challenge	4.25 Percent change from resting diameter Standard Deviation 3.17	4.89 Percent change from resting diameter Standard Deviation 2.92	5.31 Percent change from resting diameter Standard Deviation 3.43	—	—	—

PRIMARY outcome

Timeframe: V2 up to 4 weeks from enrollment visit , fasting, pre challenge session

FEV1 is a primary measure of pulmonary disease obtained by spirometry that will be assessed before and after an acute exposure challenge. These are per-challenge values

Outcome measures

Measure	Exclusive Smokers n=112 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=162 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Forced Expiratory Volume (FEV1)- Pre Challenge	82.9 percentage of volume exhaled Standard Deviation 18.9	93.8 percentage of volume exhaled Standard Deviation 13.3	92.0 percentage of volume exhaled Standard Deviation 13.4	—	—	—

PRIMARY outcome

Timeframe: V2 up to 4 weeks from enrollment visit, only done pre-challenge

Carotid Intima-Media Thickness is a cardiovascular biomarker and a measure of sub-clinical arterial injury and atherosclerosis as a result of chronic exposure. IMT will be measured via ultrasonography.

Outcome measures

Measure	Exclusive Smokers n=116 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=164 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=113 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Carotid Intima-Media Thickness (IMT)	0.67 mm Standard Deviation 0.18	0.54 mm Standard Deviation 0.10	0.54 mm Standard Deviation 0.10	—	—	—

PRIMARY outcome

Timeframe: During Visit 2 (1 - 4 weeks post enrollment) before and after smoking/vaping challenge and for controls after a 10 minute break

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw.

Visit 2 was scheduled up to 4 weeks from enrollment visit, fasting.. They came in the morning after 8 hours of fasting and refraining from nicotine products. Systolic blood pressure (left brachial artery using an oscillometric method) was measured supine, after 10 minutes rest ("Pre") and repeated after they underwent smoking or vaping changes. The "post challenge" blood pressures were recorded 15-20 minutes post end of exposure. For controls, all measurements were repeated in the same order after a 10 minute break.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=99 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=164 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=163 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=115 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=115 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Systolic Blood Pressure Pre- and Post-challenge.	118.4 mmHg Standard Deviation 11.72	120.25 mmHg Standard Deviation 12.00	119.74 mmHg Standard Deviation 11.21	125.40 mmHg Standard Deviation 11.54	126.43 mmHg Standard Deviation 16.72	132.00 mmHg Standard Deviation 16.09

PRIMARY outcome

Timeframe: before and after smoking/vaping challenge during Visit 2 (up to 4 weeks from enrollment)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw.

Participants returned for V2 up to 4 weeks from enrollment visit, fasting. They came in the morning after 8 hours of fasting and refraining from nicotine products. Diastolic blood pressure (left brachial artery using an oscillometric method) was measured supine, after 10 minutes rest ("Pre") and repeated after they underwent smoking or vaping changes. The "post challenge" blood pressures were recorded 15-20 minutes post end of exposure. For controls, all measurements were repeated in the same order after a 10 minute break.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=99 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=164 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=163 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=115 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=115 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Diastolic Blood Pressure Pre- and Post-challenge.	70.40 mmHg Standard Deviation 7.13	72.51 mmHg Standard Deviation 7.73	71.12 mmHg Standard Deviation 7.52	75.31 mmHg Standard Deviation 8.54	76.64 mmHg Standard Deviation 10.72	81.04 mmHg Standard Deviation 10.78

PRIMARY outcome

Timeframe: Before and after smoking/vaping challenge during Visit 2 (up to 4 weeks from enrollment)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw.

Visit 2 was scheduled up to 4 weeks from enrollment visit, fasting. Participants attended fasting and refraining from nicotine products for at least 8 hours prior. All visits were in the morning. Pre-challenge heart rate measured supine, after 10 minutes rest from blood pressure monitor (dinamap). The post challenge heart rates were recorded 15-20 minutes post end of exposure to smoking or vaping challenge completion or in the case of controls after a 10 minute break.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=99 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=164 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=163 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=115 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=115 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Heart Rate Pre- and Post-challenge.	59.57 beats per minute (bpm) Standard Deviation 8.19	58.42 beats per minute (bpm) Standard Deviation 7.88	58.34 beats per minute (bpm) Standard Deviation 9.22	63.17 beats per minute (bpm) Standard Deviation 10.13	65.31 beats per minute (bpm) Standard Deviation 11.65	69.15 beats per minute (bpm) Standard Deviation 12.05

PRIMARY outcome

Timeframe: before and after smoking/vaping challenge during Visit 2 (up to 4 weeks from enrollment)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw.

Visit 2 was scheduled up to 4 weeks from enrollment visit. Participants attended fasting and refraining from nicotine products for at least 8 hours prior. All visits were in the morning. Pre-challenge brachial artery diameter imaged with ultrasound after resting supine for 10 minutes before and repeated 15-20 minutes after smoking/vaping challenge ended. or in the case of controls after a 10 minute break.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=99 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=164 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=163 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=113 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=113 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Brachial Artery Diameter Pre- and Post-challenge	0.378 centimeters (cm) Standard Deviation 0.062	0.370 centimeters (cm) Standard Deviation 0.063	0.388 centimeters (cm) Standard Deviation 0.064	0.378 centimeters (cm) Standard Deviation 0.063	0.410 centimeters (cm) Standard Deviation 0073	0.398 centimeters (cm) Standard Deviation 0.068

PRIMARY outcome

Timeframe: Testing was done after 10 minutes rest and fasting for pre- and post-challenge. The post challenge FMD were recorded 15-20 minuted after end of exposure (up to 4 weeks from enrollment)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw.

Visit 2 was scheduled up to 4 weeks from enrollment visit. Participants attended fasting and refraining from nicotine products for at least 8 hours prior. All visits were in the morning. Pre-challenge ultrasound of brachial artery diameter imaged with ultrasound after resting supine for 10 minutes before and repeated 15-20 minutes after smoking/vaping challenge ended. or in the case of controls after a 10 minute break. The FMD protocol includes measuring % change in resting diameter after 60-90 seconds post fore-arm cuff occlusion release.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=99 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=164 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=163 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=113 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=113 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Brachial Artery Flow Mediated Dilation (FMD) Pre- and Post-challenge	5.31 percent change Standard Deviation 3.43	4.22 percent change Standard Deviation 3.01	4.89 percent change Standard Deviation 2.92	4.62 percent change Standard Deviation 3.52	4.25 percent change Standard Deviation 3.17	3.57 percent change Standard Deviation 2.26

PRIMARY outcome

Timeframe: During V2 (scheduled up to 4 weeks from enrollment) and obtained after 10 minutes of supine rest, before and after smoking/vaping challenge

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw. Some participants pre or post challenge due to poor ECG signals (noise) or frequent premature ventricular contractions did not have a usable 10 minute recording

Expressed as a percentage of beats (supine recordings had be 5 minutes or longer to be valid). We used the SphygmoCor system for these recordings (Atcor medical). Participants attended V2 1-2 weeks after enrollment visit. They came in the morning fasting and refraining from nicotine for at least 8 hours. Heart rate variability was recorded supine for 10 minutes or more, pre and post smoking/vaping challenge. For controls is was repeated after a 10-minute break.

Outcome measures

Measure	Exclusive Smokers n=105 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=92 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=158 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=152 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=105 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=110 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Percent of Sequential Heart Cycles That Differ by More Than 50 ms From Each Other in Length (PNN50, %) Pre- and Post-challenge	33.64 percent of sequential intervals Standard Deviation 20.83	36.46 percent of sequential intervals Standard Deviation 21.96	34.82 percent of sequential intervals Standard Deviation 21.85	31.02 percent of sequential intervals Standard Deviation 22.90	18.46 percent of sequential intervals Standard Deviation 19.72	15.45 percent of sequential intervals Standard Deviation 18.61

PRIMARY outcome

Timeframe: heart rate variability recordings of at least 10 minutes per-challenge and 15 minutes post-challenge (up to 4 weeks from enrollment)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw. Some participants pre or post challenge due to poor ECG signals (noise) or frequent premature ventricular contractions did not have a usable 10 minute recording

Participants attended V2 up to 4 weeks after enrollment visit. They came in the morning fasting and refraining from nicotine for at least 8 hours. Heart rate variability was recorded supine for 10 minutes or more, pre and post smoking/vaping challenge. For controls it was repeated after a 10 minute break.

Outcome measures

Measure	Exclusive Smokers n=105 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=92 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=158 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=152 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=105 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=110 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Root Mean Square of Successive Differences Between Normal Heart Beats (RMSSD, ms) Pre- and Post-challenge	66.44 milliseconds Standard Deviation 34.49	71.10 milliseconds Standard Deviation 38.78	71.20 milliseconds Standard Deviation 44.42	64.40 milliseconds Standard Deviation 46.33	48.29 milliseconds Standard Deviation 35.01	44.44 milliseconds Standard Deviation 38.73

PRIMARY outcome

Timeframe: Ratio was measured pre- and post- smoking/vaping challenge after completion of the 10 minutes of heart rate variability measures (up to 4 weeks from enrollment)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw. Some participants pre or post challenge due to poor ECG signals (noise) or frequent premature ventricular contractions did not have a usable recording

We used the SphygmoCor system for these recordings (Atcor medical). Participants attended V2 up to 4 weeks after enrollment visit. They came in the morning fasting and refraining from nicotine for at least 8 hours. Heart rate variability standing ratio was assessed pre and post smoking/vaping challenge. For controls is was repeated after a 10-minute break. Ratio between maximal heart rate after abrupt standing from a supine position and the subsequent lowest heart rate value within 40 seconds of peak.

Outcome measures

Measure	Exclusive Smokers n=105 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=85 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=139 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=140 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=94 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=84 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Heart Rate Variability Standing Ratio Pre- and Postchallenge	1.57 ratio (unitless) Standard Deviation 0.26	1.55 ratio (unitless) Standard Deviation 0.22	1.55 ratio (unitless) Standard Deviation 0.23	1.51 ratio (unitless) Standard Deviation 0.23	1.38 ratio (unitless) Standard Deviation 0.21	1.34 ratio (unitless) Standard Deviation 0.23

PRIMARY outcome

Timeframe: before and after smoking/vaping challenge during Visit 2 (1-4 weeks after enrollment visit)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw. Some spirometry recordings were of poor quality and upon review by pulmonologist they were deemed not usable.

maximum amount of air that the subject can forcibly expel during the first second following maximal inhalation, expressed as a percentage of the predicted normal values in the population. Participants attended V2 1-4 weeks after enrollment. They came in the morning, fasting and refraining from nicotine exposure for at least 8 hours prior. Pre-challenge spirometry was performed sitting before all other tests and repeated within 15 minutes after smoking/vaping challenge.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=100 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=162 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=161 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=112 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=111 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Predicted Forced Expiatory Volume in 1 Second (FEV1, %) Pre- and Post-challenge	92.00 predicted percentage of population Standard Deviation 13.41	91.12 predicted percentage of population Standard Deviation 14.13	93.83 predicted percentage of population Standard Deviation 13.32	89.76 predicted percentage of population Standard Deviation 15.63	82.91 predicted percentage of population Standard Deviation 18.90	80.43 predicted percentage of population Standard Deviation 18.25

PRIMARY outcome

Timeframe: before and after smoking/vaping challenge during Visit 2 Visit 2 which was scheduled 1 to 4 weeks from enrollment visit, fasting

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw. Some spirometry recordings were of poor quality and upon review by pulmonologist they were deemed not usable.

Amount of air that can be forcibly exhaled after taking the deepest breath possible expressed as a predicted percentage from the normal population. Participants attended V2 1-4 weeks after enrollment. They came in the morning, fasting and refraining from nicotine exposure for at least 8 hours prior. Pre-challenge spirometry was performed sitting before all other tests and repeated within 15 minutes after smoking/vaping challenge.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=100 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=162 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=161 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=112 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=111 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Forced Vital Capacity (FVC, %) Pre- and Post-Challenge.	96.45 predicted percentile Standard Deviation 15.06	95.00 predicted percentile Standard Deviation 14.19	98.25 predicted percentile Standard Deviation 13.50	96.77 predicted percentile Standard Deviation 15.79	90.28 predicted percentile Standard Deviation 15.99	87.88 predicted percentile Standard Deviation 16.55

PRIMARY outcome

Timeframe: before and after smoking/vaping challenge during Visit 2 (1-4 weeks after enrollment visit)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw. Some spirometry recordings were of poor quality and upon review by pulmonologist they were deemed not usable.

The post challenge spirometry was recorded <15 minutes post end of exposure. Participants attended V2 1-4 weeks after enrollment. They came in the morning, fasting and refraining from nicotine exposure for at least 8 hours prior. Pre-challenge spirometry was performed sitting before all other tests and repeated within 15 minutes after smoking/vaping challenge.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=100 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=162 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=161 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=112 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=111 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Ratio Between Predicted Forced Expiatory Volume in First Second and Predicted Total Vital Capacity (FEV1/FVC Ratio) Pre- and Post-challenge	95.74 ratio (unitless) Standard Deviation 9.63	95.93 ratio (unitless) Standard Deviation 8.28	95.66 ratio (unitless) Standard Deviation 8.90	92.23 ratio (unitless) Standard Deviation 11.67	91.18 ratio (unitless) Standard Deviation 12.56	90.89 ratio (unitless) Standard Deviation 11.12

PRIMARY outcome

Timeframe: Spirometry performed pre-challenge and within 15 minutes post-challenge (up to 4 weeks from enrollment)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw. Some spirometry recordings were of poor quality and upon review by pulmonologist they were deemed not usable.

Participants attended Visit 2 (1-4 weeks after enrollment visit). They came in the morning, fasting and refraining from nicotine exposure for at least 8 hours prior. Pre-challenge spirometry was performed sitting before all other tests and repeated within 15 minutes after smoking/vaping challenge.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=100 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=162 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=161 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=112 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=111 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Percent Predicted Forced Expiratory Flow at 25 and 75% of the Pulmonary Volume (FEF 25-75, %) Pre and Pos-challenge	86.91 predicted percentile Standard Deviation 27.33	85.17 predicted percentile Standard Deviation 25.68	87.94 predicted percentile Standard Deviation 23.45	80.20 predicted percentile Standard Deviation 23.35	71.09 predicted percentile Standard Deviation 31.09	68.49 predicted percentile Standard Deviation 27.12

PRIMARY outcome

Timeframe: before and after less than 15 minutes from smoking/ vaping product (up to 4 weeks from enrollment)

Population: Not all controls (never users) were assessed post (after 10 minute break) due to time restrictions in personnel and one exclusive e-cigarette user was not assessed post due to a vaso-vagal response during blood draw. Other missing records were due to equipment malfunction or participant not being able to follow instructions to complete the test correctly.

Participants attended V2 1-4 weeks after enrollment. They came in the morning, fasting and refraining from nicotine exposure for at least 8 hours prior. Pre-challenge FeNO was obtained sitting and repeated within 15 minutes after smoking/vaping challenge.

Outcome measures

Measure	Exclusive Smokers n=114 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=100 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=163 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge n=161 Participants Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge n=111 Participants Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge n=108 Participants Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Changes in Fractional Exhaled Nitric Oxide (FeNO, Ppb) Pre- and Post-challenge	16.17 parts per billion (ppb) Standard Deviation 11.04	16.97 parts per billion (ppb) Standard Deviation 12.52	14.51 parts per billion (ppb) Standard Deviation 14.71	13.64 parts per billion (ppb) Standard Deviation 14.47	9.67 parts per billion (ppb) Standard Deviation 12.26	9.93 parts per billion (ppb) Standard Deviation 11.84

SECONDARY outcome

Timeframe: Participants attended V2 generally 1-4 weeks after enrollment with a window that allowed up to 4 weeks after enrollment

Heart Rate pre-acute exposure challenge was obtained after resting supine for 10 minutes during V2 in the morning, fasting and refraining from nicotine exposure for at least 8 hours prior.

Outcome measures

Measure	Exclusive Smokers n=115 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=164 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Heart Rate (HR)	65.3 beats/minute Standard Deviation 11.7	58.3 beats/minute Standard Deviation 9.2	59.6 beats/minute Standard Deviation 8.2	—	—	—

SECONDARY outcome

Timeframe: V2 two was generally scheduled 1-4 weeks after enrollment visit with a window up to 4 weeks. HRV measures obtained after resting supine for 10 minutes

Population: heart rate variability depends on a good quality electrocardiogram, and some participants due to noise, significant pauses, very slow heart rate or frequent premature ventricular contractions did not have usable records, hence lower number analyzed.

Heart Rate Variability PNN50(%) measured before an exposure challenge. Participants attended visit 2 fasting and refraining from nicotine for at least 8 hours.

Outcome measures

Measure	Exclusive Smokers n=105 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=158 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=105 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Heart Rate Variability (HRV) - Pre Product Use Challenge	11.4 percentage of intervals Interval 2.3 to 27.95	37.1 percentage of intervals Interval 15.0 to 51.98	31.0 percentage of intervals Interval 16.05 to 48.8	—	—	—

SECONDARY outcome

Timeframe: V2 was up to 4 weeks from enrollment visit, after resting supine for 10 minutes

Blood Pressure measured using the oscillometric technique before an acute exposure challenge following standardized protocol. After resting supine for 10 minutes blood pressure was measured on both arms and the average of the last two values was used.

Outcome measures

Measure	Exclusive Smokers n=115 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=164 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Systolic Blood Pressure (BP)	126.4 mmHg Standard Deviation 16.7	119.7 mmHg Standard Deviation 11.2	118.4 mmHg Standard Deviation 11.7	—	—	—

SECONDARY outcome

Timeframe: recordings obtained during V2 in the morning, fasting and refraining from nicotine for at least 8 hours. This visit was generally 1-2 weeks after enrollment date with a window up to 4 weeks

Forced Vital Capacity is a measure of how much air can be exhaled forcefully obtained by spirometry pre acute exposure challenge.

Outcome measures

Measure	Exclusive Smokers n=112 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=162 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Forced Vital Capacity (FVC)	90.3 Percent predicted FVC Standard Deviation 16	98.3 Percent predicted FVC Standard Deviation 13.5	96.5 Percent predicted FVC Standard Deviation 15.1	—	—	—

SECONDARY outcome

Timeframe: recordings obtained during V2 in the morning, fasting and refraining from nicotine for at least 8 hours. This visit was generally 1-2 weeks after enrollment date with a window up to 4 weeks

Fractional Exhaled Nitric Oxide is a measure of airway inflammation measured before an acute exposure challenge.

Outcome measures

Measure	Exclusive Smokers n=111 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=163 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Fractional Exhaled Nitric Oxide (FeNO)	9.7 ppb Standard Deviation 12.3	14.5 ppb Standard Deviation 14.7	16.2 ppb Standard Deviation 11	—	—	—

SECONDARY outcome

Timeframe: v2 was generally 1-2 weeks after enrollment visit, with a window up to 4 weeks from V1

Root mean square of standard deviation of rr intervals. Obtained fasting and refraining from nicotine exposure using the Sphymocor system. We used 10 or more minutes of supine data to derive heart rate variability measures.

Outcome measures

Measure	Exclusive Smokers n=105 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=158 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=105 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Autonomic Measures - RMSSD	43.6 ms Interval 25.95 to 56.2	63.3 ms Interval 40.6 to 89.5	58.3 ms Interval 41.4 to 82.8	—	—	—

SECONDARY outcome

Timeframe: v2 was generally 1-2 weeks after enrollment visit, with a window up to 4 weeks from V1

Analysis of radial pressure wave forms allows for non-invasive estimation of central aortic pressures, accounting for pressure amplification and the amplitude of the arterial pulse wave as it moves through arteries away from the heart. The Atcor Sphygmacor system can derive central aortic pressures from radial tracings using a validated transfer function. This computation is performed using the pulse wave analysis (PWA) mode. Pulse Wave Analysis via radial tonometry was obtained as a measure of chronic exposure.

Outcome measures

Measure	Exclusive Smokers n=117 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=161 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Arterial Pulse Wave Analysis (PWA), Augmentation Index (at 75 Bpm, %)	19.5 percentage of central pulse pressure Interval 7.25 to 29.0	0.50 percentage of central pulse pressure Interval -8.5 to 12.0	1.00 percentage of central pulse pressure Interval -9.0 to 11.13	—	—	—

SECONDARY outcome

Timeframe: Treadmill test done only once at the end of v2 after completion of all other post-challenge assessment tests. V2 was scheduled 1-4 weeks from enrollment vist

An ETT to determine exercise capacity will be completed as a measure of chronic exposure. Peak metabolic equivalents (METs, 1 MET=3.5 ml O2 uptake/kg body weight/minute) were determined at all exercise stages, peak exercise, and 1-minute post-exercise.

Outcome measures

Measure	Exclusive Smokers n=83 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=157 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=110 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Exercise Treadmill Stress Test (ETT)-Peak METS	8.39 METS Standard Deviation 3.19	10.29 METS Standard Deviation 2.01	11.06 METS Standard Deviation 2.42	—	—	—

SECONDARY outcome

Timeframe: V2 was generally 1-2 weeks after enrollment with a window up to 4 weeks from V1, recorded after resting supine for 10 minutes

During V2, Diastolic Blood Pressure was measured using the oscillometric technique before an acute exposure challenge following a standardized protocol. After resting supine for 10 minutes blood pressure was measured on both arms and the average of the last two values was used. Participants attended v2 in the morning, fasting and refraining from nicotine products for at least 8 hours.

Outcome measures

Measure	Exclusive Smokers n=115 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=164 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Diastolic Blood Pressure (DBP)	76.6 mmHg Standard Deviation 10.7	71.1 mmHg Standard Deviation 7.5	70.4 mmHg Standard Deviation 7.1	—	—	—

SECONDARY outcome

Timeframe: During V2 (1-4 weeks after enrollment visit) the treadmill stress test was done last, following Nicotine-containing product challenge (users) or pretend 10 minute exposure for controls

Peak RPP was calculated by multiplying maximun heart rate during exercise by systolic blood pressure as a reliable assessment of cardiac workload

Outcome measures

Measure	Exclusive Smokers n=84 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=157 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=110 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Peak Rate Pressure Product (RPP, Peak Heart Rate Multiplied by Peak Systolic Blood Pressure)	249.99 mmHg x bpm Standard Deviation 62.82	284.76 mmHg x bpm Standard Deviation 51.36	290.86 mmHg x bpm Standard Deviation 48.61	—	—	—

SECONDARY outcome

Timeframe: During V2 (1-4 weeks after enrollment visit) the treadmill stress test was done last, following Nicotine-containing product challenge (users) or 10 minute pretend exposure for never-users

Measure of maximal exercise capacity adjusted for age, calculated as max heart rate during treadmill divided by (220 minus the participant's age in yrs)

Outcome measures

Measure	Exclusive Smokers n=84 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=157 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=110 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
Heart Rate Reserve (%)	83.25 percentage of heart rate reserve Standard Deviation 11.58	87.89 percentage of heart rate reserve Standard Deviation 8.81	91.72 percentage of heart rate reserve Standard Deviation 7.58	—	—	—

SECONDARY outcome

Timeframe: During V2 (1-4 weeks after enrollment visit) the treadmill stress test was done last, following Nicotine-containing product challenge (users) or pretend 10 minute exposure for controls

Difference in heart rate 60 seconds post treadmill minus maximal heart rate during treadmill..

Outcome measures

Measure	Exclusive Smokers n=84 Participants Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=157 Participants E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=110 Participants \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime	Exclusive E-cigarette Users Post-challenge Vapers completed a maximum of 15 minute ad libitum product use challenge , Vaping their own electronic cigarettes	Exclusive Smokers Pre-challenge Exclusive cigarette smokers assessed after 8 hours refraining from smoking	Exclusive Smokers After Smoking Challenge Smokers completed a maximum 15-minute ad libitum product use challenge, they smoked their combustible cigarettes in a dedicated room with external ventilation, under remote supervision by two trained observers.
60 Seconds Heart Rate Recovery (Beats Per Minute)	19.62 beats per minute (bpm) Standard Deviation 10.38	26.74 beats per minute (bpm) Standard Deviation 9.06	28.06 beats per minute (bpm) Standard Deviation 8.26	—	—	—

Adverse Events

Exclusive Smokers

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Exclusive E-Cig Users

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Never Users

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Measure	Exclusive Smokers n=117 participants at risk Smokes Daily; \>/= 5 cigarettes/day for last 6 months Cigarettes: smokes daily	Exclusive E-Cig Users n=164 participants at risk E-cig usage \>/= 5 days/week for last 3 months E-Cigarettes: E-cigarette usage \>/= 5 days/week	Never Users n=114 participants at risk \< 100 cigarettes in lifetime, none for \> 5 years; \< 3 E-cig usage in lifetime
Gastrointestinal disorders Nausea	0.00% 0/117 • 2 years	0.61% 1/164 • Number of events 1 • 2 years	0.00% 0/114 • 2 years
General disorders Vasovagal response	0.00% 0/117 • 2 years	0.00% 0/164 • 2 years	0.88% 1/114 • Number of events 1 • 2 years

Additional Information

Dr James H. Stein

University of Wisconsin-Madison

Phone: 608-262-2075

Email: jhs@medicine.wisc.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place