--\> This is a substudy of the main ESTxENDS trial (NCT03589989). Pulmonary function outcomes should be considered secondary outcomes of the main smoking cessation outcome formulated in NCT03589989. Cigarette smoking is the leading cause of preventable death in Switzerland and still more than a quarter of the Swiss population smokes cigarettes. Recently, electronic nicotine delivery systems (ENDS; also called vaporizer, e-cigarette or electronic cigarette) have become popular with smokers who want to stop smoking or reduce their exposure to inhaled chemicals since ENDS use appears to be safer than tobacco smoking. The inhaled ENDS aerosol appears safe in laboratory conditions, its long-term effects on pulmonary function remains unknown. This study will therefore investigate the impact of ENDS on lung function in smokers, who attempt to quit using ENDS compared with smokers, receiving only smoking cessation counseling with nicotine replacement therapy (NRT). Multiple breath washout (MBW) is an established technique for assessment of peripheral airway function in pediatrics and its use is emerging in adult medicine, as it offers a better sensitivity to assess small airway disease before large airway involvement can be detected using conventional pulmonary function tests (PFT - spirometry, body plethysmography and diffusing capacity test). Preliminary evidence from limited studies suggest MBW parameters (LCI, Scond, Sacin) can be impaired in smokers with normal lung function and improve after smoking abstinence. Primary objective of this substudy is to assess changes in LCI from baseline to 6 months post target quit date (TQD) in cigarette smokers randomized to the intervention group compared to the control group. For the main ESTxENDS trial (NCT03589989), cigarette smokers motivated to quit smoking cigarettes will be included. Participants in the intervention group will receive an ENDS and nicotine-containing e-liquids, which they will be allowed to use ad libitum. Additionally, they will receive standard of care, i.e. smoking cessation counseling and encouragement to use NRT. Smoking cessation counseling will be provided in person at the first clinical visit and then over the phone at the target quit date and again at week 1, 2, 4 and 8 after the target quit date. Participants in the control group will receive only standard of care. All participants will be followed over a 6-month period. After 6 months, participants will be asked to come to a final clinical visit.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
130
Participants in the intervention group will receive an ENDS and nicotine-containing e-liquids, which they will be allowed to use ad libitum. Additionally, they will receive standards of care, i.e. smoking cessation counseling and encouragement to use NRT. Smoking cessation counseling will be provided in person at the first clinical visit and then over the phone at the target quit date and again at week 1, 2, 4 and 8 after the target quit date. All participants will be followed over a 6-month period. After 6 months, participants will be asked to come to a final clinical visit. PFT and MBW will be performed at baseline and after the 6 months follow-up period in all participants of the substudy.
Participants in the control group will receive standard of care only, i.e. i.e. smoking cessation counseling and encouragement to use NRT. Smoking cessation counseling will be provided in person at the first clinical visit and then over the phone at the target quit date and again at week 1, 2, 4 and 8 after the target quit date. All participants will be followed over a 6-month period. After 6 months, participants will be asked to come to a final clinical visit. PFT and MBW will be performed at baseline and after the 6 months follow-up period in all participants of the substudy.
University Clinic for General Internal Medicine, Bern University Hospital
Bern, Switzerland
Department of Pneumology
Bern, Switzerland
Changes in Lung Clearance Index (LCI)
Measured by multiple breath washout (MBW) of a tracer gas (N2). LCI is defined as the cumulative expired volume/functional residual capacity (CEV/FRC) at 5% and 2.5% tracer gas concentration in the exhaled breath. An LCI with a z-score \< + 1.645 (upper limit of normal according to Singer F et al, PLoS One. 2012;7(4):e36083) is considered normal.
Time frame: Change from baseline to 6 months post quit date
Lung Clearance Index (LCI)
Measured by multiple breath washout (MBW) of a tracer gas (N2). LCI is defined as the cumulative expired volume/functional residual capacity (CEV/FRC) at 5% and 2.5% tracer gas concentration in the exhaled breath. An LCI with a z-score \< + 1.645 (upper limit of normal according to Singer F et al, PLoS One. 2012;7(4):e36083) is considered normal.
Time frame: 6 months post quit date
Changes in Scond and Sacin
Measured by multiple breath washout (MBW). MBW assesses ventilation of the peripheral airways.
Time frame: Change from baseline to 6 months post quit date
Scond and Sacin
Measured by multiple breath washout (MBW). MBW assesses ventilation of the peripheral airways.
Time frame: 6 months post quit date
Forced Expiratory Volume in 1 Second (FEV1)
Measured by spirometry. Spirometry is a conventional pulmonary function test measuring airflow.
Time frame: 6 months post quit date
Changes in Forced Expiratory Volume in 1 Second (FEV1)
Measured by spirometry. Spirometry is a conventional pulmonary function test measuring airflow.
Time frame: Change from baseline to 6 months post quit date
Forced Expiratory Volume in 1 Second/Functional Vital Capacity Ratio (FEV1/FVC)
Measured by spirometry. Spirometry is a conventional pulmonary function test measuring airflow.
Time frame: 6 months post quit date
Changes in Forced Expiratory Volume in 1 Second/Functional Vital Capacity Ratio (FEV1/FVC)
Measured by spirometry. Spirometry is a conventional pulmonary function test measuring airflow.
Time frame: Change from baseline to 6 months post quit date
Total Lung Capacity (TLC)
Measured by body plethysmography. Body plethysmography is a conventional pulmonary function test measuring lung volumes.
Time frame: 6 months post quit date
Changes in Total Lung Capacity (TLC)
Measured by body plethysmography. Body plethysmography is a conventional pulmonary function test measuring lung volumes.
Time frame: Change from baseline to 6 months post quit date
Residual Volume (RV)
Measured by body plethysmography. Body plethysmography is a conventional pulmonary function test measuring lung volumes.
Time frame: 6 months post quit date
Changes in Residual Volume (RV)
Measured by body plethysmography. Body plethysmography is a conventional pulmonary function test measuring lung volumes.
Time frame: Change from baseline to 6 months post quit date
Residual Volume to Total Lung Capacity (RV/TLC)
Measured by body plethysmography. Body plethysmography is a conventional pulmonary function test measuring lung volumes.
Time frame: 6 months post quit date
Changes in Residual Volume to Total Lung Capacity (RV/TLC)
Measured by body plethysmography. Body plethysmography is a conventional pulmonary function test measuring lung volumes.
Time frame: Change from baseline to 6 months post quit date
Diffusing Capacity of the Lungs for Carbon Monoxide (DLCO)
Measured by diffusing capacity test.
Time frame: 6 months post quit date
Changes in Diffusing Capacity of the Lungs for Carbon Monoxide (DLCO)
Measured by diffusing capacity test.
Time frame: Change from baseline to 6 months post quit date
Fraction of exhaled nitric oxide (FeNO)
Measured by the levels of nitric oxide in the exhaled breath.
Time frame: 6 months post quit date
Changes in Fraction of exhaled nitric oxide (FeNO)
Measured by the levels of nitric oxide in the exhaled breath.
Time frame: Change from baseline to 6 months post quit date
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