Emphysema
Conditions
Brief summary
The investigators will study the effect of pulmonary arterial vasodilation to see if it eliminates indices of persistent lung injury in smokers that are susceptible to emphysema.
Detailed description
The purpose of this research study is to find out if smoking cessation combined with sildenafil, an FDA approved drug for pulmonary hypertension, will decrease inflammation in the lung. Even if a smoker stops smoking, the harmful effects caused by previous smoking may recruit inflammatory cells to those affected areas, leading to lung injury. In about 30-40% of smokers, this inflammation combined with irregular blood flow in the lungs may lead to emphysema. The study goal is to measure and compare individual responses to smoking cessation, Sildenafil and placebo used three times per day, and imaging of the lungs using non-contrast and contrast CT scans to see if there is a possible decrease of inflammation and an increase of blood flow in the lungs. The study also intends to see if using Sildenafil three times per day, in addition to smoking cessation will restore blood flow to the possible injured areas of the lungs. Sildenafil is an FDA approved medication for pulmonary hypertension but will be used off-label to study the effects it may or may not have on the blood flow in possible injured areas of the lungs. Non-smokers will be enrolled to compare lung imaging and the effects of Sildenafil on their lungs with that of smokers undergoing a smoking cessation program with placebo or Sildenafil. Non-smokers will complete identical measurements as smokers, with Sildenafil used three times per day or no medication across a similar 90 day period of time. Vascular measurements of pulse wave velocity, carotid artery compliance/stiffness and pressure wave reflection will be done at baseline and 90 day visits.
Interventions
DRUGSildenafil 20 MG
Sildenafil, 20mg three times daily for 3 month period.
DRUGPlacebo Oral Tablet
Placebo manufactured to look like Sildenafil 20 MG
DIAGNOSTIC_TESTPulse wave velocity
Vascular pulse measurement at the radial, brachial, femoral, and carotid arteries are taken using a tonometer probe.
DIAGNOSTIC_TESTCarotid artery compliance and stiffness
An echocardiogram is done by using a probe placed on the skin.
DIAGNOSTIC_TESTPressure wave reflection
Carotid pulse measurement taken using a tonometer probe
Sponsors
National Institutes of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Eric A. Hoffman
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Masking description
Subject and study team are masked to which arm subject is assigned (study drug or placebo). Investigational pharmacy will not be masked. For the non-smoker groups, both subjects and the study team will know which group they are assigned to (study drug or no medication).
Eligibility
Sex/Gender
ALL
Age
21 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
(Smokers): * Between the age of 21 to 65 at baseline * Be willing to participate in a smoking cessation program * Be willing to attend all clinic visits * Must be currently smoking at least ½ pack/day at baseline (confirmed with cotinine level and CO Smokerlyzer) * \>5 pack-year history of smoking * Global Initiative for Chronic Obstructive Lung Disease (GOLD) 0: FEV1≥0.80 and FEV1/FVC\>0.70 Forced Expiratory Volume in 1 second (FEV1), Forced Vital Capacity (FVC) * GOLD 1: FEV1≥0.80 and FEV1/FVC \< 0.70 * GOLD 2: 0.50≤FEV1\<0.80 and FEV1/FVC \< 0.70 * Be willing to abstain from using any nicotine patches, e-cigarettes, or marijuana for the duration of the study. Inclusion Criteria (Non-smokers): * Between the age of 21 to 65 at baseline * Be willing to attend all clinic visits * Have never smoked (confirmed with cotinine level and CO smokerlyzer) * GOLD 0: FEV1≥0.80 and FEV1/FVC\>0.70
Exclusion criteria
(Smokers and Non-smokers): * Women only: Cannot be pregnant or nursing at baseline or plan to become pregnant during the course of the study * Body Mass Index (BMI) \> 35 * Allergies to shell fish, seafood, eggs or iodine * Heart disease, kidney disease or diabetes * Diagnosis of asthma * Any metal in or on the body (that cannot be removed) between the nose and the abdomen * Any major organ system disease (by judgment of the study medical team) * A glomerular filtration rate of 60 cc per minute or less. * Nitroglycerin usage or nitrates and use of phosphodiesterase 5 (PDE5) inhibitors * Prior history of hypersensitivity to sildenafil * Currently prescribed a phosphodiesterase (PDE) inhibitors medication (ex: Viagra, Cialis, etc) * Known Pulmonary Hypertension * Has used e-cigarettes and marijuana \<1 years * Use of ACE Inhibitors, Calcium Channel Blockers, Angiotensin II Receptor Blockers for control of blood pressure or any combination of these three types of medications.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Measure and compare individual smokers' responses to smoking cessation, Sildenafil and placebo with lung imaging to determine decrease of inflammation and increase of blood flow in lungs. | 90 Days | Our outcome measure is the change in regional blood volume between baseline and interventions with CT imaging, sildenafil/placebo and smoking cessation. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pulse wave velocity of carotid radial, brachial, femoral and carotid arteries | Baseline and 90 day | Our outcome measure is the difference of arterial stiffness between baseline and 90 day visits. |
| Carotid beta-stiffness index | Baseline and 90 Day | Our outcome measure is the difference of common carotid artery stiffness between baseline and 90 day visits |
| Carotid augmentation index | Baseline and 90 Day | Our outcome measure is the difference of pressure wave reflection between baseline and 90 day visits |
Countries
United States
Outcome results
None listed