Cardiopulmonary Study Effects of Secondhand-Smoke (FAMRI)

The investigators are conducting a study to test whether exposure to secondhand tobacco smoke causes negative effects on the subject's health. In particular, the investigators wish to find out whether secondhand tobacco smoke exposure causes heart or lung problems.

This study aims to ascertain whether standard exercise stress testing can detect subclinical cardiopulmonary disability in subjects with significant exposure to second hand tobacco smoke (SHS). The ultimate goal of this study is to contribute to the understanding of SHS-related illnesses, and to the care of future patients with SHS exposure.

The main hypothesis of this study is that exposure to the secondhand tobacco smoke (SHS) in the confined workspace of commercial aircraft prior to the ban against cigarette smoking is responsible for long-term damage to the lungs of nonsmoking flight attendants. Although only some flight attendants show evidence of this damage on their lung function at rest, the majority of the flight attendants will have abnormal diffusing capacity during exercise as the damage may be too subtle to be detected with lung function measurements at rest. To test these hypotheses, we will compare pre- and post-ban flight attendants to each other and to two groups of age-matched, nonsmoking controls living at sea level stratified on the basis of SHS exposure. The results of our study should permit us to determine whether SHS alone could account for the lung damage in flight attendants, or whether some more complex interaction (involving cabin factors such as ozone, altitude, radiation and SHS) may be involve.

This is a cross-sectional observational study of cases (flight attendants exposed to secondhand tobacco smoke, SHS) and controls (flight attendants not exposed to SHS).

Inclusion Criteria:

• Pre-ban flight attendants:

  1. Never smoker flight attendants who began working for airlines before the smoking ban on aircrafts went into effect. Never smoker is defined those with history of tobacco use of less than 100 cigarettes in their lifetime.
  2. SHS exposure > 5 years while working with the airlines.
• Post-ban control flight attendants:

The control patients will be age matched flight attendants without aircraft cabin second hand smoke exposure (those who started flying after the tobacco ban). The purpose of having these control groups is to determine if any differences in cardiopulmonary data is due to SHS exposure or other factors associated with flying.

In addition, we will recruit non-flight attendants volunteers with and without history of SHS exposure from a previously characterized cohort. These subjects will be age-matched control group of never smokers, and must have grown up and spent the majority of their adulthood at sea level and have had no connection with the airline industry.

Exclusion Criteria:

1. History of clinically overt cardiac disease, including: stable or unstable angina; coronary artery disease (abnormal stress test; cardiac catheterization showing > 70% coronary artery stenosis; history of revascularization; pathologic Q waves on EKG); uncontrolled resting hypertension (SBP > 160/ DBP>95); congestive heart failure (EF < 55%; physical exam findings of CHF; symptomatic pulmonary edema); significant (> mild) valvular heart disease; congenital heart disease.
2. History of clinically overt pulmonary disease, including: asthma, including childhood; COPD; chronic interstitial lung disease; pulmonary hypertension.
3. Debilitating chronic illness, including untreated thyroid disease.
4. Pregnancy.
5. Abnormalities of baseline examination including: resting hypertension (> 160/95); abnormal cardiopulmonary physical examination; abnormal baseline electrocardiogram (left ventricular hypertrophy; ischemic changes; prior myocardial infarction; arrhythmia other than premature atrial contractions); abnormal baseline echocardiogram (LVEF < 55%, segmental wall motion abnormalities, > mild valvular heart disease).
6. Physical inability to perform supine bicycle exercise testing, including: paralysis, weakness, amputation, or symptomatic arthritis of the lower extremities; disabling back pain.