Specific Aim 1. Characterize the long-term effects of secondhand smoke (SHS) on vascular health in pre-ban flight attendants (FAs). Investigators will measure arterial stiffness (pulse wave velocity and augmentation index) and endothelial dysfunction (reactive hyperemia index) in the pre-ban FA cases, and compare to the cardiovascular risk-factor matched Framingham controls.

It is hypothesized that pre-ban FA cases have increased arterial stiffness (higher pulse wave velocity and higher augmentation index) and increased endothelial dysfunction (lower reactive hyperemia index) compared to Framingham controls.

Specific Aim 2. Determine the extent in which remote pre-ban SHS exposure (hours) is associated with increased arterial stiffness or endothelial dysfunction.

Investigators hypothesize that pre-ban SHS exposure is positively associated with both increased arterial stiffness and increased endothelial dysfunction.

Specific Aim 3. Investigators will calculate the cardiovascular risk scores (Framingham, Reynolds, and ASCVD) by using subjects' age, blood pressure, family history, lipid panel, and highly sensitive C-reactive protein. Investigators will explore the association of the risk scores with measures of vascular aging (arterial stiffness and endothelial dysfunction). These scores do not include SHS exposure. Investigators will also test the additive value of SHS exposure in increasing arterial stiffness and endothelial dysfunction using the risk scores as an adjustment value.

It is hypothesized that the cardiovascular risk scores are associated with vascular aging (arterial stiffness and endothelial dysfunction), and that the association between SHS exposure and vascular aging remains significant after adjusting for the cardiovascular risk scores.

The significance of this proposal and impact will be (1) mechanistic insights into how remote SHS exposure leads to hypertension and vascular stiffness, (2) increased understanding of how SHS exposure can increase risk of cardiovascular disease, which is the number one cause of death in the United States.

The investigators propose a cohort study, in which investigators will assess for evidence of accelerated vascular aging in 300 pre-ban FAs with pre-ban SHS exposure, and compare their vascular measures of arterial stiffness and endothelial dysfunction to those of age and risk-factor matched Framingham controls. It is hypothesized that pre-ban FAs have increased arterial stiffness and endothelial dysfunction compared to the Framingham subjects, related to SHS exposure.

Inclusion Criteria:

• 40 years of age and older;
• Flight attendant, including current or past employment with the airlines;
• Non-smoking flight attendant (current and prior, defined as smoking <100 cigarettes in your lifetime);
• Exposed to secondhand tobacco smoke for at least one year, while working on the aircrafts

Exclusion Criteria:

• History of Raynaud's syndrome
• Had mastectomy or arm/hand abnormality in which blood pressure cannot be measured on the arm

Flight attendants that are 40 years of age and older, with prior occupation secondhand smoke (SHS) exposure pre- and post- smoking ban.