Immediate effect of passive smoking on microcirculatory flow

Area of Science:

• Cardiovascular physiology
• Environmental health
• Toxicology

Background:

• Secondhand smoke (SHS) exposure is linked to increased cardiovascular events.
• Active smoking acutely decreases microcirculatory blood flow velocity.
• The acute effects of SHS on microcirculatory flow remain undemonstrated.

Purpose of the Study:

• To investigate the acute effects of passive smoking (SHS) on microcirculatory blood flow velocity in healthy nonsmokers.
• To quantify changes in cerebral blood flow (CBV) during and after SHS exposure.

Main Methods:

• Healthy male and female nonsmokers were exposed to SHS from two burning cigarettes for 10 minutes.
• In vivo vital capillaroscopy (Capiflow®) was used for continuous assessment of microvessel cerebral blood flow (CBV).

Main Results:

• CBV significantly decreased from a baseline of 514 mm/sec to 306 mm/sec at the end of SHS exposure (p < 0.0001).
• A further reduction in CBV to a nadir of 240 mm/sec was observed four minutes post-exposure (p < 0.0001).

Conclusions:

• Passive inhalation of secondhand cigarette smoke causes an immediate and significant reduction in CBV.
• The observed decrease in CBV is prolonged, indicating a sustained impact on microcirculation in healthy nonsmokers.