REF-1473 · Vardavas et al., 2012 · Chest · Paper · PubMed

Does vaping tighten the airways?

In 30 smokers, 5 min of use raised airway resistance by about 0.04 kPa/(L/s), meaning for exercise unknown, and lowered exhaled NO, measured at rest straight after. No exercise tested. From the abstract.

Main caveat: Abstract only; publisher page behind a bot check.
limited, mixed evidenceMeasured on non-athletes and recreational people

Vardavas and colleagues (Harvard and Athens) tested whether 5 min of e-cigarette use affects pulmonary function tests and FeNO in healthy adult smokers. Thirty smokers (aged 19-56, 14 men) took part, with ad lib use with the cartridge (experimental, n = 30) or with it removed (control, n = 10).

FeNO fell by 2.14 ppb (P = .005) in the experimental group but not in the control group (P = .859). Total respiratory impedance at 5 Hz rose by 0.033 kPa/(L/s) (P < .001), and flow resistance at 5, 10 and 20 Hz also rose.

Regression controlling for baseline gave higher impedance (0.04 kPa/(L/s), P = .003), resistance at 5 Hz (0.04, P = .003), 10 Hz (0.034, P = .008) and 20 Hz (0.043, P = .007), and peripheral airway resistance (β 0.042, P = .024). The authors conclude that the immediate effects resemble some of those of tobacco smoking.

Our reading: an acute, measurable rise in airway resistance, of a size whose meaning for exercise is unknown; a 2012 device and a small control group.

Protocol

Participants: n = 30 healthy smokers, 19-56 years, 14 men.
Conditions: 5 min ad lib e-cigarette use with the cartridge (n = 30) or removed (n = 10). How control participants were picked, and order, are not in the abstract.
Outcomes: pulmonary function tests, respiratory impedance and flow resistance at 5, 10 and 20 Hz, peripheral airway resistance, FeNO.
Funding and interests: PubMed lists non-US government support; no funder or conflict statement in the record.

Key Results

Outcome after 5 min of useChangeP
FeNO, experimental group−2.14 ppb.005
FeNO, control groupno significant change.859
Total respiratory impedance at 5 Hz+0.033 kPa/(L/s)<.001
Impedance, baseline-adjusted0.04 kPa/(L/s).003
Flow resistance, 5 Hz, adjusted0.04 kPa/(L/s).003
Flow resistance, 10 Hz, adjusted0.034 kPa/(L/s).008
Flow resistance, 20 Hz, adjusted0.043 kPa/(L/s).007
Peripheral airway resistance, adjustedβ 0.042 kPa/[L/s].024
Not in the abstract: nicotine content and device, spirometry values, duration of the effect, symptoms.

Mechanisms

Measured: small rises in airway resistance and impedance, and a small fall in FeNO, immediately after use.
Authors' interpretation: immediate adverse physiologic effects similar to some of those seen with tobacco smoking; long-term effects unknown.
Inference: what narrows the airways is not settled by this design. The nicotine-free or aerosol-free split is not tested: the control had the cartridge removed, not a nicotine-free cartridge.

Practical Application

Does vaping tighten the airways? In 30 smokers, 5 min of use raised airway resistance by about 0.04 kPa/(L/s), meaning for exercise unknown, and lowered exhaled NO, measured at rest straight after. No exercise tested. From the abstract.
For an athlete with wheeze or chest tightness: this gives no threshold. Not from this paper; the base's own practice: chest pain or breathlessness out of proportion goes to a doctor (PHYS-15), and recurrent post-session cough or wheeze is screened for exercise-induced bronchoconstriction (REF-607).
What it does not show: that performance falls; how long the effect lasts; anything in non-smokers or trained athletes, or with modern devices.

Limitations

Abstract only; publisher page behind a bot check.
Control: only 10 people, not described as randomised; no blinding described.
Marker, not performance; the size has no known meaning for exercise.
Who was measured: adult smokers, not athletes; recent smoking status before the test is not in the abstract.
Early device (2012) and nicotine content unknown.
Funding and interests: non-US government support per PubMed; no statement in the record.
How this entry was checked and changed
Why this level

(from the abstract) — a small experiment not described as randomised (rubric B) with further serious limits: a marker, not performance, an unequal control and no blinding described