The evidence that ecigs have adverse effects on smokers’ lung function keeps piling up

Andreas Lappas and colleagues just published “Short-term respiratory effects of e-cigarettes in healthy individuals and smokers with asthma,”  which shows that when smokers use an e-cigarette, it worsens lung function, with bigger effects in smokers who already have asthma.
 
This is an important finding because it indicates that dual use of cigarettes and e-cigarettes, by far the most common use pattern, is worse than smoking alone.
 
Here is the abstract:
 
Background and objective:  This study investigated the duration of immediate respiratory effects of e-cigarette smoking (ECS) and tested the hypothesis that ECS has more prominent effects in asthmatics compared with healthy smokers (HS).
Methods; Fifty-four smokers, 27 healthy (HS group) and 27 with intermittent asthma (mild asthma (MA) group) underwent a control session (no liquid, no resistor coil inside e-cigarette cartridge) and an experimental session of ECS using standardized puffing settings. Impulse oscillometry impedance (Z), resistance (R), reactance (X) and fractional exhaled nitric oxide (FeNO) were measured before and 0, 15 and 30 min after control and experimental sessions.
Results: Control session revealed no significant changes. In the experimental session, immediately post-ECS, both groups exhibited a significant increase in respiratory system total impedance at 5 Hz (Z5) (P  MA exhibited higher baseline values and a more prominent effect immediately after ECS compared with HS for Z5 (P = 0.022), R5 (P = 0.010) and R10 (P = 0.013).
FeNO decreased significantly in both groups (P  Conclusion:  A single session of ECS had respiratory mechanical and inflammatory effects, which were more prominent in smokers with asthma.
 
The citation is AU  - Lappas, et al.  Short-term respiratory effects of e-cigarettes in healthy individuals and smokers with asthma.   Respirology 2017  http://dx.doi.org/10.1111/resp.13180 and the paper is available here.