Thursday, October 3, 2013

The E-Cigarette As “Genuine Competitor” – Czech Survey

A survey of smokers in the Czech Republic shows that e-cigarettes “may develop into a genuine competitor to conventional cigarettes.” 

The lead author of the study, which was published online by Chest (abstract here), is Dr. Eva Kralikova of the Faculty of Medicine at Charles University.

Kralikova and colleagues asked 2,012 smokers in 17 Czech cities to answer brief questions about their smoking; 1,738 (86%) participated.  Smokers were not told that e-cigarettes were a focus of the survey; this eliminated a potential source of bias in the results.

First, smokers were asked about their experience with e-cigarettes.  Only 3% had never heard of them, 47% had heard of them but not tried them, 24% had tried them once, 17% tried them repeatedly and 9% used them regularly. 

E-cig users were then asked to describe their first experience: disappointed, as expected, or pleasantly surprised.  A majority (53%) of one-time users were disappointed, while 32% reported as expected and 15% were surprised.  Repeat users reported a lower disappointment rate (35%), and a higher proportion chose as expected (38%) or surprised (27%).  The majority (69%) of regular users had been pleasantly surprised at first use; a lower proportion chose as expected (29%) and very few were disappointed (2%).

Kralikova asked one-time and repeat e-cig users why they weren’t using them regularly.  The majority (60%) reported that e-cigs had poor taste or were not satisfying, 18% thought that they were impractical or embarrassing, 14% cited the cost, and 8% had other reasons. 

These are important findings, and the authors’ discussion is judicious and balanced.  Kralikova and colleagues confirm the views expressed in this blog: “The key issue would then be the degree of risk [e-cigarette] use may pose. Research on switching from cigarettes to snus (references here and here) and on long-term use of nicotine replacement  (references here and here) shows that nicotine intake from a non-smoked source carries low or no health risks.  Inhalation of propylene glycol and glycerol is considered safe for most people, but inhaling e-cigarette vapour affects airways acutely (reference here) and effects of EC use over an extended period of time remain to be evaluated.”

The researchers conclude: “Some 20% of smokers who try the current versions of e-cigarettes can be expected to go on to become regular users. The public health community needs to balance the possible benefits and possible risks of a scenario where EC become attractive enough to start to replace conventional cigarettes on a population scale. Our findings suggest that e-cigarettes may indeed have the potential to do so.”

The authors warn of an unintended consequence of e-cig over-regulation: “Strict, slow and expensive regulation is likely to limit the spread of e-cigarettes and to stunt their development … careful consideration needs to be given to various regulatory proposals and bans to ensure that they do not have an unintended consequence of ensuring the monopoly of deadly conventional cigarettes.”

That’s a keen observation.

1 comment:

Rursus said...

",but inhaling vapour affects airways acutely".

This is not true! These statements are not supported by the study.

When we look more closely at the study, we'll reveal the overall problems of Vardavas et al.

(See: "Acute pulmonary... (later corrected to "Short-term pulmonary" [1]) effects of using an electronic cigarette impact on respiratory flow resistance, impedance, and exhaled nitric oxide."
Constantine I. Vardavas, Nektarios Anagnostopoulos, Marios Kougias, Vassiliki Evangelopoulou, Gregory N. Connolly and Panagiotis K. Behrakis Chest;Prepublished online December 22, 2011 DOI 10.1378/chest.11-2443)

The following methods were used

For the pulmonary function test (spirometry), the so-called flow/volume measurement is used to evaluate the function of the lungs and respiratory system.
Contrary to tobaccocigarettes, there is no measurable difference, in this study, before and after using an e-cigarette.

Impulse Oscillometry System (IOS)
For the IOS, the airway resistance is measured. („constriction of the bronchial system“). A minimum raise of airway resitance after vaping was measured in this study. This value was NOT pathological and so small, that according to the authors, there is is no clinical relevance.

FeNO concentrations
Nitric oxide (NO) is a gaseous mediator which has an important role in several physiological processes in the respiratory tract including vascular regulation, neurotransmission, host defense, and cytotoxicity. FeNO measurements reflects the intensity of inflammation of the bronchial systems:

The greater a possible inflammationt, the more NO ist producted, but there was measured a reduction in this study!
A reduction in the NO value may mean that the e-cigarette has adverse effects, but that is not clear!

The authors made the mistake to make the propyleneglycol responsible for this effect.

The authors gives one fact the cold shoulder: The bronchia narrowing effect of inhaled nicotine, which is clearly identified as the cause of the first phase of tobaccosmoke! [2]
A simple blind test "vaping a liquid with nicotine" compared to "vaping a liquid without nicotine" would have quickly shown the truth and would have removed two weak points of that study.

This study is cherry-picking, at its best!

J. Mellin