Glantz’s declaration is based on his review of lab results from two groups of smokers three months after (1) continuing to smoke or (2) switching to IQOS. The studies, from Japan and the U.S., were submitted by PMI in its application (available at the FDA website here).
It is well known that individuals’ lab results do not improve instantly upon smoking cessation. The PMI submission clearly indicated that many of the subjects’ lab values are not expected to change for 6-12 months or longer after quitting.
Beyond that, Glantz completely ignored a third PMI study group: smokers who had quit completely for three months.
In this post I present the comparison that Glantz emphasized – IQOS users versus continuing smokers – but I add an equally important comparison that Glantz ignored – IQOS users versus complete quitters. Because the U.S. study had too few subjects in the latter group (n=9) for stable comparisons, I will focus on the Japan study, which involved 70 IQOS users, 41 continuing smokers and 37 complete quitters. I will also note one omission in Glantz’s comparison.
The comparisons of IQOS and continued smoking in the table below were calculated by PMI and presented in its application. PMI also calculated differences for IQOS versus quitting, but I could not find them in the material released so far by the FDA. So those comparisons in the table are from my assessment of point estimates and confidence intervals from the submission. All differences in the table are described positively with respect to health (e.g. IQOS significantly lower). “NS” indicates no significant difference between groups for that test.
|Comparison of Laboratory Values After 3 Months: IQOS Users Versus Continuing Smokers and Versus Complete Quitters in Japan|
|Lab Marker||IQOS Versus Smoking||IQOS Versus Complete Quitting*|
|White blood cell count||IQOS significantly lower**||NS|
|Soluble ICAM||IQOS significantly lower||NS|
|Prostaglandin F2 alpha||IQOS significantly lower||IQOS possibly lower|
|11-DTX-B2||NS||Quitting possibly lower|
|High density lipoprotein||IQOS significantly higher||NS|
|Low density lipoprotein||NS||NS|
|Triglycerides||NS||IQOS possibly lower|
|Forced expiratory vol, 1 sec.||NS||NS|
** Omitted by Glantz
The PMI calculations show that IQOS users had four statistically significant favorable comparisons at 3 months compared with smokers. Other results show no differences. My assessment of IQOS users versus complete quitters reveals no significant differences for ten lab results. There were only two possibly significant results favoring IQOS and one favoring complete quitting.
In summary, the results at three months do not prove anything definitive, which was emphasized in PMI’s application. These results were not used by PMI to support any positive claims about IQOS; they should not have been used by Professor Glantz to make any counter claims.