Deficient and Unreliable Studies of Vaping and Disease

 

At least a dozen medical studies over the past few years have found that vaping is associated with heart attack, stroke, hypertension, emphysema and other lung disease, as well as diabetes (see the list at the end of this entry).  The studies are cross-sectional; they are drawn from population samples at one point in time.  They only produce associations, but those are then inflated to imply or outright claim that vaping causes those disease conditions.  The studies appeared in respected medical journals and, together, form a powerful disincentive for smokers to switch to vaping.  They also add fuel to the regulatory fire to suppress vape products, which are actually vastly safer than cigarettes. 

My research group has published a new analysis entitled, “Cross‑sectional e‑cigarette studies are unreliable without timing of exposure and disease diagnosis,” in the journal Internal and Emergency Medicine.

Our analysis shows that the dozen are irrevocably deficient and unreliable.  Some used data from National Health Interview Surveys (NHIS), the Behavioral Risk Factor Surveillance System (BRFSS), or the FDA’s Population Assessment of Tobacco and Health (PATH) surveys, all of which profile participants who smoked and/or vaped and who had ever been diagnosed with numerous diseases.  However, there is absolutely no information in the NHIS or BRFSS about when participants started to smoke or vape, or when they were first diagnosed with a disease. Absent this critical data, it is impossible to demonstrate that smoking or vaping preceded the disease, and therefore had any role in causing it.

While authors of some of the studies tried to use a statistical sleight of hand by claiming that their results were “adjusted” for smoking, that is not a legitimate work-around for the missing cause-and-effect information.

Some studies used PATH data, which does contain all of the information needed to analyze whether smoking and vaping preceded the diseases and therefore might have caused them.  Readers of my blog know that my research group in 2019 used PATH data to demonstrate that a heart attack study published in the flagship journal of the American Heart Association was pure fiction, resulting in its retraction by journal editors.  Now we have analyzed PATH data to demonstrate that none of the vaping-caused-disease claims in the recent studies are valid.

Our design was simple: We started by determining at what age participants were diagnosed with smoking-attributable diseases – chronic obstructive pulmonary disease (COPD), emphysema, myocardial infarction (MI, or heart attack) and stroke.  We then noted when participants started smoking or vaping.  The results were crystal clear.  As we reported in our study, “Only 4% of COPD and emphysema cases, 6% of MIs and 11% of stroke had occurred in PATH participants who had used e-cigarettes prior to the diagnoses. In contrast, over 94% of all cases occurred after smoking cigarettes fairly regularly.” 

In summary, the cited studies’ claims that vaping is related to or causes airway and circulatory diseases are not valid, as the authors lacked or ignored causative pathway information.  As for those few cases in which vaping preceded the disease, we note in our article, this may indicate “a potential reverse association between e-cigarette use and these diseases. In other words, having a diagnosis for respiratory and cardiovascular diseases leads smokers to use e-cigarettes.”

 

   Deficient and Unreliable Studies of Vaping and Disease

   Alzahrani T, Pena I, Temesgen N, Glantz SA (2018).  Association between electronic cigarette use and myocardial infarction.  Am J Prev Med 55(4):455-461. https://pubmed.ncbi.nlm.nih.gov/30166079/   

Vindhyal MR, Okut H, Ablah E, Ndunda PM, Kallail KJ, Choi WS (2020).  Cardiovascular outcomes associated with adult electronic cigarette use.  Cureus 12(8): e9618.  https://pubmed.ncbi.nlm.nih.gov/32923219/ 

Wills TA, Pagano I, Williams RJ, Tam EK (2019).  E-cigarette use and respiratory disorder in an adult sample.  Drug Alc Depend 194:363-370.  https://doi.org/10.1016/j.drugalcdep.2018.10.004 

Osei AD, Mirbolouk M, Orimoloye OA, et al (2019).  Association between e-cigarette use and cardiovascular disease among never and current combustible-cigarette smokers.  Am J Med 132:949-954.  https://doi.org/10.1016/j.amjmed.2019.02.016 

Parekh T, Pemmasani S, Desai R (2020).  Risk of stroke with e-cigarette and combustible cigarette use in young adults.  Am J Prev Med 58(3):446-452.

   Bircan E, Bezirhan U, Porter A, Fagan P, Orloff MS (2021).  Electronic cigarette use and its association with asthma, chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome among never cigarette smokers.  Tob Ind Dis 19:23. https://doi.org/10.18332/tid/132833 

   Wills TA, Choi K, Pokhrel P, Pagano I (2022).  Tests for confounding with cigarette smoking in the association of e-cigarette use with respiratory disorder: 2020 national-sample data. Prev Med  https://doi.org/10.1016/j.ypmed.2022.107137

Perez MF, Atuegwu N, Mead E, Oncken C, Mortensen EM (2018).  E-cigarette use is associated with emphysema, chronic bronchitis and COPD.  Am J Respir Crit Care Med 197:A6245.  

Zhang Z, Jiao Z, Blaha MJ, et al (2022).  The association between e-cigarette use and prediabetes: results from the Behavioral Risk Factor Surveillance System, 2016-2018.  Am J Prev Med 62(6):872-877.  https://doi.org/10.1016/j.amepre.2021.12.009 

Atuegwu NC, Perez MF, Oncken C, Mead EL, Maheshwari N, Mortensen EM (2019).  E-cigarette use is associated with a self-reported diagnosis of prediabetes in never cigarette smokers: results from the Behavioral Risk Factor Surveillance System Survey.  Drug Alc Depend 205: 107692. doi:10.1016/j.drugalcdep.2019.10769

Miller CR, Shi H, Li D, Goniewicz ML (2021).  Cross-sectional associations of smoking and e-cigarette use with self-reported diagnosed hypertension: findings from Wave 3 of the Population Assessment of Tobacco and Health Study.  Toxics 9:52 https://doi.org/10.3390/toxics9030052 

Osei AD, Mirbolouk M, Orimoloye OA et al. Association between e-cigarette use and chronic obstructive pulmonary disease by smoking status: Behavioral Risk Factor Surveillance System 2016 and 2017.  Am J Prev Med 58, ISSUE 3, P336-342, March 01, 2020.  https://doi.org/10.1016/j.amepre.2019.10.014  

Osei AD, Mirbolouk M, Orimoloye, OA et al. The association between e-cigarette use and asthma among never combustible cigarette smokers: Behavioral Risk Factor Surveillance System (BRFSS) 2016 & 2017. BMC Pulm Med 19, 180 (2019). https://doi.org/10.1186/s12890-019-0950-3

Smokeless Tobacco Users Are Not Dying from Diseases Associated with Smoking

American health authorities for years failed to directly compare the health effects of smoking with those of smokeless tobacco (ST) use, as it would have meant acknowledging the large difference in deaths attributable to these products. 

That changed last year, when Altria’s Michael Fisher and colleagues published the first-ever follow-up mortality study of cigarette smokers and ST users, using the U.S. Government’s national surveys and National Death Index.

My colleague Nantaporn Plurphanswat and I conducted a similar study, which was published last fall in Harm Reduction Journal.  Like Fisher et al., we analyzed data for dipping/chewing and smoking participants from the eight years of National Health Interview Surveys (NHIS), between 1987 and 2010, in which ST users were counted.  The fact that the NHIS rarely calculated ST users suggests that the government didn’t think ST use was important.

We had access to cause-of-death information from federal data through 2015.  Smokers and ST users are always compared with never users of either product using the hazard ratio (HR), which is interpreted similarly to relative risk (i.e. a multiplier).  Current and former smokers are in the top two sections of each chart, while exclusive current ST users are highlighted by open green boxes.  Squares are men 40-59 years old; circles are men 60-79 years.

The first chart above displays results for all causes of death.  Note that current smokers have double the odds of death, while former smokers’ odds are elevated around 30% (It pays to quit!)  Also note the 44% elevation among current ST users, which is explained in the second chart (click on it for a larger version) with information about specific diseases.

Smokers have elevated death rates for all diseases.  They are twice as likely to die of heart diseases and cancer, and 6-13 times of respiratory diseases.  On the other hand, current exclusive ST users do not have significant elevations for any of these diseases. 

The third chart contains results divided into two mutually exclusive and exhaustive categories, smoking-related and everything else.  It shows that ST users’ death rates are primarily elevated by other causes; this is true especially among younger ST users, circled in red.  These causes included accidents, Alzheimer’s disease, kidney diseases, suicides and drug overdoses.      

Our analysis, studying only men age 40+ years, was designed to maximize the chance of finding significant results.  All previous studies had included women, who rarely use ST, and young men, among whom death is rare; those groups do not produce relevant information.  Consider: If a researcher wants to accurately measure the rate of breast cancer, they don’t count men.  Breast cancer occurs in men, but at such a minuscule rate that it would cut the rate among women in half, making it grossly inaccurate.

In summary, our study demonstrates that exclusive ST users do not demonstrate significantly elevated mortality from any smoking-related diseases.  Younger ST users, however, had elevated deaths from all other causes.  While we were unable to determine which specific diseases were involved, our findings for other causes are consistent with a recent CDC report and a recent study in JAMA showing increased mortality among adults age 25 to 64 years, which specified  drug overdoses, suicides and organ system diseases.

 

FDA Cigar Study Part II: Heart & Lung Disease Nearly Zero for 1-2 Cigars Per Day

As noted in my last blog post (here), data presented in a recent FDA review of cigar health risks (here) showed that smoking up to two cigars per day, while not completely safe, is neither associated with significantly increased risks for death from all causes, nor smoking-related cancers.       

Now we examine the FDA data regarding cigar-related circulatory and lung diseases. Here are the overall results:

Table 1. Relative Risks for Mortality From Circulatory Diseases and Emphysema Among Men Who Smoke Cigars
Disease	Study, Year	Relative Risk (95% CI)
Coronary heart disease	Kahn, 1966	1.04 (0.96 – 1.13)
	Carstensen, 1987	1.16 (0.84 – 1.57)
	Ben-Schlomo, 1994	0.45 (0.17 – 1.22)
	Shanks, 1998	1.05 (1.00 – 1.11)
	Jacobs, 1999	1.30 (1.05 – 1.62) 1
	Jacobs, 1999	0.93 (0.72 – 1.21) 2
Stroke	Kahn, 1966	1.08 (0.91 – 1.28)
	Shanks, 1998	0.96 (0.87 – 1.06)
Aortic Aneurysm	Kahn, 1966	2.06 (1.32 – 3.07)
	Carstensen, 1987	5.10 (1.33 – 13.19)
	Shanks, 1998	1.76 (1.29 – 2.35)
Atherosclerosis	Kahn, 1966	0.97 (0.69 – 1.33)
Emphysema	Kahn, 1966	0.79 (0.25 – 1.86)
	Carstensen, 1987	1.30 (0.00 – 7.45)
	Lange, 1992	3.70 (1.10 – 12.00)
	Shanks, 1998	1.42 (0.96 – 2.03)

¹Age 30-74 years

²Age 75+ years

    

Compared with never smokers, cigar smokers in most studies had no elevated risks for coronary heart disease, which is one of the most common smoking-related causes of death in the U.S.; the single exception was a subgroup of men, age 30-74 years, in the Jacobs study.  Cigar smokers also did not have increased risks for two other frequent causes of death, stroke and atherosclerosis (hardening of the arteries).

Aortic aneurysm – a bulge in the heart’s main artery – is the only disease risk that is consistently elevated in cigar smokers.  It is a serious disorder but a distinctly uncommon cause of death; the mortality rate due to aortic aneurysm among those 45 and older dropped precipitously from 16 deaths per 100,000 in 2000 to 7.4 in 2014.

For men who smoke only one or two cigars a day, the health risks are even lower.

Table 2. Relative Risks for Mortality From Circulatory Diseases and Emphysema Among Men Who Smoke 1 or 2 Cigars Per Day
Disease	Shanks, 1998	Other Studies
Coronary heart disease	0.98 (0.91 – 1.07)	1.00 (0.90 – 1.10)1
		1.18 (0.76 – 1.82)2
Stroke	1.01 (0.88 – 1.17)
Aortic Aneurysm	1.82 (1.11 – 2.81)
Emphysema	1.39 (0.74 – 2.38)

¹Kahn 1966, fewer than 5 cigars per day.

²Jacobs 1999, 1 cigar per day.

No elevated risks for coronary heart disease, stroke or emphysema among men smoking 1-2 cigars per day.  The only disease that was significantly elevated was aortic aneurysm.

The Take-Home Message for Cigar Smokers

Puffing and/or inhaling the smoke of burning tobacco is not without risks.

The FDA, which now regulates tobacco products, seems inclined to treat cigars the same as cigarettes.  FDA staff wrote in their cigar study that “…cigar smoking carries many of the same health risks as cigarette smoking…We have observed that some risks associated with cigar smoking can be as high or higher than those associated with cigarette smoking, especially at the highest doses and levels of inhalation for cigar smoking.”

The problem with such a sweeping indictment is that it ignores scientific evidence and misleads cigar smokers who could substantially benefit from truthful harm reduction guidance.

Like any risky behavior, the degree of risk is proportional to dose and duration of exposure.  In other words, risk is based on frequency of cigar smoking and the degree to which smoke is puffed and/or inhaled.