Wednesday, August 25, 2010

Snus Use Is Not Associated with Gastrointestinal Problems

A new study (abstract here) published in the European Journal of Epidemiology finds that snus use in Sweden is not associated with gastrointestinal (GI) problems.

A detailed GI symptoms questionnaire was distributed to 3,000 adults age 18 to 80 years in the northern Swedish cities of Kalix and Haparanda. Questions concerned gastroesophageal reflux (GER), dyspepsia (pain above the stomach and/or nausea and feeling uncomfortably full after a meal), irritable bowel syndrome (IBS) and other conditions.

About 1,000 survey respondents were subjected to endoscopic exams of their upper GI tracts, searching for ulcers of the esophagus, stomach and small intestine and for evidence of infection by Helicobacter pylori (bacteria which can cause stomach ulcers). Snus users (n = 96), smokers (n = 165) and dual users (n = 22) were compared with non-users (n = 432).

The percentages of snus users reporting GI symptoms were no different than those among non-users. In contrast, smokers were more likely to report dyspepsia (OR = 1.6, 95% CI = 1.1 – 2.2), and dual users were more likely to report dyspepsia (OR = 2.8, CI = 1.1 – 7.3) and IBS (OR = 3.3, CI = 1.3 – 8.2).

With respect to the endoscopy findings, snus users were no more likely than non-users to have ulcers of the esophagus, stomach or small intestine. Smokers were more likely to have peptic ulcer disease (OR = 2.3, CI = 1.0 – 5.2). The published paper presents detailed findings of numerous other minor studies that were performed. Compared with non-users, neither snus users nor smokers had elevated rates of Helicobacter infections.

It is widely known that Swedish snus users place the tobacco in their upper lip, which results in minimal tobacco juice production, eliminating the need to spit. But a small amount of tobacco extract is swallowed, causing some users to worry about potential effects on the GI tract. This study offers reassurance that snus use is not associated with any significant GI symptoms or disorders.

Friday, August 20, 2010

Federal Agencies Agree: Phrase “Spit Tobacco” Is Inappropriate

Readers of this blog may remember my July 14 post (available here) describing the use of the derogatory term “spit tobacco” on websites run by the FDA and the National Institute of Dental and Craniofacial Research (NIDCR). At that time, I wrote to the directors of the agencies, asking them to remove this offensive language from their sites.

I have just received reply letters from both agencies. Susan Johnson, Director of the Office of Communications and Health Education at NIDCR, wrote that the institute “is in the process of substituting ‘smokeless’ (or product-specific terms) for ‘spit’ in our online materials; we anticipate these changes will be completed by the end of August 2010.”

In a separate letter, Anne Henig, from the Office of the Director of the FDA Center for Tobacco Products, advised: “NIDCR has updated its webpage and changed the title to Smokeless Tobacco: A Guide for Quitting” (here)...FDA has also updated its webpage to reflect NIDCR’s change. I hope these modifications will address your concerns.”

I appreciate the timely responses from NIDCR and FDA. I’m encouraged that officials at these agencies have joined the CDC in resolving to treat smokeless tobacco users with respect and dignity.

Tuesday, August 17, 2010

New Study Confirms No Significant Risk for Cardiovascular Diseases Among Smokeless Users

A study just released by the American Journal of Epidemiology (abstract here) confirms that smokeless tobacco use is NOT associated with a significantly increased risk of cardiovascular diseases.

Regrettably, this important finding will not dominate the headlines. Authors Hiroshi Yatsuya and Aaron Folsom chose to emphasize a partially analyzed result that vilifies smokeless tobacco, while largely ignoring the most valid estimate of smokeless risks, namely that they are only minimally elevated and not statistically significant.

The research was based on the Atherosclerosis Risk in Communities (ARIC) study, which recruited almost 16,000 people age 45-64 years in 1987-89 from Forsyth County North Carolina; Jackson Mississippi; suburbs of Minneapolis; and Washington County, Maryland. An enormous amount of information about cardiovascular risk factors was collected, and episodes of heart attacks and strokes were recorded up to 2005.

This Yatsuya study reported hazard ratios (interpreted similarly to relative risks, which are described here) for heart attacks and strokes among smokeless tobacco users compared with never users. When reporting risk due to one factor – in this case, smokeless tobacco – investigators must adjust the estimate for differences in other well-recognized risk factors that might affect the results. This is especially important for heart attacks and strokes, which have many risk factors.

The importance of such adjustments is easily explained. In this study, for example, smokeless users had a higher rate than nonusers of diabetes, a potent risk factor for heart attacks that is not related to smokeless use. Therefore, researchers use techniques to adjust the heart attack risk for smokeless tobacco users to account for the difference in the diabetes rate. This process is repeated for all the other risk factors.

After adjustment for age, sex, race, education, income, alcohol use, physical activity and smoking, Yatsuya and Folsom reported that smokeless tobacco users have a 29% excess risk of heart attacks and strokes (95% Confidence Interval, 8 – 55%). Adjusting for all of these factors is appropriate, but not complete.

After further adjusting for pipe/cigar smoking and exposure to secondhand smoke, the excess heart attack and stroke risk among smokeless users was 27% (CI = 6 – 52%). This is the only result that Yatsuya and Folsom chose to highlight in the abstract. It is still only a partial result, because they had information on many other important risk factors, such as blood pressure, use of blood pressure medicines, diabetes, weight, and serum fat levels. The result after adjustment for these factors was buried in the fine print of the paper. The excess risk dropped to 21% (CI = 0 – 45%), which is 22% lower than their touted number and not statistically significant.

Why did Yatsuya and Folsom downplay the most valid result for smokeless tobacco users? Why did the journal’s reviewers and editors not insist that Yatsuya and Folsom report the results in a fair and balanced manner? One possible answer: An unbiased report about smokeless tobacco use would not have offered these strident conclusions in both the paper and the abstract: “Current users of smokeless tobacco should be informed of its harm and advised to quit the practice. Current smokers should also be given sufficient information on safe, therapeutic methods of quitting which do not include switching to smokeless tobacco.”

Can we conclude from this study that smokeless tobacco is not associated with heart attacks and strokes? Of course not. But the most valid risk estimate is so small that the authors had to all but bury it in order to support their abstinence agenda. The bottom line for consumers is that this study confirms that smokeless tobacco use is NOT associated with a significantly increased risk of cardiovascular diseases.

Wednesday, August 11, 2010

Straight Talk About E-Cigarettes

Electronic cigarettes (e-cigarettes) pose important issues relevant to tobacco harm reduction. This post will review the facts about these products, which have been the subject of exaggerated claims by e-cigarette proponents and nicotine prohibitionists alike. As with most complex issues, the truth about e-cigarettes lies somewhere in between.

When users draw on them, battery-powered e-cigarettes vaporize a mixture of water, propylene glycol, nicotine and flavorings. Nicotine is one of the most intensively studied drugs in history; while it is highly addictive, it is not the primary cause of virtually any of the diseases related to smoking. In fact, long-term nicotine consumption is about as safe as that of caffeine. Propylene glycol is approved by the FDA for use in a large number of consumer products; it, too, is sometimes vaporized, forming artificial smoke in theatrical and other productions.

It is almost certain that e-cigarette use (also called vaping) is vastly safer than cigarette smoking, but this is based on limited scientific evidence. Some questions remain unanswered.

The health effects of long-term exposure of the respiratory tract to propylene glycol vapor are unknown, and unknowable. As a health professional, I am more comfortable recommending a product with a defined risk profile, where a clear risk-benefit analysis can be evaluated. That is why I have been a strong supporter of smokeless tobacco products as cigarette substitutes. I recommend these products knowing that we have 50 years of epidemiology documenting the extremely low level of health risks. E-cigarette consumers must understand that the safety of e-cigarettes can not be guaranteed, despite the likelihood that they pose but a tiny fraction of the health risks of regular cigarettes. But given the paucity of legitimate research, specific safety claims for e-cigarettes can not be made.

There is a lot of uncertainty with respect to the reliability of e-cigarettes, essentially all of which are imported from China. One of my colleagues ordered numerous products with the intent of performing some routine tests; many of these products did not function properly right out of the box. According to a recent clinical study of two brands (abstract here), “…neither of the electronic cigarettes exposed users to measurable levels of nicotine or [carbon monoxide]…” Not inhaling carbon monoxide is a good thing, but for addicted smokers, not getting nicotine may be a problem. Many e-cigarette users know that the devices often don’t deliver enough nicotine to satisfy them, so they re-load cartridges with even higher doses from commercially available concentrated solutions. Concentrated nicotine is dangerous, and this kind of experimentation is bound to lead to injuries.

The same study showed that “…both [brands] suppressed nicotine/tobacco abstinence symptom ratings.” This is impressive, because it indicates that e-cigarettes simulate the behavioral aspects of smoking and therefore may be successful in ways that no other smoking cessation product can match.

E-cigarette cartridges may contain hazardous contaminants. Last year, the FDA conducted laboratory tests on a few e-cigarette cartridges. Although the tests were biased and flawed (as I discussed here), they found in one cartridge traces of diethylene glycol, a poisonous impurity found previously in propylene glycol (reported here).

Consumer products should be free of contaminants. Cartridges, as well as the hardware, should be subjected to independent quality control testing. The FDA tests underscored the need for regulatory oversight. This could be accomplished if the FDA regulated e-cigarettes as recreational tobacco products under authority from the Tobacco Act. Instead, the FDA is attempting, inappropriately according to one federal judge, to regulate them as drug-delivery devices (discussed here). That would effectively remove them from the American market, leaving hundreds of thousands of e-cigarette users with no satisfactory alternative to tobacco combustion.

There is no justification or scientific rationale to ban e-cigarettes. Still, anti-tobacco extremists are campaigning against them, claiming, entirely without proof, that they are a starter tobacco product for children. As with all tobacco products, they should not be available to minors.

Another battle rages over whether e-cigarettes can be used safely indoors. Some militant users object to any indoor restrictions, while prohibitionists claim that second-hand vapor is annoying and/or toxic. The latter claim is preposterous, but e-cigarette users who are courteous and respectful toward bystanders are likely to lead longer, healthier and less stressful lives.

Wednesday, August 4, 2010

To the American Cancer Society: Tell Americans (And the Wall Street Journal) the Truth

Wall Street Journal numbers guy Carl Bialik wrote an article in April about the how the health risks from smokeless tobacco use were distorted and overblown by officials from the American Cancer Society (read it here). Specifically, Bialik pointed out that claims of a “50” fold elevated risk for mouth cancer for smokeless users have no scientific credibility.

The American Cancer Society could not defend continued use of the “50” number, so it immediately put out the white flag of surrender. Bialik wrote that “Dr. Thomas Glynn, director of cancer science and trends for the American Cancer Society, said this week that his organization will no longer use the statistic citing a 50-fold increase in risk.”

It turns out that Glynn was not telling Bialik the truth. The Cancer Society has released its annual booklet, “Cancer Facts and Figures 2010.” (available here) On page 43 under “Smokeless Tobacco Products” is the following text: “The risk of cancer of the cheek and gums is increased up to 50-fold among long-term snuff users.”

As I detailed in an earlier blog post (here), this number is a complete fabrication. Carl Phillips provided other insights about how this number is totally bogus (here).

The American Cancer Society is not telling the truth about the health risks of smokeless tobacco. This is bad enough, but it is disgraceful that the practice persists even after Cancer Society assertions to the contrary.