Thursday, June 28, 2012

Smokeless Reduces Smoking in Small Clinical Trial

Dr. Dorothy Hatsukami and colleagues have published a small clinical study documenting that smokeless tobacco products appeal to and satisfy smokers, reducing smoking and promoting abstinence.  The research was conducted at the University of Minnesota and the Oregon Research Institute; it appears in Drug and Alcohol Dependence (abstract here). 

Smokers of at least 10 cigarettes a day were recruited in the Minneapolis and Eugene, OR areas; 99 smokers formally entered the intensive 5-week trial (65% were men) and 91 completed it. 

Over two weeks, smokers sampled five products (and flavors): Stonewall dissolvable tobacco (wintergreen, java, natural), Camel snus (frost and mellow), Ariva dissolvable tobacco (wintergreen, java), Marlboro snus (spearmint, peppermint, rich), and General snus portions (unflavored).  A sampling protocol was followed in order to collect information “on relief from withdrawal, relief from craving, ease of use, and general satisfaction and likeability.” 

In the following two weeks, subjects were instructed to quit smoking but were told they could use a preferred smokeless product; three clinic visits were required, for data collection purposes.  A final clinic visit occurred one week later, and a follow-up phone call completed the study at week nine.  During visits, abstinence was verified with an exhaled carbon monoxide test.  Subjects were paid up to $300. 

No subjects chose General for the treatment period; the other four products were each preferred by about a quarter of participants.

At the start of the treatment period, subjects used on average about seven smokeless products daily, and smoked 1-3 cigarettes.  After two weeks, smokeless use dropped to 4-6, while cigarette use was 1-4 daily, depending on the smokeless product.  Camel snus use correlated with the lowest cigarette use.
The following table shows the key trial results.  Almost 60% of Camel snus users were cigarette-abstinent during the treatment period, and their continued use of smokeless products was high.  Other products were accompanied by lower abstinence and smaller rates of continued use.  This may be due to Camel’s higher level of available nicotine (1.7 to 2.0 mg. per portion) as measured by Hatsukami, compared to Marlboro (0.1 to 0.4), Stonewall (0.3 to 0.6) and Ariva (0.2).  Camel snus users also had the highest satisfaction scores and the lowest craving scores.

Smokeless Tobacco as a Cigarette Substitute
Product Abstinent During Treatment Period (%)Continued Use After Treatment (%) Continued Use At Week Nine (%)
Camel snus596748
Marlboro snus302617
Stonewall dissolvable294621
Ariva dissolvable253825

Dr. Hatsukami concluded that “smokers who chose the [Camel] snus product with higher nicotine levels tended to report greater craving and withdrawal relief, more satisfaction, smoking less cigarettes and achieving greater short-term abstinence.”  These are important findings, since they validate the effectiveness of smokeless tobacco products as temporary cigarette substitutes. 

This is an excellent study, but one question remains: Were subjects given complete and accurate information about health risks from smokeless tobacco use and smoking?  Institutional Review Boards require full disclosure of this information to research subjects of clinical trials, and the substance and style of this disclosure could have profound effects on the outcome.  A description of this disclosure would have been informative.

Evidence from this clinical trial will be valuable when the FDA reviews applications for modified risk tobacco products.  Dr. Hatsukami is a member of the FDA Tobacco Products Scientific Advisory Committee, adding to the work’s credibility. 

Wednesday, June 20, 2012

Tobacco Prohibition Expands on U.S. College Campuses

The pernicious march toward tobacco prohibition continues at American universities.  Ohio Board of Regents Chairman James Tuschman said he will ask trustees at all of the state’s two- and four-year institutions to ban tobacco on campus (here).  In neighboring West Virginia, the Board of Governors announced that it will impose a tobacco ban at West Virginia University in July 2013 (link).

It is distressing that institutions that ought to stand for tolerance and diversity are implementing not only indoor smoking bans (which have a solid scientific rationale) and outdoor smoking bans (which have virtually no scientific rationale), but universal bans of all tobacco products, including significantly less harmful smokeless tobacco.

WVU’s tobacco ban is in stark contrast to its alcohol policy (here) which allows alcoholic beverages to be served on campus within certain guidelines.  University officials are banning smokeless tobacco, which carries a risk about equal to driving an automobile, while allowing alcohol, which is significantly more dangerous. 

A comprehensive national review of alcohol use among college students (link) found that 42% (3.8 million) consumed 5 or more drinks on an occasion in the past month.  Thirty-one percent (2.8 million) admitted to driving under the influence of alcohol in the past year.  The data also show that over 500,000 college students are unintentionally injured per year because of alcohol; more than 600,000 are hit or assaulted by another drinking student; and over 1,700 die from alcohol-related motor vehicle accidents and other injuries.

Campus tobacco prohibition is illogical, oppressive and difficult to enforce.  Modern smokeless tobacco products are spit-free and invisible in use.  WVU anti-tobacco extremists warn that “Consistent communication about the policy will be essential and will require commitment from all levels of leadership from President Clements, deans and directors, supervisors to resident assistants in the dorms. University Police officers should be called upon to help inform violators of the new policy” (here).

Will campus police employ tobacco-sniffing dogs at security checkpoints?  Will faculty and staff conduct random mouth checks before university lectures? 

There is no rational basis for colleges and universities to prohibit the use of smokeless tobacco products.  Comprehensive campus bans on tobacco are impractical, inappropriate and a distraction from truly important health risks facing our nation’s college students. 

Wednesday, June 13, 2012

Cell Phone Use & Brain Cancer: A Study in Responsible Data Use

An international study links high levels of cell phone use with an increased risk for glioma, one of the deadliest forms of brain cancer.  The study, conducted by an international team of investigators, involved five countries (Australia, Canada, France, Israel and New Zealand) using the Interphone protocol (abstract here).

Compared with never regular cell phone users, those with the highest cumulative call time had a 70% increased glioma risk.  Those with the highest level of radio frequency (RF) exposure over 7 years prior to diagnosis had a 90% increased risk for glioma (odds ratio, OR = 1.91, 95% confidence interval = 1.05 – 3.47) and double the risk for meningioma (OR = 2.01, CI = 1.03 – 3.93), another type of brain tumor.  With cell phone use starting 10 years prior to diagnosis, there was an almost three-fold increase in glioma risk (OR = 2.80, CI = 1.13 – 6.94).  All of these increases were statistically significant. 

This research confirms earlier studies finding increased risk of glioma among cell phone users, with brain tumors occurring in as little as 7 years after exposure.  Some might conclude that children who accumulate high call-time and radio frequency exposures are at especially high risk; they would cite this data to support a ban on cell phone use by children, and limits on adult use.

But is that a legitimate interpretation and application of the data?

The results in the second paragraph above are entirely accurate, but these are only a few of the many ORs that were produced in the extensive study.  The authors put their findings in perspective:

“There were suggestions of an increased risk of glioma in long-term mobile phone users with high RF exposure and of similar, but apparently much smaller, increases in meningioma risk. The uncertainty of these results requires that they be replicated before a causal interpretation can be made.”

The conclusions in the third paragraph above about children are, therefore, hyperbolic and indefensible. While the investigators did find some modest risk, they recommended further investigation, not a cell phone ban.

This study is relevant to tobacco harm reduction in several ways. 

The risk estimates for diseases related to long-term smokeless tobacco use are similar to the risks for cell phones.  As I discussed previously, while smokeless tobacco use cannot be proven to be absolutely safe, risk elevations for cancers (discussed here), as well as heart disease and stroke (here) are modest and usually not statistically significant. 

Elevated risks seen in the Interphone study do not justify the prediction of a cell phone-driven brain cancer epidemic.  That sort of leap for smokeless use, however, is not uncommon.  Surgeon General Antonia Novello in 1992 predicted “an oral cancer epidemic beginning two or three decades from now if the current trends in spit tobacco use continue.” (article here).  Two decades later, we see increased smokeless tobacco consumption, but no oral cancer epidemic.   

While the Interphone study results were consistent with prior research, the investigators did not call for drastic action to prevent cell phone use.  In contrast, questionable findings by the American Cancer Society (discussed here) and the Karolinska Institute (here) have been used to justify a ban on snus in the European Union, and to dissuade American smokers from switching to safer smoke-free substitutes.

The Interphone results suggest that heavy cell phone users might want to consider a “harm reduction” measure: use of a Bluetooth headset. This is comparable to recommending smokeless tobacco use to smokers.  Although there is no evidence that Bluetooth headsets are perfectly safe, they generally operate at lower radiated output power than cell phones, and therefore expose the user’s brain to lower RF doses than do cell phones.

Cell phones, like tobacco, are fixtures of modern society.  Their safe use is informed by responsibly conducted and interpreted epidemiologic studies, and guided by the principles of harm reduction.

Wednesday, June 6, 2012

E-Cigarettes Can Effectively Deliver Nicotine

A small clinical study of eight veteran e-cigarette users demonstrates that the products are capable of delivering nicotine doses that are similar to those of cigarettes.  The study was conducted by Andrea Rae Vansickel and Thomas Eissenberg of Virginia Commonwealth University and was published in Nicotine and Tobacco Research (abstract here). 

Vansickel and Eissenberg studied blood nicotine levels and heart rate among subjects who used e-cigarettes according to a standard protocol after 12 hours of abstinence.  All subjects had quit smoking 11 months earlier and were veteran vapers.  Seven of the study participants used devices that operated with higher voltage and larger battery capacity than products typically sold in convenience stores. 

Blood nicotine levels increased from 2 nanograms per milliliter (ng/ml) at baseline, to 10 ng/ml within 5 minutes of the first puff, and to 16 ng/ml at the end of the ad lib period of use.  These levels are similar to those produced with cigarette smoking.

Vansickel and Eissenberg report that “User experience and/or device characteristics likely influence e-cigarette nicotine delivery and other effects.”  This is important, because Eissenberg previously reported that e-cigarettes did not deliver measurable nicotine (article available here).  However, that study recruited 16 smokers who had no prior experience with e-cigarettes, and they were told to “puff normally.”  It is well known that use of e-cigarettes involves a learning curve; the devices require more vigorous inhalation than combustible cigarettes.  It therefore makes sense that na├»ve smokers didn’t achieve measurable nicotine levels.  Still, e-cigarettes produced somewhat lower craving scores.

Vansickel and Eissenberg conclude: “One important potential benefit of e-cigarette regulation may be more consistent nicotine delivery, device performance, and cartridge and vapor content.”

While regulation could ensure that consumers get reliable e-cigarette devices and liquids with consistent nicotine levels and no contaminants, it is essential that regulation not introduce barriers to smokers’ access to these potentially life-saving products.