Odds of quitting smoking are affected by genetics

NIH-funded research shows genetics can predict success of smoking cessation and need for medications

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Genetics can help determine whether a person is likely to quit smoking on his or her own or need medication to improve the chances of success, according to research published in today’s American Journal of Psychiatry. Researchers say the study moves health care providers a step closer to one day providing more individualized treatment plans to help patients quit smoking.

The study was supported by multiple components of the National Institutes of Health, including the National Institute on Drug Abuse (NIDA), the National Human Genome Research Institute, the National Cancer Institute, and the Clinical and Translational Science Awards program, administered by the National Center for Advancing Translational Sciences.

“This study builds on our knowledge of genetic vulnerability to nicotine dependence, and will help us tailor smoking cessation strategies accordingly,” said NIDA Director Nora D. Volkow, M.D. “It also highlights the potential value of genetic screening in helping to identify individuals early on and reduce their risk for tobacco addiction and its related negative health consequences.”

Researchers focused on specific variations in a cluster of nicotinic receptor genes, CHRNA5-CHRNA3-CHRNB4, which prior studies have shown contribute to nicotine dependence and heavy smoking. Using data obtained from a previous study supported by the National Heart Lung and Blood Institute, researchers showed that individuals carrying the high-risk form of this gene cluster reported a 2-year delay in the median quit age compared to those with the low-risk genes.  This delay was attributable to a pattern of heavier smoking among those with the high risk gene cluster. The researchers then conducted a clinical trial, which confirmed that persons with the high-risk genes were more likely to fail in their quit attempts compared to those with the low-risk genes when treated with placebo. However, medications approved for nicotine cessation (such as nicotine replacement therapies or bupropion) increased the likelihood of abstinence in the high risk groups. Those with the highest risk had a three-fold increase in their odds of being abstinent at the end of active treatment compared to placebo, indicating that these medications may be particularly beneficial for this population.

“We found that the effects of smoking cessation medications depend on a person’s genes,” said first author Li-Shiun Chen, M.D., of the Washington University School of Medicine, St. Louis. “If smokers have the risk genes, they don’t quit easily on their own and will benefit greatly from the medications. If smokers don’t have the risk genes, they are likely to quit successfully without the help of medications such as nicotine replacement or bupropion.”

According to the Centers for Disease Control and Prevention, tobacco use is the single most preventable cause of disease, disability, and death in the United States. Smoking or exposure to secondhand smoke results in more than 440,000 preventable deaths each year — about 1 in 5 U.S. deaths overall. Another 8.6 million live with a serious illness caused by smoking. Despite these well-documented health costs, over 46 million U.S. adults continue to smoke cigarettes.

The study can be found at: http://ajp.psychiatryonline.org/article.aspx?articleID=1169679. For information on tobacco addiction, go to: www.drugabuse.gov/drugs-abuse/tobacco-addiction-nicotine. For more information on tools and resources to help quit smoking, go to: www.smokefree.gov/.

All ‘Boomers’ should be tested for Hepatitis C infection

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ATLANTA — With “baby boomers” believed to account for 75% of the hepatitis C infected population in the U.S. — the CDC is recommending that everyone ages 47 to 67 be tested for infection.

The CDC estimates that some two million Americans born from 1945 to 1965 are infected with HCV — that’s about 3% of the boomer generation. But because many years usually elapse before noticeable symptoms develop, most don’t know they are infected.

The CDC said one-time HCV testing of all “baby boomers” “could identify more than 800,000 additional people with hepatitis C, prevent the costly consequences of liver cancer and other chronic liver diseases, and save more than 120,000 lives.”

“CDC believes this approach will address the largely preventable consequences of this disease, especially in light of newly available therapies that can cure up to 75% of infections,” the agency said in a statement issued Friday.

Most boomers do not have the risk factors that, until now, the CDC had used as the basis for testing recommendations. Those risk factors include use of illegal injected drugs, receiving blood products or organ transplants before HCV testing became routine, known exposures to HCV, presence of hepatitis symptoms, and all patients with HIV.

Vietnam era veterans — all baby boomers — are a well-know risk group due to blood exposure in military field hospitals as well as drug use.

Infection with HCV often leads to liver cancer. However, the recent introduction of HCV protease inhibitors, including telaprevir (Incivek) and boceprevir (Victrelis), has made the disease more manageable, possibly even curable.

The recommendation will be open for public comment from May 22 to June 8, after which the CDC will release a final version.

The CDC also set Saturday, May 19, as “National Hepatitis Testing Day,” and announced that it would make a total of $6.5 million in grants to make testing available to specific populations including Asian-American Pacific Islander communities (which have high rates of hepatitis B infection) and injection drug users, as well as members of the “boomer” generation.


John Gever

Senior Editor

John Gever, Senior Editor, has covered biomedicine and medical technology for 30 years. He holds a B.S. from the University of Michigan and an M.S. from Boston University.

Indoor tanning is associated with an increased risk for skin cancer

Indoor tanning is associated with an increased risk for skin cancer, the most common form of cancer in the United States (1,2).

The World Health Organization considers ultraviolet (UV) tanning devices to be a cause of cancer in humans (3).

Exposure to UV radiation, either from sunlight or indoor tanning devices, is the most important, avoidable known risk factor for skin cancer (4,5).

Annually, skin cancer costs an estimated $1.7 billion to treat and results in $3.8 billion in lost productivity (6).

Reducing the proportions of adolescents and adults who report using artificial sources of UV light for tanning are Healthy People 2020 objectives (7).

Current state-level policies to restrict indoor tanning are directed at youths aged <18 years. To examine the proportion of the adult U.S. population reporting indoor tanning in the past 12 months, CDC and the National Cancer Institute analyzed data from the 2010 National Health Interview Survey (NHIS). Overall, the age-adjusted proportion of adults reporting indoor tanning in the past 12 months was 5.6%, with higher rates among whites, women, and adults aged 18–25 years. Nationwide, the highest rates of indoor tanning were among white women aged 18–21 years (31.8%) and 22–25 years (29.6%). Among white adults who reported indoor tanning, 57.7% of women and 40.0% of men reported indoor tanning ≥10 times in the past 12 months. Continued public health efforts are needed to identify and implement effective strategies for reducing indoor tanning among adults in the United States, particularly among whites, women, and adults aged 18–25 years.

Click here to read the entire article with research citations >>> http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6118a2.htm?s_cid=mm6118a2_e