August 21, 2017

Peer Influence Doubles Teen Smoking Risk

Peer influence has long been known as a major risk factor for adolescent smoking, but findings have varied about how big the risk is or how this dynamic unfolds. A new, rigorous meta-analysis of 75 longitudinal teen smoking studies finds that having friends who smoke doubles the risk that children ages 10 to 19 will start smoking and continue smoking. It also found that peer influence is more powerful in collectivist cultures than in those where individualism is the norm.

There has been a great deal of research about peer influences on adolescents, says the study's senior author, Dolores Albarracín, PhD, a professor of psychology at the University of Illinois at Urbana-Champaign, but often findings rely on individual studies. "Meta-analysis is a summary of all we know," she says, "giving us a more reliable, robust number that is better supported by the facts."

"One of our most intriguing findings is that culture actually matters in how much influence adolescents have on their peers," says the study's lead author, Jiaying Liu, PhD, a recent graduate of the Annenberg School for Communication at the University of Pennsylvania. "Meta-analysis allowed us to examine studies from across the globe. We predicted that people in collectivistic cultures would be more likely to be influenced by peers around them, and that held true. In those most collectivistic countries, adolescents whose peers smoke are 4.3 times more likely to pick up smoking compared to people who have no peers smoking. By contrast, having peers who smoke made adolescents from those most individualist countries 1.89 times more likely to smoke."

Peer Influence Stronger in Some Cultures

The study included data from 16 countries, both collectivistic -- for example, China, South Korea, Jordan and Portugal -- and individualistic like the United States, Australia, Canada, the Netherlands and the United Kingdom.

The authors also examined the ethnic origins of the adolescents in each study, regardless of nationality. "We found that peer influence was much weaker in samples with higher proportions of adolescents with a European background, but much stronger in samples with higher proportions of adolescents with an Asian background," Liu says.

This finding about ethnic and cultural background may also explain why the results of teen smoking studies have varied in how big an effect peer influence has.

Closer Friends Have Biggest Influence

In addition, the study found that closer friends were more likely to influence peers to start smoking when compared to more distant friends. The closeness of peer friendships did not impact whether adolescents who smoke continued to smoke, however, indicating that perhaps the addictive nature of tobacco was an overriding factor.

The study was also able to better avoid what is often seen as the "chicken or the egg" problem of peer influence smoking studies: Do teens influence one another to smoke, or do those who smoke simply tend to become friends?

"By including only longitudinal studies, where peer influence was measured at an earlier time and adolescent smoking outcomes at a later date, we were better able to establish that peer influence led to the adolescent smoking outcomes, rather than the other way around," says Liu, who will be starting in the fall as an assistant professor in the University of Georgia's Department of Communication Studies.

Kids Need to Build Refusal Skills

The researchers hope that by providing a better understanding of the risk factors for teen smoking, they can help inform more targeted prevention efforts. By knowing who is most at risk, parents and public health officials alike can give teenagers the tools to resist tobacco.

"It's not enough just to say, 'Don't smoke it's bad for you,'" says Albarracín. "How are teenagers going to deal with temptation on a daily basis? We need much more specific campaigns dealing with normative influence -- for example, pointing out how many adolescents don't smoke. There can be more messaging in schools and training for parents on how to build refusal skills in their children."

Peer influence is particularly strong in the adolescent years, as children reduce the amount of time spent with parents and increase the amount of unsupervised time spent with peers.

Best to Start Prevention Early

"This work highlights the importance of considering the networks that surround teens, not just thinking about individuals in isolation," says co-author Emily Falk, PhD, associate professor at Penn's Annenberg School for Communication and director of its Communication Neuroscience Lab. "Behaviors spread from person to person, and keeping that in mind is essential for prevention and cure."

"The burden of smoking-caused morbidity is heavy around the world," Liu adds. "If social influence is a crucial factor in adolescents' decisions to start smoking and keep smoking, we want to understand how to leverage its power for better smoking prevention. It's always easier to stop people from starting to smoke than to change their behavior later in life."

The study was published in the journal Psychological Bulletin.

Posted by Webmaster at 12:22 PM

August 18, 2017

Smoking Can Increase Frailty in Older Adults

Smokers can greatly lower their risks of becoming frail as they grow older by quitting, even in old age. Old adults who smoke tobacco run a 60 percent greater risk of becoming frail in their later years.

British researchers have found that current smoking in older people increases the risk of developing frailty, compared with former smokers and never smokers. Former smokers, even those who quit in the past 10 years, did not appear to be at higher risk.

Smoking increases the risk of developing a number of diseases, such as chronic obstructive pulmonary disease (COPD), coronary heart disease, stroke and peripheral vascular disease, all of which can potentially have negative effects on people's physical, psychological and social health.

Frailty a Precursor to Disability

Frailty is considered a precursor to, but a distinct state from, disability. Frailty is a condition associated with decreased physiological reserve and increased vulnerability to adverse health outcomes. The outcomes include falls, fractures, disability, hospitalisation and institutionalisation. Frailty has also been shown to be linked to worse psychological or cognitive outcomes, such as poor quality of life and dementia.

Due to the potential for reversibility of frailty, identifying potentially modifiable risk factors of frailty may help to develop strategies to prevent or slow progression of adverse health outcomes associated with both frailty and smoking.

Researchers aimed to examine the association of smoking with the risk of developing frailty, controlling for important confounding variables and using data from a nationally representative sample of older men and women living in England.

The Components of Frailty

Researchers defined frailty using a combination of five physical frailty components:

  • unintentional weight loss
  • self-reported exhaustion
  • weakness
  • slow walking speed
  • low physical activity

Frailty is classified as having three or more of the five criteria.

The current study used data of participants who were aged 60 years or older. The final sample for this study was 2,542 participants, divided into two groups: current smokers and non-smokers. The non-smokers were further divided into another two groups: past smokers and never smokers. The past smokers were once again divided into two groups: those who quit within the last 10 years and those who quit more than 10 years ago. The analysis revealed that current smoking was associated with an approximately 60% increased risk of developing frailty.

There was, however, no significant association between past smoking and incident frailty in any models. Among 1,113 past smokers, 157 quit smoking within the last 10 years and 956 quit smoking for more than 10 years ago. Incident frailty risks of these two groups were not significantly different from that of never smokers in all models.

COPD Strongly Linked to Frailty

When COPD was added to the model, current smoking was no longer a significant predictor of incident frailty. In this model, COPD was strongly associated with incident frailty. These findings suggest that current smokers are more likely to develop frailty due to COPD, rather than smoking itself.

Given that smoking is a modifiable lifestyle factor, and smokers who quit did not appear to be at high risk for frailty, this research suggests that smoking cessation may potentially prevent or delay developing frailty, even in old age.

"Our study showed that current smoking is a risk factor of developing frailty. Additional analyses revealed that COPD seems a main factor on the causal pathway from smoking towards frailty," said the study's author, Gotaro Kojima, "but those who quit smoking did not carry over the risk of frailty."

The study was published in Age & Ageing, the scientific journal of the British Geriatrics Society.

Posted by Webmaster at 07:29 AM

August 14, 2017

Quitting Smoking More Difficult for Some

Psychologists are finding some success with treatments aimed at helping smokers from underserved groups, including racial and ethnic minorities and those with psychiatric disorders.

Quit Smoking Help

In the Journal of Consulting and Clinical Psychology, published by the American Psychological Association, researchers report on several effective treatments that may help these smokers in an effort to increase national smoking cessation rates. The percentage of American smokers rose from 19.8 percent in 2007 to 20.6 percent in 2008, after a 10-year steady decline in smoking rates, according to the latest figures from the Centers for Disease Control and Prevention.

"One of the reasons smoking rates have remained stagnant is because these underserved groups of smokers have not been adequately targeted by research and treatment," said the special section editor, Belinda Borrelli, PhD, who is with the Centers for Behavioral and Preventive Medicine at Brown University Medical School. Underserved smokers include those who have a 10 percent higher smoking rate than the general population, have less access to treatments, and are more likely to be excluded from long-term treatments trials, according to Borelli.

In one article, researchers found that success in stopping smoking differed for different psychiatric disorders. For example, compared to smokers with no psychiatric disorders, smokers who had an anxiety disorder were less likely to quit smoking six months after treatment.

In the same article, researchers found that people's barriers to quitting were directly related to what type of psychiatric disorder they had. For example, smokers who had ever been diagnosed with an anxiety disorder reported a strong emotional bond with their cigarettes while smokers ever diagnosed with a substance use disorder reported that social and environmental influences were especially likely to affect their smoking. "This information may help clinicians gauge relapse risk and identify treatment targets among smokers who have ever had psychological illnesses," said lead author Megan Piper, PhD, from the University of Wisconsin School of Medicine and Public Health.

Comparing Treatment

Evidence-based smoking cessation treatments are addressed in another article in this special section. Researchers from the University of Miami looked at the effect of intensive cognitive-behavioral therapy on African-American smokers. They placed 154 African-American smokers wearing nicotine patches into one of two six-session interventions. Participants in the group using cognitive-behavioral techniques were taught relapse prevention strategies and coping skills, along with other techniques. The other group participated in a health education series that explained general medical conditions that are associated with smoking, such as heart disease and lung cancer.

Compared with general health education, participation in cognitive-behavioral therapy sessions more than doubled the rate of quitting at a six month follow-up, from 14 percent to 31 percent the researchers found. "We know cognitive-behavioral therapy helps people quit, but few studies have examined this treatment's effect on African-American smokers," said the study's lead author, Monica Webb, PhD, of the University of Miami. "Hopefully, our findings will encourage smoking cessation counselors and researchers to utilize cognitive-behavioral interventions in this underserved population."

Secondhand Smoke Study

Borrelli, the section editor, examined another minority group—Latinos. She measured the amount of second-hand smoke in participants' homes and gave feedback to smokers about how much smoke their child with asthma was exposed to. For example, they were told that their child was exposed to as much smoke as if the child smoked 'x' number of cigarettes him- or herself during the week of the measurement – this was the experimental group. Smokers in the control group underwent standard cognitive-behavioral treatment for smoking cessation. Smokers in the experimental group were twice as likely to quit as the control group, Borrelli found. "The child's asthma problems may provide a teachable moment for parents whereby they become more open to the smoking cessation messages," Borrelli said. "Providing treatment that is focused on the health needs of the family, and delivered in a culturally tailored manner, has the potential to address health care disparities for Latino families."

Posted by Webmaster at 03:45 AM

August 13, 2017

Smoking Reduction Quickly Lowers Death Rates

A study by the University of Liverpool has found that a decrease in smoking rapidly reduces mortality rates in individuals and entire populations within six months. Research by Professor Simon Capewell and Dr Martin O'Flaherty at the Institute of Psychology, Health and Well-being, examined evidence from clinical trials and natural experiments.

They found that a reduction in smoking has a positive impact on mortality rates in both individuals and populations within six months. Likewise, dietary improvements get very positive results within one to three years.

Benefits Happen Quickly

Professor Capewell said:"Our research found that smoking bans and diet improvements powerfully and rapidly reduce chronic disease in both individuals and in the wider population. This actually happens quickly, within a far shorter timescale than had previously been assumed; within months and years rather than decades. This discovery means that policies such as smoking bans or reducing saturated fats are effective at improving health and would save the NHS millions very rapidly."

The study found that policies that reduce smoking consistently have a rapidly positive effect on mortality rates and hospital admissions in countries and communities around the world. After smoke-free legislation was introduced in Scotland in 2006, hospital admissions for acute coronary syndrome decreased by 17% with a 6% decrease in out-of-hospital cardiac deaths.

Similarly, when smoke-free legislation was introduced in Helena, an isolated community in the US, it resulted in a 40% drop in admission rates for acute coronary syndrome within six months in one hospital. When the law was repealed the coronary admissions returned to previous levels within six months.

Diet Changes Help Too

Changes to diet also have a rapid and positive impact on the reduction of mortality rates for coronary heart disease. Coronary death rates rose steadily during the 20th Century, peaking in the 1970s in the UK, US and Western Europe. However, closer scrutiny of national trends revealed a notch in the early 1940s. This has been attributed to sudden decreases in dietary meat and animal fats due to food rationing during the Second World War.

More recently, a study of coronary disease in Poland found that death rates from heart disease had been rising steadily. From 1990, however, they quickly dropped by 25% after meat and animal fat subsidies from the communist countries ceased and cheap vegetable oils and fruit flooded the market. A study of other central European countries confirmed very similar trends.

Posted by Webmaster at 06:35 PM

Parents Have Role in Smoking Prevention

Parents shouldn't let up when it comes to discouraging their kids from smoking. That's the message of a study presented at the Pediatric Academic Societies (PAS) annual meeting in Denver.

Previous research has shown that parents can deter adolescents from smoking by monitoring them and enforcing anti-smoking practices at home. Researchers, led by E. Melinda Mahabee-Gittens, MD, an emergency medicine physician at Cincinnati Children's Hospital Medical Center, sought to determine if family factors continue to protect adolescents as they grow older and whether these factors affect youths of varying racial/ethnic backgrounds differently.

Family Factors in Smoking

Investigators studied 3,473 pairs of white, black and Hispanic parents and nonsmoking youths who participated in the National Survey of Parents and Youth in November 1999-June 2001 (Time 1) and again in July 2002-June 2003 (Time 2). They looked at whether youths remained nonsmokers throughout the study period, and they assessed changes in family factors thought to protect against smoking initiation over time.

Results showed no differences in the rate of smoking initiation between Time 1 and Time 2 by race. In addition, youths in all three racial/ethnic groups reported associating more with peers who smoked at Time 2 than at Time 1.

The levels of protective family factors decreased significantly from Time 1 to Time 2 across all racial/ethnic groups in both smokers and nonsmokers. However, levels of protective factors were consistently higher in nonsmoking youths compared to smokers. Continued, higher levels of connectedness and monitoring by parents decreased the risk of smoking initiation by as much as 30 percent in both whites and Hispanics.

Increased Risk of Smoking

Meanwhile, decreases in the following family factors from Time 1 to Time 2 were associated with an increased risk that youths would start smoking: 1) punishment: up to 43 percent increased risk in all three racial/ethnic groups; 2) monitoring: 42 percent increased risk in blacks only; and 3) connectedness: up to 26 percent increased risk in both blacks and Hispanics.

"Even though the level of protective family factors decreased as youth grew older, they remained important in continuing to protect against smoking initiation," said Dr. Mahabee-Gittens, who is also associate professor of pediatrics at the University of Cincinnati. "These findings support smoking prevention interventions that encourage parents of all three racial/ethnic groups to enforce consistent consequences of smoking behavior, and encourage continued monitoring and connectedness in minority groups."

Posted by Webmaster at 12:00 PM

Heavy Smoking Doubles Alzheimer's Risk

Heavy smoking in midlife is associated with a 157 percent increased risk of developing Alzheimer's disease and a 172 percent increased risk of developing vascular dementia, according to a Kaiser Permanente study published in the Archives of Internal Medicine. This is the first study to look at the long-term consequences of heavy smoking on dementia.

Increased Risk Among Smokers

Researchers followed an ethnically diverse population of 21,123 men and women from midlife onward for an average of 23 years. Compared with non-smokers, those who had smoked more than two packs of cigarettes a day had more than a 157 percent increased in risk of Alzheimer's disease and 172 percent increased risk of vascular dementia during the mean follow-up period of 23 years. Vascular dementia, the second most common form of dementia after Alzheimer's disease, is a group of dementia syndromes caused by conditions affecting the blood supply to the brain.

"This study shows that the brain is not immune to the long-term consequences of heavy smoking," said the study's principal investigator, Rachel A. Whitmer, Ph.D., a research scientist with the Kaiser Permanente Division of Research in Oakland, Calif. "We know smoking compromises the vascular system by affecting blood pressure and elevates blood clotting factors, and we know vascular health plays a role in risk of Alzheimer's disease."

Researchers analyzed prospective data from of 21,123 Kaiser Permanente Northern California members who participated in a survey between 1978 and 1985. Diagnoses of dementia, Alzheimer's disease and vascular dementia made in internal medicine, neurology, and neuropsychology were collected from 1994 to 2008. The researchers adjusted for age, sex, education, race, marital status, hypertension, hyperlipidemia, body mass index, diabetes, heart disease, stroke, and alcohol use.

Brain Vessels Affected

"While we don't know for sure, we think the mechanisms between smoking and Alzheimer's and vascular dementia are complex, including possible deleterious effects to brain blood vessels as well as brain cells," said study co-author Minna Rusanen, MD, of the University of Eastern Finland and Kuopio University Hospital in Finland.

This study is the latest in a series of published Kaiser Permanente research to better understand the modifiable risk factors for dementia. This ongoing body of research adds to evidence base that what is good for the heart is good for the brain, and that midlife is not too soon to begin preventing dementia with good health.

The other studies led by Whitmer found that a large abdomen in midlife increases risk of late-life dementia, elevated cholesterol levels in midlife increase risk of Alzheimer's disease and vascular dementia, and low blood-sugar events in elderly patients with type 2 diabetes increase dementia risk. Another Kaiser Permanente study led by Valerie Crooks of Kaiser Permanente in Southern California found that having a strong social network of friends and family appears to decrease risk for dementia.

Increased Risk Among Smokers

Researchers followed an ethnically diverse population of 21,123 men and women from midlife onward for an average of 23 years. Compared with non-smokers, those who had smoked more than two packs of cigarettes a day had more than a 157 percent increased in risk of Alzheimer's disease and 172 percent increased risk of vascular dementia during the mean follow-up period of 23 years. Vascular dementia, the second most common form of dementia after Alzheimer's disease, is a group of dementia syndromes caused by conditions affecting the blood supply to the brain.

"This study shows that the brain is not immune to the long-term consequences of heavy smoking," said the study's principal investigator, Rachel A. Whitmer, Ph.D., a research scientist with the Kaiser Permanente Division of Research in Oakland, Calif. "We know smoking compromises the vascular system by affecting blood pressure and elevates blood clotting factors, and we know vascular health plays a role in risk of Alzheimer's disease."

Researchers analyzed prospective data from of 21,123 Kaiser Permanente Northern California members who participated in a survey between 1978 and 1985. Diagnoses of dementia, Alzheimer's disease and vascular dementia made in internal medicine, neurology, and neuropsychology were collected from 1994 to 2008. The researchers adjusted for age, sex, education, race, marital status, hypertension, hyperlipidemia, body mass index, diabetes, heart disease, stroke, and alcohol use.

Brain Vessels Affected

"While we don't know for sure, we think the mechanisms between smoking and Alzheimer's and vascular dementia are complex, including possible deleterious effects to brain blood vessels as well as brain cells," said study co-author Minna Rusanen, MD, of the University of Eastern Finland and Kuopio University Hospital in Finland.

This study is the latest in a series of published Kaiser Permanente research to better understand the modifiable risk factors for dementia. This ongoing body of research adds to evidence base that what is good for the heart is good for the brain, and that midlife is not too soon to begin preventing dementia with good health. The other studies led by Whitmer found that a large abdomen in midlife increases risk of late-life dementia, elevated cholesterol levels in midlife increase risk of Alzheimer's disease and vascular dementia, and low blood-sugar events in elderly patients with type 2 diabetes increase dementia risk. Another Kaiser Permanente study led by Valerie Crooks of Kaiser Permanente in Southern California found that having a strong social network of friends and family appears to decrease risk for dementia.

Posted by Webmaster at 10:57 AM

Smoking Bans Reduce Heart Attack Admissions

A nationwide smoking ban in public places would save more than $90 million and significantly reduce hospitalizations for heart attack, according to a Henry Ford Hospital study. After analyzing data from the 13 states that don't have a law banning smoking in public places, researchers concluded that more than 18,596 fewer hospitalizations for heart attack could be realized from a smoking ban in all 50 states after the first year of implementation, resulting in more than $92 million in savings in hospitals costs for caring for those patients.

The study, funded by the hospital, was at the American Heart Association's annual Quality of Care and Outcomes Research conference in Washington.

Smokers Harming Themselves

"Even if you just save one heart attack, it is something significant," says Mouaz Al-Mallah, M.D., Henry Ford's co-director of Cardiac Imaging Reearch and lead author of the study. "When people smoke, they are not only harming themselves, they're harming those around them who are exposed to secondhand smoke."

A similar study conducted in 2008 by Dr. Al-Mallah found that a smoking ban in Michigan could lead to a 12 percent drop in heart attack admissions after the first year of implementation. On May 1, Michigan became the 38th state to ban smoking in public places.

Heart Attack Rates Reduced

Prior research involving risk reduction from smoking bans has shown that heart attack rates can be reduced by 11 percent after a comprehensive smoking ban.

Henry Ford obtained 2007 data on the number of heart attack discharges, length of stay and hospital charges from the 13 states currently without a public smoking ban. Researchers found 169,043 hospitalizations for heart attack were reported in the states with a comprehensive smoking ban. When the same 11 percent risk reduction was applied to the non-smoking states, researchers concluded it would led to 18,596 fewer heart attack admissions.

Posted by Webmaster at 09:49 AM

Teen Smokers Don't Recognize Signs of Dependence

Kids who have just started smoking, but not on a daily basis, don't seem to recognize the early symptoms of dependence, according to a study. Published in the journal Pediatrics by Chyke Doubeni, MD, MPH of the University of Massachusetts, the study found that among kids who have started smoking, "an urge to smoke or being irritable because they are not able to smoke is a sign of early dependence. But they don't seem to recognize that symptoms such as irritability are harbingers of addiction."

"Previous studies have already shown that there is a strong correlation between symptoms of nicotine dependence and nicotine addiction. This study shows that adolescents who start smoking, don't appear to recognize the early signs of dependence," Doubeni said. Other signs of early dependence that go unnoticed include experiencing a desire to smoke or craving for a cigarette.

Early Signs of Nicotine Dependence

The study concluded that nondaily use of tobacco can trigger any of these early signs of dependence. Early dependence promotes increased smoking. That in turn accelerates additional signs of dependence, which leads to even higher frequencies of smoking. Eventually, it leads to addiction.

The conclusions are based on a study that surveyed adolescent smokers every three to four months, over a four-year period from 2002-2006. The study found that over those four years, of the 370 subjects who had inhaled from a cigarette, 62% smoked at least once per month, 52% experienced dependence symptoms, and 40% went on to become daily smokers.

The study, "Early Course of Nicotine Dependence in Adolescent Smokers," provides additional evidence supporting the Food and Drug Administration's (FDA) recent rules placing restrictions on tobacco marketing to youth. Tobacco companies are challenging some of the FDA's rules in court.

Posted by Webmaster at 09:26 AM

Test Could Identify Smokers at Risk of Emphysema

Using CT scans to measure blood flow in the lungs of people who smoke may offer a way to identify which smokers are most at risk of emphysema before the disease damages and eventually destroys areas of the lungs, according to a University of Iowa study.

The study found that smokers who have very subtle signs of emphysema, but still have normal lung function, have very different blood flow patterns in their lungs compared to non-smokers and smokers without signs of emphysema.

Smokers and Emphysema

This difference could be used to identify smokers at increased risk of emphysema and allow for early intervention. The findings appear this week in the Early Edition of the Proceedings of the National Academy of Sciences.

"We have developed a new tool to detect early emphysema-related changes that occur in smokers who are susceptible to the disease," said lead study author Eric Hoffman, Ph.D., UI professor of radiology, internal medicine and biomedical engineering. "Our discovery may also help researchers understand the underlying causes of this disease and help distinguish this type of emphysema from other forms of chronic obstructive pulmonary disease. This type of CT scan could even be a tool to test the effectiveness of new therapies by looking at the changes in lung blood flow."

Targeting COPD

As many as 24 million Americans have chronic obstructive pulmonary disease (COPD) -- a group of serious lung diseases that includes emphysema -- and COPD is the fourth leading cause of death nationwide. Because COPD is a group of different diseases, identifying more effective treatments may hinge on distinguishing between these diseases and targeting them separately.

The team used multi-detector row CT imaging to measure blood flow patterns in the lungs of 41 study participants -- 17 non-smokers and 24 smokers. All the participants had normal lung function, but 12 of the smokers had very subtle signs of emphysema. The CT scans showed that these 12 individuals had the most disrupted patterns of blood flow compared to the other participants.

The findings also support the idea that abnormal blood flow occurs before emphysema develops.

"Although the underlying causes of emphysema are not well understood, smoking increases the risk of developing the disease," Hoffman said. "Our study suggests that some smokers have an abnormal response to inflammation in their lungs; instead of sending more blood to the inflamed areas to help repair the damage, blood flow is turned off and the inflamed areas deteriorate."

Repairing the Damage

The cellular pathway that turns off blood flow is helpful when an area of the lung has become permanently blocked and cannot be rescued. In that case, the lung "optimizes gas exchange" and stops supplying the area with blood. However, lung inflammation caused by smoking can be resolved and resultant damage repaired by increased blood flow, which brings oxygen and helpful cellular components to the site of injury.

This study suggests that the ability to distinguish when to turn off or when to ramp up blood flow is defective in some people -- probably due to genetic differences. If this genetic difference is coupled with smoking, which increases lung inflammation, that could increase the risk of developing emphysema.

Posted by Webmaster at 09:05 AM

How Fast Does Nicotine Peak in the Brain?

Nicotine takes much longer than previously thought to reach peak levels in the brains of cigarette smokers, according to new research conducted at Duke University Medical Center.

Traditionally, scientists thought nicotine inhaled in a puff of cigarette smoke took a mere seven seconds to be taken up by the brain, and that each puff produced a spike of nicotine. Using PET imaging, Duke investigators illustrate, for the first time, that cigarette smokers actually experience a steady rise of brain nicotine levels during the course of smoking a whole cigarette.

The findings, scheduled to appear online in the Early Edition of Proceedings of the National Academy of Sciences (PNAS), could lead to more effective treatments for smoking addiction.

Nicotine Accumulates in the Brain

"Previously it was thought that the puff-by-puff spikes of nicotine reaching the brain explained why cigarettes are so much more addictive than other forms of nicotine delivery, like the patch or gum," says Jed Rose, Ph.D., director of the Duke Center for Nicotine and Smoking Cessation Research. "Our work now calls into question whether addiction has to do with the puff-by-puff delivery of nicotine. It may actually depend in part on the overall rate at which nicotine reaches and accumulates in the brain, as well as the unique habit and sensory cues associated with smoking."

Yet, when the researchers compared 13 dependent smokers to 10 non-dependent smokers, they were surprised to find the dependent smokers had a slower rate of nicotine accumulation in the brain. "This slower rate resulted from nicotine staying longer in the lungs of dependent smokers, which may be a result of the chronic effects of smoke on the lungs," surmises Rose.

The difference in rate of nicotine accumulation in the brain doesn't explain why some people become addicted to cigarettes and others don't. "Even if you correct for the speed of delivery, our study showed the non-dependent smokers eventually experienced the same high levels of nicotine in their brain as dependent smokers, yet they did so without becoming dependent. The real mystery is why."

Sensitivity to Nicotine

Rose says the absence of addiction in these smokers could be due to genetic differences, differences in the way they smoke, or differences in the psychological effects they derive. "We're still not able to fully explain why these people are able to smoke without becoming addicted."

Despite the questions raised, the study provides important insights into the role of the speed and level of brain nicotine levels, and which receptors in the brain are at work. "Different receptors respond to nicotine at different levels of sensitivity," says Rose. "Knowing the levels of nicotine that are really getting to the brain gives us clues as to which receptors are more likely to be important for the dependence-producing effects of cigarette smoking."

Posted by Webmaster at 03:22 AM

Smoking Cessation Therapy Proves Promising

A novel technology for delivering nicotine to the lungs may soon give smokers a new way to kick the habit. When compared to the nicotine vapor delivery system used in the Nicotrol/Nicorette inhaler, the new technology proved more effective at delivering nicotine to the blood stream.

As a result, it provides immediate relief of withdrawal symptoms, according to Duke University Medical Center researchers. Users also reported the new nicotine delivery method was more tolerable than the current inhaler because it caused less throat irritation.

Smoking Without Danger?

"We wanted to replicate the experience of smoking without incurring the dangers associated with cigarettes, and we wanted to do so more effectively than the nicotine replacement therapies currently on the market," said Jed Rose, Ph.D., director of the Duke Center for Nicotine and Smoking Cessation Research where the technology is being developed. He presented the data at the Society for Nicotine and Tobacco Research (SRNT) in Baltimore, MD.

The Nicotrol inhaler is a smoking cessation therapy that delivers nicotine vapor to the mouth and upper airways, but little of it reaches the lungs.

Duke's new technology employs a unique method to deliver nicotine to the lungs. In today's presentation, the researchers show the new lung delivery technology results in rapid absorption of nicotine that provides immediate relief of withdrawal symptoms and also re-creates some of the familiar sensations that are pleasurable to smokers.

Current methods that deliver medicine to the lungs -- metered dose sprays, dry powder inhalers or nebulizers that create a fine mist – do not replicate the natural inhalation used by smokers when drawing on a cigarette. And, because medication residue often deposits in the mouth and throat, doses aren't always high enough to ensure the appropriate amount reaches the lungs.

Combining Two Vapors


Duke's new technology combines the vapor phase of pyruvic acid, which occurs naturally in the body, and nicotine. "When the two vapors combine, they form a salt called nicotine pyruvate," explains Rose. "This reaction transforms invisible gas vapors into a cloud of microscopic particles which is inhaled, just like a smoker inhales from a cigarette."

In a study of the new Duke technology, nine healthy smokers inhaled 10 puffs of nicotine pyruvate in increasing doses, 10 puffs from a Nicotrol/Nicorette inhaler cartridge, and 10 puffs of room air (placebo). Blood was drawn before and after each set of inhalations. When the results were analyzed, the Duke researchers noted rapid increases in plasma nicotine concentrations following the nicotine pyruvate inhalations and less complaints of harshness/irritation when compared to the Nicotrol/Nicorette control cartridge. The smokers also said their cravings for cigarettes were substantially alleviated following the nicotine pyruvate inhalations.

"Compared to the current nicotine vapor inhaler, we are able to give smokers more nicotine, although still less than a cigarette, with less irritation, resulting in reduced cravings," said Rose. "Thus we are able to achieve a therapeutic effect with greater tolerability."

More research is needed to examine the safety and effectiveness of prolonged use of the inhalation system, and to assess its role in helping people quit smoking. But, Rose says if all goes well, he anticipates the product could become commercially available within three to five years.

He also says the novel inhalation system may one day prove useful for delivery of other medications. Duke has filed patent applications on the new technology, which was invented by Rose and his colleagues, including his brother, Seth D. Rose, Ph.D., Duke colleague, Thangaraju Murugesan, Ph.D., and James E. Turner, an inventor of the Nicotrol/Nicorette inhaler.

Posted by Webmaster at 03:14 AM