LONDON - Like UV rays and diesel exhaust fumes, working the graveyard shift will soon be listed as a "probable" cause of cancer. It is a surprising step validating a concept once considered wacky. And it is based on research that finds higher rates of breast and prostate cancer among women and men whose work day starts after dark.
Next month, the International Agency for Research on Cancer, the cancer arm of the World Health Organization, will add overnight shift work as a probable carcinogen. The American Cancer Society says it will likely follow. Up to now, the U.S. organization has considered the work-cancer link to be "uncertain, controversial or unproven."
The higher cancer rates don't prove working overnight can cause cancer. There may be other factors common among graveyard shift workers that raise their risk for cancer.
However, scientists suspect that overnight work is dangerous because it disrupts the circadian rhythm, the body's biological clock. The hormone melatonin, which can suppress tumor development, is normally produced at night.
If the graveyard shift theory eventually proves correct, millions of people worldwide could be affected. Experts estimate that nearly 20 percent of the working population in developed countries work night shifts.
Among the first to spot the night shift-cancer connection was Richard Stevens, a cancer epidemiologist and professor at the University of Connecticut Health Center. In 1987, Stevens published a paper suggesting a link between light at night and breast cancer.
Back then, he was trying to figure out why breast cancer incidence suddenly shot up starting in the 1930s in industrialized societies, where nighttime work was considered a hallmark of progress. Most scientists were bewildered by his proposal.
But in recent years, several studies have found that women working at night over many years were indeed more prone to breast cancer. Also, animals that have their light-dark schedules switched develop more cancerous tumors and die earlier.
Some research also suggests that men working at night may have a higher rate of prostate cancer.
Because these studies mostly focused on nurses and airline crews, bigger studies in different populations are needed to confirm or disprove the findings.
There are still plenty of skeptics. And to put the risk in perspective, the "probable carcinogen" tag means that the link between overnight work and cancer is merely plausible.
Among the long list of agents that are listed as "known" carcinogens are alcoholic beverages and birth control pills. Such lists say nothing about exposure amount or length of time or how likely they are to cause cancer. The American Cancer Society Web site notes that carcinogens do not cause cancer at all times.
Still, many doubters of the night shift link may be won over by the IARC's analysis to be published in the December issue of the journal Lancet Oncology.
"The indications are positive," said Vincent Cogliano, who heads up the agency's carcinogen classifications unit. "There was enough of a pattern in people who do shift work to recognize that there's an increase in cancer, but we can't rule out the possibility of other factors."
Scientists believe having lower melatonin levels can raise the risk of developing cancer. Light shuts down melatonin production, so people working in artificial light at night may have lower melatonin levels.
Melatonin can be taken as a supplement, but experts don't recommend it long-term, since that could ruin the body's ability to produce it naturally.
Sleep deprivation may be another factor in cancer risk. People who work at night are not usually able to completely reverse their day and night cycles.
"Night shift people tend to be day shift people who are trying to stay awake at night," said Mark Rea, director of the Light Research Center at Rensselaer Polytechnic Institute in New York, who is not connected with the IARC analysis.
Not getting enough sleep makes your immune system vulnerable to attack, and less able to fight off potentially cancerous cells.
Confusing your body's natural rhythm can also lead to a breakdown of other essential tasks. "Timing is very important," Rea said. Certain processes like cell division and DNA repair happen at regular times.
Even worse than working an overnight shift is flipping between daytime and overnight work.
"The problem is re-setting your body's clock," said Aaron Blair, of the United States' National Cancer Institute, who chaired IARC's recent meeting on shift work. "If you worked at night and stayed on it, that would be less disruptive than constantly changing shifts."
Anyone whose light and dark schedule is often disrupted — including frequent long-haul travelers or insomniacs — could theoretically face the same increased cancer risk, Stevens said.
He advises workers to sleep in a darkened room once they get off work. "The balance between light and dark is very important for your body. Just get a dark night's sleep."
Meanwhile, scientists are trying to come up with ways to reduce night workers' cancer risk. And some companies are experimenting with different lighting, seeking a type that doesn't affect melatonin production.
So far, the color that seems to have the least effect on melatonin is one that few people would enjoy working under: red.
___
American Cancer Society's list of known and probable carcinogens from IARC and National Toxicology Program: http://tinyurl.com/2kl5ab
International Agency for Research on Cancer: http://www.iarc.fr/
Thursday, November 29, 2007
Monday, November 26, 2007
Alzheimer drugs don't delay dementia onset: study
LONDON (Reuters) - Giving Alzheimer's drugs to people with early memory problems does not seem to delay the onset of the disease, researchers said on Tuesday.
Three main drugs -- Aricept, or donepezil; Exelon, or rivastigmine; and Reminyl, or galantamine -- are currently approved for use in mild-to-moderate Alzheimer's disease.
They are also often prescribed on a so-called "off-label" basis to people with pre-dementia.
But doctors are divided over their effectiveness, leading to differing rates of use and bitter arguments over patient access to treatment, notably in Britain where a dispute over their cost-effectiveness has led to legal clashes.
Some experts and patient groups have called for such anti-cholinesterase drugs to be given to people with mild cognitive impairment (MCI) -- a condition where people have memory problems that are more severe than those normally seen in others of their age.
People with MCI are thought to be at high risk of developing Alzheimer's or dementia.
Italian researchers, however, found that in none of six clinical trials they examined did using the drugs significantly reduce the rate of progression from MCI to dementia.
Accurate assessment of the effect of anti-cholinesterase medicines was muddied by the lack of a precise definition for MCI, Roberto Raschetti and colleagues at the National Centre for Epidemiology, Surveillance and Health Promotion in Rome reported in the online journal PLoS Medicine.
Their findings may prompt a rethink among doctors who are currently using anti-cholinesterase drugs off-label in MCI. Off-label use refers to the common practice of prescribing drugs for uses for which they are not officially approved.
In Italy, an estimated 27 percent of patients diagnosed with MCI are given Alzheimer's drugs off-label and Raschetti said it was likely the situation was similar in other countries.
He argued more clinical trials were needed, using a single agreed definition of MCI, before there could be any justification for doctors to use the drugs in pre-dementia cases, especially as the drugs can have harmful side effects.
Aricept is marketed by Japan's Eisai Co Ltd and Pfizer Inc, while Novartis AG sells Exelon. Reminyl is sold by Shire Plc and also by Johnson & Johnson under the brand name Razadyne.
A row over who should get these drugs ended up in court in London earlier this year after Britain's National Institute for Health and Clinical Excellence said they should not be given to newly diagnosed patients with mild Alzheimer's disease.
Drugmakers claimed the agency's cost-effectiveness calculations were flawed but the court backed the restrictions in a ruling handed down in August.
Three main drugs -- Aricept, or donepezil; Exelon, or rivastigmine; and Reminyl, or galantamine -- are currently approved for use in mild-to-moderate Alzheimer's disease.
They are also often prescribed on a so-called "off-label" basis to people with pre-dementia.
But doctors are divided over their effectiveness, leading to differing rates of use and bitter arguments over patient access to treatment, notably in Britain where a dispute over their cost-effectiveness has led to legal clashes.
Some experts and patient groups have called for such anti-cholinesterase drugs to be given to people with mild cognitive impairment (MCI) -- a condition where people have memory problems that are more severe than those normally seen in others of their age.
People with MCI are thought to be at high risk of developing Alzheimer's or dementia.
Italian researchers, however, found that in none of six clinical trials they examined did using the drugs significantly reduce the rate of progression from MCI to dementia.
Accurate assessment of the effect of anti-cholinesterase medicines was muddied by the lack of a precise definition for MCI, Roberto Raschetti and colleagues at the National Centre for Epidemiology, Surveillance and Health Promotion in Rome reported in the online journal PLoS Medicine.
Their findings may prompt a rethink among doctors who are currently using anti-cholinesterase drugs off-label in MCI. Off-label use refers to the common practice of prescribing drugs for uses for which they are not officially approved.
In Italy, an estimated 27 percent of patients diagnosed with MCI are given Alzheimer's drugs off-label and Raschetti said it was likely the situation was similar in other countries.
He argued more clinical trials were needed, using a single agreed definition of MCI, before there could be any justification for doctors to use the drugs in pre-dementia cases, especially as the drugs can have harmful side effects.
Aricept is marketed by Japan's Eisai Co Ltd and Pfizer Inc, while Novartis AG sells Exelon. Reminyl is sold by Shire Plc and also by Johnson & Johnson under the brand name Razadyne.
A row over who should get these drugs ended up in court in London earlier this year after Britain's National Institute for Health and Clinical Excellence said they should not be given to newly diagnosed patients with mild Alzheimer's disease.
Drugmakers claimed the agency's cost-effectiveness calculations were flawed but the court backed the restrictions in a ruling handed down in August.
MRI scans show second-hand smoke damage to lungs
WASHINGTON (Reuters) - One third of people who breath in high levels of secondhand smoke have damage to their lungs similar to that seen in smokers, doctors reported on Monday.
They used a special kind of magnetic resonance imaging, or MRI, scan to look at the lungs of non-smokers who had high exposure to other people's cigarette smoke and found evidence of the kind of damage that causes emphysema.
"We interpreted those changes as early signs of lung damage, representing very mild forms of emphysema," said Chengbo Wang, a magnetic resonance physicist at The Children's Hospital of Philadelphia, who led the study.
"Almost one third of nonsmokers who had been exposed to secondhand cigarette smoke for a long time developed these structural changes," Wang added in a statement.
"To our knowledge, this is the first imaging study to find lung damage in non-smokers heavily exposed to secondhand smoke. We hope our work strengthens the efforts of legislators and policymakers to limit public exposure to secondhand smoke."
Wang, who presented his team's findings to a meeting of the Radiological Society of North American in Chicago, said 35 percent of U.S. children live in homes where someone smokes regularly.
The team studied 60 adults between ages 41 and 79, 45 of whom had never smoked. The non-smokers were considered to have high exposure if they had lived with a smoker for at least 10 years, often during childhood.
"It's long been hypothesized that prolonged exposure to secondhand smoke may cause physical damage to the lungs, but previous methods of analyzing lung changes were not sensitive enough to detect it," said Wang.
His team used a technique called long-time-scale, global helium-3 diffusion magnetic resonance imaging.
"With this technique, we are able to assess lung structure on a microscopic level," Wang said.
They found that 57 percent of the smokers and 33 percent of the nonsmokers with high exposure to secondhand smoke had signs of early lung damage as measured by the scan.
In February, U.S. researchers reported that up to 20 percent of women who develop lung cancer have never smoked.
They used a special kind of magnetic resonance imaging, or MRI, scan to look at the lungs of non-smokers who had high exposure to other people's cigarette smoke and found evidence of the kind of damage that causes emphysema.
"We interpreted those changes as early signs of lung damage, representing very mild forms of emphysema," said Chengbo Wang, a magnetic resonance physicist at The Children's Hospital of Philadelphia, who led the study.
"Almost one third of nonsmokers who had been exposed to secondhand cigarette smoke for a long time developed these structural changes," Wang added in a statement.
"To our knowledge, this is the first imaging study to find lung damage in non-smokers heavily exposed to secondhand smoke. We hope our work strengthens the efforts of legislators and policymakers to limit public exposure to secondhand smoke."
Wang, who presented his team's findings to a meeting of the Radiological Society of North American in Chicago, said 35 percent of U.S. children live in homes where someone smokes regularly.
The team studied 60 adults between ages 41 and 79, 45 of whom had never smoked. The non-smokers were considered to have high exposure if they had lived with a smoker for at least 10 years, often during childhood.
"It's long been hypothesized that prolonged exposure to secondhand smoke may cause physical damage to the lungs, but previous methods of analyzing lung changes were not sensitive enough to detect it," said Wang.
His team used a technique called long-time-scale, global helium-3 diffusion magnetic resonance imaging.
"With this technique, we are able to assess lung structure on a microscopic level," Wang said.
They found that 57 percent of the smokers and 33 percent of the nonsmokers with high exposure to secondhand smoke had signs of early lung damage as measured by the scan.
In February, U.S. researchers reported that up to 20 percent of women who develop lung cancer have never smoked.
Monday, November 19, 2007
High Blood Pressure Linked to Disability, Dementia
MONDAY, Nov. 19 (HealthDay News) -- People with high blood pressure are at increased risk for disability and dementia as they age, two new studies suggest.
In the first report, researchers found that high blood pressure increased the risk of developing disabilities, such as not being able to lift objects, walk up or down stairs, or bathe oneself.
"High blood pressure affects many aspects of a person's life," said lead researcher Dr. Ihab Hajjar, an instructor in medicine at Harvard Medical School. "Not only does it affect the vascular system and the heart and the brain and kidney, but it also affects well-being -- the ability to be independent, ability to perform daily activities, and be physically active."
Individuals who have lower blood pressure tend to develop less disability later in life and show less decline in their physical abilities compared with people who have higher blood pressure, Hajjar said. "This is a new aspect of the risk of high blood pressure," he noted.
The report was published in the December issue of Hypertension.
Hajjar's team collected data on 999 people who took part in the Charleston Heart Study, which started in 1960. Among these people, 70 percent had high blood pressure, but only 21 percent had their blood pressure controlled to optimal levels.
The researchers found that people with high blood pressure were more likely to have difficulty lifting objects, walking up or down stairs, or bathing themselves compared with people who had normal blood pressure.
In addition, people with high blood pressure who didn't have disability in their 80s did have a 15 percent to 36 percent increased risk of developing one of the three types of disabilities by the time they were checked in their early 90s, compared with those with normal blood pressure.
According to Hajjar, people who had their blood pressure controlled by medications fared as well as those who had normal blood pressure. "Controlling blood pressure may lower the risk of disability," he said.
In the second study, in the same issue of Hypertension, Shari R. Waldstein, a professor of psychology at the University of Maryland, Baltimore County, and her colleagues reported that stiff arteries may be associated with the decline in mental function that often accompanies aging.
"People with stiffening of their arteries show a decline in memory and concentration as they grow older," Waldstein said.
The Maryland researchers collected data on 1,749 people in the Baltimore Longitudinal Study of Aging, which was started by the U.S. National Institute on Aging in 1958.
During the study, participants were screened for increased pulse pressure, which is the difference between the maximum and minimum blood pressures produced during one heartbeat. In addition, their brain function was tested. This was done through tests of verbal and non-verbal memory, working memory, and attention.
In addition, Waldstein's team looked at additional data on 582 people who had their pulse wave velocity measured. Measuring pulse wave velocity is a new method for analyzing pulse pressure. Rising pulse pressure is an indicator of arterial stiffness.
The researchers found that increases in pulse pressure and pulse wave velocity affected memory. However, arterial stiffness wasn't linked to attention, hand-eye coordination, the ability to name objects, and speech fluency.
"Arterial stiffening negatively impacts cognitive performance before people have a stroke or develop dementia," Waldstein noted.
The findings suggest that arterial stiffness may be a potential target for drugs to help preserve mental function, Waldstein said. "Early treatment of cardiovascular risk factors that lead to arterial stiffening may help to preserve brain functioning as people age," she suggested.
One expert isn't sure whether high blood pressure is a cause of disability and dementia, or whether it's a marker associated with these conditions.
"Whether reducing blood pressure reduces disability and dementia isn't really known," said Dr. Harlan M. Krumholz, a professor of medicine at Yale University School of Medicine.
"It's part of a complex syndrome," he said. "Having high blood pressure is associated with having small sub-clinical strokes and heart disease, and there can be other complications from medications that don't interact well with each other."
Krumholz thinks that for any given patient, the reasons for dementia and disability are complex. "But, even as we are trying to sort out what these studies mean, the clear and unequivocal recommendation for people is to get high blood pressure under control," he said.
More information
For more on high blood pressure, visit the American Heart Association.
In the first report, researchers found that high blood pressure increased the risk of developing disabilities, such as not being able to lift objects, walk up or down stairs, or bathe oneself.
"High blood pressure affects many aspects of a person's life," said lead researcher Dr. Ihab Hajjar, an instructor in medicine at Harvard Medical School. "Not only does it affect the vascular system and the heart and the brain and kidney, but it also affects well-being -- the ability to be independent, ability to perform daily activities, and be physically active."
Individuals who have lower blood pressure tend to develop less disability later in life and show less decline in their physical abilities compared with people who have higher blood pressure, Hajjar said. "This is a new aspect of the risk of high blood pressure," he noted.
The report was published in the December issue of Hypertension.
Hajjar's team collected data on 999 people who took part in the Charleston Heart Study, which started in 1960. Among these people, 70 percent had high blood pressure, but only 21 percent had their blood pressure controlled to optimal levels.
The researchers found that people with high blood pressure were more likely to have difficulty lifting objects, walking up or down stairs, or bathing themselves compared with people who had normal blood pressure.
In addition, people with high blood pressure who didn't have disability in their 80s did have a 15 percent to 36 percent increased risk of developing one of the three types of disabilities by the time they were checked in their early 90s, compared with those with normal blood pressure.
According to Hajjar, people who had their blood pressure controlled by medications fared as well as those who had normal blood pressure. "Controlling blood pressure may lower the risk of disability," he said.
In the second study, in the same issue of Hypertension, Shari R. Waldstein, a professor of psychology at the University of Maryland, Baltimore County, and her colleagues reported that stiff arteries may be associated with the decline in mental function that often accompanies aging.
"People with stiffening of their arteries show a decline in memory and concentration as they grow older," Waldstein said.
The Maryland researchers collected data on 1,749 people in the Baltimore Longitudinal Study of Aging, which was started by the U.S. National Institute on Aging in 1958.
During the study, participants were screened for increased pulse pressure, which is the difference between the maximum and minimum blood pressures produced during one heartbeat. In addition, their brain function was tested. This was done through tests of verbal and non-verbal memory, working memory, and attention.
In addition, Waldstein's team looked at additional data on 582 people who had their pulse wave velocity measured. Measuring pulse wave velocity is a new method for analyzing pulse pressure. Rising pulse pressure is an indicator of arterial stiffness.
The researchers found that increases in pulse pressure and pulse wave velocity affected memory. However, arterial stiffness wasn't linked to attention, hand-eye coordination, the ability to name objects, and speech fluency.
"Arterial stiffening negatively impacts cognitive performance before people have a stroke or develop dementia," Waldstein noted.
The findings suggest that arterial stiffness may be a potential target for drugs to help preserve mental function, Waldstein said. "Early treatment of cardiovascular risk factors that lead to arterial stiffening may help to preserve brain functioning as people age," she suggested.
One expert isn't sure whether high blood pressure is a cause of disability and dementia, or whether it's a marker associated with these conditions.
"Whether reducing blood pressure reduces disability and dementia isn't really known," said Dr. Harlan M. Krumholz, a professor of medicine at Yale University School of Medicine.
"It's part of a complex syndrome," he said. "Having high blood pressure is associated with having small sub-clinical strokes and heart disease, and there can be other complications from medications that don't interact well with each other."
Krumholz thinks that for any given patient, the reasons for dementia and disability are complex. "But, even as we are trying to sort out what these studies mean, the clear and unequivocal recommendation for people is to get high blood pressure under control," he said.
More information
For more on high blood pressure, visit the American Heart Association.
Friday, November 16, 2007
Transplant patient with HIV not informed donor was high-risk
CHICAGO - A woman in her 30s who is one of the four organ transplant patients infected with HIV and hepatitis was not told that the infected donor was high risk, and had previously rejected another donor "because of his lifestyle," her attorney said.
Attorney Thomas Demetrio filed a petition Thursday in Cook County Circuit Court on behalf of the woman, asking officials to keep a hospital and an organ procurement center from destroying or altering any records involving the donation.
"She's really a mess right now," Demetrio said of the Chicago-area woman. "She's still in shock."
The patient, identified in court documents as Jane Doe, received a kidney transplant at the University of Chicago Medical Center on Jan. 9, Demetrio said.
Gift of Hope Organ & Tissue Donor Network in Elmhurst and the University of Chicago both knew the kidney donor was high-risk and did not inform the patient, Demetrio said.
University of Chicago spokesman John Easton responded in an e-mail: "We believe we follow guidelines, and of course with the patient's consent we will provide necessary records and documents, as is consistent with our open process."
Gift of Hope did not immediately respond to requests for comment.
The woman had been told the donor was a healthy young man, her attorney said. But on Tuesday, hospital officials disclosed to the woman that he was actually high-risk, a 38-year-old gay man, Demetrio said. CDC guidelines say that gay men who are sexually active should not be used as organ donors unless the patient is in imminent danger of death.
The woman was told she had HIV and hepatitis on Nov. 1, he said.
"The (organ) procurement group knew, the hospital knew, but the most important person did not know," he said. "The people that dedicate their lives to these transplant surgeries, they're just great people, but they need to bring the patient into the mix and let them make an informed decision."
U.S. Centers for Disease Control and Prevention guidelines were violated twice, the attorney said. One violation was not informing the woman about the donor's status and then not testing her afterward for HIV until just recently, after HIV and hepatitis were found during tests on another patient who was being evaluated for a second transplant.
The woman had been "doing great" on dialysis and had been on the donor waiting list for over six years, Demetrio said. In fact, she had rejected a potential donor two years ago "because of his lifestyle," the attorney said.
The woman developed renal failure seven years ago but he did not know what caused it.
"The fact is the transplant took very well. She'd been bumping along" doing fine, "then she gets this phone call on Nov. 1."
She's been started on an HIV drug regimen "and unfortunately one of the side effects is it's not good for the kidneys," Demetrio said. She's not hospitalized.
Four patients got organs in January at three Chicago hospitals from a donor who died after a traumatic injury. The donor had engaged in high-risk behaviors, according to a screening questionnaire, but standard testing showed the donor did not have AIDS or hepatitis C.
Gift of Hope tested the organs and approved them for donation, telling the three hospitals that they came from a high-risk donor.
Several months later, when one of the patients was being evaluated, blood tests showed the patient had HIV and hepatitis C. The other three patients were notified and tested, showing they had both viruses.
The CDC says it's the first time ever that both viruses were transmitted simultaneously through an organ transplant. It's also the first known time since 1986 that HIV was transmitted through organ donation.
Attorney Thomas Demetrio filed a petition Thursday in Cook County Circuit Court on behalf of the woman, asking officials to keep a hospital and an organ procurement center from destroying or altering any records involving the donation.
"She's really a mess right now," Demetrio said of the Chicago-area woman. "She's still in shock."
The patient, identified in court documents as Jane Doe, received a kidney transplant at the University of Chicago Medical Center on Jan. 9, Demetrio said.
Gift of Hope Organ & Tissue Donor Network in Elmhurst and the University of Chicago both knew the kidney donor was high-risk and did not inform the patient, Demetrio said.
University of Chicago spokesman John Easton responded in an e-mail: "We believe we follow guidelines, and of course with the patient's consent we will provide necessary records and documents, as is consistent with our open process."
Gift of Hope did not immediately respond to requests for comment.
The woman had been told the donor was a healthy young man, her attorney said. But on Tuesday, hospital officials disclosed to the woman that he was actually high-risk, a 38-year-old gay man, Demetrio said. CDC guidelines say that gay men who are sexually active should not be used as organ donors unless the patient is in imminent danger of death.
The woman was told she had HIV and hepatitis on Nov. 1, he said.
"The (organ) procurement group knew, the hospital knew, but the most important person did not know," he said. "The people that dedicate their lives to these transplant surgeries, they're just great people, but they need to bring the patient into the mix and let them make an informed decision."
U.S. Centers for Disease Control and Prevention guidelines were violated twice, the attorney said. One violation was not informing the woman about the donor's status and then not testing her afterward for HIV until just recently, after HIV and hepatitis were found during tests on another patient who was being evaluated for a second transplant.
The woman had been "doing great" on dialysis and had been on the donor waiting list for over six years, Demetrio said. In fact, she had rejected a potential donor two years ago "because of his lifestyle," the attorney said.
The woman developed renal failure seven years ago but he did not know what caused it.
"The fact is the transplant took very well. She'd been bumping along" doing fine, "then she gets this phone call on Nov. 1."
She's been started on an HIV drug regimen "and unfortunately one of the side effects is it's not good for the kidneys," Demetrio said. She's not hospitalized.
Four patients got organs in January at three Chicago hospitals from a donor who died after a traumatic injury. The donor had engaged in high-risk behaviors, according to a screening questionnaire, but standard testing showed the donor did not have AIDS or hepatitis C.
Gift of Hope tested the organs and approved them for donation, telling the three hospitals that they came from a high-risk donor.
Several months later, when one of the patients was being evaluated, blood tests showed the patient had HIV and hepatitis C. The other three patients were notified and tested, showing they had both viruses.
The CDC says it's the first time ever that both viruses were transmitted simultaneously through an organ transplant. It's also the first known time since 1986 that HIV was transmitted through organ donation.
Wednesday, November 14, 2007
Diabetes drug gets heart risk warning
WASHINGTON - The widely used diabetes drug Avandia got a new warning label Wednesday telling patients that it may, or may not, increase the risk of heart attacks.
Why the confusion? The Food and Drug Administration said studies of the risk are too contradictory to tell if Avandia really is riskier than other medications for Type 2 diabetes.
Still, the FDA put the controversy in a black box on the drug's label — the most severe warning the agency can require — at the behest of its scientific advisers, while it awaits further research to settle the issue.
Further complicating the new warning label: Patients may need a medical dictionary to interpret it. The warning says that Avandia may be associated with "myocardial ischemic events such as angina or myocardial infarction." In layman's terms, that's chest pain or a heart attack.
Type 2 diabetics who also have heart disease or are at high risk for it should talk with their doctor about Avandia's potential risk as they decide among treatment options, the FDA advised.
Avandia manufacturer GlaxoSmithKline PLC has agreed to begin a major new study comparing that drug to another active blood sugar-lowering medication to better understand if there is a risk.
About 1 million Americans with Type 2 diabetes use Avandia. It helps control blood sugar by increasing the body's sensitivity to insulin.
Why the confusion? The Food and Drug Administration said studies of the risk are too contradictory to tell if Avandia really is riskier than other medications for Type 2 diabetes.
Still, the FDA put the controversy in a black box on the drug's label — the most severe warning the agency can require — at the behest of its scientific advisers, while it awaits further research to settle the issue.
Further complicating the new warning label: Patients may need a medical dictionary to interpret it. The warning says that Avandia may be associated with "myocardial ischemic events such as angina or myocardial infarction." In layman's terms, that's chest pain or a heart attack.
Type 2 diabetics who also have heart disease or are at high risk for it should talk with their doctor about Avandia's potential risk as they decide among treatment options, the FDA advised.
Avandia manufacturer GlaxoSmithKline PLC has agreed to begin a major new study comparing that drug to another active blood sugar-lowering medication to better understand if there is a risk.
About 1 million Americans with Type 2 diabetes use Avandia. It helps control blood sugar by increasing the body's sensitivity to insulin.
Tuesday, November 6, 2007
Energy drinks jolt blood pressure, study finds
ORLANDO, Florida (Reuters) - The increasingly popular high-caffeine beverages called energy drinks may do more than give people a jolt of energy -- they may also boost heart rates and blood pressure levels, researchers said on Tuesday.
The results of a small study prompted the researchers to advise people who have high blood pressure or heart disease to avoid energy drinks because they could impact their blood pressure or change the effectiveness of their medications.
The drinks generally have high levels of caffeine and taurine, an amino acid found in protein-rich foods like meat and fish that can affect heart function and blood pressure, the researchers said.
"We saw increases in both blood pressure and heart rate in healthy volunteers who were just sitting in a chair watching movies. They weren't exercising. They were in a resting state," James Kalus of Henry Ford Hospital in Detroit, who led the study, said in an interview.
The increases did not rise to dangerous levels in the group of 15 healthy volunteers, whose average age was 26, the researchers said.
But the increases potentially could be significant in people with cardiovascular disease or those taking drugs to lower heart rate or blood pressure, they told a meeting of the American Heart Association in Orlando, Florida.
"While the amount of caffeine in energy drinks or coffee may cause a slight and temporary increase in blood pressure, it would have no greater effect than walking up a flight of steps," the American Beverage Association industry trade group said in a statement responding to the findings.
"So singling out energy drinks in a unique manner, particularly when compared to a more commonly consumed caffeinated beverage like coffee, does not provide a full and proper context for consumers."
BOOSTING ENERGY
The products have names like Full Throttle, Amp and Rush. Red Bull, made by Austrian company Red Bull GmbH, is a market leader. Beverage companies market various energy drinks as soft drinks that can boost a person's energy.
Kalus declined to say which brand of energy drink was used in the study. He said the drinks generally contain similar ingredients, adding, "By giving the brand, it would dilute the message that all of these drinks need to be looked at."
Coca-Cola Co. makes Full Throttle.
The study participants were asked not to consume other forms of caffeine for two days before starting the study and then throughout a study in which they consumed two cans of energy drinks daily over seven days. Each can contained 80 milligrams of caffeine and 1,000 milligrams of taurine.
The volunteers' heart rates rose by about 8 percent on the first day and 11 percent on the seventh day.
Maximum systolic blood pressure -- the top number in blood pressure readings that represents pressure while the heart contracts -- rose by 8 percent on the first day and 10 percent on the seventh day, the study showed.
Diastolic blood pressure -- the bottom number that gives the pressure when the heart relaxes between beats -- rose by 7 percent on the first day and 8 percent on the seventh day.
The study did not identify ingredients responsible for the changes, but Kalus said it probably was caffeine and taurine.
Kalus said the study did not address possible health effects from the way some people consume these drinks, such as mixing them with alcohol.
The results of a small study prompted the researchers to advise people who have high blood pressure or heart disease to avoid energy drinks because they could impact their blood pressure or change the effectiveness of their medications.
The drinks generally have high levels of caffeine and taurine, an amino acid found in protein-rich foods like meat and fish that can affect heart function and blood pressure, the researchers said.
"We saw increases in both blood pressure and heart rate in healthy volunteers who were just sitting in a chair watching movies. They weren't exercising. They were in a resting state," James Kalus of Henry Ford Hospital in Detroit, who led the study, said in an interview.
The increases did not rise to dangerous levels in the group of 15 healthy volunteers, whose average age was 26, the researchers said.
But the increases potentially could be significant in people with cardiovascular disease or those taking drugs to lower heart rate or blood pressure, they told a meeting of the American Heart Association in Orlando, Florida.
"While the amount of caffeine in energy drinks or coffee may cause a slight and temporary increase in blood pressure, it would have no greater effect than walking up a flight of steps," the American Beverage Association industry trade group said in a statement responding to the findings.
"So singling out energy drinks in a unique manner, particularly when compared to a more commonly consumed caffeinated beverage like coffee, does not provide a full and proper context for consumers."
BOOSTING ENERGY
The products have names like Full Throttle, Amp and Rush. Red Bull, made by Austrian company Red Bull GmbH, is a market leader. Beverage companies market various energy drinks as soft drinks that can boost a person's energy.
Kalus declined to say which brand of energy drink was used in the study. He said the drinks generally contain similar ingredients, adding, "By giving the brand, it would dilute the message that all of these drinks need to be looked at."
Coca-Cola Co. makes Full Throttle.
The study participants were asked not to consume other forms of caffeine for two days before starting the study and then throughout a study in which they consumed two cans of energy drinks daily over seven days. Each can contained 80 milligrams of caffeine and 1,000 milligrams of taurine.
The volunteers' heart rates rose by about 8 percent on the first day and 11 percent on the seventh day.
Maximum systolic blood pressure -- the top number in blood pressure readings that represents pressure while the heart contracts -- rose by 8 percent on the first day and 10 percent on the seventh day, the study showed.
Diastolic blood pressure -- the bottom number that gives the pressure when the heart relaxes between beats -- rose by 7 percent on the first day and 8 percent on the seventh day.
The study did not identify ingredients responsible for the changes, but Kalus said it probably was caffeine and taurine.
Kalus said the study did not address possible health effects from the way some people consume these drinks, such as mixing them with alcohol.
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