Studies

Exercise in Adolescence May Cut Risk of Deadly Brain Tumor

TUESDAY, Oct. 6 (HealthDay News) -- Exercising during adolescence may help guard against a deadly form of brain tumor in adulthood, new research suggests.

The study also found that avoiding obesity during the teen years was associated with a lower risk of developing the cancerous brain tumors called gliomas, while being tall increased the chances of such malignancies.

The study appears in the Nov. 1 issue of Cancer Research.

Gliomas are the most common type of brain and central nervous system cancers, accounting for 80 percent of cases, according to background information in the study. Gliomas cause 13,000 deaths in the United States each year.

Though little is known about why people develop the tumors or who is at risk, previous research has hinted that "early life exposures" may increase the risk of developing the cancer in adulthood, said study author Steven C. Moore, a research fellow in the Nutritional Epidemiology Branch of the U.S. National Cancer Institute. Studies have shown that people who are left-handed, for example, are at higher risk of the disease.

In the current research, Moore and his colleagues examined data on nearly 500,000 men and women aged 50 to 71 participating in the NIH-AARP Diet and Health Study, which included questionnaires on height and weight at various points during their lives.

Those who'd reported doing substantial amounts of light, moderate and vigorous exercise between the ages 15 and 18 were 36 percent less likely to develop glioma than those who were sedentary. Activities included walking, aerobics, biking, swimming, running, heavy housework or gardening.

The researchers also found that those who were obese during their teen years had a three to four times greater risk of developing glioma than those of a normal weight. Because only 11 people who developed glioma were also obese as teenagers, researchers said the finding needed to be replicated.

"The BMI [body mass index] finding is very interesting but it's hard to know what to make of it," Moore said. "It's also hard to say if it's a causal relationship or not. It could be that obesity increases the risk of brain cancer, or if could be that some underlying condition increases both the risk of obesity and brain cancer."

Neither weight nor exercise affected glioma risk beyond the teen years.

Tall people were also at increased risk of glioma. Each 10 centimeter (about 3.9 inches) increase in height meant a nearly 20 percent increase in risk of developing glioma.

The researchers said increases in glioma risk could be related to "energy balance" during a critical period of brain development. People who are tall have higher levels of the growth factor IGF-1 during childhood. Growth factors promote the proliferation of cells.

"Anything that increases the rate of proliferation of cells could potentially be a cancer risk factor," Moore said.

Dr. Paul Graham Fisher, a professor of neurology at Stanford University, said the study was "well done," but questioned why exercise and weight did not affect glioma risk beyond the teen years.

"You start scratching your head and asking, 'Why wouldn't it be true in the 20s and 30s or later?'" Fisher said. "It's possible there is some critical window in which energy balance can impact glioma genesis."

And though researchers relied on the recollections of older adults about their weight and physical activity from many decades ago, there's no reason to suspect people who were later diagnosed with glioma had any better or worse memories, or reported their height and weight with any particular bias than those who didn't develop the brain tumors.

With the risk of developing glioma so low among the general population, the findings aren't so much a prescription for teens to exercise as more information for researchers searching for the biological underpinnings of glioma in the hopes developing new treatments.

Yet it's not a bad idea to encourage teens to stay active, too, Moore said.

"At this point in time, these data are more relevant to the biology of glioma, but they provide some preliminary evidence that physical activity could be important for glioma, too," Moore said.

More information

The U.S. National Cancer Institute has more on brain tumors.

SOURCES: Steven C. Moore, Ph.D., research fellow, National Cancer Institute, Rockville, Md.; Paul Graham Fisher, M.D., professor, neurology, Stanford University, Palo Alto, Calif.; Nov. 1, 2009, Cancer Research

Ampyra Approved for Adults With MS

FRIDAY, Jan. 22 (HealthDay News) -- Dalfampridine (Ampyra) extended-release tablets have been approved by the U.S. Food and Drug Administration to help adults with multiple sclerosis (MS) who have trouble walking.

In clinical testing, people who took Ampyra had faster walking speeds that those who took a placebo, the agency said in a news release.

MS is a chronic, often disabling disease affecting the brain, spinal cord and optic nerves. Some 400,000 people in the United States and 2.5 million globally have been diagnosed with the disease, the FDA said.

The drug, if given at doses higher than the recommended 10 milligrams twice daily, can cause seizures, the agency warned. The most common reported side effects include urinary tract infection, insomnia, dizziness, headache, nausea, weakness, back pain, nasal or throat swelling, irregularity, indigestion and burning or itchy skin.

People with moderate-to-severe kidney disease shouldn't take Ampyra, the FDA said.

The drug is marketed in the United States by Hawthorne, N.Y.-based Acorda Therapeutics.

More information

The FDA has more about this approval.

Epilepsy Drugs Don't Raise Suicide Risk, Study Shows

WEDNESDAY, Aug. 4 (HealthDay News) -- In 2008, the U.S. Food and Drug Administration required epilepsy medications to bear a warning label about an increased risk of suicidal behaviors. The move came after an agency review of 199 studies that found patients taking the drugs showed about twice the risk of suicidal behavior.

But now a study of more than 5 million patients contradicts the FDA's findings. It suggests that the increased risk of suicide has more to do with the conditions for which these drugs are prescribed than the medications themselves.

For the study, researchers in Spain and the United States evaluated the health records of primary care patients in England. They found that people with epilepsy who currently use an antiepileptic drug are at no greater risk of suicide-related events than those who aren't taking the medications.

"In our opinion, in the long term, it is not the drugs themselves that raise the risk of suicide, but the underlying disease for which these drugs are prescribed," said study author Dr. Alejandro Arana, an epidemiologist and managing partner at Risk MR Pharmacovigilance Services, in Zaragoza, Spain. "Treatment with antiepileptic drugs [AEDs] helps to control the psychiatric syndromes that are at the root of suicidal behavior in these patients."

At least one epilepsy expert said the new findings, published in the Aug. 5 issue of the New England Journal of Medicine, are powerful enough to prompt the FDA to consider reversing its decision.

"The warning on AEDs and suicide was never justified, and this data strongly argues for its removal," said Dr. Orrin Devinsky, director of the New York University Comprehensive Epilepsy Center.

"This study examined a much larger and more meaningful 'real-life' group of patients on antiepileptic drugs than the FDA study did," added Devinsky, who noted that a major flaw of the FDA analysis was that many of the people studied had more severe cases of the condition, and these patients are known to have a higher risk of suicide to begin with. Another benefit of Arana's study is that patients were followed for an average of six years, rather than the 24 weeks' follow-up in the FDA analysis.

These new findings come on the heels of two other epidemiological studies that are also at odds with the FDA's findings. Those studies, one by Harvard researchers and the other by scientists in Germany, suggested that some antiepileptic medications raise the risk of suicide, while others do not.

Arana and his colleagues studied a total of 5,130,795 patients who were seen in a general practitioner's office for at least six months between July 1988 and March 2008. First, they identified how many patients were diagnosed with epilepsy, depression or bipolar disorder (since antiepileptic medications are often given to patients with one or more of these conditions). Then they looked at how many people had received an antiepileptic medication that was included in the FDA's agency review and was also available in the U.K.

The medications studied were carbamazepine (Carbatrol, Equetro, Tegretol, Tegretol XR), gabapentin (Neurontin), lamotrigine (Lamictal), levetiracetam (Keppra), oxcarbazepine (Trileptal), pregabalin (Lyrica), tiagabine (Gabitril), topiramate (Topamax), valproate (Depakote, Depakote ER, Depakene) and zonisamide (Zonegran). Participants were followed for an average of six years. During the study period, 8,212 people attempted suicide, and 464 of these patients died as a result of their injuries.

Two subgroups of patients taking these medications were found to have an increased risk of suicide: people diagnosed with depression, and those who were prescribed an antiepileptic drug for a condition other than epilepsy, depression or bipolar disorder. Patients in the latter group were roughly two and a half times more likely to attempt or commit suicide than those who didn't take an antiepileptic medication.

The researchers weren't able to determine why patients were taking an antiepileptic medication even though they didn't have epilepsy, depression or bipolar disorder. However, they noted that it may have been for chronic pain, which has been associated with an increased risk of suicide.

One possible reason for the increased risk seen among these two groups, the authors concluded, may be that "the use of antiepileptic drugs in these patients is a marker of severe depression or the presence of another condition that may be associated with an increased risk of suicide-related events."

"Research is dialogue, and our study is just another brick in the wall of knowledge," said Arana, who noted that the study was funded by an unrestricted grant from drug maker Sepracor. "There is still the need to fine-tune the role of antiepileptic drugs in indications other than epilepsy, to study the risk in the initial period of treatment compared to the use afterwards, and to compare individual antiepileptic drugs when used to treat patients with identical types of epilepsy."

More information

For more on epilepsy, go to U.S. National Library of Medicine.

SOURCES: Alejandro Arana, M.D., managing partner, Risk MR Pharmacovigilance Services, Zaragoza, Spain; Orrin Devinsky M.D., director, Epilepsy Center, New York University Langone Medical Center, and professor, neurology, neurosurgery and psychiatry, New York University School of Medicine; Aug. 5, 2010, New England Journal of Medicine

Childbirth May Slow Progression of Multiple Sclerosis

TUESDAY, Nov. 24 (HealthDay News) -- Having children may slow the progression of multiple sclerosis, new research suggests.

Belgian researchers followed 330 women who had experienced their first MS symptoms between the ages of 22 and 38.

Women who had given birth to at least one child were 34 percent less likely to have the disease progress to a stage in which they needed walking assistance, such as a cane or brace, than women without children.

While having a baby either before or after the onset of MS symptoms seemed to help, women who had a child after they began experiencing MS symptoms were even better off. During the study, women with MS symptoms who'd had a baby were 39 percent less likely to have their disease progress to the point of needing walking assistance. In the study, women had the disease for an average of 18 years.

"Women with MS who have children seem to have a more benign MS course than those who don't," said study author Marie D'hooghe, of the department of neurology at Nationaal MS Centrum in Melsbroek, Belgium.

The research appears in the Nov. 24 online issue of the Journal of Neurology, Neurosurgery & Psychiatry.

Multiple sclerosis is an autoimmune disease in which the body's own defense system attacks myelin, or the protective fatty substance that surrounds nerve fibers in the central nervous system, according to the National Multiple Sclerosis Society. The damage causes a disruption to nerve signals traveling to and from the brain, which causes the numbness, walking problems, blurry vision and fatigue.

About 85 percent of those with MS start with a relapsing-remitting course, in which attacks are followed by partial or total recovery, according to the study. More than half go on to develop a more progressive form of the disease, in which symptoms worsen over time and there are fewer, shorter periods without symptoms. Eventually, the disease can lead to loss of vision and paralysis.

Women are twice as likely to develop MS as men, though women tend to have less severe cases than men, according to the study.

About three-quarters of the women in the study had children. The researchers measured the time it took for women to reach level 6 on the Expanded Disability Status Scale (EDSS), a rating system used by doctors to describe symptoms, with level 1 being the least severe and 10 being death due to MS. Level 6 is defined as needing a cane, crutch or brace to walk.

Women who did not have children took an average of 13 to 15 years to progress to EDSS 6, while women who had children took an average of 22 to 23 years to reach that stage, the researchers found.

"Having one or more children does seem to be beneficial," said Patricia O'Looney, director of biomedical research for the National Multiple Sclerosis Society. "But we don't know enough about the patient demographics to really draw some major conclusions."

Among the unknowns are the treatments the women in the study were getting for MS or if perhaps the women who decided to have children were feeling better and having fewer symptoms.

Though much remains to be learned about the role of pregnancy in MS, a possible reason why it may help slow the progression of the disease is that during pregnancy, the immune system is "downregulated," in part to prevent the mother's body from rejecting the fetus, O'Looney explained. Suppressing the immune system may also help to control MS, O'Looney noted.

Treatments for MS, such as interferon beta-1a and -1b, work by suppressing the immune system.

A second possibility for why childbirth might help delay the progression of MS is that during pregnancy, estrogen levels rise. Previous research has suggested estrogen may help protect from MS by stimulating the cells that make myelin. The MS Society is currently funding a clinical trial in which women with MS are given estriol, a form of estrogen, along with standard MS treatments.

"The sex hormones do seem to have some neuroprotective role, though we are not quite sure how," O'Looney said.

Still, O'Looney stressed that women should not interpret the results as reason to have a baby to delay the progression of the disease, or blame themselves if they decided not to have children.

"We still don't know a lot about the great variability of MS -- why does one person become more progressive while another follows a more benign course," O'Looney said. "What's certain is that one should not conclude it's based on whether or not you have a child. There are so many other factors, including possibly genetic factors, that determine that."

More information

The National Multiple Sclerosis Society has more on pregnancy and MS.

SOURCES: Marie D'hooghe, department of neurology, Nationaal MS Centrum in Melsbroek, Belgium; Patricia O'Looney, Ph.D., director, biomedical research, National Multiple Sclerosis Society; Nov. 24, 2009, Journal of Neurology, Neurosurgery & Psychiatry, online

Added Drug Aids MS Treatment

TUESDAY, Feb. 16 (HealthDay News) -- Adding the drug daclizumab to standard treatment with interferon beta may reduce multiple sclerosis disease activity more than interferon beta alone, a new study reports.

Previous non-randomized studies found that daclizumab -- a humanized monoclonal antibody -- reduced MS disease activity.

This new phase 2 study at 51 centers in the United States, Canada, Germany, Italy and Spain included 230 patients with active relapsing MS who were taking interferon beta. They were randomly selected to also receive either high-dose daclizumab (2 milligrams/kilogram every two weeks), low-dose daclizumab (1 milligram/kilogram every four weeks) or an inactive placebo. The combined treatments continued for 24 weeks.

MRI scans of the patients' brains were taken every four weeks between weeks 8 and 24 of the study in order to determine the number of new or enlarged gadolinium contrast-enhancing lesions, which indicate MS disease activity.

By the end of the study, the adjusted mean number of new or enlarged gadolinium contrast-enhancing lesions was 1.32 in the high-dose group (75 patients), 3.58 in the low-dose group (78 patients) and 4.75 in the placebo group (77 patients).

Levels of CD56bright natural killer cells were seven to eight times higher in patients taking daclizumab than in those taking the placebo.

"This study provides confirmatory data that daclizumab treatment causes an expansion of CD56bright natural killer cells and adds support to the theory that expansion of CD56bright natural killer cells might mediate some of the effects of daclizumab on reducing multiple sclerosis lesion activity. In addition to the results of previous trials of daclizumab in multiple sclerosis, several lines of evidence have suggested a potential immunoregulatory function for CD56bright natural killer cells: they are expanded during conditions of natural immune tolerance, for example, pregnancy," the researchers from the Neurovirology Research Laboratory at the VA Medical Center in Salt Lake City, and the University of Utah, reported in a news release.

"This randomized controlled trial indicates that daclizumab can reduce new lesion formation in relapsing multiple sclerosis compared with interferon-beta alone," the researchers concluded. "Multiple sclerosis treatments that have the potential to improve in risk-benefit ratios when compared with available treatments are needed; thus, additional studies to define the long-term clinical risks and benefits of daclizumab are warranted."

The study was released online Feb. 15 in advance of publication in the April issue of The Lancet Neurology.

More information

The U.S. National Institute of Neurological Disorders and Stroke has more about multiple sclerosis.

SOURCE: The Lancet Neurology, news release, Feb. 15, 2010