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

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

Epilepsy Drug Linked to Serious Birth Defects

WEDNESDAY, June 9 (HealthDay News) -- The offspring of women who took the epilepsy drug valproic acid during the first trimester of pregnancy are much more likely to have serious births defects affecting the brain, heart and limbs, a new study finds.

Babies whose mothers took valproic acid during the first trimester were 12.7 times more likely to have spina bifida, in which the spinal cord and backbone fail to develop or close properly, compared to babies whose mothers did not take the drug.

Babies whose mothers took valproic acid were also 2.5 times more likely to have an atrial septal defect (a heart defect); about five times as likely to have a cleft palate (a defect of the upper lip and roof of the mouth) or hypospadias (a penis abnormality); more than twice as likely to be born with an extra digit on the hand (polydactyly); and nearly seven times more likely to have craniosynostosis (premature fusion of the skull during fetal development that restricts skull and brain growth).

While valproic acid (brand names include Depakene and Depakote) was associated with a higher relative risk of the six birth defects, the absolute risk of having a baby with any of the defects remains small, the researchers noted. For example, the risk of having a baby with spina bifida was 0.6 percent, or six in 1,000, among women who took the drug compared to five in 1,000 of babies born to mothers who didn't take any epilepsy medication.

Yet given mounting evidence of the risks of valproic acid to fetuses, researchers urged women of childbearing age to try other drugs to control their seizures.

"These findings provide further evidence to avoid valproic acid, if possible, in pregnant women and [for doctors] to discuss with girls and women of childbearing potential the risk of the drug for the unborn child," said senior study author Lolkje T.W. de Jong-van den Berg, of the University of Groningen in the Netherlands.

Dr. Kimford Meador, a professor of neurology at Emory University in Atlanta, echoed that warning.

"This drug should not be used as a first-line drug for epilepsy in women of childbearing age," Meador said. "There are multiple types of malformations that can be associated with valproic acid."

The review is published in the June 10 issue of the New England Journal of Medicine.

In the review, researchers first looked at eight studies that included nearly 1,600 births and identified some 14 birth defects that seemed to be much more common among the children of women who took valproic acid early in pregnancy.

Researchers then took that information and analyzed data from a large European study that included nearly 4 million births and 98,000 birth defects. They found women who took valproic acid in early pregnancy had two to 12 times the risk of having a baby with one of six specific birth defects compared to women who took no epilepsy drugs. The findings were similar when birth defect rates among those taking valproic acid were compared to the rates for women who took other epilepsy drugs, leading researchers to conclude it was the valproic acid, not some other epilepsy drug, that was to blame.

Among those who took valproic acid during early pregnancy, the chances of having a baby with any of the defects was less than 1 percent -- cleft palate (0.3 percent), hypospadias (0.7 percent), polydactyly (0.2 percent), craniosynostosis (0.1 percent).

Previous research has also linked valproic acid to spina bifida, other birth defects and cognitive problems in children, Meador noted. In April 2009, Meador was the lead author of a study that appeared in the New England Journal of Medicine that linked exposure to valproic acid in the womb to lower IQ scores in children at age 3.

The American Academy of Neurology recommends avoiding the use of valproic acid in pregnant women, according to background information in the article. Yet since up to half of pregnancies are unplanned, according to the study, all women of childbearing age should be warned about the dangers, researchers said.

Despite such concerns, valproic acid is often still prescribed, Meador said. In 2006, valproic acid was the second most commonly prescribed epilepsy drug, he noted.

Valproic acid is also prescribed to prevent migraines and for bipolar disorder, he added.

Despite the risks, valproic acid can be a very effective drug and may be the best choice for some patients whose seizures are not well-controlled by other medications, Meador said.

More information

The National Institute of Neurological Disorders and Stroke has more on epilepsy.

SOURCES: Lolkje T.W. de Jong-van den Berg, Ph.D., department of pharmacoepidemiology and pharmacoeconomics, University of Groningen, Groningen, Netherlands; Kimford J. Meador, M.D., professor, neurology, Emory University, Atlanta; June 10, 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

Brain Changes in MS May Spur Depression

WEDNESDAY, July 7 (HealthDay News) -- Brain atrophy may be a major reason why the lifetime risk of depression in multiple sclerosis patients is as high as 50 percent, new research suggests.

This atrophy, marked by a shrinkage of brain mass, occurs in the hippocampus, a part of the brain involved in a number of functions, including mood and memory.

For this study, researchers at the University of California, Los Angeles used MRI scans to compare the brains of multiple sclerosis (MS) patients and healthy people. The scan results showed that three important sub-regions of the hippocampus were smaller in MS patients.

The research team also identified a link between this brain atrophy and hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, a part of the neuroendocrine system that controls reactions to stress and regulates many physiological functions. Excessive activity of the HPA axis may be associated with both atrophy of the hippocampus and the development of depression, the researchers suggested.

The study was released online June 19 in advance of publication in an upcoming print issue of the journal Biological Psychiatry.

The connection between HPA hyperactivity and brain atrophy hasn't received much attention, "despite the fact that the most consistently reproduced findings in psychiatric patients with depression (but without MS) include hyperactivity of the HPA axis and smaller volumes of the hippocampus," senior study author Dr. Nancy Sicotte, an associate professor of neurology, said in a news release from the university.

"So the next step is to compare MS patients with depression to psychiatric patients with depression to see how this disease progresses in each," she added.

Along with being one of the most common symptoms in patients with multiple sclerosis, depression "impacts cognitive function, quality of life, work performance and treatment compliance. Worst of all, it's also one of the strongest predictors of suicide," noted lead author Stefan Gold, a postdoctoral fellow in the UCLA Multiple Sclerosis Program.

More information

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

SOURCE: University of California, Los Angeles, news release, July 1, 2010.