May 21, 2010
NIH Podcast Episode #0110
Balintfy: Welcome to the one-hundred and tenth episode of NIH Research Radio with news about the ongoing medical research at the National Institutes of Health – the nation's medical research agency. I'm your host Joe Balintfy. Coming up in this episode, sleep apnea and stroke risk; what the genes and brains of this bird (BIRD SOUNDS) tells researchers; does the quality of early child care make a difference for kids as they get older? And, what moms need to know about gestational diabetes. But first, this news update.
Balintfy: Babies can learn in their sleep. According to a new study, newborn infants are capable of a simple form of learning while they’re asleep. The study was confined to newborns, so researchers do not know whether older children or adults are capable of learning during sleep. But researchers say this finding may one day lead to a test that can identify infants at risk for developmental disorders that do not become apparent until later in childhood. The researchers noted that the type of learning tested is controlled by a part of the brain that is implicated in many developmental disorders. They add it is the first to demonstrate that newborn infants are capable of learning about relationships between stimuli while asleep. The study involved 26 infants of whom 24 learned to scrunch their faces in response to a tone that was accompanied by a light air puff.
New research has found that an experimental Ebola vaccine protects monkeys against not only the two most lethal Ebola-virus species for which it was originally designed, but also against a newer one. Experts explain that this finding will guide future vaccine design and may open an avenue for developing a single vaccine that works against both known and emerging Ebola-virus species. Ebola viruses cause Ebola hemorrhagic fever which is a severe, often-fatal disease in humans and nonhuman primates: monkeys, gorillas, and chimpanzees. Hemorrhagic fevers typically affect multiple organs in the body and are often accompanied by hemorrhage or bleeding. There are no specific drugs to treat Ebola. Researchers say an ideal Ebola vaccine would stimulate broad immunity so that entirely new vaccines wouldn’t have to be created whenever new virus species are identified.
Scientists have identified a group of surface markers on cells linked to an aggressive type of breast cancer called estrogen receptor-negative cancer. This is a preliminary study, but important because this type of breast cancer is more difficult to treat than estrogen receptor-positive breast cancer. Estrogen receptor-positive breast cancers may be treated with medications which interfere with the activity of estrogen. But no targeted therapies are yet available for patients with estrogen receptor-negative breast tumors. These cancers are currently treated with chemotherapy drugs that are toxic to many cells, not just cancer cells, and which can be hard for patients to tolerate. Researchers say they are excited but cautious at the prospect that the presence of these surface markers on estrogen receptor-negative breast cancer cells may present a selective target for early-detection imaging and for personalized therapy.
News updates are compiled from information at www.nih.gov/news. Coming up next, sleep apnea and stroke risk; later gestational diabetes. Plus much more, stay tuned.
(BREAK FOR PUBLIC SERVICE ANNOUNCEMENT)
Sleep Apnea Tied to Increased Risk of Stroke
Balintfy: Do you have trouble sleeping due to sleep apnea? You’ll want to hear about this next study: it is the largest study to date to link sleep apnea with increased risk of stroke. Stroke is the second leading cause of death worldwide and the third leading cause of death in the U.S. Obstructive sleep apnea is associated with an increased risk of stroke in middle-aged and older adults, especially men. Wally Akinso reports on these new results.
Akinso: A study shows that obstructive sleep apnea is associated with an increased risk of stroke in middle-aged and older adults, especially men.
Twery: Men who had untreated sleep apnea were up to three times more likely to experience a stroke than men who did not have sleep apnea.
Akinso: Dr. Michael Twery is the Director of the NIH National Center on Sleep Disorders Research.
Twery: This study examined middle aged adults to determine whether they had sleep apnea at the beginning of the study and then follow them for an average of nine years to see if there was any stroke event during that period of time.
Akinso: Obstructive sleep apnea is a common disorder in which the upper airway is occasionally narrowed or blocked, disrupting sleep and breathing during sleep. Researchers from the Sleep Heart Health Study, supported by the National Heart Lung and Blood Institute, report that the risk of stroke appears in men with mild sleep apnea and rises with the severity of sleep apnea.
Twery: Investigators from the Sleep Heart Health Study have examined the relationship between sleep disorder breathing or sleep apnea and the risk of a number of different cardiovascular diseases.
Akinso: Conducted in nine medical centers across the U.S., the Sleep Heart Health Study is the largest most comprehensive prospective, multi-center study on the risk of cardiovascular disease and other conditions related to sleep apnea. In the latest report, researchers studied stroke risk in about 5400 participants aged 40 years and older without a history of stroke.
Twery: The investigators have found that the risk of stroke particularly in men has increased as much as three fold. But also that sleep apnea increases the risk of high blood pressure or hypertension and the risk of diabetes and obesity.
Akinso: The researchers propose that the differences between men and women might be because men are more likely to develop sleep apnea at younger ages. Therefore, they tend to have untreated sleep apnea for longer periods of time than women.
Twery: Women were also at risk of stroke but only when they had severe untreated sleep apnea.
Akinso: Stroke is the second leading cause of death world wide. Dr. Twery says this study provides insight on sleep apnea and how cardiovascular problems such as stroke develop.
Twery: What the Sleep Heart Health Study has revealed in this study is that people have apnea and then later develop cardiovascular disease risk—whether it be stroke or high blood pressure or heart attack and so forth—the development of apnea preceded the development of the cardiovascular disease. And this gives us an important clue as to whether treating the sleep apnea maybe a potential important way to reduce these cardiovascular risks.
Akinso: More than 12 million American adults are believed to have sleep apnea, and most are not diagnosed or treated. Treatments to restore regular breathing during sleep include mouthpieces, surgery, and breathing devices. For more information on this study, or treatment options for sleep apnea or stroke, visit www.nhlbi.nih.gov. This is Wally Akinso at the National Institutes of Health Bethesda, Maryland.
Songbird Genome Analysis Reveals New Insights
Balintfy: Did you know that a male zebra finch can learn songs? And it has the genes to do it. An international research consortium has identified more than 800 genes that appear to play a role in the male zebra finch's ability to learn elaborate songs from his father. Craig Fritz reports how researchers also found evidence that song behavior engages complex gene-regulatory networks within the brain of the songbird—networks that rely on parts of the genome once considered junk.
Fritz: Scientists at the National Institute for Neurological Disorders and Stroke and the National Human Genome Research Institute have recently mapped the genome of a songbird. This songbird, a Zebra finch, sings one complex song through its entire life and teaches that song to its male offspring. [ZEBRA FINCH SONG]
Fritz: The zebra finch is the first songbird—and the second bird, after the chicken—to have its genome sequenced. Director of the National Institute for Neurological Disorders and Stroke, Dr. Story Landis, explains why scientists chose the Zebra finch as a subject of study.
Landis: Songbirds are one of the few groups of animals other than humans that learn the sounds used for vocal communication during development. They're a particularly well studied species of songbirds. Like humans, they acquire the capacity for learned vocal communication based on auditory experience and vocal motor practice. In addition, they have highly developed brain regions that control vocal learning. So they provide a really wonderful model system for understanding neural and behavioral mechanisms of speech in people.
Fritz: By comparing the finch genome with the human genome, researchers hope to expand understanding of learned vocalization in humans. Dr. Landis and her colleagues say that this information may help researchers who are striving to develop new ways to diagnose and treat communication disorders, such as stuttering and autism.
Landis: One of the major systems that's involved in songbird learning is a dopaminergic system, a dopamine system, and that’s the same system that's actually disrupted in Parkinson's disease. So we have an opportunity to understand how dopamine interacts with behavior.
Fritz: Dopamine is a chemical messenger responsible for transmitting signals in the brain. Dr. Landis adds that the researchers also found evidence that song behavior engages complex gene regulatory networks within the brain of the songbird—networks that rely on parts of the genome once considered junk. For more on this study, visit the websites www.ninds.nih.gov, and www.genome.gov. This is Craig Fritz, National Institutes of Health, Bethesda, Maryland.
Link Between Child Care and Academic Achievement and Behavior Persists Into Adolescence
Balintfy: From nature to nurture: Teens who were in high-quality child care settings as young children scored slightly higher on measures of academic and cognitive achievement and were slightly less likely to report acting-out behaviors than peers who were in lower-quality child care arrangements during their early years. This is according to the latest analysis of a long-running study funded by the National Institutes of Health. Elizabeth Goers has the details.
Goers: A study has been following more than 1,000 children from the time they were 1 month old to look at the short and long term effects on of child care on children’s development.
Dr. Griffin: As more children were cared for outside the home at earlier ages, a concern was raised that child care might interfere with normal developmental processes such as an infant forming a secure attachment with its mother.
Goers: Dr. James Griffin is with the Eunice Kennedy Shriver National Institute of Child Health and Human Development. He explains that children in the study are evaluated periodically, most recently at 15 years-old. Multiple measures, including the students’ own assessments, evaluated the behaviors.
Dr. Griffin: These evaluations included measures of: behavioral problems, such as acting out in class; impulsive behaviors, like acting without thinking through the consequences; and risk-taking behaviors, such as behaviors that might harm themselves or others. The study investigators then compared these responses to data collected earlier in the study to determine if there was any association between their child care experiences before age 5 and their evaluation results at age 15.
Goers: Researchers found links between experiences as young children and adolescence academic and behavioral performance. Again, Dr. Griffin.
Dr. Griffin: Teens who were in high-quality child care settings before age 5 scored higher on measures of academic and cognitive achievement and reported fewer acting-out behaviors than peers who were in lower quality child care arrangements during their early years. Moreover, teens who logged more hours in child care in their first 4 1/2 years of life reported a greater tendency towards impulsiveness and risk-taking behaviors at age 15 than did peers who spent less time in child care.
Goers: Researchers still contend, however, that parent influence is far more important in child development than the type of child care they receive. For more information on this study and other children’s health issues, visit www.nichd.nih.gov. This is Elizabeth Goers, National Institutes of Health, Bethesda, Maryland.
Balintfy: Coming up next, details on the type of diabetes pregnant women need to watch out for. That’s next on NIH Research Radio. Stay tuned.
(BREAK FOR PUBLIC SERVICE ANNOUNCEMENT)
Balintfy: Earlier this month we had Mother’s Day. Also, National Women’s Health Week just wrapped up. But to keep the discussion going on important women’s health issues, our guest next is Dr. Griffin Rodgers, Director of the National Institute of Diabetes and Digestive and Kidney Diseases. The topic is gestational diabetes. And Dr. Rodgers, what exactly is Gestational Diabetes?
Dr. Rodgers: Gestational Diabetes is a form of diabetes that occurs in some pregnant women, and affects seven percent of all pregnancies in the United States, roughly 200, 000 each year. It occurs more frequently among women with a family history of diabetes, obese women and Latina, African-Americans, American Indians, Asians, Pacific Islands, and Alaska-native women.
Now, women diagnosed gestational diabetes should be tested six to 12 weeks after their baby is born. And in many cases, their blood-glucose levels will be normal, and they will no longer be considered to have diabetes. But what many women don’t realize is that their history of gestational diabetes puts them at risk for diabetes throughout their lifetime and increases the long-term risk for both the mom and for her child. So a woman with a history of GDM or gestational diabetes mellitus should be tested every three years after the initial six-week test.
Balintfy: Okay, so it’s not enough to be tested for gestational diabetes during pregnancy; it’s important to follow up and have tests after pregnancy because there are the long term risks associated with gestational diabetes, right?
Dr. Rodgers: Absolutely. And women who are diagnosed with gestational diabetes, in fact, they have about a 40 to 60 percent chance of developing diabetes within the next five to 10 years after their delivery. And, of course, diabetes is a very serious condition. If untreated it leaves numerous, serious complications: heart disease, kidney disease, non-traumatic amputation, and blindness. And additionally, the children of women who have gestational diabetes also seem to be at risk for developing obesity or diabetes. So after the delivery it’s important for them to be tested on a regular basis for an extended period of time, just because of this high rate of going on to develop diabetes between five to 10 years later.
Balintfy: Dr. Rodgers, do you know if gestational diabetes is something that’s inherited, or how does that work?
Dr. Rodgers: There probably is a genetic component to it. I mentioned the risk factors associated — it seems to cluster in families. And women of certain racial and ethnic groups appear to be at high risk.
Balintfy: Okay. What are some of the things that NIDDK is doing to help raise awareness about the dangers of gestational diabetes?
Dr. Rodgers: Well, the NIDDK and the Office for Research on Women’s Health are working together to extend the reach and visibility of the National Diabetes Education Program — “It's Never Too Early. . .to Prevent Diabetes” — gestational diabetes awareness initiative. We want all mothers with a history of gestational diabetes to really be aware of the long-term health risks and the health risks faced by their children, and most importantly, steps that they can take to keep themselves and their family healthy.
Balintfy: So then what are some of those steps that women can do to keep themselves and their families healthy?
Dr. Rodgers: Number one, regular screening is very important. In addition to the initial testing at six to 12 weeks after giving birth, women who have a history of gestational diabetes should be screened regularly for diabetes and for pre-diabetes at least every three years after that. So it’s important for them to talk to their doctors about their history of gestational diabetes, and its follow-up screening usually consists of a simple blood test. Women who have had a history of gestational diabetes should also talk to their obstetrician about earlier screening during their next pregnancy. And then finally, because children of women who have gestational diabetes are also at increased risk of obesity and diabetes, it’s a good idea for the mothers to inform the child’s pediatrician so that they know the mother has had gestational diabetes.
Second point, in addition to regular screening, women with a history of gestational diabetes can do a lot to prevent or delay their risk of developing diabetes after having had their baby. Many women who have had gestational diabetes see a nutritionist or dietician during the pregnancy, but it’s just as important to keep up with these healthy habits after the baby is born. It’s important for women with GDM to reach and maintain a healthy weight by making healthy food choices and being active at least 30 minutes a day, five days a week. And a healthy meal plan for people with diabetes is really a healthy meal plan for everyone. You want to choose foods that are high in fiber and low in saturated fats or trans fats, cholesterol, low in sodium or salt, with low in added sugars. And eating a colorful mix of fruits and vegetables, fish, lean meats – chicken or turkey without the skin, or dry peas and beans, whole grains, low fat or skim milk and cheese are all good examples of a healthy meal plan. And then setting important physical activity goals for one is really a great way of managing ones risk of developing diabetes and staying healthy.
So again, as I’ve mentioned previously, trying to work up to getting about 30 to 60 minutes of physical activity on most days a week; a brisk walk is one good example of how one might do this, but walking, dancing, swimming, biking, jogging are other very good examples. It’s finally important to stress that even if women don’t reach their goal weight, research shows that just maintaining a healthy lifestyle can help them reduce their overall risk.
Balintfy: And even just a little bit goes a long way.
Dr. Rodgers: Absolutely.
Balintfy: And Dr. Rodgers, Are there other things that that women can do, breastfeeding, for example, that could be helpful for someone with gestational diabetes?
Dr. Rodgers: Well, breastfeeding is also beneficial for both mothers and baby, and I’m glad you asked. Like all mothers, women with gestational diabetes should breast feed their babies if possible. Breastfeeding provides a number of benefits for your baby, including the right balance of nutrients and protection against certain illnesses. Breastfeeding is also beneficial for mothers. It allows the body to use up some of the extra calories that were stored during pregnancy, and losing weight after having the baby enhances one’s overall health. And it is one way to reduce the chances of developing diabetes later in life. Many women who have had gestational diabetes also find that breastfeeding improves their fasting blood-glucose levels, and allows them to maintain a lower average blood-glucose once their babies are born. So these action steps are good for the entire family. They help both the mother and the child manage their risk for developing diabetes in the future.
Balintfy: Going back a bit, those diet and fitness goals you mentioned, those aren’t just going to help diabetes, they’re going to help perhaps even cancer prevention, heart disease. . .
Dr. Rodgers: If you could put into a pill the benefits of exercise and those proper eating plans, one would be rich.
Balintfy: On a personal note Dr. Rodgers, I had dinner with a friend recently who’s first pregnancy went fine, but during her second, that’s when she was diagnosed with gestational diabetes. So is this something that you have to continue to be vigilant about?
Dr. Rodgers: You have to be vigilant about it each time. And what is clear from the research is that the child born in the first pregnancy, when she didn’t have gestational diabetes, is at a much lower risk of becoming obese or developing diabetes than the child that she had when she did develop gestational diabetes. And that’s why it is critically important for the pediatrician to be aware of that.
Balintfy: I think that covered all of my questions Dr. Rodgers. I’ll certainly put the contact information on the end. Is there anything that we missed or maybe something worth re-emphasizing?
Dr. Rodgers: The only point that I want to make is that if the listeners would like to get more information they can visit the National Diabetes Education Program, or NDEP, which is really a great resource; there are free tip sheets on gestational diabetes, including the steps to reduce one’s risk of developing diabetes. One can either call a toll-free number: 1-888-693-NDEP. That’s 1-888-693-6337. Or they can visit a website at YourDiabetesInfo.org.
Balintfy: Thank you very much Dr. Rodgers.
Rodgers: Thank you.
Balintfy: And that’s it for this episode of NIH Research Radio. Please join us again on Friday, June 4th when our next edition will be available. If you have any questions or comments about this program, or have story suggestions for a future episode, please let me know. Best to reach me by email—my address is firstname.lastname@example.org. I'm your host, Joe Balintfy. Thanks for listening.
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