September 4, 2009
NIH Podcast Episode #0092
Balintfy: Welcome to episode 92 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 we'll be talking a lot about diabetes - a disease that affects nearly 24 million Americans. First, we'll hear how a couple of risk factors for the disease may be linked to some gene variants. Then, an update on the importance of controlling type 1 diabetes. And we'll wrap with an interview about family risk for the disease. But first a story about reducing depression in stroke survivors. That's next on NIH Research Radio.
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A Brief Behavioral Intervention Can Reduce Depression in Stroke Survivors
Balintfy: A nurse-led behavioral intervention can reduce the incidence of depression in stroke survivors. This is according to the results of a study published in a recent issue of the journal Stroke. The behavioral intervention, called Living Well with Stroke, aimed to increase pleasant social interactions and physical activity as a way to elevate mood. The study was funded by the National Institute of Nursing Research. But what exactly is a behavioral intervention?
Grady: Behavioral intervention is a strategy and an approach to try to change the behavior of an individual or groups of individuals.
Balintfy: Dr. Patricia A. Grady, Director of the National Institute of Nursing Research explains the intervention, called Living Well with Stroke, provides individualized counseling sessions.
Grady: It helps them focus on realistic treatment goals and helps them develop strategies to deal with some of the frustrations in trying to reach their goals.
Balintfy: A stroke occurs when the blood supply to a part of the brain becomes blocked or interrupted, leading to brain damage in the affected area. Stroke survivors can experience a range of aftereffects. As many as one-third of stroke survivors also develop post-stroke depression. Dr. Grady adds that depression can result in a poorer response to rehabilitation, a longer delay in returning to work, more social withdrawal, and increased use of health care services.
Grady: The study was very interesting in that it did show a decrease...the endpoint was a decrease in symptoms of depression and it did show a substantial decrease in the signs of depression and that was in the experimental or the study group compared to the control group.
Balintfy: The clinical trial involved over 100 stroke survivors who exhibited symptoms of post-stroke depression.
Grady: The interesting thing was that immediately after finishing the behavioral intervention, there was improvement in the depression scores of the study group.
Balintfy: Those assigned to the study group—those getting the Living Well with Stroke intervention—received nine counseling sessions over two months with a specially trained stroke rehabilitation nurse. In these sessions, the nurse taught the participants problem-solving skills and helped them develop realistic treatment goals.
Grady: But the really interesting thing was that even up to a year after the study had started and after the counseling session interventions—up to a year afterwards, the dramatic increase or improvement in depression compared to the control group persisted.
Balintfy: Dr. Grady points out that the intervention could be used alone or in conjunction with antidepressant medications.
Grady: The effect with this intervention was more dramatic and more long lasting than with antidepressants alone. That's a very important part of the study.
Balintfy: Dr. Grady emphasizes that study participants had both a relief and remission of depressive symptoms.
Grady: This study gives hope to people whose family members are suffering from depression after a stroke because what it says…what it indicates is that there are behavioral interventions, counseling interventions, that can be carried out that will in fact improve the health of their family members in ways that…that drug therapy alone will not.
Balintfy: For more information on this study, visit www.ninr.nih.gov.
Researchers Uncover Genetic Variants Linked to Blood Pressure in African-Americans
Balintfy: Now we get into our reports and interview about diabetes. First, two risk factors for type 2 diabetes are high blood pressure, and having an African-American family background. Now, a research team has discovered genetic variants related to blood pressure in African-Americans. These findings may provide new clues to treating and preventing hypertension, also known as high blood pressure. The effort marks the first time that a relatively new research approach, called a genome-wide association study, has focused on blood pressure and hypertension in an African-American population. Wally Akinso has the details.
Akinso: Researchers discovered genes related to hypertension in African Americans.
Rotimi: Hypertension is a major problem in African Americans; actually it's a major problem world wide.
Akinso: Dr. Charles Rotimi is a National Human Genome Research Institute senior investigator and director of the trans-NIH Center for Research on Genomics and Global Health.
Rotimi: Over one third of the adult population in the United States has hypertension and that problem is typically worse for African Americans where close to 40 percent have hypertension. So it's a major problem in terms of heart diseases stroke and kidney disease.
Akinso: Researchers found five genetic variants related to blood pressure in African Americans, findings that may provide new clues to treating and preventing hypertension. This effort marks the first time that a relatively new research approach, called a genome-wide association study, has focused on blood pressure and hypertension in an African American population. Dr. Rotimi says the goal of the study was to come up with a better understanding of hypertension in African Americans.
Rotimi: We really wanted to put together a large cohort of African American families and also unrelated individuals to understand all of these conditions that is very, very prevalent in African American communities.
Akinso: Researchers analyzed DNA samples from over 1,000 participants in the Howard University Family Study, a multigenerational study of African American families from the Washington D.C., metropolitan area. Half of the volunteers had hypertension and half did not. Dr. Rotimi explains why these findings are promising.
Rotimi: Our findings are really, really exciting for us. We're able to pick out several genes or even information, what we call markers, near some genes, that we think are very promising in terms of our ability to understand hypertension and even to treat it.
Akinso: Dr. Rotimi is optimistic that these findings could help improve treatment options for African Americans, as well as other populations at risk for hypertension.
Rotimi: We hope that this will actually add to our understanding of why people get hypertension specifically also in African Americans and hopefully this can go to the level where we can either do more preventive strategy or actually become a source of understanding the biology and treatment for hypertension in all human population.
Akinso: For more information on this study, visit www.genome.gov. This is Wally Akinso at the National Institutes of Health, Bethesda, Maryland.
Intensive Glucose Control Halves Complications of Longstanding Type 1 Diabetes
Balintfy: We'll have more on the familial risk of type 2 diabetes later in the program. Now a quick look at type 1 diabetes, which used to be called juvenile-onset diabetes or insulin-dependent diabetes. The Diabetes Control and Complications Trial was a landmark clinical study in people with type 1 diabetes. The trial compared the effects of standard or intensive control of blood glucose on the development of common diabetes complications. The study found that keeping blood glucose levels as close to normal as possible slows the onset and progression of the eye, nerve, and kidney damage of diabetes. Now, recently updated information shows improved long-term outlook. Alex Green filed this report.
Green: Researcher's findings show that for people with type 1 diabetes, near-normal control of glucose beginning as soon as possible after diagnosis greatly improves the long-term prognosis of the disease. Dr. David M. Nathan, of Massachusetts General Hospital and Harvard Medical School, who co-chaired the Diabetes Control and Complications Trial, now co-chairs a follow-up study.
Nathan: The Diabetes Control and Complications Trial, which was initiated more than 25 years ago, was designed to determine whether intensive therapy aimed at achieving glucose levels as close to the non-diabetic range as we could would result in a change in the development or progression of diabetes complications.
Green: Intensive glucose control in fact halves complications of longstanding type 1 diabetes.
Nathan: Intensive therapy is now the standard so that's what all patients should be recommended to follow with type 1 diabetes.
Green: The Epidemiology of Diabetes Interventions and Complications follow-up study also found that the outlook for people with longstanding type 1 diabetes has greatly improved in the past 20 years due to a better understanding of the importance of intensive glucose control as well as advances in insulin formulations, insulin delivery, glucose monitoring, and the treatment of cardiovascular risk factors. Dr. Nathan continues to follow participants to determine the long-term effects of prior intensive versus conventional blood glucose control.
Nathan: So our patients now have been followed throughout about 30 years duration of diabetes and what the new paper shows, the one that has appeared in the Archives of Internal Medicine, that patients who are treated with modern day methods with intensive therapy have actually a very low risk of developing the severe outcomes that we used to associate with type 1 diabetes.
Green: Type 1 diabetes complications include eye damage, kidney damage and cardiovascular disease events like heart attack and stroke. In the Diabetes Control and Complications Trial, conducted from 1983 to 1989, intensive therapy meant at least three insulin injections a day or use of an insulin pump along with self-glucose monitoring at least four times a day to keep glucose in the near normal range. Dr. Nathan explains that patients in the study were randomly assigned to two groups. One aimed for a hemoglobin A1C in the normal range based on an A1C test which shows a person's average blood glucose over time.
Nathan: We demonstrated that the intensively treated group, which maintained a hemoglobin A1C of approximately 7% when compared with the conventional treatment group that had an average hemoglobin A1C of about 9% reduced the development of eye disease, kidney disease, and nerve disease by as much as 76%.
Green: Researchers conclude that while tight control is difficult to achieve and maintain, its benefits have changed the course of diabetes. Not only did intensive glucose control halve the rates of eye and kidney damage, but the rates of vision loss and kidney failure were much lower than had been seen historically. For more information on this study, visit www.niddk.nih.gov. This is Alex Green IV, National Institutes of Health, Bethesda, Maryland.
Balintfy: We wrap up this episode of NIH Research Radio with details on family risk for pre-diabetes and type 2 diabetes. Stay tuned.
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Family Risk for Diabetes, Pre-Diabetes
Balintfy: A few episodes ago, we talked to Dr. Griffin Rodgers, director at the National Institute of Diabetes and Digestive and Kidney Diseases about questions to ask when managing diabetes. Well, what if you don't have diabetes? Turns out you may have a condition called pre-diabetes – and not even know it. In this episode, we talk again to Dr. Rodgers about risk factors for diabetes in particular, pre-diabetes. We start by asking, what exactly is pre-diabetes?
Dr. Rodgers: Pre-diabetes is a condition in which the blood sugar is higher than normal, but not high enough to actually give one a diagnosis of diabetes.
Balintfy: And Dr. Rodgers, what are the symptoms of pre-diabetes and who is at risk?
Dr. Rodgers: Well, oftentimes, pre-diabetes may be asymptomatic, and that's why it's so important to know whether one has a family history of diabetes. So if one has a parent or a brother or a sister, or a first degree relative like an aunt or uncle that has a diagnosis of diabetes, that's important to know, and that should be relayed to one's health care professional. For certain other racial and ethnic groups, for example, African-Americans, Hispanic and Latinos, Asian-Americans, Pacific Islanders, Native Americans and Alaska Natives who are at higher risk for having pre-diabetes and that, obviously, by history and physical examination, your health care provider will know that.
But it's also important to realize that in this country, about nine percent of women who go through a normal pregnancy will develop what's called gestational diabetes, and not only as a mother who has gestational diabetes herself at risk for developing diabetes later on in life, but the child of -- the infant born from that mother is also at higher risk of developing diabetes sometimes later in their life, but also developing obesity. And so family history is important, being from a certain racial and ethnic group is important, certainly patients who are inactive or overweight are at greater risk, individuals who are older, for example, over 45 years of age, are also at higher risk of having pre-diabetes, and those are important factors that should be discussed with one's health care provider.
Balintfy: So if someone has one or more of these risk factors – being in one of those ethnic groups, having a family member with diabetes or having had gestational diabetes – what can they do to prevent or delay the onset of diabetes?
Dr. Rodgers: Well, a very important study done, the Diabetes Prevention Trial, showed that many of these individuals who are at high risk for developing diabetes who had pre-diabetes, many of these individuals were overweight. They were from these racial and ethnic groups that I just discussed. They generally had little in the way of physical activity previously. The study showed that… there are positive steps that one can take, modest steps that one can take to prevent or delay the onset of diabetes.
Balintfy: What exactly are some of those steps?
Dr. Rodgers: Modest lifestyle intervention — modest lifestyle intervention meant generally losing five to seven percent of one's body weight. So for example, if you were a 200-pound individual, losing just 10 or 14 pounds through a diet change, which reduced the number of calories and the amount of fat, for example, and also stress physical activity, about 30 minutes a day of brisk walking, five days a week, one could achieve that reduction in the amount of weight one has, and that translated to a delay in the development of type 2 diabetes compared to the control group.
So there are action steps that one can take, fairly modest lifestyle changes, if one is in these high risk groups, one has a family history, they should let their health care provider know about it, have them tested to determine whether they have pre-diabetes, and… they can get this information through visiting our Web site at NDEP — yourdiabetesinfo.org, or they can call a toll free number, 1-888-693-NDEP, and let me say that again. It's 1-888-693-6337.
Balintfy: Thank you very much Dr. Griffin Rodgers at NIDDK. Again, you can get more information and a free booklet from the National Diabetes Education Program at www.YourDiabetesInfo.org or by calling toll-free 1-888-693-NDEP.
Balintfy: That's it for this episode of NIH Research Radio. Please join us again on Friday, September 18 when our next edition will be available for download. I'm your host, Joe Balintfy. Thanks for listening.
NIH Research Radio is a presentation of the NIH Radio News Service, part of the News Media Branch, Office of Communications and Public Liaison in the Office of the Director at the National Institutes of Health in Bethesda, Maryland, an agency of the US Department of Health and Human Services.