April 18, 2008
NIH Podcast Episode #0056
Balintfy: Welcome to the 56th 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: how cognitive health is improving among older Americans; and a conversation about helping older adults prevent or delay diabetes. But first, how researchers have discovered a new battleground to fight viruses with vaccines. That's next on NIH Research Radio.
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Researchers Discover New Battleground for Viruses and Immune Cells
Balintfy:Vaccines have led to many positive health outcomes, but many deadly viruses, such as HIV, still avoid the efforts of scientists to develop effective vaccines against them. Wally Akinso reports on the discovery of a new battleground in this field.
Akinso: Researchers at the National Institute of Allergy and Infectious Diseases have discovered a new battleground for viruses and immune cells which could help researchers develop anti-virus vaccines. Dr. Jonathan Yewdell, Chief of the NIAID Cellular Biology Section says an improved understanding of how the immune system operates during a viral infection is critical to designing successful anti-virus vaccines.
Yewdell: What we're interested in is how the immune system recognizes viruses. The cells we're principally interested in are the killer T cells. These are the cells that go into an organ and find a virus infected cell and typically kill it. And so there's lots different ways to study it that we've done over the years. And there's a brand new way to study it that entails taking an animal infected it with a virus. The virus expresses a protein that you put in that's colored so a microscope can see it and then we take the animal and put it on a fancy microscope. And we watch how the virus infected cells interacts with the cells that we're interested in which are the T-cells.
Akinso: Dr. Yewdell and his colleague Dr. Heather Hickman focused on mouse lymph nodes, which are bean shaped organs that contain a variety of immune cells and are distributed throughout the body. The researchers discovered that immune cells confront viruses just inside of the lymph node and not deep within these organs as previously thought. Dr. Yewdell discusses the significance of the study.
Yewdell: The significance is really basically starting to really put vaccine generation on a rational basis. The way vaccines have always been designed in the past is basically you take a virus and you either kill it or not. You make it weaker. You give it to an animal and you didn't really have to know the rules to get it to work. And these vaccines have saved hundreds of millions of people but you didn't actually have to know anything about how they were working or not very much. The infectious diseases that are left to develop vaccines for are the hard ones. Things like HIV, hepatitis C virus, malaria and in all of those diseases it's thought that the cells that we're interested in, these killer T cells play an important role. And what you like to do then is to elicit the best T cell response you can. We think that it's important to do that, that you really know the rules for how it's working so then you can actually design your vaccine to take advantage of those rules.
Akinso: Dr. Yewdell says this is just a step but researchers are a long way from coming up with a vaccine for viruses such as HIV and malaria. This is Wally Akinso at the National Institutes of Health Bethesda, Maryland.
Improved Cognitive Health among the Elderly
Balintfy: With May just a couple weeks away, and because May is Older Americans Month, we’re looking at a couple topics that touch older people. First, here’s another report from Wally Akinso. It’s about recent findings from two NIH institutes showing how education is associated with cognitive health later in life.
Akinso: Cognitive health has improved among older Americans according to a study by the National Institute on Aging and the National Institute of Mental Health. Researchers compared the cognitive health of older people in 1993 and 2002. They found that higher levels of education were associated with better cognitive health. Dr. Richard Suzman, Director of the NIA's Social and Behavioral Research Program, pinpoints some of the other possible factors within the improvement of cognitive health among the elderly.
Suzman: The really interesting question is what's causing this. Some of it may be the increase in education. I mean older people are getting more and more educated, but there was also some suggestion within the data that improve treatment for stroke, heart disease, and vascular conditions might also be factors in the improvement. If that's true that's also very good news because it shows that some fraction of cognitive impairment can be affected by interventions, by medical interventions, and by lifestyle interventions. There other data that were not investigated in this particular study have also shown that exercise is very good for the brain and for cognition.
Akinso: Dr. Suzman feels that further analysis of how education, medications, cardiovascular health and lifestyle affect cognitive functioning. This is Wally Akinso at the National Institutes of Health, Bethesda, Maryland.
Balintfy: When we come back, an interview about helping older adults in the US control diabetes.
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Balintfy: Since May is Older Americans Month, we took some time to talk with Dr. Judith Fradkin, director of the Diabetes Division of the National Institute of Diabetes and Digestive and Kidney Diseases at the National Institutes of Health. We talked about diabetes among older Americans. Dr. Fradkin, how common is diabetes in older people?
Dr. Fradkin: Being older is a major risk factor for diabetes and so the frequency of diabetes steadily increases as people get older. It goes up quite a bit after the age of 45 and after the age of 60, about 600,000 people will develop diabetes each year. And all together there are about 10 and half million people in the United States over 60 who have diabetes. About a third of them don’t know they have it because in the early stages diabetes can be asymptomatic.
Balintfy: So say I am over 45, what are some of those risk factors I should start looking for?
Dr. Fradkin: A family history of diabetes is very important. If you have a parent or a grandparent or a sibling who had diabetes, then you’re at increased risk. Age itself is an important risk factor for diabetes. For women, if they had diabetes during pregnancy or gave birth to a large baby, that’s an important risk factor. People who have high blood pressure or abnormal lipids are at increased risk for diabetes. And also many minority groups, African Americans, Hispanics, Latinos and Asians are at increased risk. Being sedentary and being overweight is also a very important risk for type-2 diabetes.
Balintfy: Back to older Americans, what are the serious complications of diabetes that older Americans might face?
Dr. Fradkin: For older Americans in particular, heart disease is a very important thing to think about because diabetes increases the risk of heart disease two to four fold, and most people with diabetes will die of cardio-vascular disease. But there are many things people with diabetes can do to reduce the risk of cardio-vascular disease. So it’s very, very important to aggressively manage blood pressure and control LDL cholesterol to lower the risk of cardio-vascular disease in diabetes. Another important complication of diabetes relates to some of the organs that where diabetes affects some of the small blood vessels and that includes the eyes and the kidneys and the nerves. And for preventing that, it’s very important to control blood sugar. So this is why we talk about comprehensive control of diabetes because when you have diabetes there’s so much you can do to prevent yourself from developing the complications. But the control requires thinking not just about blood sugar but blood pressure and cholesterol.
Balintfy: You said that diabetes complications they’re not inevitable or can they be delayed or prevented?
Dr. Fradkin: Absolutely. There can be huge reductions in diabetic complications by controlling these risk factors. So for example the risk of kidney disease or eye disease can be controlled, can be reduced by more than half if people control their blood sugar. Controlling blood pressure and blood cholesterol dramatically reduces the risk of cardiovascular disease. Also, even if you already have complications, there are things that you can do to slow the progression of complications so it’s important to be tested to see if you have complications. So for example people with diabetes need to get their eyes tested every year, because if people have the start of diabetic eye disease, either lowering blood pressure, or sometimes laser photo coagulation can really, tremendously preserve vision. Similarly there are some medications as well as very strict blood pressure control that can really protect the kidneys when people start to show the first sign of diabetic kidney disease which can be seen with some protein in the urine. So it’s really important to annually get tested to make sure that if you’re developing complications of diabetes you’re doing everything that you can to slow the progression of those complications.
Balintfy: Is there a way to maybe look at it in terms are there ABCs of diabetes?
Dr. Fradkin: Yes. We talk about controlling the ABCs of diabetes where A, A1C is a blood test that tells you what your average blood sugar has been over the previous three months. So sugars can fluctuate quite a bit but when you test, say a finger stick blood sugar, but this A1C test really tells you how well you’ve been controlled over the previous months. B is for blood pressure and C is cholesterol. And if you control those ABCs you will markedly reduce the risk for developing diabetes complications.
So we ask people, when they see their doctors, to say, what are my ABCs, what should they be and what are we going to do to get them to where they should be?
And many doctors will talk about things that you yourself can do to control your ABCs as the first line of therapy. So for example, walking, being physically active, makes a huge difference for people with diabetes because insulin works on the muscles to bring sugar into the muscles and that’s the main way the body lowers blood sugar by taking it up in the muscles and burning it. So when you’re physically active and using your muscles, that helps your body to burn the sugar and it makes the insulin you have much more effective.
So exercise is important for weight loss, but even above its effects on weight loss, it helps to control blood sugar and helps to make it helps your own body’s insulin or insulin you might be taking, work more effectively.
A healthy diet is also very important. It’s very important to eat fruits and vegetables. It’s important to get your carbohydrates through complex carbohydrates like whole grains, fruits and vegetables, as opposed to very short acting forms that can cause rapid swings in blood sugar.
It’s important to eat a low fat diet both because that will prevent you from getting overweight but also because it will help keep your blood lipids in a healthy range and may reduce the need for medication to control cholesterol.
So much of controlling diabetes is what a person can do themselves. But then many people will also require medication. And if your doctor recommends you be on medication, to control your A1C, your blood pressure or your cholesterol, it’s important to remember that once you get it under control, it’s not going to stay in control unless you continue to take those medications.
So this is a very long term proposition but these medications can really do tremendous things to help prevent the complications of diabetes. And many of the medications are now available as generics. So for people who have problems affording prescriptions, talk with your doctor about whether there is a low cost version of your medication you need available.
Balintfy: That’s a lot of fantastic information. Are there ways older Americans can find additional free resources, how to learn more about what we’ve talked about today?
Dr. Fradkin: We have a website, the National Diabetes Education Program website which is at www.YourDiabetesInfo.org. Or you can simply Google National Diabetes Education Program or Your Diabetes Info. Or you can call 1-888-693-NDEP (NDEP is for National Diabetes Education Program). NDEP is a joint effort of the NIH and the Centers for Disease Control.
In addition, Medicare has a lot of information on their website for people with diabetes. Medicare has a lot of benefits that people with diabetes can access and those include nutrition information counseling, as well as diabetes self management education. These are really important tools that people should take advantage of because learning about how to manage your diabetes will help you do a much better job of taking care of yourself. So it’s really great that Medicare does now offer coverage for self management for diabetes.
Balintfy: Is there anything that you think we might not have covered or missed that you’d like to add?
Dr. Fradkin: Just that many people who have diabetes or are at risk for diabetes aren’t aware of it. About a third of diabetes in this country is undiagnosed. And there are another 54 million people who have pre-diabetes who, if they loose even ten or 15 pounds and become more physically active, can dramatically reduce their risk of developing diabetes.
To prevent diabetes you don’t have to get down to a normal weight, you simply have to make some improvements in your weight. So it’s important to be tested. If you have the risk factors for diabetes, getting a fasting blood sugar, to find out if your sugar is in the normal range, or in the pre-diabetes range or in the diabetic range is very important to help you take the steps that can really help you lead a longer and more healthy life.
Balintfy: Thanks very much to Dr. Judith Fradkin, director of the Diabetes Division at NIDDK.
Balintfy: And that’s it for this episode of NIH Research Radio. Please join us again on Friday, May 2nd 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.