January 11, 2008
NIH Podcast Episode #0049
Balintfy: Welcome to episode 49 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 new host Joe Balintfy. Coming up in this edition, we hear about cervical cancer awareness and the HPV virus, and how a Healthy Lifestyle May Lower the Risk of Cancer for African Americans. But first, we have a pair of reports from Wally Akinso the first on chronic kidney disease and the other on heart attack symptoms. That's next on NIH Research Radio.
(BREAK FOR PUBLIC SERVICE ANNOUNCEMENT)
Many People are Unaware that they have Chronic Kidney Disease
Balintfy: In this report from Wally Akinso, we hear from two experts on how kidney disease often goes unnoticed. They explain a study that looks into why this happens, and the importance of getting screened.
Akinso: A growing number of Americans have chronic kidney disease and don't know it. This trend is hampering efforts to prevent irreversible kidney failure according to a study by the National Institute of Diabetes and Digestive and Kidney Diseases. An estimated 26 million people now have chronic kidney disease, says Dr. Paul Eggers, co-author of the study. He talks about some of the elements that factor in the increase of chronic kidney disease in the U.S. population.
Eggers: We, in the paper, show some reasons which are easily defined. And that is the aging of the American population; kidney function decline with age so that's an important criteria. The increasing degree of obesity as well as diabetes in the American population also explains apart of it. And a very, very small part would be explained I guess by increases of the minority population. However that leaves a very large perhaps afore more of the increase as explained. And in fact we don't have an explanation for that.
Akinso: Dr. Eggers says though the awareness of chronic kidney disease has increased from previous years; most people still don't know they have it.
Eggers: Less than half maybe 40 percent or so are aware that they have impaired kidney function. There are a number of reasons for this but probably the most salient reason is that chronic kidney disease is a silent disease. There are very few symptoms that go with this, the major symptom which really only shows up at the highest level of impairment is maybe fatigue. And of course if you also consider that this occurs largely in the elderly then it becomes a matter of is it anemia, is this kidney disease. So without actual measurement and consultation with the physician it's pretty darn easy to miss this.
Akinso: Kidney disease raises the risk of early death, heart attack, stroke, and high blood pressure. In 2005, at least 107,000 Americans learned they had kidney failure which requires dialysis or a transplant. Dr. Andrew Narva, a kidney specialist from the NIDDK, explains how this study impacts public health.
Narva: The importance of this study is that it shows that there's a large proportion of the population which has kidney disease and that most people aren't aware of it. So it's important for people who are in high risk groups would include all racial and ethnic minorities, people with diabetes, people with a family history of kidney disease and people with hypertension to be screened for kidney disease.
Akinso: Dr. Narva said if an individual is at risk of this disease they should be screened for kidney damage with routine blood and urine tests. This is Wally Akinso at the National Institutes of Health Bethesda, Maryland.
Heart Attack Symptoms are more likely in Women than Men
Balintfy: In this next report, we find out that women are more likely to get heart attack symptoms other than chest pains compared to men. Again, Wally Akinso reports on a study funded by the National Heart, Lung, and Blood Institute.
Akinso: Researchers examined 35 years of research that yield 69 studies and found that between 30 and 37 percent of women did not have chest discomfort during a heart attack. In contrast, 17 to 27 percent of men did not experience chest discomfort. Dr. George Sopko co-author of the study, said women and their physicians need to pay attention to other symptoms rather than just chest pains.
Sopko: There are some other presentation which patient physician need to pay attention to and those include a discomfort somewhere other than chest, it could be in a back, could be in a neck, could be in a jaw, shortness of breath, fatigue, or weakness, dizziness, and palpitations.
Akinso: Dr. Sopko discusses the importance of awareness.
Sopko: Well the take home message is we would like to increase awareness that women are not immune to heart disease. That heart disease is number one killer and starts at the age of 45 plus. Number two is that there are a variety of symptoms which can reflect the heart attack. As I said the bottom is earlier recognition hopefully translates to early treatment. Early treatment many times translates to minimal or no damage.
Akinso: Researchers also found that older people are more likely to have heart attack without chest discomfort. However, because women are on average nearly a decade older than men at the time of their initial attack, the researchers call for more studies to determine the degree to which gender alone influences heart attack symptoms. Dr. Sopko said the NHLBI has come up with various programs and initiatives to increase the awareness of a heart attack. If you would like to check out some of these initiatives or programs visit www.nhlbi.nih.gov. This is Wally Akinso at the National Institutes of Health Bethesda Maryland.
Balintfy: When we return, more from Wally: feature interviews on cervical cancer awareness and the HPV virus.
(BREAK FOR PUBLIC SERVICE ANNOUNCEMENT)
Cervical Cancer Awareness and the HPV Virus
Akinso: January is cervical cancer awareness month and although the incidence of the disease has dropped off over the last 40 to 50 decades largely due to screening, the disease remains a serious health threat world wide. Dr. Diane Solomon a senior investigator in the Division of Cancer Prevention at the National Cancer Institute discusses the screening and testing process involved with this disease.
Solomon: Over the last four to five decades, cervical cancer screening has largely been the pap test, cervical cytology where cells are scraped from the cervix. They’re spread on a slide and looked at under the microscope. Over the past several years, there have been a number of advances on many fronts. In terms of cervical cytology, we now have new techniques whereby instead of spreading cells on a glass slide, now the sampling instruments can be rinsed in fixative. And that collects more of the cells that were obtained from the cervix. There also are techniques to use computers to help the laboratory personnel, cyto-technologists who are scanning the slides for abnormal cells. The computer can assist in locating potentially abnormal areas on the slide and focus their attention to those areas. In addition we have new testing modalities such as HPV testing, where we’re actually looking for the DNA of the human papillomavirus in the cell material from the cervix.
Akinso: Cervical cancer can be caused by several types of a virus called human papillomaviruses known as HPV. HPVs are a group of more than 100 viruses. They are called papillomaviruses because certain types may cause warts, or papillomas, which are benign noncancerous tumors. During a presentation, Dr. Allan Hildesheim, Senior Investigator for the Division of Cancer Epidemiology and Genetics at the National Cancer Institute talked about the history of HPV.
Hildesheim: We know that HPV infection is common and that it often occurs shortly after initiation of sexual activity that’s a very important point for when you want target vaccination we’ll come back to that. We now know that the vast majority of these infections clear and that they usually clear within 1 to 2 years with no sequela. That it’s the women with persistent HPV infection that have a higher risk of progression to pre-cancer. And that there’s a group of 15-18 oncogenic HPV types which are necessary for the development of cervical cancer and of those, HPV 16 and 18 infections are the most worrisome, the most likely to persist and to progress. And they together account for up to 70% of all cervical cancer cases world wide.
Akinso: The HPVs that cause the common warts which grow on hands and feet are different from those that cause growths in the throat or genital area. Some types of HPV are associated with certain types of cancer. These are called oncogenic or carcinogenic HPVs. Dr. Solomon and Dr. Hildesheim explained the importance of the HPV vaccine and the screening process.
Hildesheim: Just to point out, this is what people countries have done in the developed world where papsmear screening has been effective at reducing rates of cervical cancer. They’ve screened over and over starting at the age of 18 over and over and over again for decades. And it works because of this intense screening. Now we have a vaccine that prevents infection with two of the most important types that cause cervical cancer. It is meant to prevent infection. It is meant to be given to young individuals before sexual debut. And now we can have HPV tests that are very sensitive as I showed you. And in one round of testing can accomplish what usually takes multiple rounds of papsmear screening. So now we maybe able to instead of cytology screening to use HPV testing at much more limited time points, and this combination of vaccinating the young and limited screening in older women targeting the age where the prevalence of infection has gone down and the rates of cancer are beginning to go up. This is the time to begin to screen right here, so you can prevent all of the cancers by testing for HPV with out picking up all of these infections that happen early on that are inconsequential.
Solomon: We now have a vaccine against two of the carcinogenic, oncogenic HPV types, 16 and 18. The vaccine has been shown to be very effective for women who have not previously been exposed to 16 and 18 in protecting them against infection and subsequent cell abnormalities that might have derived from an infection with 16, 18. So this is very, very promising.
Akinso: Types 16 and 18 are the most common HPV types which can cause cervical cancer. Dr. Solomon said that it’s important to emphasize that the vaccine does not have any affect on women who have or have been infected.
Solomon: The vaccine is very important for young girls, who should be vaccinated before sexual exposure. It’s important to emphasize however that screening is still the mainstay of cervical cancer prevention. It’s very important for women who are beyond the recommended age range for vaccination, they should continue with the recommended cervical screening. And it’s also important to understand that even if girls and women have been vaccinated, they still need to continue with cervical screening because the vaccine protects against only two of the cancer-causing HPV types. There are several other HPV types that can cause cervical cancer that are not covered by the vaccine.
Akinso: Dr. Solomon lends some advice to women about screening.
Solomon: Women should be screened for cervical abnormalities, depending on their age. Women who begin sexual activity should be screened about three years after they first start having sex, or at the latest by age 21. For women 30 and over, in addition to pap testing, in addition to cervical cytology, we have the option of doing a dual test, of cervical pap smear screening plus HPV test. And that combination of dual testing provides greater sensitivity and therefore the test can actually be done less often.
Balintfy: For more information on HPV and cervical cancer, visit the National Cancer Institute website at www.cancer.gov.
A Healthy Lifestyle May Lower the Risk of Cancer for African Americans
Balintfy: A lot of us are making plans to eat and live more healthily now that the New Year has started. In this report, Wally Akinso finds out that African Americans in particular need to keep their lifestyle in check or face a higher risk of cancer.
Akinso: The holiday season has passed, and perhaps many of us had a lot to eat during the last couple of weeks. However by eating unhealthy and not getting physically active, many African Americans are putting themselves at risk of developing cancer. Researchers are learning that a healthy lifestyle can reduce the risk of cancer. Dr. Tanya Agurs-Collins, a Nutritionist at the National Cancer Institute, discusses the forms of cancer that are prominent in the African American community.
Collins: The three top would be breast, colon, and prostate cancer. So for example, African Americans males have a higher prevalence or a higher incidence of prostate cancer, the highest in the United States. Also colorectal cancer is high among African Americans particularly African American males. Breast Cancer, the incidence is much higher in African American women who are less than 35 years of age and the mortality rates are much higher in African Americans for all of these types of cancers.
Akinso: Dr. Collins said research suggest that a healthy diet can help decrease cancer risk. However African Americans tend to eat foods which are high in saturated fat and high in calories. Dr. Collins provides some healthy dieting types for African Americans.
Collins: There are a number of different ways that they can substitute certain foods. Particularly the focus should be on decreasing the fat in the diet particularly saturated fat which are found in animal products. And so one way to do that it would be to substitute those foods that are not real healthy, for example instead of using ham hock and pork in your greens you can substitute that and actually use leaner types of meat such as turkey. We all love macaroni and cheese, instead of using the regular cheese you can substitute and use low fat cheese. If the recipe calls for cream you can use evaporated milk. So those are just some examples of how one can lower the fat content in their diet.
Akinso: Researchers are learning that physical activity can also affect the risk of cancer. There is evidence that physical activity is associated with a reduced risk of cancers of the colon, breast, prostate, and lung. According to Dr. Collins, despite these health benefits many African Americans aren’t physically active on a regular basis.
Collins: Unfortunately we are not as active as we should be. You know a lot of it is the time. You know the change in times. In other words there are more individuals who are playing video games and watching TV. We need to get together as a family and start walking and getting out more. So the level of physical activity in the African American community is much lower than what it should be and so that’s something that we need to encourage at least increasing or engaging in activity at least 20 to 30 minutes a day, 5 to 7 days a week.
Akinso: The NCI has funded several studies, which deal with lifestyle factors such as measuring physical activity, and examining dietary factors and how they may influence breast cancer and colorectal cancer. If you’re looking for some healthy lifestyle tips to lower the risk of cancer, visit, www.cancer.gov. This is Wally Akinso at the National Institutes of Health Bethesda, Maryland.
Balintfy: And that’s it for this episode of NIH Research Radio. Please join us again on Friday, January 25th when our anniversary 50th episode of NIH Research Radio will be available for download. I'm your host, Joe Balintfy.
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.