STRONG HEART STUDY I NVESTIGATING C ARDIOVASCULAR D ISEASE IN A MERICAN I NDIANS

strongheart.ouhsc.edu Volume 17, Number 2 November 2005

CONTENTS SHS Begins Exciting New Chapter – Phase V!

Page 1 Strong Heart Study (SHS) investigators Richard B. Devereux, Weill Medical

SHS Phase V were successful in securing funding for College of Cornell University, for the

Assessing CHD risk Phase V of the Strong Heart Study. New Cardiology Reading Center; and Dr. Jean funding will allow a second examination W. MacCluer, Southwest Foundation for

of the Family Study participants as well Biomedical Research, for the genetics as continuing follow-up of the health of laboratory and analysis center. Page 2 & 3 the original SHS participants. Five Genetics The Strong Heart Study was initiated in grants were awarded by the National 1988. With the new award, funding will Fat cells & proteins Heart, Lung, and Blood Institute. Grants continue the Study until 2010. With were awarded to Dr. Barbara V. Howard, more than 120 publications to date, the MedStar Research Institute, for the SHS has contributed to better under- Page 4 field center and central standing of heart and its risk laboratory; Dr. Elisa T. Lee, University Save the date! factors in American Indians and of the of Health Sciences Center, for relationship of to heart structure the Oklahoma field center and the data and function. Based on SHS data, a National Diabetes coordinating center; Dr. Lyle G. Best, prediction equation specific to American Prevention Meeting Missouri Breaks Industries Research, Indians has been developed to estimate Aug 21-24, 2006 Inc., for the Dakotas field center; Dr. in OKC th (Continued on the top of page 4)

Assessing Heart Disease Risk in Patients with Diabetes

Some studies have shown that Strong Heart Study (SHS) levels of protein in the urine), people with diabetes are at as investigators examined the in- high blood pressure, current much risk for heart disease as fluence of risk factors for heart smoking, and fibrinogen (a people who already have heart disease, and heart disease and substance in the blood needed disease but do not have diabetes. , in 4549 SHS participants. for blood clotting). In other words, people with The investigators studied parti- diabetes have the same chance of cipants with and without It was found in both men and having a heart attack as people diabetes and with and without women that 1) diabetes in- with heart disease have of having heart disease or heart disease and creased the risk for heart dis- another heart attack. Because of stroke. The risk factors for heart ease and 2) heart disease risk this risk, doctors propose more disease that were studied was higher in diabetic men aggressive treatment goals for included gender, and women if they had people with diabetes. values, albuminuria (abnormal unhealthy cholesterol levels (Continued on the bottom of page 4) 1 SHS Newsletter November 2005 Testing Possible Heart Disease Genes

One of the main called “candidate gene” goals of SHS-Phase analysis. This looks for changes IV is to find out in known genes that may have a how genes we possible effect on heart disease. inherit from our Most of these candidate gene parents affect our changes have already been chances of having suspected of increasing the risk heart disease, of heart disease in other, non- diabetes, and other Indian populations. The risk factors. This is researcher then checks to see if mainly being done by a method these changes are present more called “linkage analysis”, which often in people who have the date gene studies. Research attempts to find the location of condition (such as a heart colleagues of Dr. Howard’s in genes along the chromosomes, or attack, diabetes or stroke), Washington, DC and others will DNA of a person. The genetic compared with those who have be checking on changes investigators of the SHS are stayed healthy. involving the AKT-1 gene, beginning to present some of the which seems to have a strong first exciting results from this In past newsletter articles we effect on how insulin works and part of the study; and another have described candidate gene on the digestion of carbo- article in the next newsletter will studies that have been done in hydrates. It is thought that this provide more details about that. the SHS and are now reported will tell us more about what in medical journals. The SHS happens in people who develop The other method of testing for steering committee has now diabetes. SHS scientists working genetic influences on disease is approved two additional candi- (Continued on the bottom of page 3)

Recent Findings Shed Light on the Role of Fat Cells in Disease

terns of disease emerge, In other words, what the relationship between which are known as risk changes happen in the body fatness and risk of factors. For example, as body, at a cellular level, to disease. Most fat in the Strong people get heavier, the cause diabetes as weight body is stored in fat cells. Heart Study (SHS) hormone, insulin, does not goes up? What changes Until recently it was research helps doctors work as well (known as lead to heart disease when thought that these cells and scientists understand “insulin resistance”) and someone has diabetes? did little but act as fat why some Native the risk of diabetes in- The Strong Heart Study stores. We now know Americans are more creases. Similarly, having plays an important part in adipose cells are active in likely to develop certain diabetes or kidney disease trying to answer these producing a variety of conditions and increases the risk of heart questions for American protein messengers (sub- while others are not. disease. With these risk Indians through continued stances made in one part Even though each factors clearly established, research. of the body which tell the next step is under- another part of the body individual is unique Recent work by other within the SHS, when standing exactly why scientists suggests that fat to do something) to overweight and diabetes change how the body you look at data from cells, known as adipocytes, are such important risk works. Intriguingly, large numbers of play an important part in participants, some pat- factors for heart disease. many of these protein (Continued on the top of page 3) 2 SHS Newsletter November 2005

Recent Findings Shed Light… (Continued from bottom of page 2)

messengers also act to diabetes, but we wanted Adiponectin did not change levels of to know whether there however predict later heart (re- was a relationship disease in our study. sponse of the body between adiponectin and when injured or heart disease. The SHS Resistin is a newly found “attacked” in some tested and compared circulating protein which way) in the body. stored samples from 500 may affect both how the this appears mainly to Recent studies by the participants, some of body handles glucose and reflect higher levels of SHS examined two of whom developed heart the development of heart resistin in those with these protein mes- disease in later years and disease. Scientists at the diabetic kidney disease. sengers, known as some of whom did not. MedStar Research Institute Studies on proteins, like adiponectin and resis- We found a number of (Washington, DC) found adiponectin and resistin, tin. Research on other important things. We raised levels of resistin in are in their infancy. ethnic groups suggests found adiponectin levels persons with atheroscler- However, each year that these messengers were higher in women osis (the thickening of research advances, relate to diabetes, and in persons (both men artery walls that is the bringing with it new overweight, and heart and women) without basis of heart disease) in a insights on how these disease. Is this the diabetes. We also found predominantly white and other protein case for American that those with higher population. To determine messengers in the body Indians? levels of adiponectin had if this was the case for might alter the risk of higher levels of HDL- American Indians with disease. It is exciting Adiponectin is a cholesterol (“good” cho- similar heart disease, we for Strong Heart invest- protein made by fat lesterol) and higher analyzed samples from tigators to be involved in cells. Oddly, the fatter levels of insulin sensi- participants in the third such promising research a person gets the lower tivity (how sensitive the Strong Heart examination that will ultimately help the level of adipo- cells in your body are to to assess resistin blood in designing new treat- nectin tends to be. We the effects of insulin). levels. We found that SHS ments to further cut the already know that Levels of adiponectin participants with coronary risk of diabetes and lower levels of tended to be lower in heart disease also have heart disease in Amer- adiponectin increase persons with more body higher resistin levels. ican Indian commun- the risk of getting fat and larger waistlines. Unexpectedly, however, ities. SHS

Genes …(Continued from top of page 2)

with others at the many different populations findings continue to hold true University of Texas in around the world; but no one after further tests, or if they Dallas, Texas, will be knows if American Indian ever turn out to be helpful to testing the effects of people might also carry some doctors taking care of another gene called of these changes, and what patients, is still unknown. We ENPP-1, which also effect it might have on their are excited though, to begin seems to work with health. the process of learning about insulin to play a role in the the effect of genes on our All of this testing is in a very cause of diabetes. Changes in health. SHS this gene have been studied in early stage and whether these

3 STRONG HEART STUDY COORDINATING CENTER Non-Profit Organization U.S. Postage

University of Oklahoma Health Sciences Center

Center for American Indian Health Research PAID

College of Public Health Oklahoma City, Oklahoma Permit No. 220 P.O. Box 26901 Oklahoma City, OK 73190-3040

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S t r o n g H e a r t S t u d y Newsletter November 2005

SAVE-THE-DATE! SHS Phase V (Continued from the top of page 1) the 10-year risk of from existing August 21-24, 2006 risk factors. Data have been collected that will help IHS and Tribal clinicians to better serve their American Indian 2006 National Conference: communities.

Reducing Health Disparities in American Indians There are additional benefits to the communities and Alaska Natives by Preventing Diabetes participating in the Strong Heart Study. Research Throughout the Life Cycle findings have led to clinical trials to determine if interventions can be identified to reduce the risk of diabetes and cardiovascular disease in American Indians.

One of these spin-off studies, the Pathways study, was SHS investigators will make major presentations conducted in the early 1990s to determine the on SHS findings effectiveness of a school-based intervention to prevent PURPOSE the development of obesity. Another spin-off study, the To provide a forum for sharing & exchanging information Stop Atherosclerosis in Native Diabetics Study (SANDS) about ongoing prediabetes and diabetes prevention efforts. is currently being conducted to determine if the risk of Focus is on community empowerment and involvement in cardiovascular disease among those with diabetes can be diabetes prevention throughout the lifecycle: infancy, reduced by aggressive intervention on high blood youth, adult, and elder. pressure and high cholesterol levels. Strong Heart investigators will continue looking for solutions as our WHO SHOULD ATTEND understanding of heart disease in American Indians American Indians & Alaska Natives interested in diabetes increases through Phase V of the Strong Heart Study. SHS prevention, Special Diabetes Program for Indians grantees, tribal leaders and health program directors, health care professionals, diabetes prevention advocates and Assessing heart disease… researchers, and health policy makers. (Continued from the bottom of page 1) WHERE and higher albuminuria, blood pressure, and fibrinogen. Cox Convention Center, Oklahoma City, OK

Results from the SHS indicate that wide variation exists SPONSORED BY (export.ouhsc.edu ) in rates of heart disease in American Indians with The Oklahoma Native American EXPORT Center of the diabetes, depending on individual risk factors. Therefore, University of Oklahoma Health Sciences Center, the the investigators propose that it may be best to base Oklahoma City Area Indian Health Service (IHS), & the treatment targets on your entire risk factor profile (which IHS Clinical Support Center-Accreditation Sponsor. SHS considers all of your risk factors together), rather than just the fact that you have or do not have diabetes. SHS 4