Section 3: Risk Factors for Heart Disease and Stroke Among Alaska Natives and American Indians by State

High Blood Pressure

The JNC7 report also notes that only 34% of Americans with high blood pressure have it under control. Research shows that even a 5 mmHG decrease in diastolic blood pressure can reduce heart disease risk by 21% (Arch Intern Med 2001;161:2657–60). A systolic blood pressure <120 mmHG and a diastolic blood pressure <80 mmHG is considered normal.

The IHS is working to better identify and reduce high blood pressure among American Indian and Alaska Native (AI/AN) people—for example, through electronic alerts to health care providers and audits of patients’ charts. It also is administering numerous diabetes grants that include strategies to reduce high blood pressure and other cardiovascular risk factors.

CDC funds state programs to assess the prevalence of high blood pressure, increase compliance with treatment guidelines among managed care organizations, and prevent high blood pressure in the United States, with special programs tailored to minority groups and inner–city residents.

Figure 1. Prevalance of Self-Reported High Blood Pressure Among Adults >18 Years by Race/Ethnicity, BRFSS, 2001 and 2003 Combined.

Definition of High Blood Pressure

We defined self–reported high blood pressure on the basis of the following Behavioral Risk Factor Surveillance System (BRFSS) question: "Have you ever been told by a doctor, nurse, or other health care professional that you have high blood pressure?" This question was only asked in odd–numbered years, so the data for this analysis are from 2001 and 2003. Age–adjusted prevalences were calculated for adults ages ≥18 years.

Prevalence Variations

We found substantial state–to–state differences in the prevalence of high blood pressure among AI/AN people (see facing map and Table 1). A 1.8–fold difference existed between the midpoint of the lowest quartile (20%) and that of the highest quartile (35%).

The national prevalence among all AI/AN people was 28%. Prevalences were 26% for women and 29% for men. AI/AN people ranked second among U.S. racial/ethnic groups (see Figure 1).

A Cautionary Note

Prevalences are based on a sample of AI/AN people surveyed by telephone for the BRFSS. They are likely lower than the true prevalence of high blood pressure and are more representative of AI/AN people living in urban rather than rural areas or on reservations (see Appendix B for details).

Maps and Tables

• Prevalence of Self-Reported High Blood Pressure 2001 and 2003 Combined; American Indians and Alaska Natives Ages 18 Years and Older
• Prevalence of Self-reported High Blood Pressure Among American Indians and Alaska Natives, by State

High Cholesterol

Studies have shown that people with blood cholesterol levels in the highest 10% of the population are four times more likely to die of heart disease and stroke than those with cholesterol levels in the lowest 10% (MMWR 1992;41[36]). Diet modification, physical activity, weight control, and medication can help to lower blood cholesterol levels, according to the American Heart Association.

Cholesterol is a fatty substance that the human body needs to function properly. When there is too much cholesterol in the body, it deposits in arteries, causing them to narrow. People with blood cholesterol levels >240 mg/dL are considered to be at high risk for heart disease and stroke (National Cholesterol Education Program).

Prevalence of high cholesterol is increasing among American Indian and Alaska Native (AI/AN) people (MMWR 2003;52 [47]1148–52). In response, the IHS has developed several programs to ensure appropriate screening and to improve control of this risk factor. Sample activities include educating people about the dangers of high cholesterol levels, implementing electronic systems for quality assurance and reminders to health care providers, and awarding diabetes and cardiovascular health grants to tribes and AI/AN communities.

CDC currently funds 32 states and the District of Columbia to develop strategies and implement programs that reduce the prevalence of heart disease and stroke and related risk factors, including high cholesterol.

Figure 2. Prevalence of Self-Reported High Cholesterol Among Adults >18 Years by Race/Ethnicity, BRFSS, 2001 and 2003 Combined.

Definition of High Cholesterol

We defined self–reported high cholesterol on the basis of "yes" answers to the following Behavioral Risk Factor Surveillance System (BRFSS) question: "Have you ever been told by a doctor or other health professional that your cholesterol is high?" This question was only asked in odd–numbered years, so the data for this analysis are from 2001 and 2003. Age–adjusted prevalences were calculated for adults ages ≥18 years.

Prevalence Variations

We found substantial state–to–state differences in the prevalence of high cholesterol among AI/AN people (see map below and Table 2). A greater than 1.8–fold difference existed between the midpoint of the lowest quartile (23%) and that of the highest quartile (41%). Many of the states in the eastern half of the United States did not have sufficient data (i.e., <50 BRFSS respondents) to calculate a stable prevalence.

The national prevalence for all AI/AN people was 30%. Prevalences were similar for women (29%) and men (31%). The prevalence for AI/AN people was similar to those for other U.S. racial/ethnic groups (see Figure 2).

A Cautionary Note

Prevalences are based on a sample of AI/AN people surveyed by telephone for the BRFSS. They are likely lower than the true prevalence of high cholesterol and are more representative of AI/AN people living in urban rather than rural areas or on reservations (see Appendix B for details).

Maps and Tables

• Prevalence of Self-Reported High Cholesterol 2001 and 2003 Combined; American Indians and Alaska Natives Ages 18 Years and Older
• Prevalence of Self-Reported High Cholesterol Among American Indians and Alaska Natives, by State

Cholesterol Screening

Screening for blood cholesterol levels in the general population is important because high cholesterol can be lowered with medication and behavior change. Studies have shown that a 1% decrease in cholesterol level can reduce the risk for heart disease and stroke by 2% (MMWR 1992;41[36]). Cholesterol levels <200 mg/dL are considered desirable (National Cholesterol Education Program, http://hin.nhlbi.nih.gov/ncep.htm).

In 1998, about 67% of U.S. residents ages ≥20 years reported having their cholesterol level checked within the past 5 years (Healthy People 2010). Healthy People 2010 calls for raising this proportion to 80%. National guidelines recommend that people ages ≥20 years have their cholesterol measured at least once every 5 years (National Heart, Lung, and Blood Institute).

The IHS is working to increase cholesterol screening among American Indian and Alaska Native (AI/AN) people. It is developing an electronic system to notify health care providers of current national guidelines, remind them to screen patients, and track compliance. The IHS also is administering numerous diabetes and cardiovascular health grants that include strategies (e.g., cholesterol screening) to reduce cardiovascular risk factors.

CDC currently funds 32 states and the District of Columbia to 1) develop strategies, such as policy, environmental, and systems changes, that improve prevalence of cholesterol screening and 2) conduct activities to reduce the burden of heart disease and stroke.

Figure 3. Prevalence of Self-Reported Cholesterol Screening Among Adults >18 Years by Race/Ethnicity, BRFSS, 2001 and 2003 Combined

Definition of Cholesterol Screening

We defined self–reported cholesterol screening on the basis of "yes" responses to the following Behavioral Risk Factor Surveillance System (BRFSS) question: "Have you ever had your blood cholesterol checked?" This question was only asked in odd–numbered years, so the data for this analysis are from 2001 and 2003. Age–adjusted prevalences were calculated for adults ages ≥18 years.

Prevalence Variations

We found state–to–state differences in cholesterol screening prevalence among AI/AN people (see map and table 3 below). A 1.3–fold difference existed between the midpoint of the lowest quartile (61%) and that of the highest quartile (82%).

The national prevalence for all AI/AN people was 71%. Prevalences were similar for women (72%) and men (71%). The prevalence for AI/AN people was higher than that for Hispanics, the same as Asians, and somewhat lower than other U.S. racial/ethnic groups (see Figure 3).

A Cautionary Note

Prevalences are based on a sample of AI/AN people surveyed by telephone for the BRFSS. They are likely higher than the true prevalence of cholesterol screening and are more representative of AI/AN people living in urban rather than rural areas or on reservations (see Appendix B for details).

Maps and Tables

• Prevalence of Self-Reported Cholesterol Screening 2001 and 2003 Combined; American Indians and Alaska Natives Ages 18 Years and Older
• Prevalence of Self-Reported Cholesterol Screening Among American Indians and Alaska Natives, by State

Diabetes

Diabetes is the sixth leading cause of death in the United States, accounting for more than 200,000 deaths each year. More than 18 million Americans have diabetes, and the disease costs nearly $132 billion annually (http://www.cdc.gov/nccdphp/aag/aag_ddt.htm). Surprisingly, about one–third of people with diabetes are unaware that they have the disease (Diabetes Care 1998;21:518–24).

Adults with diabetes are 2–4 times more likely than those without diabetes to die of heart disease or stroke (http://www.cdc.gov/diabetes/). High blood pressure, high blood cholesterol, and obesity—all risk factors for heart disease and stroke—also are common among people with diabetes.

Diabetes was once rare among American Indian and Alaska Native (AI/AN) people, but the prevalence is rising dramatically. The IHS recently received a significant increase in funding to prevent and control diabetes among AI/AN people. In addition, it has funded numerous community grants and prevention efforts, as well as an aggressive medical intervention program.

In 2001, CDC and the National Institutes of Health conducted a landmark clinical trial that found that Americans at risk for diabetes can reduce this risk 58% with lifestyle changes in diet and exercise. CDC also supports 59 state and territorial diabetes prevention and control programs (http://www.cdc.gov/diabetes/news/docs/dpp.htm).

Figure 4. Prevalence of Self–Reported Diabetes Among Adults >18 Years by Race/Ethnicity, BRFSS, 2001–2003.

Definition of Diabetes

We defined self–reported diabetes on the basis of "yes" responses to the following Behavioral Risk Factor Surveillance System (BRFSS) question during 2001–2003: "Have you ever been told by a doctor that you have diabetes?" Age–adjusted prevalences were calculated for adults ages ≥18 years.

Prevalence Variations

We found dramatic state–to–state differences in the prevalence of diabetes among AI/AN people (see map and table links below). A threefold difference existed between the midpoint of the lowest quartile (5.7%) and that of the highest quartile (18%).

The national prevalence for all AI/AN people was 12%. Prevalences were similar for women (12%) and men (11%). They also were highest in the Northern Plains (14%) and lowest in Alaska (5%). The prevalence for AI/AN people was the same as that for blacks.

A Cautionary Note

Prevalences are based on a sample of AI/AN people surveyed by telephone for the BRFSS. They are likely lower than the true prevalence of diabetes and are more representative of AI/AN people living in urban rather than rural areas or on reservations (see Appendix B for details).

Maps and Tables

• Prevalence of Self–Reported Diabetes 2001–2003; American Indians and Alaska Natives Ages 18 Years and Older
• Prevalence of Self–Reported Diabetes Among American Indians and Alaska Natives, by State

Cigarette Smoking

Cigarette smoking is a major cause of heart disease and stroke, accounting for 30% of all U.S. deaths from coronary heart disease (Circulation 1997;96:3243–7). Cigarette smokers are 2–4 times more likely than nonsmokers to develop coronary heart disease (Reducing the Health Consequences of Smoking: 25 Years of Progress; 1989) and twice as likely to suffer a stroke (Circulation 1997;96:3243–7). For both conditions, the smoking–related risk for death increases if other CHD risk factors are present.

CDC provides national leadership for a comprehensive approach to reducing tobacco use that includes preventing young people from starting to smoke, eliminating human exposure to secondhand smoke, promoting smoking cessation, and eliminating disparities in tobacco use among different populations. CDC also funds eight tribal tobacco control support centers, which provide resources for tobacco prevention and cessation in American Indian and Alaska Native (AI/AN) communities.

Tobacco control programs in AI/AN communities must distinguish between traditional ceremonial use and addictive abuse of tobacco. In ceremonial settings, small amounts of tobacco are used, and the potential for addiction or health problems is low (BMJ 1997;75:1690–3). IHS offers numerous tobacco cessation programs, many of which were developed with partners and other federal agencies. In areas with high smoking prevalences, IHS actively promotes cessation through clinic–based and community programs.

Figure 5. Prevalence of Self–Reported Cigarette Smoking Among Adults >18 Years by Race/Ethnicity, BRFSS, 2001–2003.

Definition of Cigarette Smoking

We defined self–reported current cigarette smoking on the basis of responses to two questions from the Behavioral Risk Factor Surveillance System (BRFSS) during 2001–2003. The first was, "Have you smoked at least 100 cigarettes in your entire life?" Respondents who answered "yes" were then asked a follow–up question: "Do you now smoke cigarettes every day, some days, or not at all?" People who reported smoking at least 100 cigarettes in their lifetime and smoking now every day or some days were defined as current smokers. Age–adjusted prevalences were calculated for adults ages ≥18 years.

Prevalence Variations

We found dramatic state–to–state differences in smoking prevalence among AI/AN people (see map and table listed below). A twofold difference existed between the midpoint of the lowest quartile (21%) and that of the highest quartile (50%). The national prevalence for all AI/AN people was 38%, with men (42%) smoking more than women (34%). This gender difference is similar to that observed for the general U.S. population. The Northern Plains (41.3%) and Alaska (41.1%) had the highest prevalence (41%), whereas the Southwest had the lowest (21%) (see table below). AI/AN people had the highest smoking prevalence among U.S. racial/ethnic groups (see Figure 5 above).

A Cautionary Note

Prevalences are based on a sample of AI/AN people surveyed by telephone for the BRFSS. They are likely lower than the true prevalence of cigarette smoking and are more representative of AI/AN people living in urban rather than rural areas or on reservations (see Appendix B for details).

Maps and Tables

• Prevalence of Self–Reported Cigarette Smoking 2001–2003; American Indians and Alaska Natives Ages 18 Years and Older
• Prevalence of Self–Reported Cigarette Smoking Among American Indians and Alaska Natives, by State

Obesity

Obesity and a sedentary lifestyle account for about $90 billion in direct health care costs each year (http://www.cdc.gov/nccdphp/aag/aag_dnpa.htm). Obesity also increases the nation’s prevalence of weight–related risk factors for cardiovascular disease, including high blood pressure, high blood cholesterol, and diabetes (Arch Intern Med 2004;164:249–58).

Preventing or reducing these risk factors by eating a healthy diet and increasing physical activity can lower a person’s risk for heart disease and stroke. For example, losing at least 10 lbs and maintaining that loss for 36 months can lower a person’s blood pressure significantly (Ann Intern Med 2001;134:1–11).

CDC provides national leadership for obesity control through programs that promote increased fruit and vegetable consumption (e.g., 5 A Day for Better Health) and physical activity (e.g., KidsWalk–to–School) among adults and children. CDC also sponsors 12 state programs to help prevent obesity by improving nutrition and increasing physical activity in these states.

The high prevalence of obesity among American Indian and Alaska Native (AI/AN) people is contributing to a high incidence of diabetes in this population. The IHS recently received a significant increase in funding to prevent and control diabetes among AI/AN people. It is implementing community and health care system programs as part of the IHS Director’s Prevention Initiative.

Figure 6. Prevalence of Self–Reported Obesity Among Adults >18 Years by Race/Ethnicity, BRFSS, 2001–2003.

Definition of Obesity

We defined self–reported obesity on the basis of questions from the Behavioral Risk Factor Surveillance System (BRFSS) that asked respondents their height and weight during 2001–2003. We used this information to calculate respondents’ body mass index (BMI). People with a BMI ≥30.0 were considered obese. Age–adjusted prevalences were calculated for adults ages ≥18 years.

Prevalence Variations

We found dramatic state–to–state differences in the prevalence of obesity among AI/AN people (see map and table listed below). A twofold difference existed between the midpoint of the lowest quartile (17%) and that of the highest quartile (36%).

The national prevalence for all AI/AN people was 28%. Prevalences were similar for women (28%) and men (27%). AI/AN people ranked second among U.S. racial/ethnic groups, with only blacks having a higher prevalence (see Figure 6).

A Cautionary Note

Prevalences are based on a sample of AI/AN people surveyed by telephone for the BRFSS. They are likely lower than the true prevalence of obesity and are more representative of AI/AN people living in urban rather than rural areas or on reservations (see Appendix B for details).

Maps and Tables

• Prevalence of Self–Reported Obesity 2001–2003; American Indians and Alaska Natives Ages 18 Years and Older
• Prevalence of Self–Reported Obesity Among American Indians and Alaska Natives, by State

Physical Inactivity

Physical inactivity and unhealthy diets are leading causes of preventable death in the United States (JAMA 2004;291;1238-42). In addition to reducing a person’s risk for death, increased physical activity can reduce the risk for chronic diseases and conditions such as cardiovascular disease, diabetes, obesity, and musculoskeletal conditions (Proceedings of the 1992 International Conference on Physical Activity, Fitness and Health; 1994).

CDC recommends at least 30 minutes of moderate–intensity physical activity (e.g., walking briskly, mowing the lawn, dancing, swimming, bicycling) at least 5 days a week (Physical Activity and Health: A Report of the Surgeon General; 1996).

Healthy People 2010 calls for reducing the proportion of the total U.S. population with no leisure–time physical activity to 20%. It also seeks to increase the proportion of people who regularly participate in moderate physical activity to 30%.

The IHS is implementing community–based programs that promote healthier diets and increased physical activity among American Indian and Alaska Native (AI/AN) people in the context of their traditional values and cultures.

Figure 7. Prevalence of Self–Reported Physical Inactivity Among Adults >18 Years by Race/Ethnicity, BRFSS, 2001–2003.

Definition of Physical Inactivity

We defined self–reported physical inactivity on the basis of "no" responses to the following Behavioral Risk Factor Surveillance System (BRFSS) question during 2001–2003: "During the past month, other than your regular job, did you participate in any physical activities or exercise such as running, calisthenics, golf, gardening, or walking for exercise?" Age–adjusted prevalences were calculated for adults ages ≥18 years.

Prevalence Variations

We found dramatic state–to–state differences in the prevalence of physical inactivity among AI/AN people (see facing map and Table 7). A 1.7–fold difference existed between the midpoint of the lowest quartile (23%) and that of the highest quartile (40%).

The national prevalence for all AI/AN people was 30%. The prevalence was higher for women (32%) than for men (28%). The prevalence for AI/AN people was lower than those for blacks and Hispanics and somewhat higher than those for other U.S. racial/ethnic groups (see Figure 7).

A Cautionary Note

Prevalences are based on a sample of AI/AN people surveyed by telephone for the BRFSS. They are likely lower than the true prevalence of physical inactivity and are more representative of AI/AN people living in urban rather than rural areas or on reservations (see Appendix B for more details).

Maps and Tables

• Prevalence of Self–Reported Physical Inactivity 2001–2003; American Indians and Alaska Natives Ages 18 Years and Older
• Prevalence of Self–Reported Physical Inactivity Among American Indians and Alaska Natives, by State

Poor Health

Self–perception of health is often used as a representative measurement of a range of factors that can affect a person’s general health and functional status. For example, studies show that a person’s perception of his general health can predict his risk for death and disability. Even after adjusting for socioeconomic (e.g., education) and health risk (e.g., number of physician visits) variables, people who report poor or fair health have an approximately twofold greater risk of death (Am J Epidemiol 1999;149:41–66).

People who report poor health also are more likely to think that they are at greater risk of having a heart attack (Behav Med 2000;26:4–13). In addition, self–perception of poor health has been linked to risk factors associated with heart disease and stroke, such as diabetes, smoking, high blood pressure, and physical inactivity (MMWR 1996;46:906–11).

To support the Healthy People 2010 goal of increasing Americans’ quality and years of healthy life, CDC developed the Healthy Days surveillance measure to monitor leading health indicators such as physical activity, obesity, and tobacco use (Measuring Healthy Days; 2000). The resulting data can guide policy changes designed to improve the health of the nation and decrease the number of people reporting poor general health.

Figure 8. Prevalence of Self–Reported Poor Health Among Adults >18 Years by Race/Ethnicity, BRFSS, 2001–2003.

Definition of Poor Health

We defined self–reported poor health on the basis of "poor" responses to the following Behavioral Risk Factor Surveillance System (BRFSS) question during 2001–2003: "Would you say that in general your health is excellent, very good, good, fair, or poor?" Age–adjusted prevalences were calculated for adults ages ≥18 years.

Prevalence Variations

We found substantial state–to–state differences in the prevalence of poor health among American Indian and Alaska Native (AI/AN) people (see map and table listed below). A twofold difference existed between the midpoint of the lowest quartile (18%) and that of the highest quartile (36%).

The national prevalence for all AI/AN people was 26%. The prevalence was higher for women (28%) than for men (24%). AI/AN people ranked second among U.S. racial/ethnic groups, with only Hispanics having a higher prevalence (see Figure 8).

A Cautionary Note

Prevalences are based on a sample of AI/AN people surveyed by telephone for the BRFSS. They are likely lower than the true prevalence of poor health and are more representative of AI/AN people living in urban rather than rural areas or on reservations (see Appendix B for more details).

Maps and Tables

• Prevalence of Self–Reported Poor Health 2001–2003; American Indians and Alaska Natives Ages 18 Years and Older
• Prevalence of Self–Reported Poor Health Among American Indians and Alaska Natives, by State
   

Date last reviewed: 05/12/2006
Content source: Division for Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion