Hypertension and Diabetes Risk Factors in the African American Population
The high prevalence of hypertension and diabetes in African Americans increases their risk for CHD. The presence of cholesterol abnormalities (i.e., increased LDL, triglycerides, and decreased HDL) in conjunction with these two major risk factors puts this population at an even greater risk for cardiovascular morbidity and mortality. It is imperative that pharmacists recognize this population as one requiring special considerations with regard to monitoring and counseling. Hypertension appears to increase with the prevalence of certain lifestyles. In the rural South (as well as in other areas), certain cultural food preferences still exist. For example, chitterlings, salt back, pickled pig parts, fat back, sweet potato pie, and boiled peanuts are major components of many African American diets. Many of these foods are high in fat and sodium, and low in potassium. Diets high in fried foods and low in fruits, vegetables, and grains pose significant challenges for the patient with dyslipidemia, making lifestyle modifications more critical. The assistance of a dietitian may be particularly useful for recommending low-fat, low-sodium alternatives to the patient.

To prevent hypertension, African Americans should increase consumption of high-potassium foods (such as fresh fruits and vegetables), use low-fat dairy products, and avoid salt. The Dietary Approaches to Stop Hypertension (DASH) diet is particularly effective in significantly lowering high blood pressure in African Americans. This diet is low in cholesterol, high in dietary fiber, potassium, calcium, and magnesium, and moderately high in protein, and has been shown to lower blood pressure even when an individual’s weight and salt intake remained constant. One major obstacle facing many African Americans in the treatment of hypertension, is the cost of medications. Many of the newer medications are more effective and have fewer side effects than older medications, but they are costly. In addition, many African Americans do not receive proper medical care until hypertension has been present for some time. This results in otherwise avoidable damage to the kidneys and other organs. It may also account for the high rate of hypertension-related morbidity and mortality that exists among African Americans.

It should also be taken into consideration that African Americans tend to respond differently than other populations to treatment for high blood pressure. Because African Americans experience higher rates of diabetes, renal insufficiency and heart failure, they may benefit more from aggressive treatments to lower blood pressure.

Conclusion
Dyslipidemia is a major risk factor in the development of coronary heart disease. This risk factor, as well as other risk factors, can be altered through pharmacologic, dietary and other lifestyle modifications. Cultural norms affecting health among African Americans do exist and should not be overlooked by healthcare providers. Increased awareness by the pharmacist and the use of culturally sensitive information and materials can greatly enhance patient understanding and adherence to the prescribed regimen.
Pharmacists have a responsibility to assist in the management of lipid disorders. This can be accomplished by developing individual or collaborative practices in various healthcare settings. Pharmacists interested in strengthening their skills in this area can enroll in courses offered by several organizations.

Both epidemiologic and clinical trials have documented the prevalence of lipid disorders, and have proven that elevated levels of low-density lipoprotein (LDL) cholesterol and decreased levels of high-density lipoprotein (HDL) are associated with an increased risk of CHD. (Pharmacists should be aware that certain diseases and medications are also capable of affecting cholesterol levels. Therefore, patient medication profiles and medical histories should be reviewed thoroughly to rule out these possible secondary causes of dyslipidemia.) In addition to elevated cholesterol, other risk factors for CHD have been identified:

• Age: Male 45 years or older; female 55 years or older, or experiencing premature menopause without estrogen replacement therapy
• Family history: History of premature CHD (definite myocardial infarction or sudden death before age 55 in father or other male first-degree relative, or before age 65 in mother or other female first-degree relative)
• Current cigarette smoking
• Hypertension (blood pressure 140/90 mmHg or greater) or taking antihypertensive medicine
• Diabetes mellitus

Management of Elevated Cholesterol
The National Cholesterol Education Program (NCEP) of the National Heart, Lung and Blood Institute (NHLBI) has established guidelines for the prevention and treatment of lipid disorders. According to the NCEP guidelines, all patients at least 20 years of age should have an initial cholesterol measurement. It is recommended that the initial laboratory test measure both total and HDL cholesterol. The American Diabetes Association (ADA) recommends that diabetic patients receive a complete lipid profile (i.e., LDL, HDL and triglycerides) annually. Further evaluation of the patient is based on the results of these initial tests. The goals of lipid-lowering interventions vary depending on whether the focus is primary or secondary prevention of CHD. In primary prevention the goal is to prevent the onset of CHD; secondary prevention focuses on avoiding further CHD events. Treatment should be modeled after NCEP recommendations. These guidelines include nonpharmacologic, lifestyle modifications (e.g., diet, exercise, smoking cessation), and pharmacologic measures. Table 1 outlines the LDL treatment goals based on the number of CHD risk factors present.

Lifestyle Modification: Dietary therapy is the first line of treatment for elevated cholesterol levels. NCEP recognizes dietary modification as the cornerstone in the management of dyslipidemia. The general goal of dietary therapy is to reduce elevated serum cholesterol while maintaining a nutritionally appropriate eating pattern. A reduction in saturated fat and cholesterol in the diet, as well as regular physical activity, are two important lifestyle changes that pharmacists must emphasize to patients. Dietary therapy is a two-step process. Step I begins the process of reducing intake of saturated fat and cholesterol. The diet should involve an intake of 10% of total calories from saturated fat, 30% or less of calories from total fat, and 300 mg or less of cholesterol per day (Table 2). If the goals of therapy are not achieved with Step I, patients should be advanced to the Step II diet. Step II requires further reduction in saturated fat and cholesterol. For this step, a registered dietitian should assist with management.

Both physical activity and weight reduction are considered essential components in the nonpharmacologic management of elevated serum cholesterol. A program of physical activity for at least 20 minutes three times weekly provides significant cardiovascular benefit. The benefits of physical activity include an increase in HDL and a decrease in weight, especially for obese and overweight patients. It may also lead to a reduction in triglyceride levels. Patients should be advised to consult their physician prior to initiating an exercise program.
Smoking cessation should also be encouraged. Pharmacists should have information available, and be able to direct patients to local smoking cessation programs. They should be knowledgeable about the various smoking cessation aids available (e.g., nicotine gum and patches).

Pharmocologic Measures: The goal of drug therapy is to reduce the LDL cholesterol to below 160 mg/dL or to below 130 mg/dL if two other risk factors are present. Drug therapy is considered for the adult patient who has an LDL cholesterol level of 190 mg/dL or greater without two other risk factors; or 160 mg/dL or greater with two other risk factors. Table 3 outlines the NCEP guidelines for treatment, and Table 4 summarizes patient counseling information specific to each lipid-lowering agent available.

If those three words describe your personality, you may have more of a problem than just the lack of friends. Researchers at Arizona State University in Tempe have proven that people with hostile dispositions also have greater increases in diastolic blood pressure (the second number in a blood pressure reading).

A higher diastolic pressure means that the vessels in the body are under increased pressure even when the heart is between beats, a situation than can contribute to heart disease and stroke.

At the beginning of the study, the researchers designated 80 males and females as either high or low in hostility after taking a test measuring their suspiciousness, cynicism, mistrust, and resentment. Then each volunteer participated in a one-on-one discussion of capital punishment with a person who was trained to remain calm while presenting a point-of-view that disagreed with the volunteer’s.

The blood pressure of those who had been categorized as high-hostile began rising even before the conversation started, and they continued to have higher blood pressure readings than those categorized as low-hostile. This could mean, according to researchers, that people with hostile attitudes have high levels of mistrust and anticipate trouble in interpersonal relationships—even before they have proof that there is reason for suspicion.

Another factor that raised blood pressure of the people in the high-hostile group, according to researchers, was the need to control the situation between the person conducting the conversation and themselves.

Men and women whose scores placed them in the high-hostile group had similar increases in blood pressure.

Researchers examined the attitudes of nearly 1,100 men. The investigators from Brown University School of Medicine in Providence, Rhode Island, found that those with hostile attitudes were more likely to be overweight, especially in the upper part of the body which is a greater risk factor for heart disease than extra weight carried in the hips and legs. The subjects also were more likely to exhibit insulin resistance, often a precursor of diabetes.

A hostile attitude in this second study also appeared to be linked to lower income and educational status.

“We’ve been focusing on diastolic through the years, but we now know that systolic blood pressure is a better predictor of future cardiovascular events such as heart attacks, strokes, and heart failure, and that treating it reduces those risks,” says Dr. Edward Roccella, NHBPEP coordinator.

“As people age, there’s a tendency for systolic blood pressure to rise, while diastolic pressure declines [after age 55]“, he explains. This is related to arteriosclerosis, a stiffening of the arteries that accompanies ageing, and may lead to increased blood pressure. “We used to think [increasing blood pressure] was a natural part of ageing. That gave rise to the erroneous belief that a systolic BP of 100 plus your age was acceptable.” Regardless of age, the Sixth Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommended blood pressure (BP) goal is 140 over 90 mm Hg; achieving it may be a long-term challenge for older people.

Because diastolic BP tends to fall in older people, its predictive and diagnostic capabilities in that population are greatly reduced compared with systolic BP. For instance, the proportion of participants in the NHLBI’s Framingham Heart Study correctly identified as candidates for antihypertensive therapy was 91% using systolic BP alone, compared with 22% using only diastolic pressure. The diagnostic power was further increased in people over 60.

Isolated systolic hypertension (ISH) (systolic 140 mm Hg or above, diastolic less than 90 mm Hg) is the most common form of high blood pressure, note advisory authors. About two-thirds of hypertensive people over age 60 have isolated systolic hypertension, yet less than a quarter of hypertensive Americans over 70 years of age have managed to meet recommended BP goals. While systolic hypertension is notably more difficult to manage than diastolic pressure, it’s well worth the effort.

Dr. Roccella cites the Systolic Hypertension in the Elderly Program (SHEP) study, in which 4,736 individuals over 60 years of age with isolated systolic hypertension were randomized to receive thiazide diuretic-based treatment, with or without beta-blockers, or placebo. After five years, those receiving treatment had an overall systolic BP reduction from 171 to 142 mmHg. Heart attacks were reduced by 27%, strokes by 37%, and heart failure by 55%; as well, trends toward improvement in depression and dementia scores were noted. “Even more astounding, if you’ve had a previous heart attack, lowering your blood pressure can reduce the chance of developing heart failure by 90%,” he said.
Lifestyle changes alone may make the difference, he says. Lose some weight, walk daily, eat a high-fiber, low-salt diet, and if you drink alcohol, do so moderately. “If that fails to bring BP down to goal, stick with it, because it could improve the effectiveness of medications.”

Diet and blood pressure

Researchers have known for some time that the characteristics of a Mediterranean-type diet are important in controlling blood pressure levels. These characteristics include:

- high fiber intake,
- high fruit and vegetable intake,
- high MUFA and low saturated fat intake and,
- low sodium and high potassium, magnesium and calcium intake.

It may be that one or a combination of these factors helps decrease blood pressure levels. And since high blood pressure is a risk factor for stroke, the third leading causes of death in the United States, olive oil may reduce the incidence of stroke.

MUFA vs. PUFA

Ferrara and his colleagues designed a study to look at the effects of a diet high in monounsaturated fatty acids vs. diets high in polyunsaturated fatty acids (PUFA). Twenty-three people with mild to moderate hypertension (10 males and 13 females, ages 25-70 years) were randomly assigned to either a diet high in MUFA using extra-virgin olive oil, or high in polyunsaturated fatty acids using sunflower oil for six months. Both diets contained less total and saturated fat than the subjects’ usual diets. Their usual diets contained 34% total fat and 11% saturated fat, while the study diets contained 26% total fat and 6% saturated fat. After the initial six-month study period, the groups switched to the other type of diet. Both types of diets contained similar amounts of calories, saturated fat, cholesterol, fiber and minerals (sodium, potassium, magnesium and calcium). The only significant difference in the two study diets was the amount of MUFA vs. PUFA.

Ferrara and his colleagues found that while on the extra-virgin olive oil diet, subjects reduced the amount of antihypertensive medication necessary to control blood pressure levels by 48%, vs. only a 4% reduction on the sunflower oil diet. In addition, eight subjects on the extra-virgin olive oil diet required no antihypertensive medications; all subjects on the sunflower oil diet required antihypertensive medication. The authors conclude that a diet lower in total fat and saturated fat that contains higher amounts of MUFA can lower blood pressure levels and reduce or eliminate the need for medications in people with hypertension.

Possible role of olive oil in reducing blood pressure

So why does olive oil lower blood pressure? One possible reason is its polyphenol content. Polyphenols are potent antioxidants which help arteries dilate, thereby reducing blood pressure. Ten grams of extra-virgin olive oil contains five mg of polyphenols; sunflower oil has no polyphenols.

Our recommendations

There are numerous health benefits to replacing saturated and polyunsaturated fatty acids with monounsaturated fatty acids such as olive and canola oil. Switching from polyunsaturated oils such as sunflower, safflower, soybean, and corn to oils high in monounsaturated fatty acids such as olive oil and canola oil leads to decreased risk of stroke by lowering blood pressure levels; and also helps decrease risk of heart attack by lowering total and LDL cholesterol levels. Use olive or canola oil in cooking or salad dressings, and look for margarine-like spreads based on olive or canola oil to use on toast, vegetables, and potatoes to reap the heart-healthy benefits.

Remember that while replacing saturated fats with MUFAs is a step towards improved heart health, moderation remains important. Also, if you follow a very low fat diet and still have high blood pressure, consider adding one to three tablespoons of olive oil to your daily food choices and monitor your blood pressure for any changes.