BETHESDA CLINIC

"Health is Wealth"

High Blood Pressure

This is quite a common disease in Kenya. This patient information from MD Consult is an introduction to the disease.

What Is High Blood Pressure?

High blood pressure, also called hypertension, occurs when the body's smaller blood vessels (known as the arterioles) narrow, which causes the blood to exert excessive pressure against the vessel walls. The heart must therefore work harder to maintain this higher pressure. Although the body can tolerate increased blood pressure for months and even years, eventually the heart can enlarge and be damaged (a condition called hypertrophy), and injury to blood vessels in the kidneys, the brain, and the eyes can occur.

Two numbers are used to describe blood pressure; the systolic and diastolic. For example, optimal blood pressure is less than 120/80 mm Hg (systolic/diastolic). The systolic pressure (the higher and first number) measures the force that blood exerts on the artery walls as the heart contracts to pump out the blood. The diastolic pressure (the lower and second number) is the measurement of force as the heart relaxes to allow the blood to flow into the heart.

Blood pressure is now categorized as optimal, normal, high normal, and hypertensive. Optimal pressure is below 120/80 (systolic/diastolic); normal pressure is between 120/80 and 130/85 and should be everyone's upper goal. High normal is considered to be between 130-139/85-89. A diagnosis of hypertension is given when blood pressure is over 140/90. Hypertension is further categorized into three stages: stage 1 or mild (140-159/90-99), stage 2 or moderate (160-179/100-109), and stage 3 or severe (over 180/110). American expert groups now recommend that blood pressure above normal should be attended to with appropriate treatments. Some studies indicate that even high normal puts one at higher risk for heart events and stroke, although some international experts argue that the evidence for this is not strong in people who are not diabetic. They are concerned that such guidelines may unnecessarily increase the use of antihypertensive drugs. A child's blood pressure is normally much lower than an adult's. Children are at risk for hypertension if they exceed the following levels: 116/76 for ages 3-5, 122/78 for ages 6-9, 126/82 for ages 10-12, and 136/86 for ages 13-15.

If one measurement is normal and the other elevated, the higher category of either measurement is usually used to determine severity. For example, if systolic pressure is 165 (moderate) and diastolic is 92 (mild), the patient would still be diagnosed with moderate hypertension. Previously, physicians have focused on abnormal diastolic levels, which are strong predictors or heart attack and stroke in young adults. In the great majority of adults over 60, however, relying on a normal reading of diastolic blood pressure when systolic pressure is even only slightly high may lead to the under-diagnosis and under-treatment of hypertension. A number of studies have now reported that an elevated systolic blood pressure is a significantly more accurate indicator of hypertension and the need for treatment than diastolic blood pressure, particularly in the elderly. One interesting small study reported that in cases when systolic pressure is elevated and diastolic pressure is normal, calculating the pulse pressure, which is the difference between the systolic and diastolic reading, may prove to be an accurate way of determining whether the patient is actually endangered.

What Will Confirm The Diagnosis Of High Blood Pressure?

Measuring Blood Pressure

It is a rare physical examination that does not include blood pressure measurement. The process is familiar to everyone: an inflatable cuff is placed around the arm, and the person taking the blood pressure listens with a stethoscope over the artery. Patients should not smoke or drink caffeinated beverages within 30 minutes of the measurement. Although this test has been used for 90 years, it is not completely accurate. A person who has recently exercised or a heavy smoker who has not smoked for a while can have a temporarily low pressure reading. Temporary high pressure can result from an arm cuff that is too small, talking during the test, or from having recently eaten foods that raise blood pressure. If a first blood pressure reading is above normal, the health professional may take two or more measurements separated by two minutes with the patient sitting or lying down, as well as one taken after the patient has been standing for two minutes. Even if blood pressure remains mildly elevated, it may not indicate hypertension. A phenomenon called white-coat hypertension is a common occurrence in which a patient's blood pressure rises in the presence of a physician and, presumably, returns to normal at home.

Home Monitoring. A number of home tests are available for checking blood pressure between doctor visits. A physician may loan a patient a portable unit that records blood pressure during a full day's activity. This test, known as ambulatory monitoring, is particularly useful for those who experience wide blood pressure swings, such as those who have white-coat hypertension or show resistance to drug therapy. In fact, according to one study, accurately measuring blood pressure at home over a full day was a significantly better predictor of cardiovascular risk than standard office-based measurements. In general, everyone's blood pressure varies in the same way throughout a given day. It is usually highest at work and then drops slightly at home. Blood pressure falls to its lowest level during sleep but suddenly increases at waking, the highest risk period for heart attack and stroke in those with severe high blood pressure. (A higher-night-to-day ratio in blood pressure is a particular risk factor for stroke and heart attack.) Manual cuffs and stethoscopes are fairly accurate, but they require practice to use, and the cuff must be the right size (one size does not fit all). Devices that use a digital readout and a cuff that can be electronically inflated and deflated are proving to be as accurate as a stethoscope. Some studies, however, have reported that when patients record and report their own blood pressure, they are unreliable and don't always tell the truth. Despite the difficulties and controversy surrounding this issue, studies indicate that home blood pressure monitoring has been shown to improve blood pressure control and thereby reduce the risk of cardiovascular events. To improve clinical outcomes, many devices are now available that allow 24-hour ambulatory blood pressure monitoring and electronically store results for analysis by the physician.

Follow-Up. People with normal blood pressure (below 130/85) should be rechecked every two years. Anyone whose blood pressure is high normal (130-139/85-89) or above should have their blood pressure monitored at home and be evaluated for organ damage. If white-coat hypertension is suspected, home monitoring is especially important in order to avoid unnecessary drug treatments. Studies have suggested that white-coat hypertension actually may pose a risk for future heart problems, although the increased danger appears to be small (7.9%) compared with the risk in those with steady mild hypertension (22%). An individual with mild to moderate hypertension found during a first examination and who has no evident organ damage should be retested at least twice over several weeks. An average of all the measurements will be considered in the diagnosis of hypertension. Persons with very severe high blood pressure or those exhibiting any evidence of organ damage due to hypertension should consider drug therapy immediately.

Physical Examination for Complications of Hypertension

If blood pressure is elevated, the physician will check the patient's pulse rate, examine the neck for distended veins or an enlarged thyroid gland, check the heart for enlargement and murmurs, and examine the abdomen and eyes.

Medical History

If hypertension is suspected, the physician should obtain the following information: (1) a family and personal medical history, especially incidence of high blood pressure, stroke, heart problems, kidney disease, or diabetes. (2) Risk factors of heart disease and stroke, including tobacco use, salt intake, obesity, physical inactivity, and unhealthy cholesterol levels. (3) Any medications being taken. (4) Any symptoms that might indicate secondary hypertension, such as headache, heart palpitations, excessive sweating, muscle cramps or weakness, or excessive urination. (5) Any emotional or environmental factors that could affect blood pressure.

Laboratory and Other Tests

If a physical examination indicates hypertension, additional tests may help determine whether it is secondary hypertension (caused by another disorder) or essential hypertension (no other disorder is present) and whether organ damage is present. These tests include a complete blood count and urinalysis and measurements of potassium, blood urea nitrogen, fasting blood glucose, serum cholesterol, and serum uric acid. An electrocardiogram (ECG) should also be performed. Of possible value is a blood test that measures high levels of renin, an enzyme that stimulates production of angiotensin, which constricts blood vessels. High levels may predict heart attacks in white males with high blood pressure (although possibly not in women or African American men). A urine test that detects high levels of albumin, a protein, may be an indicator of complications. An exercise stress test could be important for those with borderline hypertension. Stress-induced blood pressure in such patients has been associated with a risk for left ventricular hypertrophy.

What Causes High Blood Pressure?

Essential Hypertension

Hypertension is referred to as essential, or primary, when the physician is unable to identify a specific cause. This is by far the most common type of high blood pressure, occurring in up to 95% of patients. Genetic factors appear to play a major role in essential hypertension. Several genetic factors, however are probably involved that regulate important physiologic processes and interact with environmental influences to produce essential high blood pressure. Experts appear to have located the chromosomes (13 and 18) that house the genes responsible for blood pressure regulation, although pinning down the range of specific genes involved in hypertension is more difficult.

Abnormalities in the Angiotensin-Renin-Aldosterone System. Genes under intense study are those that regulate a group of hormones known collectively as the angiotensin-renin-aldosterone system. This system influences all aspects of blood pressure control, including blood vessel contraction, sodium and water balance, and cell development in the heart. Experts believed that it evolved millions of years ago to protect early humans by retaining salt and water and narrowing blood vessels to ensure adequate blood flow and repair injured tissue. Over time, however, this system has become obsolete and instead of protecting people it wreaks havoc on modern humans. Of particular importance in these harmful responses are the hormone aldosterone and a peptide called angiotensin II.

Inherited Abnormalities in the Sympathetic Nervous System. Studies suggest that some people with essential hypertension may inherit abnormalities of the sympathetic nervous system, which is the part of the autonomic nervous system that controls heart rate, blood pressure, and the diameter of the blood vessels.

Insulin, Obesity, and Diabetes Type 2. Hypertension is the health problem most commonly associated with obesity, which in turn is strongly associated with type 2 diabetes. People with this form of diabetes generally have normal or high levels of insulin, a critical hormone in the metabolism of sugar. However, they are unable to use the insulin, a condition called insulin resistance. Some research indicates that insulin resistance stimulates parts of the sympathetic nervous system and may cause sodium retention, a contributor to high blood pressure. Not all people with insulin resistance have hypertension, however, and not all those with high blood pressure have this problem, so any causal relationship is uncertain. Some research indicates that obesity is the only common element between insulin, diabetes type 2, and high blood pressure. Obesity has a number of possible effects that could lead to hypertension. It may blunt certain actions of insulin that open blood vessels, cause structural changes in the kidney and abnormal handling of sodium, and is associated with alterations in the systems that regulate blood flow.

Low Levels of Nitric Oxide. Nitric oxide affects the smooth muscles cells that line blood vessels; it helps keep them relaxed, flexible, and may also help prevent blood clotting. Low levels of nitric oxide have been observed in people with high blood pressure (particularly in African Americans) and may be an important factor in essential hypertension.

Low Birth Weight. Low birth weight has been associated with high blood pressure in both childhood and adulthood. Whether this relationship is due to malnutrition in the mother or abnormalities in the placenta is not clear.

Secondary Hypertension

Secondary hypertension has recognizable causes, which are usually treatable or reversible.

Medical Conditions. Kidney disease is the most common cause of secondary hypertension, particularly in older people. Sleep apnea, a disorder in which breathing halts briefly but repeatedly during sleep, is associated with hypertension and increased sympathetic nerve activity. Patients with this disorder also have a poorer response to anti-hypertensive medications. Treatment with a device known as nasal continuous positive airway pressure may help lower blood pressure in some of these patients. Other medical conditions that contribute to temporary hypertension are pregnancy, cirrhosis, and Cushing's disease.

Medications. Certain prescription and over-the-counter drugs can cause temporary high blood pressure. Some prescription medications include cortisone, prednisone, estrogen, and indomethacin. Long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) may injure the kidney and is an important cause of secondary hypertension in the elderly population. Such drugs include aspirin, ibuprofen (Advil, Motrin, Rufen), naproxen (Anaprox, Naprosyn, Aleve), and many others. Of these drugs, aspirin appears to have the least detrimental effect on blood pressure. Cold medicines containing pseudoephedrine have also been found to increase blood pressure in hypertensive people, although they appear to pose no danger for those with normal blood pressure. High blood pressure is known to be an uncommon side effect in a few women taking oral contraceptives (the Pill). Stopping the Pill nearly always reduces blood pressure, although a recent study suggests that oral contraceptives may produce a small but significant increase in diastolic pressure that persists in some older women who have been off the Pill for years.

Alcohol, Caffeine, Smoking, and Drugs. An estimated 10% of hypertension cases are caused by alcohol abuse, three alcoholic drinks a day or more, with heavier drinkers having higher pressure. In one study, binge-drinkers had even higher blood pressure than people who drank regularly. Although moderate drinking (one or two drinks a day) appears to have benefits for the heart and may even protect against some types of stroke, it is critical for heavy drinkers to abstain from alcohol.

Caffeine causes a temporary increase in blood pressure, which has been thought to be harmless in people with normal blood pressure. Studies are suggesting, however, that regular, heavy coffee drinking (an average of 5 cups per day) can boost blood pressure, and in one study, this was sufficient to increase the risk for heart disease in healthy men. The study was small, but there is growing evidence that a high intake of coffee may be harmful in people with hypertension and may even increase their risk for stroke. Drinking coffee also increases excretion of calcium, which also may affect blood pressure. (Anyone who drinks coffee should maintain an adequate calcium intake.)

The potential risk of caffeine, however, pale next to the dangers of smoking. One study reported that smokers have blood pressures up to 10 points higher than nonsmokers. Although cigar smoking does not appear to cause coronary artery disease, it can double the risk of death from cardiomyopathy and hypertension. Cocaine is known to cause acute episodes of hypertension.

Other Causes of Secondary High Blood Pressure. Temporary high blood pressure can result from stress, exercise, and long-term consumption of large amounts of licorice. Exposure to even low lead levels also appears to cause hypertension in adults. More studies are needed to clarify this relationship.

A 1999 study reported an association between exposure to mercury in the womb followed by higher blood pressure during childhood in a population living in the Faroe Islands. (The diet of such inhabitants includes whale meat, which increases the risk for mercury exposure.) High blood pressure associated with mercury exposure may persist long after the mercury has been removed. The findings of this study may be of concern for people who have diets that are high in fish protein. One small study showed that mobile phone use triggers a temporary rise in blood pressure, which may be harmful in people with existing hypertension.

Who Gets High Blood Pressure?

Studies show that the prevalence of high blood pressure in the US is declining, mostly due to drug treatments in older people and lifestyle changes in younger adults. Still, an estimated 50 million Americans have high blood pressure, about 25% of all adults, but only about 68% are aware of their condition, and only 27% have it under control. Although the majority of people have mild hypertension, even this condition requires attention.

Age, Gender, and Ethnic Difference

In both men and women, the risk for high blood pressure increases as one ages. More men than women have hypertension until age 55; after that the ratio reverses, and women are more likely to have high blood pressure than are men. In 1996, 58.5% of the deaths from hypertension were in women and 41.5% were in men. High blood pressure is significantly more prevalent and dangerous in African Americans than other groups. As of 1991, prevalence of hypertension for those aged 65 to 74 years was 72% for African Americans, 53% for Caucasians, and 55% for Mexican Americans. In general over half of all men and slightly less than half of women who are African American have hypertension, and it may account for 30% of all deaths in men and 20% of women in this group. Among all population groups, young African American men have the highest rates of early severe high blood pressure and the lowest rates of blood pressure awareness, treatment, and control, mostly because of intense social and economic obstacles, including a higher incidence of alcohol and drug abuse, social isolation, and unemployment. Some studies have indicated that African Americans may have lower levels of nitric acid than whites; nitric oxide keeps arteries flexible and open, which may partially account for their higher proportion of hypertension. They also may be more sensitive to salt. Economic issues certainly play a role, however. For example, one study of African villagers, whose diets were high in fish, reported only a 3% rate of high blood pressure. Both whites and African Americans in the Southeast have a higher incidence of hypertension and stroke than people living in other parts of the country. Such populations are also at risk for many contributing factors found in lower socioeconomic groups, such as stress, anxiety, and depression, and for diets low in potassium and high in salt.

The prevalence of hypertension in Hispanic Americans appears to be similar to that in Caucasians, and the rate is much lower in Asian Pacific Islanders. In any case, hypertension appears to be dangerously undertreated in major minority groups, including African and Mexican Americans. Inadequately controlled hypertension is the major factor for the higher mortality rate from heart disease among African Americans.

Weight

About one-third of patients with high blood pressure are overweight; even moderately obese adults have double the risk of hypertension as nonobese individuals. In fact, the increase in blood pressure in aging Americans may be due primarily to weight gain. (In other cultures old age does not necessarily coincide with weight gain or high blood pressure.) Children and adolescents who are obese and newborns who are underweight are at greater risk for high blood pressure when they reach adulthood. As the prevalence of overweight and obesity increases among youth in this country, it is becoming more important to prevent and treat obesity in children and adolescents as early prevention against high blood pressure and heart disease.

Family History

Some experts now believe that essential hypertension may be inherited in 30% to 60% of cases. According to a recent study, being a brother or sister of someone with premature coronary artery disease is a greater risk factor for hypertension than having a parent with the disease.

Emotional Disorders

People who are anxious or depressed may have over twice the risk for high blood pressure than those without these problems. It is not clear whether these mood disorders contribute to high blood pressure due to some physiologic effect on blood vessels or if they may lead to behaviors, such as weight gain or alcohol abuse, that are also risk factors for hypertension. Anger does not appear to predict high blood pressure, although suppressed anger may.

Seasonal Factors

Seasonal changes may influence variations in blood pressure, with hypertension increasing during cold months and declining during the summer, particularly in smokers. While cold may narrow blood vessels, lack of light has also been associated with higher blood pressure.

How Serious Is High Blood Pressure?

High blood pressure directly killed over 41,600 Americans in 1996 and may have contributed to 202,000 deaths. The mortality rate rose 6.8% over the previous ten years and the actual number of deaths increased by 34%. It is particularly deadly in African Americans. High blood pressure contributes to 75% of all strokes and heart attacks. Compared with normal individuals, hypertensive people can have as high as ten times the risk of stroke and five times the risk of a heart attack, depending on the severity of the hypertension.

Emergency Conditions

Malignant hypertension, an emergency condition resulting from untreated primary hypertension, can be lethal. [ see What Are the Symptoms of High Blood Pressure, below.]

Damage to Other Organs

Hypertension can cause certain organs (called target organs), including the kidney, eyes, and heart, to deteriorate over time, and patients who do not control high blood pressure face a reduced life span.

Effect on the Heart. Hypertension increases the risk for congestive heart failure, a condition in which the heart pumps inefficiently and eventually fails, often because of structural changes in the heart muscles. In hypertension, the heart muscles thicken to compensate for increased blood pressure, and over time the force of their contractions weaken and they have difficulty relaxing, thereby preventing the normal filling of the heart with blood. Heart cells appear to enlarge in response to high blood pressure, and undergo molecular changes that cause an abnormal release of calcium, a mineral crucial for healthy heart contractions. This defect appears to be irreversible, so detecting and reducing high blood pressure as soon as possible is an extremely important preventive measure.

Effect on the Kidneys. High blood pressure causes 30% of all cases of kidney failure, a rate second only to diabetes. In fact, there has been an increase in hypertension-related end-stage kidney ( renal) disease, in contrast to the lower incidence of stroke and heart attack that has resulted from antihypertensive therapy.

Effect on the Eyes. High blood pressure can even injure the eyes, causing a condition called retinopathy.

Bone Loss

Hypertension also increases the elimination of calcium in urine that may lead to loss of bone mineral density, a significant risk factor for fractures, particularly in elderly women. In one study of Englishwomen, those with the highest blood pressure lost bone density at nearly twice the rate of those in the lowest range. It is not clear whether this effect occurs in men or non-white women.

Sexual Dysfunction

Some form of sexual dysfunction occurs in about a quarter of hypertensive men. It is often caused by medications that treat high blood pressure. One study suggested, however, that impotence in hypertensive men most likely occurs as a consequence of the blood-pressuring-lowering effects of antihypertensive drugs (rather than specific actions in the drugs themselves), blocked arteries (which are common in people with hypertension), or both. Impotence related to hypertension is treatable. Men who wish to take the oral drug sildenafil (Viagra) to restore erectile function, however, should be aware that the drug interacts with many medications that affect blood pressure, is associated with reports of fatal heart events, and early trials were not conducted using men with hypertension. A study found that women with high blood pressure, regardless of medications, found it difficult to achieve sexual satisfaction and had impaired vaginal lubrication.

Mental Deterioration

Uncontrolled chronic high blood pressure is associated with mental deterioration in older people, including reduced short-term memory and attention, Alzheimer's disease, and dementia. The higher the blood pressure the greater the risk for mental impairment. In one 1999 study, patients with uncontrolled hypertension were at six times the risk for a significant loss of mental ability than patients with healthy blood pressure levels, and over a period of four years about 22% of these hypertensive patients experienced significant declines in mental function. Fortunately, a number of studies have now demonstrated that controlling blood pressure can reduce or even prevent memory loss and mental decline due to hypertension.

Pregnancy and Preeclampsia

Severe, sudden high blood pressure in pregnant women caused by a condition called preeclampsia can be very serious for both mother and child. It occurs in up to 10% of all pregnancies usually in the third trimester of a first pregnancy, and resolves immediately after delivery. According to one report, women with existing hypertension are at higher risk for preeclampsia if they have high diastolic blood pressure, high blood pressure for at least four years, or have had preeclampsia in a previous pregnancy. This condition may be caused by a failure of the placenta to embed properly in the uterus, which causes it to misconnect with the mother's blood vessels. As a result, the fetus does not receive a sufficient blood supply and the mother's own blood pressure increases. Symptoms and signs of preeclampsia include protein in the urine and swollen ankles. The reduced supply of blood to the placenta can cause low birth weight and eye or brain damage in the fetus. Severe cases of preeclampsia can cause kidney damage, convulsion, and coma in the mother and can be lethal to both mother and child. New studies suggest that women at risk for preeclampsia may benefit from having an ultrasound of uterine arteries at 20 to 24 weeks' gestation followed, if abnormal, by 24-hour blood pressure monitoring.

Outlook for Children with Hypertension

Results of studies evaluating outcomes of children with hypertension suggest that early abnormalities, including enlarged heart and abnormalities in the kidney and eyes, may occur even in children with mild hypertension. Children and adolescents with hypertension should be monitored and evaluated for any early organ damage.

Side Effects of Hypertension Treatments

One of the most difficult issues that hypertensive patients face, particularly those with primary hypertension, is that the treatment may make them feel worse than the disease, which is almost always without symptoms. Patients face a life-long prospect of taking drugs with unpleasant side effects, reducing their salt intake, exercising, and watching their diet. Whatever the difficulties, compliance with a drug and lifestyle program is worth the effort and the cost.

What Are The Symptoms Of High Blood Pressure?

Hypertension has been aptly called the "silent killer" because it usually produces no symptoms. It is important, therefore, for anyone with risk factors to have their blood pressure checked regularly and to make appropriate lifestyle changes. Such recommendations are urged for individuals who have overall high-normal blood pressure, mild or above systolic with normal diastolic pressure, family histories of hypertension, or who are overweight or over forty years old.

Untreated hypertension increases slowly over the years. In rare cases (fewer than one percent of hypertensive patients), the blood pressure rises quickly (with diastolic pressure usually rising to 130 or higher), resulting in malignant or accelerated hypertension. This is a life-threatening condition and must be treated immediately. Symptoms may include drowsiness, confusion, headache, nausea, and loss of vision. Hypertensive individuals should call a physician immediately if these symptoms appear. People with a history of heart failure are at increased risk for such a hypertensive crisis. People on antihypertensive agents are much less likely to experience such an event, although one small study reported a twofold risk in people taking clonidine, a second- or third-line hypertensive agent. Such people may have had harder to treat blood pressure.

What Are The General Guidelines For Choosing The Appropriate Treatments For High Blood Pressure?

Aggressive drug treatment of long-term high blood pressure can significantly reduce the incidence of mental decline and death from heart disease and other serious physical effects of hypertension. In people with diabetes, controlling both blood pressure and blood glucose levels prevents serious complications of that disease. However, despite widespread access to medical care, there has been a reduction in awareness, treatment, and control of high blood pressure over the past decade. In a 1999 study of white Minnesotan adults, researchers reported that although over half of subjects had hypertension, 39% were unaware of their hypertensive status. Only 16.6% were treating and controlling their hypertension, and nearly 28% were being treated but their blood pressure was not under control. These results were significantly worse than those of a 1986 study of the same population. According to the American Heart Association, only one in four of 50 million people with high blood pressure are adequately treated.

To help make basic treatment choices for people with high-normal or high blood pressure, The National Heart, Lung and Blood Institute has created categories (denoted as Groups A, B, and C) according to a patient's risk factors for heart disease. Such risk factors include the following: smoking, unhealthy cholesterol and lipid levels, diabetes, being over 60 years old, being a man or postmenopausal woman, and women under 65 and men under 55 with a family history of heart disease. Applying these categories to the severity of hypertension helps determine whether lifestyle changes alone or medications are needed [s ee Table ]. (Regardless of their risk category, everyone with evidence of abnormal blood pressure should adapt a healthy diet and exercise program.) One study analyzed normal to severely hypertensive patients by risk group category and reported that only 2.4% (all women) were in risk group A, 59.3% were in group B, and 38.2% were in group C. In addition slightly over 60% were on or needed medications, according to the criteria.

TREATMENT RECOMMENDATIONS BY STAGE AND RISK GROUPS

Guidelines for Drug Therapy

General Recommendations for Specific Antihypertensives. Dozens of antihypertensive drugs are available. They usually fall into the following categories: (1) diuretics, which cause the body to excrete water and salt, (2) ACE inhibitors, which reduce the production of angiotensin, a chemical that causes arteries to constrict, (3) beta-blockers, which block the effects of adrenaline, thus easing the heart's pumping action and widening blood vessels, (4) vasodilators, which expand blood vessels, and (5) calcium-channel blockers, which help decrease the contractions of the heart and widen blood vessels. A single-drug regimen can often control mild to moderate hypertension. More severe hypertension often requires a combination of two or more drugs. Prolonged-release drugs are being developed so that they are most effective during early morning periods, when patients are at highest risk for heart attack or stroke.

As first-line treatment, experts generally recommend beta-blockers, diuretics, or both. They are inexpensive, safe, and effective for most people with hypertension who have no complicating problems. Individuals, however, may have special requirements that call for specific drugs. Of some concern are studies indicating that beta-blockers used alone may not improve survival rates or reduce the risk for heart attack in hypertensive patients. They also increase the risk for diabetes. One analysis of many studies reported that diuretics were better than beta-blockers on all important points, including reducing heart attacks, strokes, and mortality rates. In fact, studies that have reported benefits were generally reporting on combinations of diuretics and beta-blockers. One study even suggested that the combination is less effective than diuretics alone in some people. In any case, diuretics continue to be the best choice for most older adults and for many African Americans, who are more likely to be salt-sensitive and so respond well to these drugs. Drug combinations containing low-dose diuretics along with other antihypertensives may prove to be particularly useful for elderly patients. Isolated high systolic pressure is usually treated with a diuretic; a long-acting calcium channel blocker may be an alternative. For diabetics and perhaps for other patients with high-risk factors for heart problems, the best drugs are angiotensin-converting enzyme (ACE) inhibitors. This drug class has been shown to delay the onset and progression of kidney disease by 30% to 60% and to limit progression of other complications. People with heart failure should be given ACE inhibitors and diuretics; specific drugs in these classes may be particularly beneficial for these patients because they reduce left ventricle hypertrophy.

Side Effects and Compliance. All drugs used for hypertension have side effects, some very distressing, and ongoing compliance is difficult. Some physicians have been concerned about the long-term effects of anti-hypertensive drugs on mental processes. One study reported change in brain tissue on scans of people who took calcium-channel blockers or loop diuretic; those who took beta-blockers had no such changes. This is an isolated study, and more research is needed to confirm it. A 1999 study reported, in fact, that diuretics protect against dementia. On an encouraging note, one major study found that people taking blood pressure drugs did not experience any greater decline in the general quality of life or daily functioning over five years than did people who were not on blood pressure medication. In all cases, healthy lifestyle changes must accompany any drug treatment. It is very important, in any case, to rigorously maintain a drug regimen.

Withdrawal From Antihypertensive Medications. Patients whose blood pressure has been well-controlled and who are able to maintain a healthy life style may choose to withdraw from hypertensive medications. They should do so in a step-down manner (gradual reduction) and be monitored regularly. Stopping too quickly can have adverse effects, including serious effects on the heart in some cases. Research is ongoing to determine which patients are more likely to sustain control of their blood pressure after withdraw. Long-term success rates (more than a year after withdrawal) in patients whose blood pressure had been well controlled range from 15% to more than 80%. The highest success rates are more likely in those who lose weight and reduce sodium intake and who are able to control their blood pressure within five years of an initial diagnosis and treatment with a single agent. Of concern was a 1998 study reporting that patients, particularly smokers and younger adults, who discontinue antihypertensive therapy are at a significantly increased risk for stroke.

What Lifestyle Changes Are Needed To Control High Blood Pressure?

Dietary Factors and Weight Loss

DASH Diet. A diet known as Dietary Approaches to Stop Hypertension (DASH) is now recommended as an important step in managing blood pressure. It is low in saturated fat (although includes calcium-rich dairy products that are no- or low-fat) and rich in whole grains, fruits, and vegetables. (One recent study reported a reduced need for anti-hypertension medication in people with a high monounsaturated-fat diet.) The DASH diet includes a daily choice of nuts, seeds, or legumes and contains modest amounts of protein (preferably fish, poultry, or soy products). In one study, after eight weeks on the diet, subjects from a broad range of backgrounds and experienced a significant reduction in blood pressure. This diet is not only rich in important nutrients and fiber but also includes foods that contain two and half times the amounts of electrolytes--potassium, calcium, and magnesium--as are found in the average American diet. Important foods include most fruits, many vegetables (especially, carrots, spinach, celery, alfalfa, mushrooms, lima beans, potatoes, avocados, broccoli), chicken, liver, and no-fat or low-fat milk. According to one study a low-calorie oat or wheat diet may significantly reduce blood pressure, however more work is needed to confirm these findings. Many of these foods are also high in fiber, which is protective against many diseases. It should be noted that grapefruit (but not other citrus fruits) boosts the effects of calcium channel blocking drugs used for hypertension. The long-term effect of the diet on the heart is unknown.

Weight Loss. An estimated 97 million adults in the US are overweight or obese. Weight gain seems to be a primary determinant in blood pressure increase, and weight loss may be even more important than salt restriction in controlling blood pressure. Losing weight, particularly in the abdominal area, immediately reduces blood pressure and helps reduce heart size. Weight loss, particularly accompanied by salt restriction, may allow patients with mild hypertension, even older people, to safely reduce or go off medications.

Salt Restriction. Diets high in salt accelerate hypertension in everyone as they age. Anyone with hypertension should reduce salt intake. One study indicated that even moderate salt restriction may be beneficial for people with mildly elevated blood pressure. Salt restriction is particularly important for those who are at risk for being salt-sensitive, which means that sodium is more likely to increase their blood pressure and salt restriction to lower it. Among those at higher risk for salt sensitivity are African Americans, people with diabetes, and elderly people. Slightly less than half of people with high blood pressure are salt-sensitive. High-salt diets in such people may harm the kidney and brain, even independent of high blood pressure. Restricting salt is also very important in overweight individuals, who may absorb and retain sodium differently from people with normal weights. In fact, one 1999 study reported that high sodium intake was associated with an increased risk of heart disease and all-cause mortality in overweight, but not in normal weight, people. Unfortunately, because overweight people generally consume more calories, they are also likely take in more sodium. Restricting salt also enhances the benefits of nearly all standard antihypertensive drugs by reducing potassium loss, and may help protect against kidney disease in patients who are also taking calcium-blocker drugs. Although it is not clear whether restricting sodium adds any benefits for most people whose diets are rich in fruits, vegetables, and low-fat dairy products and who are not salt-sensitive, it is always wise to aim for a maximum of 2,400 mg sodium intake.

Simply eliminating table and cooking salt can be beneficial. Salt substitutes, such as Cardia, containing mixtures of potassium, sodium, and magnesium are now available but are expensive. It should be noted, however, that about 75% of the salt in the typical American diet comes from processed or commercial foods, so the benefits of table-salt substitutes are likely to be very modest. Some sodium is essential to protect the heart, but most experts agree that the amount is significantly less than that found in the average American diet.

Potassium, Magnesium, and Calcium. Some experts believe that sufficient intake of minerals, particularly potassium, magnesium, and calcium, may be more beneficial than salt restriction for reducing blood pressure. Studies have indicated that potassium deficiencies increase the risk for high blood pressure, and recent studies indicate that a potassium-rich diet may reduce hypertension, and possibly even stroke, in groups as diverse as African American adolescents and middle-aged men. A number of studies have also shown that daily potassium supplements can modestly reduce blood pressure. The recommended goal is 3,500 mg of potassium a day. Some patients, such as those taking certain diuretics that do not spare potassium, may require supplements. Excess potassium, however, can cause abdominal distress, muscle weakness, and, in rare cases, dangerous heart events. Some people should be particularly cautious about potassium supplements, including those with conditions, such as diabetes or kidney disease, that increase potassium levels or who are taking medications, such as ACE inhibitors or potassium-sparing diuretics, that limit the kidney's ability to excrete potassium. Most people should obtain this mineral from potassium-rich foods that include potatoes, avocados, bananas, nonfat milk products, red beans, oranges, prunes, and cantaloupes [ see also Useful Foods, above].

Studies are also finding that magnesium supplements may induce small but significant reductions in blood pressure. No major studies, however, have been done on long-term benefits or risks of magnesium supplements.

Calcium regulates the tone of the smooth muscles lining blood vessels, and population studies have found that people who have sufficient dietary calcium have lower blood pressure than those who do not. Hypertension itself increases calcium loss from the body. Some, but not all, studies have found modest beneficial effects on blood pressure from calcium supplements. One study found protection against stroke in men whose diets were rich in magnesium and potassium but no similar effects from diets high in calcium. Sufficient calcium is important, in any case, for strong bones.

Vitamin C. Vitamin C apparently has specific benefits for hypertension by preventing dangerous effects on nitric acid, the substance that keeps arteries flexible.

Caffeine Intake, Alcohol, and Smoking

Everyone should quit smoking and, if they drink alcohol at all, should do so in moderation. In healthy people with normal blood pressure, drinking a couple of cups of coffee a day is unlikely to do any harm. Caffeine drinkers, however, would do better to choose tea, which may have beneficial nutrients, and people with existing hypertension should avoid caffeine altogether.

Exercise

Studies indicate that regular exercise helps keep arteries elastic, even in older people, which in turn keeps blood flowing and blood pressure low. Sedentary people have a 35% greater risk of developing hypertension than athletes do. No person with high blood pressure should start an exercise program without consulting a physician. Studies have shown that high-intensity exercise may not lower blood pressure as effectively as moderate-intensity exercise. In one study, for example, moderate exercise (jogging two miles a day) controlled hypertension so well that more than half the patients who had been taking drugs for high blood pressure were able to discontinue the medication. Studies have indicated that T'ai Chi, an ancient Chinese exercise involving slow, relaxing movements, may lower blood pressure almost as well as moderate-intensity aerobic exercises.

An estimated 1.5 million heart attacks occur every year; of these, 75,000, or about 5%, occur after heavy exertion, leading to 25,000 deaths. Isometric work-outs, such as snow shoveling, tend to stress the heart and raise blood pressure for a brief period; it can also cause spasms in the arteries leading to the heart. Some studies indicate that competitive sports, which couple intense activity with aggressive emotions, are more likely to trigger a heart attack than other forms of exercise. One major study found that sedentary people who throw themselves into a grueling workout increase the risk of heart attack by 107 times over that which would occur with low or no exertion.

Certain antihypertensive medications, including diuretics and beta-blockers, can interfere with exercise capacity. ACE inhibitors or calcium-channel blockers are the best drugs for active individuals. However, patients who must take drugs that interfere somewhat with exercise capability should still adhere to an exercise program and consult a physician on how best to balance medications with exercise.

Good Sleep Habits

Insufficient sleep may raise blood pressure in patients with hypertension, placing them at increased risk of cardiovascular morbidity and mortality. According to a 1999 Italian study, blood pressure and heart rate were higher the morning after a sleep-deprived night compared with the morning after a full night of sleep. Stress hormone levels increase with sleeplessness, which can activate the sympathetic nervous system, a strong player in hypertension. Patients who have chronic insomnia or other severe sleep disturbances should consider consulting sleep experts if life style measures are not helpful. Physicians whose hypertensive patients are habitually poor sleepers should consider long-acting blood pressure medications to help counteract the increase in blood pressure that occurs in the early morning hours.

Stress Reduction and Psychologic Therapy

Emotional factors or psychologic stress are possible precursors to hypertension. One study found that 73% of patients with mild to moderate hypertension who underwent cognitive-behavioral therapy were able to reduce their medication after 6 weeks; after 12 months, 55% required no medication. Two small studies also reported that religious faith and activity was associated with healthy blood pressure levels, possibly indicating the benefits of a strong social network and reduced stress from spiritual activities. (Listening to religious services on the radio or watching them on television had no impact on blood pressure.) In another study, a simple relaxation technique called transcendental meditation (TM), which involves silent repetition of a single sound, was shown to be effective in reducing blood pressure.

What Are The Specific Drug Treatments Used For High Blood Pressure?

Diuretics

For decades, diuretics, which cause reduction of water and sodium, have been the mainstays of antihypertensive therapy and are still considered the first choice by experts, especially for treating the elderly. Diuretics have reduced the incidence of stroke by a significant 40% and, to a lesser degree (about 16%), the incidence of hypertension-related heart attacks. They may also protect against blood clots. Diuretics come in many brands and are generally inexpensive. Some need to be taken once a day, some twice a day. A diuretic used as the initial single agent is particularly effective in elderly and African-American patients. Diuretics may also help reduce the rate of fractures in elderly people who have taken them for a long time. It has been thought that long-term use of diuretics can be harmful to patients with diabetes; one large study, however, reported that a low-dose diuretic reduced the risk of major heart disease with few adverse effects in older patients who had type 2 diabetes and isolated systolic hypertension. Experts believe that diuretics should be the first line of therapy for such patients.

Three primary types of diuretics exist: thiazides, loop diuretics, and potassium sparing agents. Thiazides often serve as the basis for high blood pressure treatment, either taken alone for mild to moderate hypertension or used in combination with other types of drugs. There are many thiazides and thiazide-related drugs; some common ones are chlorothiazide (Diuril), chlorthalidone (Hygroton), and hydrochlorothiazide (Esidrix, HydroDiuril). Loop diuretics block sodium transport in parts of the kidney; they act faster than thiazides and have a great diuretic effect. It is important therefore to control the medication and avoid dehydration and potassium loss. Loop diuretics include bumetanide (Bumex), furosemide (Lasix), and ethacrynic acid (Edecrin).

The loop and thiazide diuretics deplete the body's supply of potassium, which can cause arrhythmias, heart rhythm disturbances that can, in rare instances, lead to cardiac arrest. In such cases, physicians will either prescribe lower doses of the current diuretic, recommend potassium supplements, or use potassium-sparing diuretics either alone or in combination with a thiazide. Some potassium-sparing diuretics include amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium). Studies indicate that people who take a potassium-sparing diuretic with a low-dose thiazide have a lower risk for cardiac arrest than those taking either a beta-blocker or thiazide alone. Potassium-sparing drugs have their own risks, which include dangerously high levels of potassium in people with damaged kidneys or who have a high potassium intake from other sources. It should be noted, however, that, in general, all diuretics are more beneficial than harmful. (Arrhythmias can also occur as an interaction between diuretics and certain drugs, including some antidepressants, anti-arrhythmic drugs themselves, and digitalis.)

Common side effects of diuretics are fatigue, depression, irritability, urinary incontinence, loss of sexual drive, breast swelling in men, and allergic reactions. Diuretics can trigger attacks of gout; they may also increase the risk of gastrointestinal (GI) bleeding. They and may raise cholesterol level and, used alone, they have no effect on enlarged heart size (hypertrophy).

Beta-Blockers

Beta-blockers affect the force and frequency of heart beats; they slow certain metabolic processes, ease the workload of the heart, and reduce pressure. They are very effective in reducing blood pressure and have been associated with a lower risk for a second heart attack or sudden death after a first heart attack. Studies are reporting, however, that, when used alone, they do not reduce mortality rates.

Many beta-blockers are now available, including propranolol (Inderal), acebutolol (Sectral), atenolol (Tenormin), betaxolol (Kerlone), carteolol (Cartrol), metoprolol (Lopressor), nadolol (Corgard), penbutolol (Levatol), pindolol (Visken), and timolol (Blocadren). The drugs may differ in their effects and benefits. Carvedilol (Coreg), which is a mild beta-blocker with some vasodilating properties, has been found to improve very severe heart failure. A similar drug, bucindol, is in development. Atenolol has been found to reduce left ventricular hypertrophy and, when used with the diuretic chlorthalidone, was found to significantly reduce the risk for heart failure, particularly in patients at high risk for it.

These drugs are not as effective as ACE inhibitors in people with or at risk for kidney disease, and there is some indication they increase the risk for diabetes. Because they can narrow bronchial airways and constrict blood vessels, patients with asthma, emphysema, and chronic bronchitis should avoid them whenever possible. Carvedilol appears to have a better effect on insulin sensitivity than other beta-blockers and so may prove to be a good choice for people with diabetes. (In general, however, experts recommend that people with diabetes who are susceptible to hypoglycemia avoid beta-blockers.) Some beta-blockers tend to lower HDL cholesterol (the beneficial cholesterol) by about 10%; the effect is most marked in smokers. Fatigue and lethargy are the most common psychologic side effects. Some people experience vivid dreams and nightmares, depression, and memory loss. Exercise capacity may be reduced. Other side effects may include cold extremities, asthma, decreased heart function, gastrointestinal problems, and sexual dysfunction. If side effects occur, the patient should call a physician, but it is extremely important not to stop the drug abruptly. Angina, heart attack, and even sudden death have occurred in patients who discontinued treatment without gradual withdrawal.

Angiotensin Converting Enzyme Inhibitors and Similar Drugs

Angiotensin Converting Enzyme Inhibitors. Angiotensin converting enzyme (ACE) inhibitors block the effects of the angiotensin-renin-aldosterone system, which is thought to have many harmful effects on the heart and blood vessels. ACE inhibitors include captopril (Capoten), enalapril (Vasotec), quinipril (Accupril), benazepril (Lotensin), ramipril (Altace), and lisinopril (Prinivil, Zestril). ACE inhibitors are recommended as first-line treatment for people with diabetes and kidney damage, for some heart attack survivors, and for patients with heart failure when taken with diuretics. Recent studies are offering sound medical proof that ACE inhibitors can improve a patient's odds of surviving a heart attack. A major 2000 study on the effects of ramipril in a high-risk group of patients has now strongly supported other studies that report benefits of ACE inhibitors beyond lowering blood pressure, including lowering the risk of death, heart attack, stroke, heart failure, and complications related to diabetes, including kidney disease. Another study suggests that long-term use of ACE inhibitors may even reduce the risk of cancer, particularly in women. African-American patients usually do not respond to ACE inhibitors unless they are combined with diuretics.

Side effects include an irritating cough, excessive drops in blood pressure, and allergic reactions. (The drug picotamide can help reduce the frequency of coughs.) Although ACE inhibitors can protect against kidney disease, they also cause the kidneys to retain potassium, which can result in cardiac arrest if levels become too high. Because of this action, they are not generally given with potassium-sparing diuretics or potassium supplements. They may also interact with aspirin, although more studies are needed to confirm this. One rare but severe side effect, granulocytopenia, has been observed, which is an extreme reduction in white blood cells.

Angiotensin II Receptor Antagonists. Drugs known as angiotensin II receptor antagonists, including losartan (Cozaar, Hyzaar), candesartan (Atacand), telmisartan (Micardis), eprosartan, and valsartan (Diovan), have benefits similar to ACE inhibitors and may have fewer or less severe side effects, including coughing. They may also have positive effects on blood vessels. In one study, eprosartan was more effective than enalapril in reducing systolic pressure in African American patients. Also now available is a combination medication containing valsartan and the diuretic hydrochlorothiazide (Diovan HCT).

Vasodilators

Vasodilators, which widen blood vessels, are often used in combination with a diuretic or a beta-blocker. Representative vasodilators include hydralazine (Apresoline), prazosin (Minipress), clonidine (Catapres, available in tablets or as a skin patch), and Minoxidil (Loniten). Some of these drugs should be used with caution or not at all in people with angina or who have had a heart attack.

Calcium-Channel Blockers

Calcium-channel blockers, or calcium antagonists, have an immediate effect on reducing blood pressure. Sustained-release calcium-channel blockers provide stable and persistent low blood pressure. Calcium-channel blockers approved for high blood pressure include diltiazem (Cardizem, Dilacor), amlodipine (Norvasc), felodipine (Plendil), isradipine (DynaCirc), verapamil (Calan, Isoptin, Verelan), nisoldipine (Sular), nicardipine (Cardene), and nifedipine (Adalat, Procardia). Others under investigations are lercanidipine (Zanidip), nitrendipine, and benidipine. These drugs are chemically diverse depending on their mechanisms for blocking calcium; the major types are phenylalkylamine (eg, verapamil), benzothiazepine (diltiazem and others), and dihydropyridine (eg, nifedipine). They are often beneficial in combination with other antihypertensive agents, and they may be a good option for people who cannot take beta-blockers. They may also have particularly benefits for select hypertensive patients who also have certain other conditions, such as Raynaud's phenomenon or migraine. These drugs vary widely and one calcium-channel blocker may have different effects--for good or bad--from another. They also differ in their effects on population groups. For example, one study reported that African Americans responded more successfully to dilitiazem than Caucasians. Studies are still needed to help define which calcium-channel blockers offer real benefits for which specific patients. In spite of their effectiveness in lowering blood pressure itself, clear evidence is lacking on the benefits of calcium-channel blockers in improving overall survival.

Side Effects. Side effects vary among different preparations. Most drugs can cause fluid accumulation in the feet, constipation, fatigue, impotence, gingivitis, flushing, and allergic symptoms. Interactions with foods and drugs also differ depending on the drug. Overdose on many of these agents can cause a sever drop in blood pressure. For example, verapamil interacts with digoxin, but diltiazem does not. Grapefruit juice appears to boost their effects, particularly in the elderly.

Possible Effects on the Heart. Some of the calcium blockers (short acting forms, sustained-release nifedipine, intravenously administered agents) increase the activity of the sympathetic nervous system, which regulates the heart. Certain short-acting drugs, such as isradipine, have been linked to an increased risk for angina, and of major concern were reports of an increased risk of death and serious heart events from abrupt drops in blood pressure in people taking short-acting nifedipine. The FDA has strongly warned against the use of sublingual (under-the-tongue) nifedipine for the treatment of hypertensive emergencies. One study reported that women who took calcium-channel blockers had a significantly higher risk for heart attack than those on diuretics, although these results may not reflect the current trend toward taking long-acting calcium-channel blockers. Most studies on long-acting calcium blockers such as verapamil, used after a heart attack, reported no adverse effects on the heart and even benefits. At this time, however, even long-acting calcium-channel blockers should be used with caution or not at all by people who have had a recent heart attack, who have unstable angina, or who have or at risk for congestive heart failure. There have also been reports of a higher risk for heart attacks from both short- and certain long-acting agents in people with diabetes. Calcium-channel blockers are often recommended for people with diabetes, however, because they do not effect kidneys, blood sugar levels, or cholesterol. The calcium-channel blocker nitrendipine, in fact, was reported to reduce the incidence of stroke in older diabetic patients with systolic hypertension, but the drug is not yet available in the US. Another long-acting calcium-channel blocker, benidipine, was shown in a Japanese study to improve insulin resistance in patients with essential hypertension.

Other worrisome studies have pointed to a higher rate of cancer (particularly breast cancer in women) in those taking calcium-channel blockers, although major studies in Europe and the US have found no such risk. Studies have found a significantly increased risk for blood loss during surgery in patients taking these drugs. A higher risk for gastrointestinal bleeding was not confirmed in one major study, and researchers believed that the higher incidence of bleeding previously observed was due to taking aspirin.

Other Investigative Agents

Moxonidine and rilmenidine are investigative agents known as selective imidazoline receptor agonists (SIRAs). Early European studies are showing promise for reducing blood pressure with fewer side effects than other drugs. Of concern, however, were reports of increased deaths in heart failure patients being treated with moxonidine, although the form of the drug used was slightly different from that used in high blood pressure.

Treatment During Pregnancy

Most women who develop high blood pressure only during pregnancy (gestational hypertension) are at low risk for preeclampsia and require no treatment other than monitoring. Treating pregnant women who have chronic, mild hypertension is probably not necessary, although no large studies have been done to confirm this. Many of the standard antihypertensive drugs, particularly ACE inhibitors, have potentially harmful effects to a fetus. Women who have taken ACE inhibitors before pregnancy will not endanger the fetus if they discontinue therapy during the first trimester. Atenolol is also associated with adverse effects on the fetus; studies on other beta-blockers are conflicting. Treatment for preeclampsia ranges from monitoring to emergency treatments, depending on severity. It does not respond well to standard drug treatments. Preventive treatment using magnesium sulfate during labor is recommended by some experts. Experts hoped that aspirin might help prevent preeclampsia in high-risk women, but studies indicate that it has little effect.

Where Else Can Help Be Found For High Blood Pressure?

National Heart, Lung, and Blood Institute, Information Center, P.O. Box 30105, Bethesda, MD 20824-0105. Call (301-251-1222) or on the Internet (www.nhlbi.nih.gov/nhlbi/nhlbi.htm )
Associated with the National Institute of Health, this organization offers printed information.

The web site also includes the DASH diet. For latest expert guidelines on hypertension (http://www.nhlbi.nih.gov/health/prof/heart/index.htm#hbp )

American Heart Association, 7272 Greenville Ave., Dallas, Texas 75231-4596. Call (214-373-6300 or 800-242-8721) or on the Internet (www.americanheart.org ).

This is a primary source of information for heart problems. They are very responsible and will send free pamphlets and reading material, including useful diet information and locations of local representatives.

The American Society of Hypertension, 515 Madison Ave, Suite # 1212, New York, NY 10022. Call (212-644-0650) or on the Internet (http://ash-us.org/ )

Excellent site for information on the DASH diet (http://dash.bwh.harvard.edu/dashdiet.html )

The above information is from MD Consult. Used with permission.

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                                        10/27/2001