Under pressure

One in three adults suffer from high blood pressure. 63% don’t know it. Healthcare Middle East explores the latest treatment techniques for tackling hypertension.

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By  Joanne Bladd Published  June 12, 2006

|~|Heart2.jpg|~|"Many hypertensives have not been diagnosed and most are undertreated."|~|The American Heart Association calls hypertension the silent killer. It’s an apt term. As a major cause of strokes, heart attacks, and kidney disease, high blood pressure can be lethal; the higher the pressure, the higher the risk. And since most people feel perfectly well until it has produced permanent damage, the disease often escapes notice.
Hypertension should also be known as the silent epidemic. Millions of people have high blood pressure, but a third don’t know it. Even fewer have heard of prehypertension, though tens of millions have it, increasing their risk for illness and premature death whether or not they go on to develop full-blown hypertension. As the population grows older, heavier, and more sedentary, this silent epidemic is sure to grow, creating a problem that needs more attention and more action from doctors and patients alike.

Does treatment work?
Dozens of studies around the world have asked this question and have come up with the same answer: yes, it does. Although the details vary, it’s reasonable to expect that a 10 mm Hg reduction of systolic blood pressure or a 5 mm Hg drop in diastolic pressure will reduce a person’s risk of stroke by 30%–40% and their risk of heart attack by 15%–25%.
Treatment works. But it can be hard to determine who should be treated and trickier still to determine which therapy is best. That’s because several important conditions add to the risks of high blood pressure and call for specific treatment goals.

Compelling indications
‘Compelling indications’ is the term used by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, in its seventh report (JNC 7), to describe the conditions that influence the need for blood pressure treatment, the goals of therapy, and the choice of medication. According to the JNC 7 report, people with compelling indications such as diabetes mellitus or renal insufficiency, should receive treatment earlier, should aim for lower pressures, and should receive drugs tailored to their individual needs. In all cases, therapy must be designed to fit each person’s particular needs. For every patient, drugs and doses must be adjusted to arrive at the desired blood pressure without producing significant side effects.

Lifestyle therapy
Lifestyle changes are the foundation of every blood pressure programme — and they should be the choice for healthy people as well. Here are the basics:

The Dietary Approaches to Stop Hypertension (DASH) diet an effective way of aiding treatment. It involves a reduction in dietary sodium to 2,400 mg a day or less. The less salt in a person’s diet, the better; 1,600 mg a day is a tough goal that can be achieved only by motivated people. The DASH diet also calls for a low consumption of animal fat and processed foods. However, there’s still plenty to eat, for the programme also includes many fruits, vegetables, wholegrains, and low or nonfat dairy products. This combination of foods, along with sodium restriction, can lower systolic blood pressure by 10–22 mm Hg.
Regular exercise is important for good health, and blood pressure control is among its many benefits. As little as 30 minutes of moderate exercise, such as brisk walking, will produce enormous benefits, as long as it’s done nearly every day. Exercise should lower systolic pressure by 4–9 mm Hg.
Weight control
As one of the most important ways to reduce blood pressure, weight control is also one of the hardest to achieve. Despite the claims made by diet books, plans, and supplements, there is no quick fix. But there is a slow fix: a calorie-restricted healthy diet, such as DASH, plus regular exercise. An obese person who sheds 20 pounds can expect a 5–20 mm Hg drop in systolic pressure.
Moderate alcohol use
Small amounts of alcohol won’t raise pressure, but heavier drinking will. Patients should limit themselves to two drinks per day (counting 5 ounces of wine, 12 ounces of beer, or 1½ ounces of spirits as one drink). For smaller men and women, one drink a day may be a wiser limit. Low-dose alcohol appears to reduce the risk of heart disease and stroke, but no one should take up drinking strictly for its medical benefits. People who reduce heavy drinking can shave at least 2–4 mm Hg off their systolic blood pressures.
Stress control
Stress management is harder to quantify than other lifestyle goals, but a number of studies suggest that meditation and other relaxation techniques can help lower blood pressure. Mental tension and hypertension are not synonymous, and plenty of laid-back people have high blood pressure. But if a patient is under stress, winding down is likely to help his or her health.

Bad habits, including poor nutrition, lack of exercise, and alcohol abuse, are responsible for an alarming rise in chronic diseases such as obesity and diabetes. They also contribute mightily to hypertension. Healthy living will prevent many cases of high blood pressure, and it can replace or reduce medications for many hypertensives. But many patients will need medication despite clean living. Fortunately, drug therapy is better than ever.

Medications: general principles
With a billion hypertensive people in the world today and a highly competitive global pharmaceutical industry, it’s no surprise that hundreds of antihypertensive medications are on the market, with new ones joining the ranks all the time. It’s confusing for medical professionals, as well as patients. Fortunately, several principles can help guide therapy.
Blood pressure reduction is the major goal. Although many classes of medication can achieve similar blood pressure reductions, some have been proven better at reducing the risk of complications such as stroke, heart attack, and premature death. In general, thiazide diuretics and angiotensin-converting–enzyme inhibitors have had the best track records. Other favoured medications include angiotensin-receptor blockers and beta blockers. And, after an up-and-down career, calcium-channel blockers have rejoined the list of top choices. See Table 2 for examples of these drugs and their doses.
Each major class of drugs contains many individual medications. In general, the members of a class have far more similarities than differences, and many individual drugs are sold under several brand names or as generics. Widely speaking, the various brands and generic forms of a drug are considered equivalent.
Therapy must always fit the individual. The first priority is to design a programme that will control blood pressure and provide maximum vascular protection with minimum side effects. Patients with specific needs, such as those with diabetes, heart disease, and kidney disease, require special consideration. All things being equal, prescribe the least expensive member of the drug class that’s best for each patient. Since the person will be taking it every day, you should also pick the most convenient preparation; one dose a day is often best.

Multi-drug regimens are often required to attain good blood pressure control. Doctors used to favour the strategy of starting with a single drug, increasing its dose step-by-step, and adding a second drug from a complementary drug class when the first reached maximum dose. It’s still a sound approach, but some experts now prefer moving to low-dose dual therapy earlier. Many combination drugs are available that make double therapy more convenient, but they are generally more expensive.
Monitor patients with hypertension carefully, checking for side effects as well as blood pressure control. Most of these medications take time to work, so you’ll need to adjust therapy at monthly intervals, then reduce the frequency of visits once a stable regimen is established. Patients can help by monitoring their pressure at home, and they should always report side effects as they occur. Patients who have urgent medical problems require more intensive therapy. Here’s a rundown of the major drugs:

Thiazide diuretics
By far the oldest and least expensive of the major antihypertensive drugs, the thiazides have been underprescribed. However, this is starting to change. Although the thiazides lack glamour, they are unsurpassed in their ability to reduce the risk of heart attack, stroke, and premature death in people with high blood pressure. Low doses are as effective as high doses in most people.

The thiazides act by flushing sodium into the urine, but they are active even in people on low-salt diets. Frequent urination, dehydration, and low potassium levels are among the most common side effects. Other potential problems include erectile dysfunction, elevated blood sugar levels, gout, and a sensitivity to the sun.
Because of their effectiveness, safety, low cost, and convenience, most experts recommend low-dose thiazides for initial treatment in the average patient. They are particularly useful in people with congestive heart failure and previous strokes, but may be less useful in patients with kidney disease or gout. Potassium-sparing diuretics such as spironolactone (Aldactone; particularly useful in congestive heart failure), triamterene, or amiloride may be combined with a thiazide. Patients who are allergic to thiazides may be able to tolerate loop diuretics such as furosemide (Lasix) or bumetanide (Bumex).

Angiotensin-converting–enzyme inhibitors (ACEIs)
ACEIs act by preventing the body from producing angiotensin, a critical protein that narrows blood vessels and promotes salt retention. ACEIs rival thiazides in their ability to reduce cardiovascular problems in people with hypertension. In 2002, the landmark study ALLHAT found that thiazides came out on top; but in a 6,083-subject Australian trial in 2003, ACEIs were slightly superior to thiazides, especially in older men. The HOPE trial of 2000 showed that an ACEI even reduced the risk of heart attack, stroke, and premature death in at-risk patients whose blood pressures were normal to begin with.
Many experts recommend an ACEI as the second drug when a thiazide is not sufficient, or as the first drug for hypertension. ACEIs are particularly desirable for patients with diabetes, congestive heart failure, recent heart attacks or major cardiac risk factors, previous strokes, and various forms of kidney disease. Coughing is the most frequent side effect. Other problems may include high potassium levels, abnormal kidney function, dizziness, and impaired taste and smell. Angiotensin-receptor blockers are valuable alternatives when ACEI therapy is complicated by coughing.

Angiotensin-receptor blockers (ARBs)
ARBs prevent angiotensin from acting on its cellular target. Since both ARBs and ACEIs blunt the action of angiotensin, they have many similarities in their benefits and side effects. The major advantage of ARBs is that they do not produce coughing (see Table 2). Because they are much newer, ARBs have been studied less extensively, so it’s not certain that they will provide the same wide range of benefits as ACEIs. ARBs also tend to be more expensive than ACEIs.Many experts recommend them as substitutes for ACEIs when a cough or allergic reaction disqualifies the use of an ACEI.

Beta blockers
By blocking some actions of adrenaline, beta blockers treat hypertension by widening blood vessels, relaxing the heart muscle, and slowing the heart rate. Potential side effects include an excessive slowing of the heart, wheezing, fatigue, cold extremities, and sleep disturbances. Depression and sexual dysfunction are less common than once believed.
Beta blockers are particularly desirable in patients with recent heart attacks, angina, and (with special care) congestive heart failure. They are helpful in some patients with abnormal heart rhythms (arrhythmias), but harmful in others. Patients with asthma and chronic obstructive lung disease should receive cardioselective beta blockers.

Calcium-channel blockers (CCBs)
CCBs treat hypertension by widening blood vessels; some also slow the heart rate. The first generation of CCBs were short-acting and were greeted with considerable enthusiasm. Despite high expectations, some studies raised concern that they might be hazardous in certain patients with heart disease. But the newer, long-acting CCBs appear safe and effective in controlling high blood pressure and in preventing strokes and other complications. As a result, they have been endorsed as first-line antihypertensives by the JNC and other experts. Many doctors add them when thiazides, ACEIs or ARBs, and beta blockers are not sufficient. CCBs may be particularly helpful in patients with angina, but they are less desirable in those with recent heart attacks and congestive heart failure. Potential side effects include dizziness, fluid retention, constipation, flushing, headache, and slow heart rates.

Other medications
Most patients with hypertension can achieve excellent blood pressure control with lifestyle changes plus medication from one or more of the five classes of first-line drugs summarised in Table 2. But some patients require other medication as well. The alpha blockers are particularly interesting to many men since they also have an important role in treating benign prostatic hyperplasia, (BPH), and many preparations containing two (or even three) drugs are also available. (See Figure 2.)

The bigger picture
Hypertension is an unusual disease. It is extremely common and easy to detect, yet is a very important cause of death and disability, playing a major role in strokes, heart attacks, and kidney failure. It can easily be treated, and treatment can prevent nearly all the damage and distress it causes. And the simple habits that help treat high blood pressure can go a long way toward preventing hypertension in the first place.
These features should make high blood pressure a high priority. Unfortunately, it’s often not. Many hypertensives have not been diagnosed, and most are undertreated. In part, the neglect results from the fact that most patients with the disease feel perfectly well for years, even decades, until a cataclysm occurs. Also, many blood pressure drugs are expensive, and some are inconvenient. And some people experience side effects that make them feel a bit worse than they did initially.
Don’t turn your back on hypertension. Every adult should have their blood pressure checked at least every two years; older adults and those with prehypertension should be checked once a year or more and should adjust their lifestyles to keep their pressures as low as possible. Patients with hypertension should work with their doctors to attain the blood pressure goals set forth in the 2003 JNC 7 report. It may take a series of office visits and a number of drugs to achieve maximum control with minimum side effects, but it’s surely worth the effort.
Good blood pressure readings are important, but the goal is good health, not just pretty numbers. Be sure that blood pressure control is part of a package that also includes helping patients to manage their cholesterol and blood sugar, factors that add significantly to the toll of hypertension. And remember that, although many patients need medication, all can benefit from the good diet, regular exercise, weight control, tobacco avoidance, and restrained drinking that are so important for everyone’s health. ||**||

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