Jewish World Review April 1, 2003 / 28 Adar II, 5763

HEALTH SENSE: Ace vs. diuretics --- U.S. and Australian studies differ on how to treat high blood pressure

By Judy Foreman | Two studies, both published in major medical journals, gave conflicting advice to the 50 million Americans who have high blood pressure.

The first told them that old-fashioned, cheap diuretics -- "water pills'' -- work at least as well and sometimes better than more expensive drugs called ACE inhibitors. The study of more than 42,000 white and black Americans was published in the Journal of the American Medical Association in December.


> But the second study, published last month in the New England Journal of Medicine, concluded just the opposite. The research involving 6,000 mostly white Australians found that ACE inhibitors, which lower blood pressure by dilating blood pressure, actually work better, although only for men (for unclear reasons).

Between now and May, it falls to Dr. Aram Chobanian, dean of the Boston University School of Medicine, and his committee of experts picked by the National Heart Lung and Blood Institute to reconcile the studies and tell people with high blood pressure what to do.

Their conclusions are crucial. Hypertension doubles the risk of heart attack and is the leading risk factor for stroke and heart failure. One in four adult Americans has hypertension -- defined as a reading of 140/90 millimeters of mercury or higher. (The top number is the systolic pressure, taken as the heart muscle contracts. The lower number is the diastolic, as the heart relaxes. Normal blood pressure is 120/80, but even readings of 130/85 should be considered a red flag.)

High blood pressure is so common, especially among older people, that many patients don't take it as seriously as they should. "High blood pressure doesn't make you feel bad,'' said Dr. Michele Hamilton, co-director of the heart failure program at the University of California at Los Angeles. That makes people less willing to change their diets, lose weight, reduce stress and take hypertension medications. High blood pressure is also tricky for doctors because, in 95 percent of cases, they don't know the underlying cause.

Basically, blood pressure is a matter of hydraulics. If the pressure inside artery walls is too low, a person can go into shock and die. If the pressure is too high, because vessels are too narrow or rigid or the heart beats too hard, a person may develop heart or kidney failure, and stroke.

With age, the risks get worse because blood vessels become more rigid, which creates more resistance for blood flow. Data from the Framingham Heart Study show that a person who has a normal blood pressure at 55 has a 90 percent chance of developing high blood pressure over the rest of the life span.

Regulation of blood pressure is complex, but one of the most important players is angiotension II, a kidney hormone that makes vessels constrict.

If you have hypertension, the first remedy to try is behavioral -- nutrition and exercise. Even losing just 10 pounds can lower blood pressure significantly.

It's not clear whether consuming too much salt actually causes hypertension. But age-related increases in blood pressure can be minimized by reducing sodium intake to about 2.4 grams a day. (This is equivalent to 6 grams, or about 1 teaspoon, of table salt.)

In practice, this means not adding salt when cooking or eating, and avoiding soy sauce, and many canned and fried foods.

A diet called DASH, or dietary approaches to stop hypertension, has been shown in a study sponsored by the National Heart, Lung and Blood Institute to lower blood pressure. The DASH diet endorses fruits, vegetables, and low-fat dairy foods, foods that are rich in potassium, calcium, magnesium, fiber and protein. The diet is low in total and saturated fat, and avoids red meat, sweet foods, and sugary drinks.

Stress reduction helps, too. Dr. Thomas Graboys, chairman of the Lown Cardiovascular Foundation, asks patients two questions: Do you look forward to going to work? And, do you look forward to going home at night? "If someone says no to either,'' he said, stress may be contributing to that person's hypertension problems.

To combat stress, Dr. Herbert Benson, president of the Mind-Body Medical Institute and associate professor of medicine at Harvard Medical School, recommends the "relaxation response.'' That means taking 10 to 20 minutes a day to meditate, pray or quiet the mind and body through focused concentration. Stress reduction, he said, can minimize the "vicious cycle'' in which people panic about their hypertension, making it worse.

If you've done all this and still have high blood pressure, you probably need medication. And that's where doctors disagree: Not on whether medication is needed, but on which drugs to try first. If hypertension is stubborn, you'll probably need several drugs, and there are many to choose from.

Diuretics such as Hydrodiuril or Hygroton flush excess water and salt from the body, thus reducing the volume of fluid, which allows the heart to work less hard. One reason diuretics fared well in the December study published in JAMA is that 32 percent of participants were black. Blacks, perhaps for genetic reasons, tend to be sensitive to salt and, so, respond well to diuretics.

Beta-blockers such as Inderal, which reduces nerve impulses to the heart and blood vessels, allow the heart to beat more slowly and with less force.

ACE-inhibitors such as Zestril (lisinopril) lower blood pressure by blocking formation of angiotensin II.

And then there are the calcium channel blockers, or CCBs, drugs such as Lotrel. They lower pressure by blocking calcium, which also can cause vessels to constrict.

Granted, it's a bit confusing. But it's "very reassuring'' that the first study found diuretics to be so effective, said Dr. Sid Smith, past president of the American Heart Association and professor of medicine at the University of North Carolina at Chapel Hill.

And because diuretics are cheap -- about 13 cents a pill versus 10 times that for other medications -- "there is no cost-quality tradeoff,'' as Dr. Lawrence J. Appel, a hypertension specialist at Johns Hopkins Medical Institutions, noted in a JAMA editorial.

As to which drug to start with, stay tuned for the findings from Chobanian's committee. In the meantime, work with your doctor until you find a drug, or combination of drugs, that gets your blood pressure out of the danger zone.

Judy Foreman is a lecturer at Harvard Medical School. Comment by clicking here.


© 2003, Distributed by TMS