TUESDAY, April 5, 2005 (HealthDay News) -- Diuretics work better than other drugs at lowering high blood pressure and reducing the risk of heart disease, so they should be a first-line treatment for hypertension, new research suggests.
About 65 million Americans, or one in four adults, have high blood pressure. It is one of the leading risk factors for heart disease and the leading risk factor for heart failure and stroke.
Studies have long shown that blacks are at especially high risk for hypertension, but until now it's remained unclear whether drugs that work well in white patients will perform just as effectively in blacks.
However, this major new study suggests that, "in both blacks and non-blacks, diuretics are essentially unsurpassed. This is very clear," said Dr. Jackson T. Wright Jr., lead author of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT).
"Diuretics should be included in the regimen of the vast majority of hypertensives, and especially black hypertensives," he added.
Results of the trial, which was sponsored by the National Heart, Lung, and Blood Institute, appear in the April 6 issue of the Journal of the American Medical Association.
These new results confirm previous ALLHAT findings suggesting that diuretics are at least as effective as other drugs, such as beta blockers, ACE inhibitors or calcium channel blockers, in preventing coronary heart disease; that they are more effective in preventing heart failure; and more effective than beta blockers and ACE inhibitors in preventing stroke.
"Diuretics have been around for over half a century, and they have been shown in multiple previous studies to prevent the complications of high blood pressure," Wright said.
Nevertheless, there had been a shift in recent years to newer agents such as ACE inhibitors and calcium channel blockers because they seemed to have less of an effect on blood sugar and blood cholesterol than diuretics, Wright explained.
And, until now, experts had not known with certainty whether the superiority of diuretics applied to all races.
"In hypertension, there's been an ongoing debate for years about whether or not some therapies work better in blacks than whites," said James D. Neaton, co-author of an accompanying editorial and a professor of biostatistics at the University of Minnesota School of Public Health. "This is probably the first study that had enough patients -- both blacks and whites -- that could definitively compare different classes of drugs. This is the largest, most powerful subgrouping analysis that's been carried out so far."
For this study, 33,357 participants, about 35 percent of whom were black, were randomly assigned to assigned to receive either a calcium channel blocker, an ACE inhibitor or a thiazide-type diuretic.
Participants taking calcium channel blockers had a 37 percent higher risk of heart failure compared to those taking diuretics. Diuretics were more effective in preventing cardiovascular disease (especially heart failure) than ACE inhibitors, among all participants. That reduction in high blood pressure and prevention of stroke was even more pronounced in blacks, the researchers note.
"In blacks, it is very clear that the difference in effect is magnified such that not only is there a reduced benefit in terms of preventing heart failure, but also reduced benefits in lowering blood pressure, preventing stroke and preventing essentially all cardiovascular outcomes," Wright said.
"It indicates in our mind that the first-line treatment should be diuretics, or at least the second drug. That's the sensible take-home message from this," Neaton said.
Another expert agreed.
"The ALLHAT study is very powerful because it enrolled over 33,000 patients and the follow-up was multi-year," said Dr. Robert A. Phillips, chairman of the department of medicine at Lenox Hill Hospital in New York City. "It confirms that, despite all the concerns that people continue to raise about the efficacy and safety of using diuretics as first-line therapy, once again we have further proof that diuretics should be the first-line therapy in patients with high blood pressure."
For more on how to prevent, detect and treat high blood pressure, visit the National Heart, Lung, and Blood Institute.