TUESDAY, June 5, 2001 (HealthDayNews) -- Patients with kidney disease caused by dangerously high blood pressure do much better with an ACE inhibitor drug than with a calcium channel blocker, a federally sponsored study finds.
That finding, which might seem a fine point to outside observers, can be a matter of life or death to patients with the disease.The study, reported in the June 6 issue of The Journal of the American Medical Association, shows that an ACE inhibitor slows the progression to complete kidney failure much better than the calcium channel blocker does.
Both drugs are widely prescribed for high blood pressure but have different modes of action. ACE stands for the angiotension-converting enzyme, which produces a substance that causes blood vessels to constrict. The inhibitors keep the vessels from tightening up by blocking the enzyme's action. Calcium channel blockers, on the other hand, relax blood vessels by preventing the entry of calcium.
The new study broadens a finding seven years ago that showed ACE inhibitors slowed the progression of kidney disease in diabetics, says Dr. Janice G. Douglas, the chairwoman of the study's steering committee and the chief of the hypertension division at Case Western Reserve University and the University Hospital of Cleveland.
"This shows that the benefit is generalizable to all persons who have high blood pressure because of mild-to-moderate renal problems," Douglas says.
And although the patients in the study were all African-Americans, the results apply to all patients regardless of race, she adds.
The study was focused on African-Americans because previous, smaller trials had indicated that ACE inhibitors did not work as well for them as for white patients. The patients were enrolled in the study starting in 1995. Some were given the ACE inhibitor ramipril, marketed as Altace, and others got the calcium channel blocker amlodipine, marketed as Norvasc.
One portion of the study was stopped last September when a monitoring board found that one specific group of ACE inhibitor patients, those with abnormally high levels of protein in the urine caused by diminished kidney function, had a 36 percent slower decline in kidney function than patients on calcium channel blockers.
"That is a very, very important issue because it shows that using ACE inhibitors could delay the progression of kidney failure and the need for dialysis," says Dr. Vasilios Papademetriou, director of hypertension and cardiovascular research at the Veterans Affairs Medical Center in Washington, D.C.
Papademetriou, the author of an editorial accompanying the article on the study, adds: "It is important because we have so many patients on dialysis, which is very costly for the patients and has a major effect on lifestyle."
However, Douglas points out, the final word on drug treatment for patients with high blood pressure and kidney disease is not yet in.
The results being reported come from a larger study that is looking at ACE inhibitors and calcium channel blockers along with beta blockers, another kind of high blood pressure drug that blocks the action of adrenaline. It will take some time for the study to indicate the best kind of drug treatment for these patients, Douglas say.
What To Do
Because high blood pressure often causes no symptoms, being aware of your blood pressure and the readings that indicate a need for changes in lifestyle and medical treatment is an elementary health measure for everyone.
For more information on high blood pressure, go to the American Heart Association.
Or take a look at these previous HealthDay stories on high blood pressure.