Hypertension drugs work for blacks and whites

Differences in how blacks and whites respond to antihypertensive drugs are small, and race should not be a determining factor in whether to prescribe them, according to a paper published in the March issue of Hypertension. The study was released online a month earlier.

"Physicians are taught that blacks and whites respond differently," said Ashwini R. Sehgal, MD, lead author and associate professor at Case Western Reserve University in Cleveland. "But there isn't really that much difference."

Dr. Sehgal performed a meta-analysis of 15 large studies that included data about race in connection to response to antihypertensives in an attempt to quantify how long documented differences may actually impact patients.

He found differences, but he also found a great deal of similarities. For example, 90% of whites and blacks had comparable changes in blood pressure after treatment with beta-blockers even though several studies have shown this treatment results in Caucasians' readings decreasing an average of six points more than that of African-Americans.

"What I'm arguing is that when we look at different racial groups we should look not just at the average differences but also at the extent of overlap," said Dr. Sehgal. "And when we make decisions about what drugs to use in particular patients, we shouldn't be focusing so much on their race."

Feeding the debate

This study is the latest wrinkle in the ongoing debate about racial differences in drug response and how clinically relevant these factors are for individual patients.

"It's been preached for years that blacks were much more sensitive to diuretics and whites were much more sensitive to beta-blockers," said R. Gregory Sachs, MD, governor of the New Jersey chapter of the American College of Cardiology and a senior cardiologist at Summit Medical Group. "This data says that might be statistically accurate but clinically, probably not terribly important."

Specialists widely praised the research for attempting to quantify what racial differences may mean in real life.

"It's about time that an article came out that actually matches real-world clinical practice," said John D. Baker, MD, a cardiologist at Irvine Regional Hospital and Medical Center in Irvine, Calif. "There have been several articles reporting on various drugs being inferior or superior in African-Americans and other minority populations. None of which seems to bear out in clinical practice."

But experts said these findings were not the end of questions about the role of race in hypertension or the hunt for the reasons why outcomes are still widely divergent even though the drugs may be similar in their effect. Hypertension is more common in African-Americans, and mortality for hypertension and related conditions is significantly higher.

This study indicates the need to focus on factors more common to one race or another that may be hampering treatment. African-Americans are more likely to be obese, diabetic and have problems accessing care. They are also more likely to have a lower socioeconomic status than Caucasians. Experts say a better understanding of how these issues interact may result in improved treatments for all.

"Within these racial disparities in blood pressure response lie important clues that need to be investigated that will help all hypertensives, both black and white," said John Slack, MD, MPH, associate chair of the Dept. of Medicine at Wayne State University in Detroit. "When we follow up on these clues, they are really the pot of gold at the end of the rainbow."

But the observation that there are some differences in drug response may prove to be part of the problem. Most hypertension treatment guidelines and labels on drugs note racial differences but also point out that this should not have a significant impact on treatment choices.

Anecdotal evidence suggests that some doctors hesitate before prescribing some of these drugs to African-Americans because of a belief they will be less effective. Attempting to counter this, the International Society on Hypertension in Blacks published a consensus statement in March 2003 in the Archives of Internal Medicine encouraging their more appropriate use.

"Race is not a very accurate predictor of blood pressure response despite the differences at the group level," said Dr. Slack, who is also president of the society.