Researchers found that nearly one-half of the younger children in the trial, all of whom were African American, responded differently to asthma treatments than older African American children and African American adults in the trial (and they responded differently than white children in other studies). The research evaluated responses to what’s known as “step-up treatment,” the practice of adding additional medicines or increasing doses for uncontrolled asthma. Experts say that part of the reason this difference in response to treatment may not have been identified until now is that, historically, African Americans were underrepresented in research studies. “Most of the studies that have been done in the past that have resulted in national guidelines on how to progressively treat worsening asthma have not included minorities including black children,” says Mani Latifi, MD, a pulmonologist at Cleveland Clinic in Ohio, who was not involved in this research. “These results highlight an important point; it’s really hard to generalize the care that people of different backgrounds and ethnicities should get, specifically in asthma. What works for one person may not work for another.” RELATED: How to Tell if You’re Having an Asthma Attack
Asthma Is More Severe in African American Community
There are approximately 25 million people in the United States with asthma, which includes 19 million adults and 6.2 million children, according to the Centers for Disease Control and Prevention (CDC). The disease is more prevalent among African Americans, in both children and adults.
Only 7.7 percent of white children under 18 have asthma compared with 12.6 percent of African American children.In white adults, 8.1 percent have asthma compared with 9.2 percent of African American adults.Black children are 4 times more likely to be admitted to the hospital for asthma as compared with non-Hispanic white children, according to the U.S. Department of Health and Human Services Office of Minority Health (OMH).In 2014, African Americans were almost 3 times more likely to die from asthma related causes than the white population.
These factors were all taken into consideration when planning this research, says lead author Michael Wechsler, MD, professor of medicine at National Jewish Health in Denver. “There’s been a lot of data published on treatment strategies in the general population, but we know that there’s no ‘one size fits all’ in asthma treatment,” says Dr. Wechsler. After analyzing many of the Asthma Clinical Research Network Studies, Wechsler and his team found there were differences in response rates and treatment failures in blacks compared with whites. “For instance, blacks responded less well to beta agonists,” he says. These findings indicated that a prospective study on how African American children and adults responded to different therapies was a necessary next step, says Wechsler. RELATED: Surprising Symptoms of Asthma That’s why for this study, the researchers only included children and adults with asthma who were African American and evaluated whether or not among these populations, the asthma treatments they expected to work best actually did.
Researchers Find Different Reponses to Different Asthma Treatments
For this study, researchers conducted two randomized, double-blind trials: one involving 280 children ages 5 to 11 and the other with 294 adolescents (12 and older) and adults. In both trials, participants had to have asthma that wasn’t controlled by the use of low-dose inhaled glucocorticoids (steroids), which is the standard treatment people with asthma start on. Everyone in the study had to have had at least one grandparent who identified as black. To find out how the individuals responded to “step-up” asthma medication, participants cycled through four different treatment regimens: doubling the dose of the inhaled steroid, quintupling the dose of the inhaled steroid, adding a long-acting beta agonist (LABA) to an inhaled steroid, or doubling the inhaled steroid dose in addition to adding the LABA. Everyone in each trial was on each treatment regimen for 14 weeks, during which time the patients’ asthma symptoms were measured. The researchers measured response to each treatment regimen based on a composite score that incorporated measures of how many days the asthma was controlled, how frequently the study participants’ asthma symptoms flared up while on the treatments, and how participants performed on a breathing test. The data showed:
More African American adults and adolescents ages 12 and up responded better to adding the LABA therapy to the doubled inhaled steroid dose (49 percent) versus increasing steroids alone (28 percent). This response was similar to what’s been seen in previous clinical trials with primarily white subjects — which is somewhat surprising because other studies have suggested other differences in asthma treatment responses for African American adults compared with white adults, according to the authors.
In the younger African American children, there was a split between which treatment regimen worked best: 46 percent had a superior response to a quintupled dose of inhaled corticosteroids and 46 percent of the children had a superior response by doubling the steroid and adding a LABA. This finding was surprising, as data from previous studies would suggest most of the children would respond best to increasing the steroid dose alone, the study authors noted.
Although the study also included assessments to look at biomarkers, patient characteristics, and variation in ancestry to see if any of those factors influenced the findings, the researchers didn’t find a connection between superior response to specific treatments based on the participant’s ancestry or baseline biomarkers. In previous research, however, African ancestry has been associated with asthma related phenotypes, such as low lung function and exacerbations, according to authors. The next steps of this research will be to evaluate the genetic component in a bit more detail, says Wechsler. “We’re going to do more genetic analysis on the population we studied to see if there are, in fact, differences in response rate based on other genetic profiles — not just based on ancestry,” he says. “We need to do larger studies in the black population,” Wechsler says. “I think one thing these results tell us is that you can’t extrapolate results from large clinical trials to entire other populations that may be different, whether that’s based on race or other factors,” he says. The more diverse the research, the more researchers will be able to slice and dice data going ahead to identify who responds best to what treatments, so that doctors and clinicians can better tailor treatments to individuals’ needs, Wechsler says. But to do that type of granular analysis, better genetic markers and other biomarkers need to be part of the research, he adds. “We’re in an era where we want to achieve personalized medicine for our patients. People want to know what therapy is going to be best for them specifically,” says Wechsler. Even if there are clinical trials that say one drug is better than another for an entire population, it doesn’t mean that is true for each individual, he says.
