Dec. 11 (UPI) -- Untreated sleep apnea makes black people twice as likely to develop uncontrolled blood pressure, a study says.
A new study, funded largely by the National Heart, Lung and Blood Institute, or NHLBI, looked at 664 African-Americans with hypertension who had also participated in the Jackson Study, the largest study of causes of cardiovascular disease in African-Americans.The researchers found that over a quarter of them had moderate or severe sleep apnea.
"This is an example of how NHLBI funded research is making important advances to our basic understanding of cardiovascular risk and sleep health," Michael Twery, director of the National Center on Sleep Disorders Research at NHLBI, said in a news release. "This report underscores the need for studies to determine whether screening groups at high risk for sleep apnea, such as African-Americans, would facilitate early medical intervention and reduce the risk or severity of heart disease."
While the researchers found no association with mild sleep apnea and blood pressure, participants with severe sleep apnea were 3.5 times as likely to have resistant hypertension.
The researchers also noted that 48 percent of the participants had uncontrolled high blood pressure, which means it remains elevated even though they take one or two antihypertensive medications. And 14 percent of participants had resistant hypertension, or they had the condition while taking three or more medications.
Resistant hypertension carries a higher risk of heart disease and death than severe hypertension, according to the researchers.
About one in four African-Americans in the United States have moderate or severe sleep apnea, yet most go undiagnosed, according to a prior study conducted by Johnson.
"This study identifies a risk factor for hard-to-control hypertension that until now has gone underrecognized in African-Americans," said study leader Dayna Johnson, an assistant professor at Emory University and study leader.