Sleep apnea found to be prevalent, undiagnosed in African-American community

Sleep apnea is a common sleep disorder that is associated with an increased prevalence of cardiovascular disease, hypertension, diabetes and other chronic health disorders. About 80 to 90 percent of individuals with sleep apnea are undiagnosed and a large number of them are African-Americans.

A new study by investigators at Brigham and Women's Hospital determined the prevalence of sleep apnea among 852 African-American men and women living in Jackson, Miss., and participating in the Jackson Heart Sleep Study. Researchers explored sleep apnea predictors and estimated the proportion of undiagnosed cases. They found a high prevalence of sleep apnea among this large sample of African-American men and women, and the majority—95 percent—were undiagnosed and untreated. Results are published on Sept. 5 in the journal Sleep.

"We discovered that only 5 percent of individuals with moderate or severe sleep apnea had been diagnosed. In other words, over 95 percent of this sample experience nightly stresses associated with periods when breathing stops and oxygen levels fall. Untreated sleep apnea can increase risk for hypertension-related diseases such as stroke, a condition disproportionately common in African-Americans," said Dayna A. Johnson, Ph.D, associate epidemiologist in the Division of Sleep and Circadian Disorders at Brigham and Women's Hospital and lead author of the study. "We also learned that asking about habitual snoring and measuring neck size (a risk factor for sleep apnea) can help identify individuals at risk."

Researchers found that among 852 adults in the study, 24 percent had moderate or severe sleep apnea, but only 5 percent had been diagnosed by a doctor. Men had a 12-15 percent higher prevalence of the disorder compared to women. Habitual snoring, higher body mass index and larger neck size were important markers of sleep apnea. The average age of the study sample was 63 years old—66 percent of participants were female and 53.8 percent college-educated. This is the first-known study of its size to conduct objective testing for sleep apnea and administer validated questionnaires in a sample of African-Americans.

"There is a large burden of untreated sleep apnea in the population. Our results point to the opportunity to improve sleep apnea screening and diagnosis in the population as a means for reducing health disparities," said Susan Redline, MD, MPH, senior physician in the Division of Sleep and Circadian Disorders at BWH and senior author of the study.

"These findings in the Jackson Heart Study reveal that sleep apnea is underdiagnosed and a potential threat to the health and safety of African-Americans," said Michael Twery, Ph.D., director of the National Center on Sleep Disorders Research at NHLBI, part of the National Institutes of Health. "Further studies are needed to develop the tools and systems required to facilitate diagnosis and treatment of sleep apnea in African-Americans and other communities."