There has been a flattening of sleep apnea–related mortality rates in the United States over the past 10 years. The exception is among Black men, for whom mortality from sleep apnea has continuously increased over the past 21 years, new research shows.
“OSA (obstructive sleep apnea) has been recognized as an important cause of medical morbidity and mortality and contributes to the development of systemic hypertension, cardiovascular disease, and abnormalities in glucose metabolism,” Yu-Che Lee, MD, University at Buffalo–Catholic Health System, Buffalo, New York, and colleagues note.
“This study provides the first systematic assessment and demonstrates remarkable demographic disparities of age-adjusted sleep apnea–related mortality in the US, with higher rates in males than females and Blacks than Whites,” they conclude.
The study was published online in Sleep Medicine.
Data on sleep apnea–related mortality were obtained from the National Center for Health Statistics and were provided by the Centers for Disease Control and Prevention for the years 1999–2019. Over that 21-year interval, sleep apnea was documented as the underlying cause of death in 17,053 decedents, including 2593 Black patients and 14,127 White patients.
The age-adjusted mortality rate attributed to sleep apnea was 2.5 per 1,000,000 population. The mortality rate was higher for men, at 3.1 per 1,000,000, than among women, 1.9 per 1,000,000 (P < .001). For both sexes, “unadjusted mortality rates were higher in groups aged ≥35 years, and the highest mortality rates were observed in groups aged 75–84,” the authors note. The rate was 11.3 per 1,000,000 for those aged 75–84 and 13.3 per 1,000,000 for those older than 85.
This was also true among Black and White patients, the authors add, although the age-adjusted mortality rate was higher among Black patients than among other racial groups, at 3.5 per 1,000,000 (P < .001). “Over the 21-year study period, the overall age-adjusted mortality rate rose from 1.2 per 1,000,000 population in 1999 to 2.8 per 1,000,000 in 2019,” Lee and colleagues note. Interestingly, while the annual percentage change in sleep apnea–related mortality rose by 10.2% (95% CI, 8.4% – 12.0%) between 1999 and 2018, no significant change was observed between 2008 and 2019.
On the other hand, when examined by race and sex, age-adjusted mortality rates increased significantly by an annual percentage change of 7.5% (95% CI, 3.3% – 11.9%) among Black women and by 8.2% (95% CI, 6.8% – 9.6%) between 1999 and 2009 in White men and by 11.5% (95% CI, 8.9% – 14.1%) in White women. “Again, these uptrends were no longer observed after that time interval,” the authors stress.
Only among Black men was there no turning point in age-adjusted mortality rates; they experienced a steady, significant, 2.7% (95% CI, 1.2% – 4.2%) annual percent increase in age-adjusted mortality rate between 1999 and 2019. The highest age-adjusted mortality rate for Black persons was recorded in Indiana, at 6.5 per 1,000,000 population; Utah recorded the highest mortality rate for White persons, at 5.7 per 1,000,000.
For both Black persons and White persons, the lowest mortality rates were in New York, at 1.2 per 1,000,000 and 1.5 per 1,000,000, respectively. Among four geographic regions analyzed, the highest age-adjusted mortality rates were in the Midwest for both sexes; Black men in the West and those in three other regional groups in the Northwest had the lowest mortality rates.
Multiple Causes of Death
Black women were more likely to have multiple causes of death, including cardiac arrest, heart failure, and hypertension. White women were more likely to die of arrhythmia, respiratory failure, pneumonia, and depression. Black men were also more likely to die of cardiac arrest, hypertension, and obesity; arrhythmias, ischemic heart disease, and chronic obstructive pulmonary disease were more common in White men.
The authors point out that continuous positive airway pressure (CPAP) is the mainstay of therapy for adults with OSA, but many studies have demonstrated decreased CPAP adherence among Black persons. For example, one report indicated that Black persons use CPAP on average 92 minutes less a day after 1 month of therapy than do White persons, for reasons that are not well understood. Asked by Medscape Medical News why Black men are so adversely affected by sleep apnea, Lee pointed out that previous studies have shown that sleep apnea is more severe in Black men when first diagnosed.
“We know that the severity of sleep apnea is a risk factor for mortality and cardiovascular outcomes,” he said, “so maybe delayed diagnosis, delayed treatment, and noncompliance with CPAP among Black men may help explain why mortality from sleep apnea among Black men has continued to increase.” Why nonadherence to CPAP is higher among Black men is also not clear. Even when access to CPAP is equal for Black patients and White patients, studies have found that rates of noncompliance to CPAP are higher among Black persons than among White patients.
“This is again a hypothesis,” Lee emphasized, “but perhaps health literacy among Blacks is lower than it is among White patients, and they may not realize that CPAP can improve health outcomes from sleep apnea,” he suggested. The use of CPAP requires a high level of self-advocacy, which might explain part of their noncompliance.
Other health behaviors and environmental factors may contribute to the tendency among Black patients to be noncompliant with CPAP. “I think this is the first study to show that there is a significant racial disparity in mortality from sleep apnea among Black males, and it should give physicians some insight into the problem; they can develop strategies or interventions to try and reduce racial disparities in outcomes from sleep apnea,” Lee said.
“So, this study is only the beginning, and we need to have more insight and strategies to improve outcomes among Black males,” he affirmed. Asked by Medscape Medical News to comment on the findings, Diego Mazzotti, PhD, assistant professor, Division of Medical Informatics, the University of Kansas Medical Center, felt that the study helps bring attention to existing health disparities related to sleep disorders.
“Some of the trends observed by the authors seem to explain the increased recognition that sleep apnea may be a risk factor for cardiovascular morbidity and mortality,” he said in an email.
Mazzotti added, “Trends in certain minority groups and certain regions in the US suggest that physicians need to recognize the impact of untreated sleep apnea on the cardiovascular health of these patients.”
Lee and Mazzotti have disclosed no relevant financial relationshps.
Sleep Med. 2022;90:204-213. Full text