Obstructive sleep apnea (OSA) is highly prevalent in those age 50 years and older, but manifests differently by race/ethnicity and sex, with the most rapid-eye-movement (REM) sleep respiratory events in Black women and the highest oxygen saturation (SpO2) levels in Mexican American women. These were among study findings published in the Annals of the American Thoracic Society.
Researchers conducted the Dormir Study to explore whether OSA parameters during REM and non-REM sleep differed by race/ethnicity or sex in community-dwelling adults age 50 years and older. The Dormir Study is an ancillary to the Health and Aging Brain Study–Health Disparities (HABS-HD), an ongoing multi-ethnic study of brain aging in community-based Black, Mexican American, and non-Hispanic White adults.
Dormir, conducted from 2020 to 2024, invited eligible HABS-HD participants aged 50 years and older to undergo a comprehensive sleep examination, including an overnight assessment with a wrist-mounted, type III home sleep apnea test (WatchPAT 200), 7-day actigraphy, and sleep diary completion. OSA parameters of interest included the respiratory event index (REI; based on 3% desaturations of ≥15/hour) and oxygen desaturation index (ODI; the average number of ≥4% desaturation episodes per hour) during REM and non-REM sleep; SpO2 levels; and percentage of sleep time with snoring volume greater than 40 dB.
The analysis compared participants’ demographic data, comorbidities, and sleep-related characteristics by race and ethnicity. The cohort included 821 participants (mean [SD] age, 66.6 [8.5] years; 66.1% women); of those, 176 (21.4%) had mild cognitive impairment or dementia, 363 (44.2%) were non-Hispanic White, 284 (34.6%) were Mexican American, and 174 (21.2%) were Black. OSA prevalence (REI≥5) was 87.8%, and 50.5% of all participants had moderate to severe OSA (REI≥15), with 72.7% of participants having REM-REI of at least 15 and 39.5% having NREM-REI of at least 15.
“
Given the close link between REM OSA and elevated cardiovascular disease risk, clinicians should pay more attention to this sleep apnea phenotype, especially in minoritized populations.
The overall prevalence of moderate to severe OSA was comparable in Black (54.0%), Mexican American (51.4%), and non-Hispanic White (50.5%) participants, but REM-specific indices of OSA indicated that Black and Mexican American individuals had significantly increased REM-REI and higher REM-ODI.
Compared with the general population, Mexican American individuals had increased average saturation of peripheral oxygen (SpO2) levels, Black participants had a shorter REM duration, and Black and Mexican American participants had a higher percentage of time spent with snoring volume greater than 40 dB (P <.003 for all).
Overall OSA prevalence was not significantly associated with sex, but female individuals had significantly greater REM sleep duration vs male participants. Black female individuals had the highest mean REM-REI measure, 28.0, and the highest proportion of snoring volume greater than 40 dB (18.2%). The highest average SpO2 levels were observed in Mexican American female individuals. Non-Hispanic White male participants had the lowest REM-REI (21.7) and REM-ODI (9.5).
After adjustment for age, sex, employment, body mass index, history of diabetes or heart disease, and other risk factors, Black individuals still had increased mean REM-REI values (23.4) compared with Mexican American individuals (20.8; P =0.15) and significantly increased levels compared with non-Hispanic White participants (20.4; P =0.05). After adjustment, Mexican American participants had higher average SpO2 levels (P <.0001) and a lower percentage of sleep with SpO2 less than 90% (P <.04) vs other groups.
Among several limitations, WatchPAT has not been specifically validated in racial/ethnic minority groups, and may overestimate oxygen levels in individuals with dark skin tones. Also, REM sleep was not classified with neurophysiologic evaluation, sleep was only observed for 1 night, and additional information on comorbid pulmonary disease or daily alcohol use was not obtained.
“Given the close link between REM OSA and elevated cardiovascular disease risk, clinicians should pay more attention to this sleep apnea phenotype, especially in minoritized populations,” the study authors stated.
