Objective sleep quality in diverse older adults: a cross-sectional study on the importance of race and ethnicity and sex.

Background: Research on sleep disparities across different sociodemographic groups is limited and often yields inconsistent findings. We aimed to examine differences in objective sleep measures by race and ethnicity, sex, and age within a diverse cohort of community-dwelling older adults.

Methods: We analyzed cross-sectional data from 838 participants aged ≥ 50 years in the Dormir Study (2020-2024). Sleep metrics, including sleep duration, sleep efficiency, wake after sleep onset (WASO), and sleep fragmentation index (SFI), were derived from a minimum of four nights of wrist actigraphy (mean = 6.1 ± 0.7 nights). Race and ethnicity (Black; Mexican American (MA); Non-Hispanic White (NHW)), sex, and age (< 65; ≥ 65 years) were self-reported. We compared sleep metrics across sociodemographic groups and assessed their multivariable associations using linear, logistic, and multinomial regression models.

Results: We studied 190 (22.7%) Black, 282 (33.6%) MA, and 366 (43.7%) NHW Dormir participants, with a mean age of 66.7 ± 8.4 years, and 64.8% women. Compared to NHW participants, Black and MA participants had shorter mean sleep duration (Black: 7.1 ± 1.2 h; MA: 7.1 ± 1.1 h; NHW: 7.5 ± 1.1 h; p < 0.0001), lower median sleep efficiency (Black: 87.2%; MA: 87.8%; NHW: 90.6%; p < 0.0001), longer median WASO (Black: 61.2 min; MA: 56.7 min; NHW: 44.4 min; p < 0.0001), and higher mean SFI (Black: 32.0 ± 11.0%; MA: 27.3 ± 9.7%; NHW: 24.0 ± 9.0%; p < 0.0001). Compared to men, women had longer mean sleep duration (women: 7.4 ± 1.1 h; men: 7.1 ± 1.2 h; p = 0.0004) and lower mean SFI (women: 25.9 ± 8.8%; men: 28.9 ± 12.1%; p = 0.0001). Older participants had longer mean sleep duration (old: 7.4 ± 1.1 h; young: 7.1 ± 1.1 h; p < 0.0001), higher median sleep efficiency (old: 89.8%; young: 87.7%; p < 0.0001), shorter median WASO (old: 48.5 min; young: 56.8 min; p < 0.0001), and lower mean SFI (old: 26.1 ± 10.2%; young: 28.1 ± 10.2%; p = 0.007). After adjusting for socioeconomic and behavioral factors, comorbidities, and sleep medications, findings were consistent except for age group comparisons in which differences were no longer significant.

Conclusions: Our findings demonstrate significant variations in objective sleep measures across sociodemographic groups, with non-White participants and men experiencing poorer sleep quality. These disparities may contribute to health inequalities, emphasizing the need for targeted interventions to support at-risk populations.