Socioeconomic status, stress, and actigraphy-derived measures of sleep among middle-aged to older African American adults.

BACKGROUND

Stress purportedly mediates the association between socioeconomic status (SES) and sleep health. However, this mediation pathway remains poorly delineated, especially among African Americans.

METHODS

Data from the Health among Older Adults Living in Detroit study included African American adults aged 50-89 years. Participants wore an actigraphy watch and completed daily diaries, including a modified 4-item Perceived Stress Scale, for five days. Measures of sleep duration (nocturnal total sleep time (TST)) and sleep quality (wake after sleep onset (WASO)) were derived from actigraphy. Participants with ≥3 valid days of actigraphy and stress data were included (n = 150). Regression was used to test the effect of SES on variability in TST and WASO. Multilevel modeling was used to test whether day-level stress mediated the effect of SES on nightly sleep measures.

RESULTS

Lower SES was associated with greater TST variability (B = -8.06, p = 0.03), WASO variability (B = -2.83, p = 0.03), and mean stress (r = -0.32, p < 0.001). No effects of SES or stress on nightly TST or nightly WASO were found. Mediation of SES by day-level stress was not supported for nightly TST (indirect Effect [95% CI] = 1.52 [-0.25, 3.23]) or nightly WASO (indirect Effect [95% CI] = 0.40 [-0.03, 1.00]).

CONCLUSIONS

No mediating effects of stress on the association between SES and sleep duration or sleep quality were found. Results suggest that SES affects within-person variability in sleep duration and sleep quality, but not night to night sleep.