Takeaway
Numerous DNA methylation (DNAm) markers are associated with daytime sleepiness in African-Americans, but only one marker is associated with daytime sleepiness across all race/ethnic groups.
Why this matters
Extreme daytime sleepiness is linked to increased morbidity and mortality.
The underlying environmental, biological, and genetic mechanisms behind race/ethnicity variation are not yet understood; these findings support the further investigation of health disparities.