White people seem to sleep longer at night, have a better quality of sleep and experience less daytime sleepiness than people identified as black, Hispanic or Asian, according to a new study from Northwestern Medicine

Researchers found that black adults have the worst quality of sleep, and Asians experience the highest amount of daytime sleepiness of the four races. These racial/ethnic differences in sleep persisted, even when researchers took into account the participants’ cardiovascular disease risk (CVD) factors and education levels. In previous studies, CVD has been associated with shorter and poor quality sleep, and persons with less education and fewer financial resources often suffer the worst sleep. The link between sleep and cardiovascular risk factors, such as obesity and diabetes, varies by race and ethnic group. This study suggests race differences in sleep characteristics are not completely explained by these cardiovascular risk factors or by differences in socioeconomic resources. Sleep quality, which is impacted by indicators such as waking during the night after initially falling asleep, was more of a problem for black versus white participants. There were minimal differences in Asian or Hispanics versus whites when it comes to sleep quality. Black, Asian and Hispanic participants reported more daytime sleepiness than white participants, with Asians experiencing the highest amount of daytime sleepiness. Average length of sleep per day for whites was 7.4 hours, Asians 6.9 hours, Hispanics 6.9 hours and blacks 6.8 hours.