Blacks, especially those with professional jobs, are less likely than whites to get more than seven hours of sleep a night, according to a new Harvard School of Public Health study.

The finding is especially troubling for blacks, who already have more high blood pressure, obesity and diabetes — factors also linked to a lack of sleep.

Study researchers used results from interviews of 137,000 U.S. adults, surveyed from 2004 to 2011 about their health, lifestyles, jobs and socioeconomic status. After adjusting for age, demographics, smoking and alcohol consumption, physical activity, medical conditions and socioeconomic status, they found that 37 percent of black respondents slept less than seven hours a night compared to 28 percent of whites.

The study appears online Sept. 9, 2013 in the American Journal of Epidemiology.

For more information: