'Researchers need to answer questions related to whether or not sleep-related disparities would exist if racial groups historically lived in similar physical and social environments,' Jackson said. (Photo courtesy of Steve McCaw)

Blacks and whites living in government-assisted rental housing, also known as public housing, showed no differences in sleep duration, according to a study by NIEHS scientists and their collaborator from Harvard University.

The team also reported that black-white disparities in cardiometabolic illnesses, such as obesity and diabetes, were fewer among residents of public housing than among renters who received no housing assistance. The team used a nationally-representative sample of individuals.

Previous studies of racial disparities in sleep and cardiometabolic health have not included the possible influences of the living environment. The new study, published online Aug. 29 in Sleep Health: Journal of the National Sleep Foundation, suggests that where one lives may be responsible for the disparities.

'Many studies have found that blacks have a higher prevalence of both poor sleep and cardiometabolic diseases compared with whites,' said Chandra Jackson, Ph.D., senior author of the paper and head of the NIEHS Social and Environmental Determinants of Health Equity Group. 'We wanted to know if these disparities remained when blacks and whites lived in comparable conditions. In this study, the groups with fewer health differences lived in public housing.'

The study showed no differences in sleep duration between black and white government-assisted renters, and fewer differences in cardiometabolic health.

Assisted and unassisted renters

Members of the research team pooled the cross-sectional data of 80,880 black and white adults from the 2004-2016 National Health Interview Survey.

Participants in the survey shared information about their housing, sleep patterns, and overall health. Survey questions also addressed aspects of sleep and cardiometabolic health, such as the following.

• Getting less than seven hours of sleep or more than nine hours each day.
• Having trouble falling or staying asleep three or more nights per week.
• Experiencing ailments associated with poor cardiometabolic health, such as obesity, high blood pressure, diabetes, heart disease, or stroke.

The scientists considered whether participants’ rental housing was government-assisted or unassisted. For those in unassisted housing, the researchers found that, compared with whites, blacks got fewer hours of sleep and had more instances of cardiometabolic disease.

By contrast, there were no differences in sleep duration between black and white government-assisted renters and fewer differences in cardiometabolic health. For example, among government-assisted renters, blacks and whites were more alike in their likelihood of being overweight and obese than were blacks and whites in unassisted housing.

The data supported the hypothesis by Jackson and her team that they would see no or fewer disparities between blacks and whites living in government-assisted housing compared with blacks and whites in unassisted rental housing.

Other factors involved

Gaston said the team is planning follow-up studies that will examine the impact of factors in the physical environment on sleep and cardiometabolic health. (Photo courtesy of Steve McCaw)

There might be several reasons why sleep and cardiometabolic health disparities differed between unassisted and government-assisted renters, according to the study’s lead author, Symielle Gaston, Ph.D., an NIEHS postdoctoral fellow working with Jackson.

On average, blacks with lower incomes and less wealth, especially those who did not receive housing assistance, were more likely to live in worse housing conditions than whites without housing assistance. Psychosocial stressors, such as lack of safety, might also lead to insufficient sleep.

'These factors could lead to shorter and poorer quality sleep, which affects blood pressure and insulin sensitivity,' said Gaston. 'These preventable health conditions can lead to cardiometabolic diseases over time.'

Jackson said few studies have explored whether disparities persist when racial groups live in similar environments, because widespread racial residential segregation makes it difficult to find truly integrated communities. Survey residents living in government-assisted public housing provided the mix of people she and her colleagues needed.

Citation: Gaston SA, Jackson II WB, Williams DR, Jackson CL. 2018. Sleep and cardiometabolic health by government-assisted rental housing status among black and white men and women in the United States. Sleep Health; doi:10.1016/j.sleh.2018.07.010 [Online 29 August 2018].