How well you sleep may depend on race

[summer]

NYT:

Moleendo Stewart can’t say for sure what’s caused his lifelong sleeping problems. But he has his suspicions.

There’s the childhood spent in loud, restless neighborhoods in Miami. “You hear people shooting guns all night, dealing drugs,” said Mr. Stewart, 41, who lives in the East Flatbush section of Brooklyn. He also cites his weight, 260 pounds, down from a peak of 310.

Sleep experts would point to another factor working against Mr. Stewart: He is a black man.

The idea that race or ethnicity might help determine how well people sleep is relatively new among sleep researchers. But in the few short years that epidemiologists, demographers and psychologists have been studying the link, they have repeatedly come to the same conclusion: In the United States, at least, sleep is not colorblind.

Non-Hispanic whites get more and better-quality sleep than people of other races, studies repeatedly show. Blacks are the most likely to get shorter, more restless sleep.

What researchers don’t yet know is why.

“We’re not at a point where we can say for certain is it nature versus nurture, is it race or is it socioeconomics,” said Dr. Michael A. Grandner, a research associate with the Center for Sleep and Neurobiology at the University of Pennsylvania. But when it comes to sleep, “there is a unique factor of race we’re still trying to understand.”

Whatever the cause, doctors say that unlocking the secret to racial sleep disparities could yield insights into why people in some minority groups experience higher rates of high blood pressure, obesity and diabetes. Helping poor or immigrant populations to get more solid sleep, they say, could also help break the cycle of poverty and disadvantage.

“When people aren’t sleeping as well during the night, they aren’t as productive during the day, and they’re not as healthy,” said Dr. Mercedes R. Carnethon, associate professor of preventive medicine at Northwestern University Feinberg School of Medicine. “It’s a self-perpetuating cycle.”

The latest evidence that race and ethnicity can affect sleep came in June at the annual meeting of the Associated Professional Sleep Societies, held in Boston. In one of two studies on the topic presented there, white participants from the Chicago area were found to get an average of 7.4 hours of sleep per night; Hispanics and Asians averaged 6.9 hours and blacks 6.8 hours. Sleep quality — defined as ease in falling asleep and length of uninterrupted sleep — was also higher for whites than for blacks.

While those findings are consistent with earlier studies, this one, led by Dr. Carnethon, adjusted for risk factors like cardiovascular disease, sleep apnea and obesity. Even so, blacks and members of other minorities, who are statistically more prone to experience such problems, still got less and more disruptive sleep than whites.

One obvious remaining culprit, says Dr. Carnethon, is socioeconomics.

Because Chicago is still a fairly segregated city, “the blacks and Hispanics in our study were generally living in neighborhoods that are closer to freeways, so you have freeway noise, there’s more business noise at night, and there’s potentially more crime, which is stressful to people,” Dr. Carnethon said. People in lower-income neighborhoods are also more likely to have multiple jobs or to work odd hours, which can interfere with sleep.

The idea that differences in work and living conditions can explain the racial sleep disparities is a popular one among sleep experts. But studies that have accounted for those factors suggest a more complex reality.

One such study from 2005 — also taking place in Chicago — measured sleep among 669 participants while adjusting for education, income and employment status. In the end, black men on average still slept 82 minutes less per night than white women, who were found to sleep the best of anyone in the study.

Of course, isolating the real-life effects of social inequality can be tricky. “There are more subtle differences” among people than income and education, said Dr. Kristen Knutson, assistant professor of medicine at the University of Chicago and an author of the study. “We had no way to control for stress, and there are social stresses an African-American man might feel that a white man with the same income and education level wouldn’t.”

Mr. Stewart, the Brooklyn resident, said he did see discrimination as playing a role in his sleep problems.

“As a black person in America, even if you succeed in terms of education, you still have to deal with the inherent inequality of society,” said Mr. Stewart, an administrator for a program that exposes students in racial minorities to careers in science and math. “I don’t blame it on the majority — that’s just simplistic. But in general it’s not a fair thing, and you stress because of that.”

link to pg 2 of article
www.nytimes.com/2012/08/21/health/how-well-you-sleep-may-hinge-on-race.html?pagewanted=2&ref=health