Minorities and poor people disproportionately suffer from sleep problems and chronic disease, but the two do not appear to be directly linked, according to a new study published in Ethnicity & Disease.
“Since the racial differences in many diseases mirror the racial differences we see in sleep, we checked to see if sleep causes differences in these diseases,” said lead author Rebecca S. Piccolo, Sc.M., associate director for health services and disparities research at the New England Research Institutes.
Previous research has shown that sleep problems contribute to poor health conditions, such as obesity, high blood pressure, heart disease and diabetes.
Studies have also shown that problems with insomnia — sleeping too few hours and having restless sleep — occur more often among minorities and the poor.
Sleep problems afflict 25 to 30 percent of U.S. adults, the authors note, and prompt the expenditure of hundreds of billions of dollars in direct related medical costs. In various ways, sleep restriction causes bodily changes with profound implications for obesity and obesity-related illnesses.
Hormonal changes promote excessive fat storage; they also stimulate appetite and block signals telling the brain that a person has eaten enough. Widespread though they are, sleep=related problems are also “among the most treatable health problems,” say the researchers.
The study involved 5,502 participants aged 30 to 79 years, in three racial groups: black, Hispanic and white. Each subject underwent an in-home interview regarding their health status and the quality and amount of their usual sleep. The first interview took place between 2002 and 2005 with five year follow-up interviews between 2006 and 2010.
The findings showed that black and Hispanic men were more likely than white men to report sleeping less than five hours each night. Poorer men were also likelier to report short sleep. In fact, being of a lower socioeconomic class was a stronger predictor of sleep difficulties than were ethnic differences.
The researchers also found that when participants reported having regular restless sleep during the first interview, they had a 66 percent greater chance of being obese five years later. Restless sleep was also associated with a person have a 50 percent greater risk for developing Type 2 diabetes or cardiovascular disease.
“While we found that restless sleep was more common in people with obesity, diabetes and heart disease, our data shows that the racial difference we saw in these diseases were not likely caused by these differences in sleep, ” said Piccolo.
Timothy Monk, Ph.D., professor of psychiatry and director of the human chronobiology research program at the University of Pittsburgh Medical School, said that while the research clearly shows that there are both sleep differences and health differences that occur with race and socioeconomic status,” the health differences are not simply mediated by the sleep differences.”
This means, he said, that “there are effects over and above the sleep ones contributing to the health differences observed.”
Source: Ethnicity & Disease