Researchers have long known that differences exist between African-Americans and European-Americans when it comes to diseases like stroke, diabetes and hypertension. But the reasons why are unclear. A new study suggests that differing sleep patterns — and specifically, poor sleep patterns among African-Americans — may be in part to blame. The new study is published in the Proceedings of the National Academy of Sciences.
African-Americans experience higher rates of cardiovascular and metabolic disease than European-Americans, even when controlling for other factors such as health behaviors. To find what role sleep might play in driving these racial differences, researchers including Northwestern University’s Mercedes Carnethon assessed total sleep time and sleep efficiency — the percent of time spent in bed actually asleep — among more than 400 African-American and European-American adults. Each person’s cardiometabolic risk was calculated from biomarkers like blood pressure, weight circumference and insulin resistance. Researchers found African-Americans slept an average 40 minutes less each night than European-Americans (341 minutes vs. 381 minutes) and had 10 percent less sleep efficiency.
Said Carnethon: “This study is one of the first to examine how disparities in sleep are contributing to differences in metabolic diseases…. What we hope is that as patients and healthcare providers become aware of these associations, they will prioritize considering sleep as an essential component of a healthy lifestyle.”
Carnethon and team speculated that greater social stress, including socioeconomic conditions and experiences of discrimination, may account for the sleep differences. They conclud that more than half the racial disparities in cardiometabolic risk may be explained by these sleep differences between the two groups.