GREENVILLE, N.C. (AP) — Researchers at East Carolina University have found that middle-aged whites in North Carolina are dying at an unprecedented rate.

The university said in a release the study published in the North Carolina Medical Journal found a nearly 6 percent increase in the mortality of whites aged 45 to 54 from 2000 to 2013, and a 30 percent decrease in the mortality rate of midlife nonwhites.

Lead author Dr. Chris Mansfield attributed a large portion of the mortality increase to "deaths of despair," a classification that includes suicide, liver disease and drug overdose.

The midlife white death rate saw the largest increase in North Carolina's 40 most economically distressed counties.

Mansfield says the study's findings reflect national trends, but midlife white life expectancy in Canada and Europe increased during that time.