Poor sleep ups risk of heart disease, stroke: Study

People who sleep poorly or don’t get enough of it are a higher risk for heart disease and stroke, researchers have found.

Emory University School of Medicine researchers surveyed 525 middle-aged people on their sleep quality and sleep duration.

Acute sleep deprivation leads to an increased production of inflammatory hormones and changes in blood vessel function, but more research is needed on the physiological effects of chronic lack of sleep, said Alanna Morris.

The team assessed sleep quality using the Pittsburgh Sleep Quality Index survey, where a score over six (based on the median sleep score of the study population) is considered poor.

Individuals who reported six or fewer hours of sleep had higher levels of three inflammatory markers: fibrinogen, IL-6 and C-reactive protein.

In particular, average C-reactive protein levels were about 25% higher (2mg per litre compared to 1.6) in people who reported fewer than six hours of sleep, compared to those reporting between six and nine hours.

C-reactive protein is used extensively as a marker of inflammation and heart disease risk.

"It remains uncertain whether short sleep duration contributes directly to cardiovascular mortality, or whether it is a mediating or moderating factor," Morris said.

Previous research has shown that people who sleep between seven and eight hours per night live longest, and that especially short or especially long sleep durations bring higher mortality.

The results were presented on November 14 at the American Heart Association Scientific Sessions in Chicago.