People with symptoms of insomnia did not have higher levels of cholesterol than people without insomnia, according to new research published in the journal SLEEP. However, patients with insomnia who took sleeping pills were 118% more likely to have high LDL cholesterol than people who took sleeping pills but did not have insomnia.

Patients and healthcare providers have wondered whether there was a link between insomnia and heart disease in part because of reports that sleep apnea is linked with cardiovascular disease, according to lead author Dr Nicholas Vozoris, a respirologist at St Michael’s Hospital (Toronto).

The study was based on the 2005-06 and 2007-08 National Health and Nutrition Examination Survey, a series of studies designed to assess the health and nutritional status of adults and children across the United States. The survey is unique in that it combines interview and laboratory data.

Among all the people in the survey over age 20, 10.7% had elevated LDL cholesterol, 16.3% had high triglycerides and 22.1% had low levels of HDL or healthy cholesterol. The chances of having abnormal cholesterol were not significantly different for the people who reported having symptoms of insomnia versus those who did not.

“The observed link between sleeping pill use and elevated LDL cholesterol is particularly concerning given the dramatic rise in the use of sedative medicine in the general population in recent years,” he said.

He said the finding may suggest that insomniacs who take sleeping pills simply have more severe insomnia and that more severe insomnia, rather than sleeping pill use, may be the reason for the high LDL cholesterol. But he said he found no evidence of higher LDL levels and other markers of insomnia severity, such as frequent insomnia, insomnia symptoms coupled with daytime fatigue and insomnia symptoms coupled with short sleep time.