New research shows that poor sleep can increase the risk of hospitalization among heart failure patients, illuminating a new risk factor of the nation’s number one killer.

“Sleep is important for everyone and we all have to sleep to feel good,” Dr. Peter Johansson, a researcher at the University Hospital of Linköping in Sweden and first author of the new study, said in a press release. “We know that sleep problems are common among patients with heart failure.”

“But until now there was no data on whether poor sleep persists over time and how that relates to hospitalizations," he explained.

To investigate, the researchers surveyed 499 heart failure patients involved in the Outcomes and Advising Counseling in Heart failure (COACH) sample — a study on heart-related mortality and hospitalization conducted at the University Medical Center Groningen in the Netherlands. During each patient’s initial hospitalization, Johansson and colleagues gathered data on physical capacity, mental health, and sleep patterns. They then tracked the participants’ health records for a follow-up period of 12 months.

The findings, which were presented at the EuroHeartCare conference in Norway, suggest that patients who didn’t sleep well were twice as likely to be readmitted to the hospital compared to patients who didn’t report sleep problems. The elevated risk persisted after the team controlled for other physical and mental factors known to influence hospitalization rates.

A Well-Rested Heart Is a Healthy Heart

For Johansson, the results underscore the importance of an often overlooked factor of good health. “In Sweden we don't generally ask our heart failure patients about sleep and this study shows that we should,” he explained. “If patients say their sleep is poor that may be a warning signal to investigate the reasons."

Cardiovascular disease is currently the leading cause of death in the United States, killing about 600,000 people each year —or, about one-fourth of all fatalities, according to the Centers for Disease Control and Prevention (CDC). On average, deaths and illnesses associated with coronary heart disease cost the nation $109 billion annually.

“Patients who say they consistently have poor sleep should be taken seriously,” Johansson told reporters. “To help the patients, health professionals for example can look at their medications or send them to a sleep lab for a sleep apnea investigation."

Source: Johansson P, et al. Sleep, heart and mind: The cardiovascular benefits of a good night’s sleep. EuroHeartCare. 2014.