Cardiac patients face a higher risk of death within a year of being discharged from the hospital if they feel lonely, according to a new study published Monday in the journal Heart.
Researchers looked at the mortality rates of 13,446 patients a year after they were discharged from a specialist heart center with coronary heart disease, abnormal heart rhythm, heart failure or valve disease over the course of a year in 2013 and 2014. The average age of the patients was 66 and 70% of them were men.
When they were discharged, the patients shared information on their physical health, psychological well-being, quality of life, and levels of anxiety and depression. They also reported on their lifestyle, whether they smoked, drank and how often they took their medication. The researchers used national data to determined if the patients lived alone. They compared it to the national registry a year later to determine what happened to the patients' cardiac health and how many died.
Lonely women were nearly three times as likely to have died from any cause as women who didn't feel lonely, while lonely men were more than twice as likely to have died from any cause.
"This builds up on evidence that loneliness is a very, very serious risk factor," said Anne Vinggaard Christensen, lead author of the study. "Now we know that loneliness is associated with so many poor health outcomes."
Regardless of the diagnosis, loneliness was associated with significantly weaker physical health, the researchers found. Patients who said they felt lonely were nearly three times as likely to be anxious and depressed and to say they had a significantly lower quality of life as those who said they didn't feel lonely.
"It's the subjective feeling that's important, not necessarily that you live alone," Vinggaard Christensen said.
Living alone wasn't associated with feeling lonely, the study found — it was actually associated with a lower risk of anxiety and depression that than for those who live with other people. Possible reasons for this include that older populations, like those included in the study, are more likely to live with another person who is sick and that social relations can be negative, Vinggaard Christensen said. Living alone, however, was associated with a higher risk of poor cardiac health among men.
The study was observational and can't provide a cause for the link between loneliness and health, but the researchers said there are several reasons for higher mortality rates that should be considered: behavioral, psychological and biological.
Behaviorally, people who feel lonely might be less physically active and not follow medical regimes, Vinggaard Christensen said.
"You feel less motivated to make healthy choices compared to if you have a social network around you," she added.
Psychologically, a social network provides general feelings of security and safety. Having people around "helps buffer the potential harmful risks of stressful life events," she said.
Biologically, people who feel lonely can show physical impacts of their loneliness, like high stress levels and lower immune functions.
Loneliness should be made a priority for public health initiatives and should be included in clinical risk assessment in cardiac patients, the researchers said.
"The health risks associated with loneliness is comparable to the health risks associated with severe obesity, which is commonly acknowledged today as a risk factor," Vinggaard Christensen said. "The problem with loneliness is we don't have a simple solution for it ... we don't have a simple golden solution on how to deal with this."