Loneliness linked to more heart problems: scientific review

Loneliness can have a literal impact on the heart, according to a new scientific statement, with researchers finding that social isolation has been linked in numerous studies to a higher risk of heart attack and stroke, among other effects harmful to health.

The statement, published Thursday in the Journal of the American Heart Association, assessed all of the available scientific literature regarding social isolation in the context of cardiovascular and brain health to provide an overview of what the research indicates.

The researchers noted that, as this is a review of a large number of studies, the aim was not to prove or address a specific research question, but to summarize the scope and nature studies.

“More than four decades of research have clearly demonstrated that both social isolation and loneliness are associated with adverse health effects,” said Dr. Crystal Wiley Cené, chair of the scientific statement writing group and professor of clinical medicine at the University of California. Diego Health, said in a press release. “Given the prevalence of social disconnection in the United States, the public health impact is quite significant.”

The statement said the risk of social isolation increases as we age, with a quarter of American adults over the age of 65 reporting being isolated. The prevalence of loneliness in this cohort ranges from 22 to 47%.

But loneliness is also increasing among young adults according to other studies, the statement said, which appears to align with many reports of increased loneliness during the pandemic.

Cené clarified that social isolation and loneliness refer to measures of two different things.

“While social isolation and feeling lonely are related, they are not the same thing,” says Cené. “Individuals may lead relatively isolated lives and not feel lonely, and conversely, people with many social contacts may still experience loneliness.”

To compile the statement, researchers reviewed relevant scientific literature up to July 2021, searching four databases: PubMed, PsycInfo, Cumulative Index of Nursing and Allied Health, and Scopus.

Overall, they found that the body of research indicates that social isolation and loneliness are common determinants of cardiovascular and brain health.

Some other main points that came up consistently were that lack of social connections is associated with an increased risk of premature death, particularly in men, and that social isolation during childhood was associated with increased levels of risk factors. cardiovascular problems in adulthood.

However, it was less certain to link social isolation and loneliness to specific cardiovascular and brain outcomes.

“There is strong evidence linking social isolation and loneliness to an increased risk of poorer heart and brain health in general; however, data on the association with certain outcomes, such as heart failure , dementia and cognitive impairment, are rare,” Cené said.

The clearest associations in the literature were between social isolation/loneliness and the risk of death from heart disease and stroke.

Researchers say there was a 29% increased risk of heart attack or death from heart disease, and a 32% increased risk of stroke and death from stroke in those who had said to be isolated or solitary.

“Social isolation and loneliness are also associated with a worse prognosis in people who already have coronary heart disease or stroke,” Cené added.

For many specific outcomes, data were inconsistent.

For example, in 19 previous studies, researchers found that in 16 of them, social isolation increased the risk of incident coronary heart disease. In the other three, loneliness was associated with an increased risk.

But a recent large-scale study from 2021 found that social isolation – measured in this study by looking at whether they lived alone and how often they had contact with friends, family or participated in groups – n was not associated with incident coronary artery disease.

Another review found that patients with existing coronary heart disease were 2-3 times more likely to die during the six-month follow-up if they were socially isolated.

According to the researchers, there was little data to paint a clear picture of whether social isolation or loneliness played a role in heart failure. However, in terms of survival rates following heart failure, the researchers said the five-year survival rate was lower in people who were both socially isolated and clinically depressed compared to people without these difficulties. at a survival rate of 60% versus 79% respectively.

No studies have yet looked at the links between social isolation, loneliness and vascular dementia that researchers have been able to find.

The researchers also looked at how the body of research considered depression, which is often studied alongside social isolation and loneliness. They said most research found it to be a feedback loop, with loneliness and isolation capable of causing depression, and depression capable of exacerbating loneliness and isolation.

Although the body of research as a whole contains less specificity on certain health outcomes, the researchers say it’s clear that we should take social isolation and loneliness more seriously as a risk factor.

“Clinicians should ask patients about their frequency of social activity and whether they are satisfied with their level of interactions with friends and family,” Cene said. “They should then be prepared to refer socially isolated or lonely people — especially those with a history of heart disease or stroke — to community resources to help them connect with others.”

She noted that we don’t know if there is a measurable difference in clinical outcomes between those who are truly socially isolated – as in being physically alone with little connection to others by phone or internet – and those who perceive themselves to be socially isolated.

“Further research is needed to examine the associations between social isolation, loneliness, coronary heart disease, stroke, dementia, and cognitive impairment, and to better understand the mechanisms by which social isolation and loneliness influence cardiovascular and brain health outcomes,” she said.