Chronic feelings of loneliness and social isolation are associated with around a 30 percent increased risk of developing heart disease or of having a stroke, according to a new analysis of the existing research.
The size of that increase is similar to that for several other recognized risk factors for heart disease and stroke, including anxiety and job-related stress, the study also points out.
“Our findings suggest that tackling loneliness and isolation may be a valuable addition to [heart disease] and stroke prevention strategies,” conclude the study’s authors.
The research was published Wednesday in the journal Heart.
Other studies have identified three main pathways through which social relationships may impact health, including heart health. Behaviorally, people who feel lonely and socially isolated are less likely to be physically active and more likely to smoke. Psychologically, they are more likely to have low self-esteem and poor coping skills. And, physiologically, they are a greater risk of having a compromised immune system and high blood pressure.
Loneliness has also been associated with a greater risk of premature death.
The aim of the current review study was to determine the strength of the association between social relationships and the incidence of heart disease or stroke — two of the developed world’s leading killers.
For the review, a team of British researchers searched 16 databases for studies that had investigated the relationship between the onset of heart disease or stroke and loneliness or social isolation. They found 23 such studies, involving more than 181,000 adults in the United States, Europe, Japan, eastern Russia and Australia. The participants were followed for periods ranging from three to 21 years.
Among the studies’ participants, 3,002 were diagnosed with a first-time stroke, and 4,628 experienced a heart-disease-related event (a heart attack, an angina attack or death).
The studies used different questionnaires to measure loneliness and social isolation, although these assessment tools elicited similar types of information from the participants: the extent of their social contacts, their perception of the availability and quality of those relationships, and how often they felt lonely. The prevalence of loneliness or social isolation ranged from 2.8 percent to 77.2 percent across all the studies.
When the data were pooled for a meta-analysis, it showed that loneliness and/or social isolation was associated with a 29 percent increased risk of developing coronary heart disease and a 32 percent increased risk of having a stroke.
Limitations and implications
As the authors of the meta-analysis stress, this was an observational study. It found only a correlation between loneliness and social isolation and an increased risk of heart disease and stroke. The findings should not be interpreted, therefore, as demonstrating that a lack of social connectedness causes disease. Other factors not measured in the study might explain the results.
One of these factors might be reverse causation, the study’s authors point out. It could be, they say, that very early, not-yet-diagnosable heart disease might interfere with social relationships in ways that lead to loneliness and social isolation.
Still, social factors shouldn’t be excluded when assessing the risk for heart disease and stroke, argue the authors of an accompany commentary.
“Given projected increases in levels of social isolation and loneliness in Europe and North America, medical science needs to squarely address the ramifications for physical health, write the commentary’s authors, psychologists Julianne Holt-Lunstad and Timothy Smith of Brigham Young University.
Physicians should ask their patients about their social networks and about their feelings of loneliness and isolation, they say. If the answers to those questions raise concerns, the physician can then refer the patient to mental health or social support services.
One of the greatest challenges will be to devise interventions that take into account the growing role that technology plays in social interaction, Holt-Lunstad and Smith add.
“With such rapid changes in the way people are interacting socially, empirical research is needed to address several important questions,” Holt-Lunstad and Smith write. “Does interacting socially via technology reduce or replace face to face social interaction and/or alter social skills?”
FMI: You can read the study and the commentary on Heart’s website.