People who are socially isolated or lonely have an increased risk for myocardial infarction, stroke, and death, independent of other factors, the American Heart Association concludes in a new scientific statement.
More than 4 decades of research have “clearly demonstrated that social isolation and loneliness are both associated with adverse health outcomes,” writing group chair Crystal Wiley Cené, MD, University of California San Diego Health, said in a news release.
Dr. Crystal Wiley Cené
“Given the prevalence of social disconnectedness across the United States, the public health impact is quite significant,” Dr. Cené added.
The writing group says more research is needed to develop, implement, and test interventions to improve cardiovascular (CV) and brain health in people who are socially isolated or lonely.
The scientific statement was published online in the Journal of the American Heart Association.
Common and potentially deadly
Social isolation is defined as having infrequent in-person contact with people and loneliness is when a person feels he or she is alone or has less connection with others than desired.
It’s estimated that one-quarter of community-dwelling Americans 65 years and older are socially isolated, with even more experiencing loneliness.
The problem is not limited to older adults, however. Research suggests that younger adults also experience social isolation and loneliness, which might be attributed to more social media use and less frequent in-person activities.
Dr. Cené and colleagues reviewed observational and intervention research on social isolation published through July 2021 to examine the impact of social isolation and loneliness on CV and brain health.
The evidence is most consistent for a direct association between social isolation, loneliness, and death from coronary heart disease (CHD) and stroke, they reported.
For example, one meta-analysis of 19 studies showed that social isolation and loneliness increase the risk for CHD by 29%; most of these studies focused on acute MI and/or CHD death as the measure of CHD.
A meta-analysis of eight longitudinal observational studies showed social isolation and loneliness were associated with a 32% increased risk for stroke, after adjustment for age, sex, and socioeconomic status.
The literature also suggests social isolation and loneliness are associated with worse prognoses in adults with existing CHD or history of stroke.
One systematic review showed that socially isolated people with CHD had a two- to threefold increase in illness and death over 6 years, independent of cardiac risk factors.
Other research suggests that socially isolated adults with three or fewer social contacts per month have a 40% increased risk for recurrent stroke or MI.
There are fewer and less robust data on the association between social isolation and loneliness with heart failure (HF), dementia, and cognitive impairment, the writing group noted.
It’s also unclear whether actually being isolated (social isolation) or feeling isolated (loneliness) matters most for cardiovascular and brain health, because only a few studies have examined both in the same sample, they pointed out.
However, a study published in Neurology in June showed that older adults who reported feeling socially isolated had worse cognitive function at baseline than did those who did not report social isolation, and were 26% more likely to have dementia at follow-up, as reported by this news organization.