It is estimated that one in seven American adults live alone. An international study of stable outpatients who were either at risk of or suffered from arterial vascular disease, such as coronary disease or peripheral vascular disease has now discovered that individuals who live alone have a higher risk of mortality and cardiovascular mortality. The study, published Online First in JAMA's Archives of Internal Medicine reveals that social isolation may be linked to poor health outcomes.

According to the study's background information, epidemiological evidence indicates that social isolation could have various implications, such as influencing health behavior and effecting access to health care. It can also potentially change neurohormonal-mediated emotional stress, which can either be linked to or lead to the development of cardiovascular risk.

Jacob A. Udell, M.D., M.P.H., from Brigham and Women's Hospital at the Harvard Medical School in Boston and his team decided to assess whether living alone was linked to a higher risk of mortality and cardiovascular (CV) disease. They evaluated data obtained from the global REduction of Atherothrombosis for Continued Health (REACH) Registry and found that 8,594 people or 19% lived alone from a total of 44,573 REACH participants.

Their results revealed a four-year mortality rate of 14.1% in those living alone, compared with 11.1% in those who lived with others. The risk of cardiovascular disease was 8.6% for those living alone, compared to 6.8% for those who did not.

In terms of age, people between the ages from 45 to 65 years who lived alone were linked to a higher death risk (7.7%) than those who lived with others (5.7%), whilst participants between the ages of 66 to 80 years had a 13.2% higher risk, compared to a 12.3% risk respectively. The results also demonstrate that those above the age of 80 who lived alone had a lower increased risk of mortality, i.e. 24.6%, compared with those who lived with someone else (28.4%).

The researchers state:

"In conclusion, living alone was independently associated with an increased risk of mortality and CV death in an international cohort of stable middle-aged outpatients with or at risk of atherothrombosis. Younger individuals who live alone may have a less favorable course than all but the most elderly individuals following development of CV disease, and this observation warrants confirmation in further studies."