Dr. Jacob A. Udell of Brigham and Women's Hospital, Harvard Medical School in Boston, and colleagues examined whether living alone was associated with increased mortality and cardiovascular risk in a global study involving 44,573 people -- 19 percent of whom lived alone.
The study, published in Online First by Archives of Internal Medicine, found those living alone were associated with higher four-year mortality of 14.1 percent versus an 11.1 percent rate for those living with someone.
The study found heart patients ages 45-65 who lived alone were associated with a 7.7 percent higher risk of death versus a rate of 5.7 percent when they lived with others.
Those ages 66-80 who lived alone also had an increased risk of death, but there was not an increased risk of death for those age 80 and older who lived alone.
"Younger individuals who live alone may have a less favorable course than all but the most elderly individuals following development of cardiovascular disease, and this observation warrants confirmation in further studies," the study authors said in a statement.