Loneliness linked to higher risk of stroke
Stroke is one of the leading causes of long-term disability and mortality worldwide. Although stroke mortality rates have declined globally over recent decades, rates of decline for stroke incidence have slowed and the global burden of stroke remains high. Social isolation and loneliness are associated with about 30% increased risk of heart attack or stroke, or death from either, according to the American Heart Association. Risk of social isolation increases with age due to life factors, such as widowhood and retirement. Nearly one quarter of U.S. adults ages 65 and older are socially isolated, and prevalence of loneliness is even higher, with estimates of 22% to 47%. People who feel chronically lonely over long periods of time are at higher risk, finds first such study of its kind. Loneliness may increase the risk of stroke by as much as 56% that experts say explains why the issue poses a major health threat worldwide.
The World Health Organization (WHO) has said loneliness is among the most significant global health concerns, affecting every facet of health, wellbeing and development. The U.S. Surgeon General has warned that its mortality effects are equivalent to smoking 15 cigarettes a day.
While previous study has linked loneliness to a higher risk of developing cardiovascular diseases, few have examined the impact on stroke risk specifically. The study, led by Harvard University, is first of its kind to examine the association between loneliness changes and stroke risk over time. These researchers found that adults 50 and above who experienced chronic loneliness had a 56% higher risk of stroke than those who consistently reported not being lonely. Those who experienced situational loneliness but did not suffer long term did not have a higher risk of stroke, suggesting the impact of loneliness on stroke occurs over many years. Loneliness is increasingly considered a major public health issue. Especially, when experienced chronically, loneliness may play an important role in stroke incidence, which is already one of the leading causes of long-term disability and mortality worldwide.
The study used data from 2006 to 2018. More than 12,000 people aged 50 and above who had never had a stroke were asked questions about loneliness between 2006 and 2008. Four years later, about 9,000 people who remained in the study responded to the same questions and researchers then grouped them depending on their answers across the two time points. The groups were “consistently low” (those who scored low on the loneliness (those who scored high at first and low at follow-up); “recent onset” (those who scored low at first and high at follow-up); and “consistently high” (those who scored high at both baseline and follow-up).
After controlling both factors such as social isolation and depressive symptoms, which are closely related to loneliness but distinct, it was found people considered lonely at the start of the study had a 25% higher risk of stroke than those not considered lonely. But among those who scored “consistently high” for loneliness at both time points, there was a 56% higher risk of stroke than those in the “consistently low” group.
Chronic loneliness was associated with higher stroke risk independent of depressive symptoms or social isolation. Addressing loneliness may have an important role in stroke prevention, and repeated assessments of loneliness over time may help identify those particularly at risk. People should be offered help based on their loneliness – which relates to how people feel even if surrounded by others – and not social isolation, which is different.