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Long-term loneliness increases risk of stroke by half

A longitudinal study in the US has found that older people who have felt lonely for a long time have a greatly increased risk of stroke

27th June 2024 about a 3 minute read
“Especially when experienced chronically, our study suggests loneliness may play an important role in stroke incidence, which is already one of the leading causes of long-term disability and mortality worldwide.” Dr Yenee Soh, research associate, Harvard University

Long-term loneliness can increase the risk of having a stroke by more than half, according to a new study by Harvard University.

Middle-aged people who reported feeling lonely were significantly more likely to have a stroke over the next decade, while those who had experienced loneliness for several years were at greatest risk, the study, published in eClinicalMedicine, found.

The researchers created a loneliness score using data from questionnaires in the Health and Retirement study, involving more than 12,000 Americans, aged 50 and above, between 2006 and 2008.

Four years later, they asked the same questions to the 8,936 people who remained in the study. The participants were ranked as either “consistently low”, “remitting” if they were previously, but no longer, lonely, “recent onset” if they scored low at the start, and “high” or “consistently high” if lonely at both intervals.

During a follow up in 2018, there had been a total of 1,237 strokes among all the people questioned, falling to 601 among those who provided two assessments.

After controlling for factors such as social isolation and depressive symptoms, researchers found that those who were lonely at the start of the study had a 25% higher risk of stroke than those not considered lonely.

The risk was greatest among those who scored consistently high – they were 56% more likely to have had a stroke than those who consistently had a low score. “Chronic loneliness was associated with higher stroke risk independent of depressive symptoms or social isolation,” the authors write. “Addressing loneliness may have an important role in stroke prevention, and repeated assessments of loneliness over time may help identify those particularly at risk.”

Stroke is a leading cause of mortality worldwide

While previous work has linked loneliness to higher risk of cardiovascular diseases, researchers said this is one of the first studies to examine links specific to stroke over time. One previous study had demonstrated baseline loneliness with higher stroke incidence in the UK, the authors write, adding: “Other studies have examined social isolation and loneliness combined, or on cardiovascular diseases, but not specific loneliness–stroke associations. Moreover, loneliness can be transient or chronic, and empirical studies of changes in loneliness are needed to better understand whether interventions for loneliness may be beneficial for stroke prevention.”

The authors also note that stroke is one of the leading causes of long-term disability and mortality worldwide, and that although stroke mortality rates have declined globally over recent decades, rates of decline for stroke incidence has slowed and the global burden of stroke remains high.

Dr Yenee Soh, a research associate at Harvard and lead author on the study, said: “Loneliness is increasingly considered a major public health issue. Our findings further highlight why that is.

“Especially when experienced chronically, our study suggests loneliness may play an important role in stroke incidence, which is already one of the leading causes of long-term disability and mortality worldwide.”

Soh said that 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.

She added: “Repeat assessments of loneliness may help identify those who are chronically lonely and are therefore at a higher risk for stroke.

“If we fail to address their feelings of loneliness, on a micro and macro scale, there could be profound health consequences.”

In older adults, loneliness is associated with a 50% increased risk of developing dementia and a 30% increased risk of incident coronary artery disease or stroke.

FCC Insight

This is a robust study tracking thousands of older people over a period of several years. It provides strong evidence, after controlling for other factors, that there is a link between loneliness and the risk of stroke. It adds to a body of research demonstrating the connection between mental and physical health. As a society we need to think about ways we can address loneliness, both as a way to improve people’s mental wellbeing but also to tackle the cost burden stroke imposes on the NHS and social care.