Even though conventional risk factors largely explain the links observed between loneliness or social isolation and cardiovascular diseases, having few social contacts remains an independent risk factor for death among those with pre-existing cardiovascular disease. This finding is presented in the largest study of its kind published online in the journal Heart.
The research was led by Professor Marko Elovainio from the University of Helsinki and drew on data from nearly 480,000 people aged between 40 and 69, who were all part of the UK Biobank study.
Previous research has increasingly highlighted links between loneliness and social isolation with cardiovascular disease. However, most of these studies have been small, with few other potentially influential factors considered, say the authors.
In this study, the participants were tracked for an average of seven years. They also provided detailed information on their educational attainment, household income, lifestyle, and depressive symptoms, and were asked a series of questions to gauge their levels of social isolation and loneliness.
Nearly 10% of respondents were deemed to be socially isolated, and 6% lonely. Both of these groups were more likely to have underlying long-term conditions and to be smokers. Those who were lonely reported more depressive symptoms.
Social isolation was associated with approximately 40% higher risk of first time heart attack or stroke when age, sex, and ethnicity were factored in. When behavioural, psychological, health, and socioeconomic factors were taken into account, these factors accounted for most of the increased risk, and the initial association was no longer significant.
Similar results were observed for loneliness and risk of first time heart attack or stroke.
However, for those with existing cardiovascular disease, social isolation was associated with increased risk of death when the other known factors were considered.
– This is an observational study so no firm conclusions can be drawn about cause and effect, say the authors of the study Elovainio and Christian Hakulinen.
– However, the size and representative nature of the study prompt us to conclude that the findings indicate that social isolation, similarly to other risk factors such as depression, can be regarded as risk factor for poor prognosis of individuals with cardiovascular disease.
Social isolation and loneliness as risk factors for myocardial infarction, stroke, and mortality: UK Biobank cohort study of 479 054 men and women. DOI: 10.1136/heartjnl-2017-312663
Christian Hakulinen, University of Helsinki
tel. +358 50 4482041
Marko Elovainio, University of Helsinki & National Institute of Health and Welfare
tel. +358 50 3020621