Loneliness and social isolation as risk factors for coronary heart disease and stroke: systematic review and meta-analysis of longitudinal observational studies
- 1Department of Health Sciences, University of York, Heslington, York, UK
- 2Department of Health Sciences, University of York, Heslington, York, UK
- 3Department of Health Sciences, University of York, Heslington, York, UK
- 4Department of Public Health and Society, Whelan Building, Brownlow Hill, Liverpool, UK
- 5Institute of Health and Society/Newcastle University Institute for Ageing, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK
- Correspondence to Nicole K Valtorta, Department of Health Sciences, University of York, Heslington, York YO10 5DD, UK;
- Received 5 October 2015
- Revised 7 December 2015
- Accepted 26 December 2015
- Published Online First 18 April 2016
Background The influence of social relationships on morbidity is widely accepted, but the size of the risk to cardiovascular health is unclear.
Objective We undertook a systematic review and meta-analysis to investigate the association between loneliness or social isolation and incident coronary heart disease (CHD) and stroke.
Methods Sixteen electronic databases were systematically searched for longitudinal studies set in high-income countries and published up until May 2015. Two independent reviewers screened studies for inclusion and extracted data. We assessed quality using a component approach and pooled data for analysis using random effects models.
Results Of the 35 925 records retrieved, 23 papers met inclusion criteria for the narrative review. They reported data from 16 longitudinal datasets, for a total of 4628 CHD and 3002 stroke events recorded over follow-up periods ranging from 3 to 21 years. Reports of 11 CHD studies and 8 stroke studies provided data suitable for meta-analysis. Poor social relationships were associated with a 29% increase in risk of incident CHD (pooled relative risk: 1.29, 95% CI 1.04 to 1.59) and a 32% increase in risk of stroke (pooled relative risk: 1.32, 95% CI 1.04 to 1.68). Subgroup analyses did not identify any differences by gender.
Conclusions Our findings suggest that deficiencies in social relationships are associated with an increased risk of developing CHD and stroke. Future studies are needed to investigate whether interventions targeting loneliness and social isolation can help to prevent two of the leading causes of death and disability in high-income countries.
Study registration number CRD42014010225.
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