Association of social isolation, loneliness and risk of cardiovascular diseases: Meta-analysis of cohort studies

Abstract Background The association between social isolation, loneliness and risk of cardiovascular diseases (CVD) is not fully understood. This meta-analysis aims to explore social isolation and loneliness whether increases the risk of CVD. Methods Data sources was PubMed and Embase from inception to 10 February 2025. The risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS). Hazard ratios (HR) with 95% confidence intervals (CI) were pooled using a random-effect model, and publication bias was assessed with funnel plots and Egger’s test. Results This meta-analysis included six cohort studies with a total of 5,253,128 participants, spanning a follow-up period of 4 to 11.3 years from publications between 1996 and 2022. All studies were of high quality (NOS score ≥ 7). The pooled analysis revealed a heightened risk of CVD among individuals experiencing social isolation or loneliness (HR = 1.17, 95% CI 1.10–1.25, I 2 = 85.1%, P < 0.001). Subgroup analysis indicated that patients with a history of social isolation had a slightly higher risk of CVD compared to those with loneliness HR = 1.39, 95% CI 1.15–1.68, I 2 = 90.2%, P = 0.001. Additionally, the risk of CVD was slightly elevated during the 4–7 year follow-up compared to 7–9 years and 10–11 years HR = 1.87, 95% CI 1.67–2.10, I 2 = 0%, P < 0.001. Those with a history of social isolation or loneliness had the highest risk of stroke HR = 1.23, 95% CI 1.07–1.43, I 2 = 74.5%, P = 0.004. Furthermore, Asian populations exhibited a slightly higher risk of CVD compared to North American and European populations HR = 1.46, 95% CI 1.12–1.91, I 2 = 0%, P = 0.005. Conclusions The increased risk of CVD among social isolation or loneliness individuals underscore the importance of prioritizing their care in clinical practice and nursing. However, the high heterogeneity in meta-analysis suggests the need for further studies to validate and explore this association thoroughly.