Loneliness, Social Isolation, and Social Support and the Development of Type II Diabetes: A Systematic Review and Meta-Analysis

BACKGROUND & OBJECTIVES: Type 2 diabetes mellitus (T2DM) is a growing global health concern. Emerging evidence suggests psychosocial factors such as loneliness, social isolation, and low social support may contribute to its development, but findings remain inconsistent. This systematic review and meta-analysis synthesizes existing literature to determine whether these social factors are associated with incident T2DM risk. METHODS: A systematic search was conducted in PubMed, PsycINFO, Scopus, and Web of Science. Eligible studies assessed loneliness, social isolation, or social support and reported incident T2DM as the outcome. Three reviewers independently screened studies, extracted data, and assessed quality using the OHAT Risk of Bias tool. Meta-analyses used a random-effects model with adjusted hazard and odds ratios. Heterogeneity was assessed using the I² statistic, and publication bias was assessed using funnel plots and Egger’s test. RESULTS: Eighteen studies were included. Individuals experiencing loneliness (RR = 1.27; 95% CI: 1.21—1.34) or low workplace social support (RR = 1.18; 95% CI: 1.06—1.32) had a significantly higher risk of developing T2DM compared to those reporting no loneliness or high workplace support. Positive but non-significant associations were observed for social isolation (RR = 1.21; 95% CI: 0.98—1.49), low structural support (RR = 1.10; 95% CI: 0.98—1.23), and low functional support (RR = 1.03; 95% CI: 0.99—1.08). CONCLUSIONS: These findings emphasize the importance of social connections in metabolic health, suggesting that interventions aimed at reducing loneliness and strengthening social and workplace support may play a role in diabetes prevention efforts.