Association between social isolation, loneliness and the incidence of irritable bowel syndrome: a prospective cohort study in the UK Biobank

BACKGROUND: Social isolation and loneliness represent significant public health issues in society. Irritable bowel syndrome (IBS) severely impacts quality of life and requires early prevention. However, the relationship between social isolation, loneliness, and IBS remains uncertain. We aim to investigate the association between social isolation, loneliness, and the incidence of IBS in a large-scale population cohort. METHODS: This prospective cohort study involved 369,653 participants without IBS from the UK Biobank. The genetic risk of IBS was evaluated using polygenic risk scores. The Cox proportional hazards model was employed to analyze the relationship between social isolation, loneliness, and the risk of IBS incidence. We examined whether depression and anxiety mediate the association between social isolation, loneliness, and IBS risk. RESULTS: Among the 369,653 participants (mean age: 56.7 ± 8.1 years; 47.7% male), 7,663 individuals were diagnosed with IBS during a median 13.6 years of follow-up. After comprehensive adjustment for socioeconomic status, lifestyle factors, health status, and genetic susceptibility, the HR for IBS incidence was 1.156 (1.073, 1.245) among socially isolated participants compared to non-socially isolated participants. The HR for IBS incidence was 1.361 (1.244, 1.490) among lonely participants compared to non-lonely participants. Subgroup analysis showed that, compared to participants without social isolation, the risk of developing IBS in participants without diabetes and those with diabetes under social isolation was 1.133 times (95% CI: 1.050-1.223) and 1.655 times (95% CI: 1.214-2.257) higher, respectively, with the risk being greater in the diabetic group (P for interaction = 0.022). CONCLUSION: Social isolation and loneliness were associated with an increased risk of developing IBS, although loneliness may have a more significant effect on risk. Participants with diabetes have a higher risk of developing IBS under conditions of social isolation. Depression and anxiety mediated the association between social isolation, loneliness, and the risk of developing IBS.