Association of loneliness and social isolation with excess risk of cardiovascular events in people with obesity: a prospective cohort study.

Background: Obese individuals face higher degrees of loneliness and social isolation, but evidence on the association between their levels of loneliness and social isolation and the excess risk of cardiovascular disease (CVD) is lacking. Our study aimed to explore the association between the level of loneliness and social isolation and the obesity-related excess risk of CVD events.

Methods: We included 432 767 individuals from the UK Biobank at baseline (100 947 with obesity and 331 820 without obesity). The levels of loneliness and social isolation were defined by a two-item scale and a three-item scale at baseline, respectively. We ascertained CVD events, including coronary heart disease, stroke, heart failure, and CVD mortality, through linkage to inpatient records from primary and secondary health care settings and death registries.

Results: A total of 29 767 non-obese and 14 312 obese participants developed incident CVD outcomes during a median (interquartile range (IQR)) follow-up of 12.48 (11.61, 13.22) years. The excess risk of CVD events, including CVD subtypes and CVD mortality, in obese people compared to non-obese people progressively decreased with lower baseline levels of loneliness and social isolation. Specifically, the excess risk of all CVD events decreased by 29% (for loneliness) and 15% (for social isolation). The excess risk of CVD mortality decreased by 25% (for loneliness) and 52% (for social isolation), respectively.

Conclusions: Lower baseline levels of loneliness and social isolation were associated with lower obesity-related excess risk of CVD events. Our findings call for the integration of community engagement and social support networks into existing intervention programmes to provide more effective cardiovascular care for obese individuals.