Comparative impact of social isolation on mortality in adults aged 40 years and above with versus without metabolic syndrome: evidence from two large cohorts in the U.S. and U.K.

Compared to individuals without MetS, those with MetS have higher mortality rates. Moreover, social isolation is associated with increased mortality regardless of MetS status. It is a risk factor for all-cause mortality, CVDM, CAM, OTM, and premature mortality in both MetS and non-MetS populations. Notably, the impact of social isolation on all-cause, cardiovascular, and premature mortality is more pronounced in individuals without MetS. Public health strategies should focus on population-wide interventions to reduce social isolation, enhance social engagement, and improve overall health and longevity, rather than targeting only high-risk groups.