Abstract
BACKGROUND: Metabolic syndrome (MetS) is a cluster of cardiometabolic abnormalities linked to cardiovascular disease and type 2 diabetes mellitus. While lifestyle and sociodemographic determinants are well established, the role of social isolation in MetS is less explored. METHODS: A nationwide cross-sectional study included 117,298 Spanish workers from multiple occupational sectors (2021-2024). MetS was defined using National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III, International Diabetes Federation (IDF), and Joint Interim Statement (JIS) criteria. Sociodemographic, lifestyle, and psychosocial variables were assessed with standardized questionnaires, including the ENRICHD Social Support Instrument. Logistic regression estimated associations with MetS prevalence. RESULTS: MetS prevalence was 28.7% (NCEP ATP III), 32.1% (IDF), and 33.5% (JIS). Men had consistently higher prevalence than women (p<0.001). Prevalence rose with age, exceeding 40% in workers ≥55 years. Low socioeconomic status was linked to a higher prevalence (p<0.001). Lifestyle factors were strongly associated: physical inactivity doubled the odds of MetS (OR≈2.0); poor Mediterranean diet adherence and smoking increased risk, while regular activity and high dietary adherence were protective (all p<0.001). Low social support independently increased the odds of MetS across all definitions, even after adjustment. CONCLUSIONS: In this large cohort, MetS was highly prevalent and strongly influenced by lifestyle, sociodemographic, and psychosocial factors. Social isolation emerged as an independent determinant, underscoring the need for workplace strategies integrating lifestyle promotion with social support.