Health-related quality of life in adults with metabolic syndrome: a multi-level analysis of family and individual level variation

Purpose The current study aimed to investigate the associations between metabolic syndrome (MetS) with health-related quality of life (HRQoL) using multilevel analysis among the Iranian adult population.Methods This cross-sectional study was conducted in the framework of the Tehran Lipid and Glucose Study (TLGS). Participants were 6113 participants (3318 women and 2795 men) aged≥20 years of the TLGS seventh phase who had completed data on HRQoL and MetS. HRQoL was assessed using the short-form 12-item health survey V.2 and MetS defined based on the guidelines outlined in the Joint Interim Statement. The two-level model was fitted to assess the association between MetS and HRQoL.Results The prevalence of MetS and its components was higher in men, and regardless of metabolic status, men exhibited higher HRQoL values. The deleterious impact of MetS on HRQoL was more pronounced in women, while the detrimental effects of MetS on men’s HRQoL were confined to specific subscales. These results were obtained through multilevel analysis, considering both familial and individual variation levels. Moreover, our investigation highlighted the positive influence of leisure-time physical activity on both the physical and mental component summaries (PCS and MCS, respectively), regardless of gender. Education had a greater positive impact on PCS in both sexes. Additionally, a history of cardiovascular diseases was associated with a decline in mental and physical HRQoL, while age was linked to a decline in PCS and MCS, and smoking was associated with a decline in MCS.Conclusion This study revealed the significant influence of gender, as well as the unique characteristics and circumstances of individuals, on the relationship between MetS and HRQoL in a general population with low/middle income.