Prevalence of Metabolic Syndrome in Iran: An Umbrella Review Across Diagnostic Criteria and Population Subgroups

Mojtaba Sepandi, Maryam Taghdir, Yousef Alimohamadi Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, IranCorrespondence: Yousef Alimohamadi, Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran, Email [email protected]: Metabolic Syndrome (MetS) is a significant public health concern globally, driven by factors like obesity and sedentary lifestyles. In Iran, numerous meta-analyses have estimated its prevalence, but results vary. This umbrella review aims to synthesize these findings to provide a definitive summary of MetS prevalence across both general and high-risk populations in Iran.Methods: We systematically searched international (PubMed/Medline, Scopus, Web of Science) and Persian databases (SID, Magiran) for meta-analyses published between January 2014 and August 2025 reporting pooled MetS prevalence in Iranian populations. Data extraction covered overall prevalence, subgroup analyses (gender, diagnostic criteria, population risk strata), and study characteristics. Methodological quality was assessed using AMSTAR 2, and evidence quality was evaluated using GRADE framework. Meta-analysis of pooled estimates was performed using random-effects models.Results: Nineteen meta-analyses comprising 119 prevalence estimates and 1,954,049 participants were included. The overall pooled prevalence of MetS in Iran was 30.4% (95% CI: 28.44– 32.33). Prevalence was higher in females (33.05%) than in males (27.57%). The prevalence varied by diagnostic criteria, with the Joint Interim Statement (JIS) criteria yielding the highest estimate (36.47%), followed by the International Diabetes Federation (IDF) criteria (32.03%), and the NCEP-ATP III criteria (26.86%). High heterogeneity (I2 > 99%) was observed. The methodological quality of included studies was predominantly moderate, and the GRADE evidence quality for most outcomes was moderate.Conclusion: Approximately one in three Iranian adults is affected by MetS, with disproportionately higher burden among women and specific high-risk populations. The choice of diagnostic criteria significantly influences prevalence estimates, and considerable heterogeneity across studies highlights the context-dependent nature of these findings. These results underscore the urgent need for targeted public health interventions and systematic screening strategies tailored to different population risk profiles.Registration Information: The study protocol was registered in the Prospero with ID, CRD420251182425.Keywords: metabolic syndrome, Iran, meta-analysis, umbrella review, prevalence