Risk factors for metabolic syndrome: an umbrella review of systematic reviews and meta-analyses

Metabolic syndrome (MetS) - a cluster of conditions including hypertension, dyslipidemia, insulin resistance, and central obesity - affects 20–30% of adults globally and elevates risks for type 2 diabetes mellitus and cardiovascular disease. Although extensive research has been conducted on individual risk factors, a comprehensive synthesis of existing evidence is urgently required to guide the development of targeted, multi-component prevention strategies. To identify observational studies which assessed the association between MetS development and risk factors, PubMed, Embase, Web of Science, and Cochrane Database were searched from inception to May 2025. A random or fix-effects model was utilized to estimate pooled odds ratios (ORs), relative risk (RR) and 95% confidence intervals (95% CIs). Statistical heterogeneity across included studies was quantified using the I² index, where values > 50% were considered indicative of substantial heterogeneity. The Egger’s test or funnel graph was used to assess the methodological quality. This umbrella review systematically analyzed 72 meta-analyses from 7,367 unique articles to evaluate associations between 101 factors and MetS development. 76 positively correlated factors and 25 negatively correlated factors were identified from the included studies and categorized into five distinct domains: lifestyle behaviors, pre-existing diseases, individual characteristics, environmental exposures, and occupational factors. From the selected studies, the most significantly positive correlation with MetS was overweight and obesity. Parental history of MetS, gestational diabetes mellitus, high screen time, and shift work were also exhibited high degrees of correlation with MetS. In our study, we also identified several modifiable dietary factors exhibited negative correlations with MetS. High-fiber diet consumption, regular nut intake, and adherence to a Mediterranean diet had higher association with MetS. MetS pathophysiology is multifactorial. Comprehensive evidence shows that multiple distinct factors performed significantly associations with MetS. Unhealthy dietary patterns, sedentary behavioral patterns, and adverse occupational patterns are the primary modifiable associated factors for MetS. Despite the limited quality of current supporting evidence, targeted intervention strategies for these factors should be prioritized in public health policies to mitigate MetS at the population level. This review provides comprehensive prevention suggestions for high-risk groups.