Abstract
BACKGROUND: Metabolic syndrome (MetS), a cluster of metabolic abnormalities, has been increasingly linked to hormone-related cancers, including endometrial cancer (EC). However, the overall magnitude and consistency of this association remain unclear. We performed a meta-analysis to evaluate whether MetS is associated with an increased incidence of EC in women. METHODS: PubMed, Embase, and Web of Science were systematically searched from inception to June 8, 2025. Eligible studies were longitudinal cohort or nested case-control studies that reported the association between baseline MetS and incident EC in the general female population. Risk ratios (RRs) and 95% confidence intervals (CIs) were pooled using a random-effects model accounting for possible influence of heterogeneity. RESULTS: Nine studies involving 11 datasets and over 9.1 million women were included. MetS was associated with a significantly increased risk of EC (pooled RR = 2.00, 95% CI: 1.67–2.40, p < 0.00001; I² = 93%). The association was stronger in prospective cohort and nested case-control studies (RR = 2.30 and 2.02, respectively) than in retrospective cohort studies (RR = 1.42; p for subgroup difference < 0.001). The results were not significantly affected by menopausal status of the women, diagnostic criteria of MetS, follow-up durations, EC validation methods, or study quality scores (p-values for subgroup difference all > 0.05). CONCLUSIONS: MetS is associated with a two-fold increased risk of EC in women. These findings underscore the importance of metabolic health management in strategies for EC prevention. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13098-025-01964-6.