Association between peri-implant disease and metabolic syndrome: a systematic review and meta-analysis

Purpose Metabolic syndrome (MetS) is characterized by metabolic and inflammatory alterations that may adversely affect peri-implant tissue health. The aim of the present systematic review and meta-analysis was to investigate the association between metabolic syndrome and peri-implant diseases, while also considering evidence from studies evaluating major metabolic components of the syndrome, particularly type 2 diabetes mellitus and impaired glycaemic control. Methods A systematic search of PubMed, Scopus, and Web of Science was conducted up to September 2026 following the PRISMA 2020 guidelines. Observational studies investigating peri-implant diseases in participants with formally diagnosed metabolic syndrome or related metabolic exposures, including type 2 diabetes mellitus and impaired glycaemic control, were included. Methodological quality was assessed using the Newcastle–Ottawa Scale (NOS). Random-effects meta-analysis was performed to estimate pooled odds ratios (ORs). Statistical heterogeneity was evaluated using the I² statistic, and publication bias was assessed with the trim-and-fill method. The review protocol was retrospectively registered in PROSPERO (CRD420261471855). Results Ten observational studies involving 2,509 observations were included. The pooled analysis showed no statistically significant difference in peri-implant disease between metabolically exposed observations and their corresponding comparison observations (OR = 1.39; 95% CI: 0.80–2.41; P = .245), with moderate heterogeneity (I² = 50.8%; 95% CI: 0–76.1%). Trim-and-fill analysis identified five potentially missing studies; however, the adjusted estimate remained non-significant (OR = 0.84; 95% CI: 0.45–1.58), suggesting a limited influence of publication bias. Conclusions Current evidence suggests a possible association between adverse metabolic status and peri-implant disease. However, because the pooled analysis combined formally diagnosed metabolic syndrome with related metabolic exposures, particularly type 2 diabetes mellitus and impaired glycaemic control, the findings should not be interpreted as demonstrating an independent effect of metabolic syndrome.