Prevalence of metabolic syndrome in patients with inflammatory bowel disease: a systematic review and meta-analysis

Objectives Patients with inflammatory bowel disease (IBD) may experience comorbidities involving metabolic syndrome (MetS). However, this association remains controversial. Our objective was to estimate the prevalence of MetS in patients with IBD and assess whether MetS is more strongly associated with ulcerative colitis (UC) or Crohn's disease (CD).Design Systematic review and meta-analysis.Data sources PubMed, Cochrane Library, Web of Science, EMBASE and MEDLINE were searched from their inception to July 2022.Eligibility criteria Observational studies reporting data regarding the rate of comorbid MetS among patients with IBD and published in English.Data extraction and synthesis The Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Meta-analysis of Observational Studies in Epidemiology reporting guidelines were followed. Pooled prevalence, ORs and 95% CIs were calculated using random-effects models. The Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality checklist were used. Heterogeneity, sensitivity and stratified analyses were performed using R (V.4.2.1).Results 11 eligible studies involving 2501 patients were included. Of these studies, four reported MetS prevalence separately by IBD phenotype, and only one contained a non-IBD comparison group. Overall, the methodological quality of the included studies was moderate. The pooled prevalence of MetS in IBD was 19.4% (95% CI 15.1% to 23.8%), with a moderate heterogeneity (I2=51.8%, Cochrane Q statistic=12.4, p=0.053). Stratified analyses demonstrated that the aggregate estimate of comorbid MetS was significantly higher in UC than in CD (38.2% vs 13.6%, chi 2=4.88, p=0.03). We found a positive association between MetS and UC compared with CD (OR=2.11, 95% CI 1.19 to 3.74, p=0.01). Additionally, four studies identified that higher age was a risk factor associated with the development of MetS.Conclusions MetS is not rare in IBD, especially in UC. However, longitudinal studies are needed to further clarify the relationship between IBD and MetS.PROSPERO registration number CRD42022346340.