Global prevalence of metabolic syndrome in patients with Rheumatoid arthritis: a systematic review and meta-analysis

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that increases the risk of systemic complications, particularly metabolic syndrome (MetS). MetS, defined by central obesity, hypertension, hyperglycemia, and dyslipidemia, not only raises cardiovascular risk but also worsens the prognosis of RA. This meta-analysis aimed to estimate the global prevalence of MetS in RA patients and identify clinical factors contributing to its occurrence.

A comprehensive literature search was conducted in PubMed, Scopus, and Web of Science. Studies included in the analysis diagnosed RA and defined MetS using standardized guidelines. Pooled estimates were calculated using a random-effects model. Heterogeneity was assessed using the I² statistic. All statistical analyses were conducted using Stata. The study is registered with PROSPERO (CRD420251007337).

The overall pooled prevalence of MetS among RA patients was 30.3% (95% CI: 28.5-32.2). Country-specific analyses showed the highest prevalence in Iraq (57.3%; 95% CI: 49.7-66.4), Croatia (49.6%; 95% CI: 35.8-63.3), and Singapore (47.1%; 95% CI: 42.7-51.6), and the lowest in Congo (12.0%; 95% CI: 5.5-20.5), Algeria (14.0%; 95% CI: 10.0-18.7), and South Korea (17.2%; 95% CI: 7.3-30.1). When stratified by continent, the estimates varied noticeably. In Africa, the proportion was 25.7% (95% CI: 21.6-30.0%); in Asia, the estimate rose to 30.8% (95% CI: 27.1-34.6%); Europe recorded a similar figure at 29.8% (95% CI: 26.9-32.7%); North America had an estimate of 31.1% (95% CI: 25.5-36.9%); and South America demonstrated the highest proportion at 38.8% (95% CI: 34.4-43.3%). Meta-regression analyses identified significant associations between MetS prevalence and key clinical variables, including waist circumference (WC) (β = 0.01; P = 0.01), body mass index (BMI) (β = 0.04; P < 0.01), triglycerides (TG) (β < 0.01; P = 0.04), and fasting blood glucose (FBG) (β < 0.01; P < 0.01), with high-density lipoprotein (HDL) levels showing an inverse association (β = -0.01; P < 0.01). Among various diagnostic criteria, the highest prevalence estimates were obtained with the National Cholesterol Education Program and International Diabetes Federation (NCEP/IDF) criteria (39.2%; 95% CI: 30.6-48.1), followed by the Joint Consensus (JC) criteria (37.2%; 95% CI: 28.0-46.9) and the 2004 revision of the National Cholesterol Education Program ATP III (NCEP 2004) criteria (35.4%; 95% CI: 29.0-42.0).

The substantial prevalence of MetS among RA patients underscores the need for a proactive, integrated approach to cardiovascular risk management. Clinicians should consider routine screening for MetS components-such as central obesity, hypertension, dysglycemia, and dyslipidemia-particularly given the significant associations with WC, BMI, TG, and FBG levels.

Not applicable.