A meta-analysis found that a third of patients with rheumatoid arthritis (RA) in a sample had metabolic syndrome, which can double the risk of cardiovascular outcomes in this population.
Metabolic syndrome (MetS) is highly prevalent in patients with rheumatoid arthritis (RA), emphasizing the importance of identifying high-risk patients to prevent cardiovascular events and mortality, according to a systematic review published in Frontiers in Medicine.
MetS refers to a set of cardiovascular risk factors such as obesity, glucose intolerance, dyslipidemia, and high blood pressure that can lead to cardiovascular disease (CVD). Also referred to as syndrome X or insulin resistance syndrome, MetS doubles the risk of CVD outcomes and increases risk of mortality by 1.5 times.
Because of the already increased risk of CVD in patients with RA, as well as the association between RA and components of MetS, the European League Against Rheumatism (EULAR) recommends immediate screening and management of CVD in those with RA and MetS.
To estimate the prevalence of MetS in individuals with RA, researchers conducted a systematic review and meta-analysis of 62 articles, including 13,644 patients with RA across 96 groups.
They found that a third of patients in the sample had MetS, with a prevalence of 32% (95% CI, 29.6-34.4).
Prevalence was slightly higher in women (34%; 95% CI, 29%-40%) than men (33%; 95% CI, 26%-39%) in women. Another meta-analysis included in this review that focused on MetS prevalence in postmenopausal women found that the highest prevalence was based on Adult Treatment Panel (ATP) III screening criteria.
MetS prevalence also slightly differed by continent, with the highest prevalence being 32.7% in studies conducted in Asia (95% CI, 29%-36.3%) and Europe (95% CI, 27.5%-37.9%), and the lowest prevalence noted in African studies at 28% (95% CI, 28.8%-32.2%).
“Given that nutritional, ethnic and sociodemographic status are the determinants of the prevalence of metabolic syndrome, the reason for this finding can be attributed to these differences in these communities,” the review authors wrote.
They noted that, in 1 study comparing MetS prevalence between Korean and American adults, the prevalence of MetS—and almost all of its components—was higher in Americans than Koreans. However, due to study design differences, the authors mentioned that further research on this finding is necessary.
Data also showed that the highest MetS prevalence was linked to ATP III criteria (37.5%; 95% CI, 30.9%-44.2%), while the lowest was related to European Group for the Study of Insulin Resistance (EGIR) criteria (14.4%; 95% CI, 10.5-18.5).
“In [World Health Organization] and EGIR criteria, the presence of hyperinsulinemia as an indicator of insulin resistance is the starting point, while in ATP III, the number of abnormalities is considered,” the authors said. “These differences have led to different prevalence being reported in a group of patients (same patients) based on different criteria, so appropriate standards should be used to diagnose MetS in different regions.”
Finally, MetS prevalence increased with age both in patients with RA and in the general population in US studies. According to the authors, this may be related to redistribution of adipose tissue, weight gain, insulin resistance, and lipid changes.
“Given that the prevalence of metabolic syndrome in patients with rheumatoid arthritis has not been studied in some countries and therefore has not been analyzed, the findings of this study should be generalized with caution worldwide,” the authors noted.
Cai W, Tang X, Pang M. Prevalence of metabolic syndrome in patients with rheumatoid arthritis: an updated systematic review and meta-analysis. Front Med. Published online April 8, 2022. doi:10.3389/fmed.2022.855141