Original article doi:10.1093/rheumatology/kes345 Metabolic syndrome in ANCA-associated vasculitis

Objective. The metabolic syndrome (MetS) is a cluster of cardiovascular risk factors and a major cause of morbidity and mortality in the western world. Despite the fact that cardiovascular diseases are a major cause of mortality in patients with ANCA-associated vasculitis (AAV), the relationship between MetS and AAV has not yet been explored. Thus it is the aim of this study to investigate the prevalence of MetS within a cohort of patients with AAV and to assess whether MetS in AAV is associated with a pro-inflammatory state. Methods. Ninety-one patients with AAV were compared with 89 healthy controls (HCs) in a cross-sectional study. Both groups underwent anthropometric measures and laboratory tests to determine the prevalence of MetS in accordance with the National Cholesterol Education Program Adults Treatment Panel III (NCEP-ATP-III) definitions. Furthermore, the clinical course of AAV was related to the occurrence of MetS. Results. Within the AAV patient group, 39 (43%) fulfilled the NCEP-ATP-III criteria for MetS compared with 22 (25%) of the controls (P = 0.012). This difference in prevalence could not be explained by current or cumulative prednisone use in patients with AAV. Among patients with AAV, the presence of MetS was significantly associated with increased levels of CRP and neopterin. Finally, the relapse rate was higher in patients with MetS as compared with those without MetS. Conclusion. The prevalence of MetS is significantly increased in AAV. MetS is associated with a more pro-inflammatory state in AAV and might increase the risk of developing a relapse of AAV. Key words: anti-neutrophil cytoplasmic antibodies, microscopic polyangiitis, vasculitis, granulomatosis with polyangiitis, inflammation, patient attitude to health