High prevalence of the metabolic syndrome in patients with systemic lupus erythematosus: association with disease characteristics and cardiovascular risk factors

Background: The metabolic syndrome is an independent risk factor for ischaemic heart disease. Patients with systemic lupus erythematosus (SLE) have accelerated atherosclerosis; however, there are no controlled studies of the metabolic syndrome in patients with SLE. Objective: To compare the prevalence of the metabolic syndrome in patients with SLE and controls and to evaluate its relationship to other cardiovascular risk factors and inflammation. Methods: 102 patients with SLE and 101 controls were studied. The prevalence of the metabolic syndrome was compared in patients and controls using the National Cholesterol Education Program Adult Treatment Panel III (NCEP) and the World Health Organization (WHO) definitions, and associations with cardiovascular risk factors and lupus characteristics were examined. Results: The metabolic syndrome was present in 32.4% of patients and in 10.9% of controls subjects (p < 0.001) using the WHO definition that requires direct determination of insulin resistance, and in 29.4% of patients with SLE and in 19.8% of controls (p = 0.14) using the NCEP definition. Among patients with SLE, both definitions were significantly associated with higher concentrations of C reactive protein (p = 0.001) and the NCEP definition was significantly associated with higher concentrations of homocysteine (p < 0.001), lipoprotein (a) (p = 0.02) and cholesterol (p = 0.04). Neither lupus disease activity nor damage scores were associated with the metabolic syndrome. Conclusions: Patients with SLE have a higher prevalence of insulin resistance and consequently of the WHO-defined metabolic syndrome than controls. In patients with SLE, the metabolic syndrome was associated with higher levels of inflammation and may provide a link between inflammation and increased cardiovascular risk.