Objectives To study the effect of the metabolic syndrome (MetS) on organ damage and mortality in patients with SLE.
Methods Consecutive patients who fulfilled ≥4 ACR criteria for SLE and were assessed for the presence of the MetS between 2010 and 2011 were included. Those patients who did not have MetS assessment or succumbed before 2010 were excluded. The MetS was defined by the updated joint consensus criteria, using the Asian criteria for central obesity, when ≥3 of the following components were present: (1) Increased waist circumference to ≥90cm in men or ≥80cm in women; (2) Elevated blood pressure to ≥130/85mmHg or requiring drug therapy; (3) Elevated serum triglyceride level to ≥1.7mmol/L; (4) Reduced serum high density lipoprotein (HDL)-cholesterol to ≤1.0mmol/L in men and ≤1.3mmol/L in women; and (5) Elevated fasting glucose level to ≥5.6mmol/L. Longitudinal data regarding new organ damage, vascular events and mortality on follow-up were retrieved from our cohort database. The association of the MetS with new organ damage and mortality was studied by logistic regression analyses.
Results 577 SLE patients were studied (93% women; age at entry 41.2±13.4 years; SLE duration 9.3±7.2 years). The mean follow-up time of the patients since entry was 66.3±1.8 months. The mean body mass index (BMI) of the patients was 22.3±3.9kg/m2 (11% >27kg/m2). A total of 85 (14.7%) patients qualified the MetS (28% fulfilling waist; 20% fulfilling blood pressure; 25% fulfilling triglyceride; 33% fulfilling HDL and 9.2% fulfilling glucose criteria). New organ damage and vascular (coronary, cerebrovascular and peripheral vascular) events developed in 128 (22%) and 23 (4.0%) patients, respectively. The most common new arterial events were stroke (50%), acute coronary syndrome (33%) and peripheral vascular disease (17%). Thirty-nine (6.8%) patients died (infection 36%; vascular causes 18%; cancer 15%; lung fibrosis 8%; suicide 3%). Patients with the MetS (N=85), when compared to those without (N=492), had significantly higher SDI accrual at their last clinic visits (0.70±1.0 vs 0.26±0.6; p<0.001). Regarding individual systems, the increase in SDI scores in the ocular, renal, cardiovascular, musculoskeletal and endocrine (new diabetes mellitus) systems were significantly higher in the MetS group of patients. New vascular events (11% vs 2.8%; p=0.001), all-cause mortality (14% vs 5.5%; p=0.003), death due to vascular complications (7.1% vs 0.2%; p<0.001) were significantly more common in patients with MetS than those without. Logistic regression revealed that the MetS was significantly associated with new damage in the ocular (OR 2.77 [1.05–7.34]; p=0.04, renal (OR 4.72 [1.86–12.0]; p=0.001), cardiovascular (OR 3.66 [1.03–12.9]; p=0.04] and endocrine system (OR 41.9 [4.93–357]; p=0.001), adjusted for age, sex, SLE duration and the antiphospholipid antibodies (IgG-anticardiolipin or the lupus anticoagulant). The presence of the MetS increased the risk of new vascular events (OR 2.94 [1.18–7.31]; p=0.02), all-cause mortality (OR 1.60 [0.73–3.47]; p=0.24) and vascular mortality (OR 30.3 [3.42–268]; p=0.002) after adjustment for the same covariates.
Conclusions In this 5-year longitudinal study, the MetS is significantly associated with new organ damage, vascular events and mortality in patients with SLE.
Disclosure of Interest None declared