Systemic lupus erythematosus: an independent risk factor for endothelial dysfunction in women

Systemic lupus erythematosus (SLE) patients have a significantly increased risk of coronary heart disease (CHD) that is not fully explained by classic risk factors. Endothelial dysfunction is an early stage in the process of atherogenesis. Our aim was to determine whether endothelial dysfunction occurs in SLE and whether it is associated with the occurrence of classic Framingham risk factors.

We studied 62 women with SLE (1997 revised criteria) and 38 healthy women. Demographic and risk factor data were collected. In patients, disease activity and treatment-related parameters were also assessed. Endothelial function was assessed by flow-mediated dilation (FMD) in the brachial artery in response to reactive hyperemia. Carotid intima-media thickness (IMT) and the presence of carotid plaques were also assessed in SLE patients. FMD was impaired in SLE patients (median, 3.6%; range, -6.3% to 13.7%; versus median, 6.9%; range, -6.6% to 17.8%, P<0.01). Using multiple regression analysis that included all subjects in which we retained all the classic CHD risk factors, we found that systolic blood pressure (P=0.019) and SLE (P=0.017) were significantly associated with impaired FMD. Within SLE patients, IMT showed a negative correlation with percent FMD (r=-0.37, P<0.01). In stepwise multiple regression of SLE patients only that also included SLE factors and IMT, IMT alone was independently associated with FMD (P=0.037).

Patients with SLE have endothelial dysfunction that remained significant even after adjustment for other classic CHD risk factors. Within SLE patients, endothelial dysfunction correlates negatively with IMT, another marker of early atherosclerosis. Understanding the mechanism(s) of endothelial dysfunction in SLE may suggest novel strategies for CHD prevention in this context.