Objective: This study focused on lipoprotein composition and properties in systemic lupus erythematosus (SLE).
Methods: The size distribution of plasma lipoproteins was studied by nuclear magnetic resonance (NMR). Cholesteryl ester transfer protein (CETP) activity was determined by enzyme-linked immunosorbent assay (ELISA). The affinity of low density lipoprotein (LDL) for proteoglycans was assayed. Twenty-six women (aged 52+/-8.2 years) with SLE and a history of cardiovascular disease (CVD) (SLE cases) were compared with 26 age-matched women with SLE and without CVD (SLE controls) and 26 age-matched population-based control women (controls).
Results: Very low density lipoprotein (VLDL) particles (nmol/L) were more prevalent among SLE cases than SLE controls (0.039) and tended to be more common in SLE cases than in controls (p = 0.073). By contrast, high density lipoprotein (HDL) particles (nmol/L) were more prevalent among controls than SLE cases (p = 0.024) whereas the number of LDL particles (nmol/L) did not differ significantly. Small dense (sd)LDL (nmol/L) were more common in controls and tended to be more common in SLE cases than in SLE controls (p = 0.036 and 0.086, respectively). Small high density lipoproteins (sHDL) (nmol/L) were more prevalent in controls than in SLE controls and SLE cases (p = 0.002 and p<0.001, respectively). VLDL or LDL size (nm) did not differ significantly between groups (data not shown) whereas HDL size (nm) was increased among SLE controls as compared to controls (p = 0.024) and tended to be increased among SLE cases as compared to controls (p = 0.070). The affinity of LDL for proteoglycans or CETP activity did not differ between groups (data not shown).
Conclusions: sdLDL was not increased and SLE cases and SLE controls had decreased levels of sHDL. VLDL differentiates between SLE cases and SLE controls. The lipid pattern in SLE-related CVD was thus not similar to the pattern seen in diabetes or in CVD in general.