Altered lipid levels may occur in autoimmune diseases, for example low cholesterol levels have been described in rheumatoid arthritis (RA). Serum lipid profiles in patients with Sjögren's syndrome (SS) have not been investigated. We hypothesized decreased lipid levels in SS patients and an inverse relationship with disease activity.
Serum lipid levels [total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides] and additional data regarding disease measures (clinical immunology parameters, focus score from labial salivary gland biopsy, salivary flow and ophthalmological measures) were available for 46 primary SS patients and 12 xerostomic controls.
Significant differences between SS patients and controls means (s.d.) were seen for HDL (P = 0.04) and total cholesterol (P = 0.02). LDL (P = 0.12) and triglyceride (P = 0.08) levels were not different. In SS patients, but not in controls, total cholesterol (P = 0.003) and HDL cholesterol (P = 0.003) predicted immunoglobulin G levels. Anti-SSA antibodies were related to a lower total cholesterol (P = 0.02) and anti-SSB antibodies to a lower HDL cholesterol level (P = 0.0497).
Significant differences were seen in serum lipid levels of primary SS patients and these were associated with serological measures of inflammation. Our results are comparable to earlier findings in RA patients and raise questions related to adverse cardiovascular consequences in SS.