Epidemiological studies indicate that rheumatoid arthritis (RA) patients have increased mortality. Cardiovascular disease seems to be one of the major causes of death in patients with RA. Lipoprotein disorders are observed in patients with systemic autoimmune disorders as well as in patients with RA. Lipoprotein Lp(a) is an independent risk factor for the development of cardiovascular disease.
The aim of the study was estimate lipoprotein Lp(a) levels and their relationship with disease activity in RA patients.
Patients with RA, n=92, aged 2271 years and normal controls, n=92, of the same age and sex were studied. All the patients fulfilled the American College of Rheumatology criteria for the diagnosis of RA. In patients and controls the levels of hematocrit, hemoglobin, erythrocyte sedimentation rate, C-reactive protein, cholesterol, triglycerides, HDL, LDL and lipoprotein Lp(a) were measured. DAS28 disease activity index was calculated in all RA patients.
Lipoprotein Lp(a) levels (normal values <30 mg/dl) were found increased in 24 of 92 RA patients (26.1%) and in 11 of 92 controls (12%). Within the group of 24 RA patients with increased Lp(a) levels 18 (75%) had increased inflammation markers and increased DAS28. A strong relationship was observed between Lp(a) levels, erythrocyte sedimentation rate (P<0.01) and C-reactive protein (P<0.01).
Lipoprotein Lp(a) levels were found increased in RA patients. RA patients are at an increased risk for the development of atherosclerosis. The increase in Lp(a) levels seems to be observed specifically in patients with active RA. Inflammation may be the factor responsible for the increase in Lp(a) levels in RA patients.