SAN FRANCISCO — Proinflammatory high-density lipoprotein has promise as a biomarker for atherosclerosis in women with systemic lupus erythematosus.
Findings from a study of 274 women with systemic lupus erythematosus (SLE) and 154 age-matched controls showed that serum levels of proinflammatory HDL were likely to be elevated in women found by B-mode ultrasound to have thickened carotid intima, indicative of plaque.
Although this association was noted in both the women with SLE and the healthy controls, the association was stronger in the women with lupus, according to one of the investigators, Dr. Maureen A. McMahon, a rheumatologist at the Ronald Reagan UCLA Medical Center, Los Angeles.
In particular, carotid artery plaque was found in 16% of the women with lupus and 15% of the women in the control group. Of the women with lupus who had plaque, 80% had measurable proinflammatory HDL cholesterol, compared with 43% of the women with SLE but no plaque. Proinflammatory HDL was found in 44% of the healthy women with plaque, compared with 10% of the healthy plaque-free women.
The mean carotid intimal thickness was 0.57 mm
Women with SLE were found to have significantly higher rates of hypertension and diabetes, compared with the control group on univariate analysis. However, age and current cigarette smoking were the only other significant risk factors for plaque in these women, according to findings from multivariate analysis, Dr. McMahon reported at the annual meeting of the American College of Rheumatology.
Paraoxonase (PON) activity or apolipoprotein A-I did not predict atherosclerosis in this study. Traditional risk factors for atherosclerosis such as hypertension, LDL cholesterol, and other protective components for HDL cholesterol were found not to be surrogates for proinflammatory HDL.
Women with SLE have long been observed to have an unexplained increased risk for atherosclerosis. Until now, the underlying mechanisms have not been explained.
None of the women had been taking statins within the 3 months preceding the study.
Levels of proinflammatory HDL cholesterol are “remarkably stable” in women with lupus, Dr. McMahon said in response to a question from the audience. Thus, levels do not increase and decrease depending on disease activity, she added, noting this has not been found to be the case in rheumatoid arthritis patients studied by other investigators.
Dr. McMahon reported that she has no financial conflicts of interest.