SAN FRANCISCO — Proinflammatory HDL cholesterol 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 cholesterol 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 controls, it was stronger in the women with lupus, said 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 healthy plaque-free women.
The mean carotid intimal thickness was 0.57 mm
Women with SLE had significantly higher rates of hypertension and diabetes, compared with the controls on univariate analysis. However, age and current cigarette smoking were the only other significant risk factors for plaque in these women, according to multivariate analysis, Dr. McMahon said at the annual meeting of the American College of Rheumatology.
Paraoxonase (PON) activity or apolipoprotein A-I did not predict atherosclerosis. 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 known to have an unexplained increased risk for atherosclerosis. Until now, the underlying mechanisms have not been explained.
None of the women had taken statins within the 3 months preceding the study.
Levels of proinflammatory HDL cholesterol are “remarkably stable” in women with lupus, Dr. McMahon said. Thus, levels do not increase and decrease depending on disease activity, she added, noting this has is not the case in RA.
Dr. McMahon reported that she has no financial conflicts of interest.