Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.
Atherosclerosis Is Associated with Low 25(OH) Vitamin D Levels, Lack of Angiotensin Converting Enzyme Inhibitor Use, and Hyperlipidemia in African-American Lupus Patients.
Ravenell3, Roneka L., Kamen4, Diane L., David5, Spence, Bruce2, Hollis, Jonas1, Almeida, Oates3, Jim C.
Department of Bioinformatics and Computational Biology, The University of Texas M. D. Anderson Cancer Center, Houston, TX
Department of Pediatrics, Medical University of South Carolina, Charleston, SC
MUSC, Charleston, SC
MUSC PO Box 250637, Charleston, SC
Robarts Research Stroke Prevention and Atherosclerosis Research Centre, London, ON, Canada
Patients with systemic lupus erythematosus (SLE) have a greater prevalence of atherosclerosis than the general population. This study was designed to identify risk factors for preclinical atherosclerosis in a predominantly African-American group of SLE patients.
Subjects with SLE but without a history of clinical cardiovascular events were enrolled. At entry, a Framingham risk factor history and medication list were recorded. Sera and plasma samples were analyzed for lipids, lupus activity markers, and total 25(OH) vitamin D (25(OH)D) levels. SLE Disease Activity Index (SLEDAI) and SLICC Damage Index scores were calculated. Carotid ultrasound measurements were performed to determine total plaque area (TPA) in both carotids as a validated measure of preclinical atherosclerosis that associates longitudinally with major cardiovascular events. Cases were defined as those with TPA values above that of age-matched controls from a population of 4272 patients in stroke and hypertension clinic. Descriptive analysis was performed on all variables between cases and controls. Associations between TPA and continuous variables were determined by correlation. Chi-square analysis was performed for ordinal variables against case or control status. Logistic regression analysis was performed to explore predictive modeling. P values < 0.05 were considered significant. A nearest related neighbor machine learning model (NRN) to explore variables associating with elevated TPA in a nonlinear or collinear fashion.
Fourteen of 51 subjects (27%) enrolled had elevated TPA compared to age-matched controls. 25(OH)D levels (16.6±3.2 vs. 22.6±1.8 ng/dl), SLEDAI scores (2.3±0.5 vs. 4.3±0.5), and anti-dsDNA antibody levels (34±18 vs. 136±59 IU) were significantly lower, while SLE disease duration (11.9±1.6 vs. 8.7±13 years) was significantly higher in cases. Age (r=0.58), C4 (r=0.36), and SLE disease duration (r=0.37) significantly correlated with TPA, while 25(OH)D levels significantly inversely correlated with age-adjusted TPA (r=-0.33). ACE-inhibitor use and a history of hypercholesterolemia were significantly associated with case status. Logistic regression models containing ACE-inhibitor use, 25(OH)D levels, and LDL levels had a diagnostic accuracy of 84%. Season of enrollment was not significant in the model. An NRN model was trained. Variables retained in the model as associating with abnormal TPA were hydroxychloroquine, ACE-inhibitor, and statin use as well as 25(OH)D levels. This model resulted in a receiver operating characteristics area under the curve of 0.75 for discriminating cases.
This study demonstrates in SLE patients novel and previously described associations between lower atherosclerotic burden and factors that are known to restore endothelial function and reduce plaque in non-SLE populations. These associations provide a rational basis for studying the effect of these therapies on endothelial function and vascular outcomes in patients with SLE.
To cite this abstract, please use the following information:
Ravenell, Roneka L., Kamen, Diane L., David, Spence, Bruce, Hollis, Jonas, Almeida, Oates, Jim C.; Atherosclerosis Is Associated with Low 25(OH) Vitamin D Levels, Lack of Angiotensin Converting Enzyme Inhibitor Use, and Hyperlipidemia in African-American Lupus Patients. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :2125