Vitamin D deficiency is common and associated with increased C-reactive protein in children and young adults with lupus: an Atherosclerosis Prevention in Pediatric Lupus Erythematosus substudy
- Angela Byun Robinson1,
- Vin Tangpricha2,
- Eric Yow3,
- Reut Gurion1,
- Grace A McComsey4,
- Laura E Schanberg5,
- for the APPLE investigators
- 1Department of Pediatrics, Rainbow Babies and Children's Hospital/Case Medical Center, Cleveland, Ohio, USA
- 2Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- 3Duke Clinical Research Institute, Durham, North Carolina, USA
- 4Department of Medicine and Pediatrics, Case Medical Center, Cleveland, Ohio, USA
- 5Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
- Correspondence to Dr Angela Byun Robinson;
Objective Epidemiological associations suggest vitamin D may play a role in inflammation and atherosclerosis. Using frozen serum and data from the Atherosclerosis Prevention in Pediatric Lupus Erythematosus (APPLE) trial, we assessed associations between 25-hydroxyvitamin D [25(OH)D] and measures of systemic lupus erythematosus (SLE) disease activity and cardiovascular risk.
Methods Baseline APPLE serum samples were used to measure 25(OH)D levels. Logistic regression models for vitamin D deficiency [25(OH)D levels <20 ng/mL] were constructed using baseline variables collected as part of the trial, including race, season, latitude, disease duration, disease activity, high-sensitivity C-reactive protein (hsCRP), proteinuria, fasting lipids and carotid intima medial thickness (CIMT).
Results Samples were available from 201 of 221 APPLE subjects; 61/201 (30%) had vitamin D deficiency at baseline. In univariable analysis, baseline vitamin D deficiency was associated with season (p<0.01), minority status (p<0.01), body mass index (p=0.04), duration of SLE (p<0.01), SLICC damage index (p=0.04), hsCRP (p<0.01), mean–max CIMT (p=0.01), LDL-cholesterol (p=0.03) and timed urine protein (p=0.03). In multivariable modelling, vitamin D deficiency was associated with age, latitude, season, minority status, proteinuria and hsCRP.
Conclusions Vitamin D deficiency is common in paediatric lupus and is independently associated with elevated hsCRP, a marker of inflammation that predicts cardiovascular disease risk. Although association is not proof of causation, this association is novel in the paediatric SLE population and suggests that vitamin D deficiency may contribute to heightened inflammation and cardiovascular risk in this population.
Trial register number NCT00065806.
- Received January 9, 2014.
- Revision received April 4, 2014.
- Accepted April 5, 2014.
- Published 1 May 2014
- Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions
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