Hypovitaminosis D is associated with greater body mass index and disease activity in pediatric systemic lupus erythematosus.
OBJECTIVE
To determine whether pediatric systemic lupus erythematosus (SLE) is associated with alterations in the vitamin D-parathyroid hormone (PTH) axis and to assess the relation between vitamin D deficiency and SLE activity.


METHODS
25-hydroxy vitamin D [25(OH)D], 1,25-dihydroxy vitamin D [1,25(OH)2D], and intact PTH were measured in subjects with SLE (n = 38) and healthy controls (n = 207), ages 5 to 21 years. Vitamin D status and its relation with disease activity were assessed using multivariable logistic and linear regression.


RESULTS
Severe vitamin D deficiency (25(OH)D <10 ng/ml) was observed in a significantly higher proportion of subjects with SLE (36.8% vs 9.2%, P < .001). In SLE, the odds ratio (OR) for severe deficiency was 2.37 (P = .09), adjusting for age, sex, race, and season. However, for each 1 SD greater body mass index (BMI) z-score, 25(OH)D levels were 4.2 ng/mL lower (P = .01) in SLE, compared with controls. Adjusting for 25(OH)D levels, SLE was associated with significantly lower 1,25(OH)2D (P < .001) and intact PTH levels (P = .03). Greater SLE disease activity index scores were observed in those with 25(OH)D <20 ng/mL (P = .01).


CONCLUSIONS
SLE was associated with vitamin D deficiency, particularly among those subjects with SLE who were overweight. Future studies should assess the effect of vitamin D supplementation on skeletal and nonskeletal outcomes in SLE.
Wright
Tracey B
TB
Department Of Pediatrics, Division of Rheumatology, University of Texas Southwestern Medical Center, Dallas, TX, USA. tracey.wright@utsouthwestern.edu
Shults
Justine
J
Leonard
Mary B
MB
Zemel
Babette S
BS
Burnham
Jon M
JM
D000293:Adolescent; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived; D044383:Black People; D015992:Body Mass Index; D002117:Calcitriol / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D016014:Linear Models; D008171:Lung Diseases / Q000453:epidemiology; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology; D008297:Male; D009092:Mucous Membrane; D010281:Parathyroid Hormone / Q000097:blood; D000069283:Rituximab; D012720:Severity of Illness Index; D012883:Skin Ulcer / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*; D055815:Young Adult
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D007155:Immunologic Factors; D010281:Parathyroid Hormone; D014807:Vitamin D; D000069283:Rituximab; C104450:25-hydroxyvitamin D; D002117:Calcitriol