Vitamin D status is linked to biomarkers of oxidative stress, inflammation, and endothelial activation in obese children.
OBJECTIVE
To examine vitamin D, parathyroid hormone, and serum calcium-phosphorus levels relationships to biomarkers of oxidative/nitrosative stress, inflammation, and endothelial activation, potential contributors for vascular complications in obese children.


METHODS
Cross-sectional clinical study of 66 obese Caucasian children aged 7 to 14 years. Cardiovascular risk factors were assessed. Malondialdehyde and myeloperoxidase as measures of oxidative stress, and plasma nitrite+nitrate, urinary nitrate, and 3-nitrotyrosine as markers of nitrosative stress were measured. Adipocytokines, inflammatory molecules (high-sensitivity C-reactive protein, interleukin-6, and tumor necrosis factor-α), endothelial activation molecules (soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule 1 [sVCAM-1]), E-selectin, and vascular endothelial growth factor were also investigated. Serum 25-hydroxy-cholecalciferol [25(OH)D], intact parathormone, and calcium-phosphorus levels were determined in these children and in a comparison group of 39 non-obese children.


RESULTS
Obese children had a significantly lower 25(OH)D level (P = .002) and a higher intact parathormone (P = .011) than non-obese children. Phosphorus and the calcium-phosphorus product were also significantly higher (P < .0001). Insufficient serum concentrations of 25(OH)D (<20 ng/mL) were detected in 5% of normal children and in 30% of the obese children. In the obese children with vitamin D insufficiency, malondialdehyde, myeloperoxidase, 3-nitrotyrosine, interleukin-6, and sVCAM-1 were substantially elevated. A partial correlation analysis showed an inverse relationship of 25(OH)D levels with 3-nitrotyrosine (r = -0.424, P = .001), and sVCAM-1 (r = -0.272, P = .032).


CONCLUSIONS
Insufficient 25(OH)D levels were detected in severely obese children with increased markers of oxidative/nitrosative stress, inflammation, and endothelial activation.
Department of Pediatrics, Dr Peset University Hospital, Valencia, Spain. pilar.codoner@uv.es
Pilar
P
Codoñer-Franch
Sandra
S
Tavárez-Alonso
Raquel
R
Simó-Jordá
Paz
P
Laporta-Martín
Arturo
A
Carratalá-Calvo
Eulalia
E
Alonso-Iglesias
D000293:Adolescent; D015415:Biomarkers / Q000378:metabolism*; D002118:Calcium / Q000097:blood; D002318:Cardiovascular Diseases / Q000517:prevention & control; D002648:Child; D003430:Cross-Sectional Studies; D004730:Endothelium, Vascular / Q000473:pathology*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood*; D008297:Male; D009584:Nitrogen / Q000737:chemistry; D009765:Obesity / Q000097:blood* / Q000150:complications*; D018384:Oxidative Stress; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D012307:Risk Factors; D014807:Vitamin D / Q000378:metabolism*
D015415:Biomarkers; D010281:Parathyroid Hormone; D014807:Vitamin D; D010758:Phosphorus; D009584:Nitrogen; D002118:Calcium