Background Vitamin D is not a classic vitamin but rather a prohormone which converted primarily in the liver into its major circulating form, 25-hydroxy-vitamin D [25(OH) D]. Serum levels of vitamin D have been found to be low in juvenile idiopathic arthritis (JIA) as in several autoimmune diseases ¹. There are some evidences of an association between serum vitamin D and cardiovascular disease risk ².

Objectives To assess the association between serums levels of 25-hydroxy-vitamin D and cardiovascular disease risk factors in juvenile idiopathic arthritis

Methods A prospective cross-sectional study was done on 30 patients with JIA according to the criteria of the International League of Associations for Rheumatology (ILAR) and 30 healthy volunteers matched for age and gender. Patients with other causes of dyslipidemia or those whom receiving vitamin D supplements or lipid-lowering medications were excluded from this study.

Systolic and diastolic blood pressure was measured to all patients and controls

Also; all patients and controls underwent laboratory tests of plasma 25(OH)D, Serum High-Density Lipoprotein (HDL), Low-Density Lipoprotein cholesterol (LDL). Echocardiography, carotid intima media thickness (cIMT), flow mediated dilatation of the brachial artery (FMD) also was done to all patients and controls.

Vit D levels were then correlated in each subgroup with the other clinical, laboratory and radiological parameters. We predefined Vit D insufficiency as being <50 nmol/l and Vit D deficiency as being <25 nmol/l.

Results The mean serum vitamin D levels of all patients were 23.8 nmol/l ±16.59. Only 7patients (23.3%) have adequate vitamin D levels (50–75 nmol/l). While Vitamin D insufficiency (serum vitamin D: 25 – 50 nmol/l) and deficiency (serum vitamin D level <25 nmol/l) were found in 9 (30%) and 14 patients (46.7%), respectively. JIA patients had significantly lower vitamin D levels as compared to controls (p<0.01). JIA patients had higher systolic and diastolic blood pressure than controls although these differences were not statistically significant (p>0.05) and all levels were still in normal values. Subjects with vitamin D deficiency or insufficiency had significantly lower values for HDL cholesterol and significantly elevated values for LDL cholesterol as compared to controls and patients with adequate vitamin D levels, with significant positive correlation between 25(OH)D and HDL cholesterol, and significant inverse correlation between 25(OH)D and LDL levels.

Patients with lower levels of vitamin D had significantly higher cIMT and lower FMD (p<0.01) With significant positive correlation between 25(OH)D and FMD, and significant inverse correlation between 25(OH)D and cIMT, while there were no significant differences in echocardiography results.

Conclusions Vitamin D deficiency is a cardiovascular risk factor in juvenile idiopathic arthritis.

References

1. Çomak E, Doğan ÇS, Uslu-Gökçeoğlu A, Akbaş H, Özdem S, Koyun M, Akman S. Association between vitamin D deficiency and disease activity in juvenile idiopathic arthritis. Turk J Pediatr. 2014; 56(6):626–31.

2. Suzanne E. Judd and Vin Tangpricha. Vitamin D Deficiency and Risk for Cardiovascular Disease. Am J Med Sci. 2009; 338(1): 40–44.

References

Acknowledgements Thanks to Dr. Samar Abd Alhamed for her efforts in completing statistics in this study.

Disclosure of Interest None declared