RT Journal Article
SR Electronic
T1 Serum vitamin D levels and severe therapy resistant asthma in children
JF Archives of Disease in Childhood
JO Arch Dis Child
FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health
SP A13
OP A13
DO 10.1136/adc.2011.212563.24
VO 96
IS Suppl 1
A1 A Gupta
A1 A Bush
A1 D Richards
A1 C Hawrylowicz
A1 S Saglani
YR 2011
UL http://adc.bmj.com/content/96/Suppl_1/A13.2.abstract
AB Background Little is known about vitamin D levels and their impact on disease control in children with severe, therapy resistant asthma (STRA). We hypothesised that children with STRA have lower serum vitamin D levels than non-asthmatic controls and that lower vitamin D levels are associated with more severe asthma, (Symptoms, spirometry and inhaled corticosteroid (ICS) treatment; and worse airway inflammation measured in bronchoalveolar lavage (BAL)). Aims To compare serum vitamin D levels in children with STRA and age-matched non-asthmatic controls, and to investigate the relationship between vitamin D levels and markers of asthma severity, including clinical and therapeutic disease variables. Methods We measured serum 25-hydroxyvitamin D in 30 asthmatics and 16 non-asthmatic children; asthma severity was categorised using the asthma control test (ACT); spirometry; ICS dose; exhaled nitric oxide at 50 ml/s (FeNO50) as a measure of inflammation; and BAL cytokines. Results In asthmatics, the prevalence of vitamin D insufficiency (<75 nmol/l) was 90%, with 78% being vitamin D deficient (<50 nmol/l). All age-matched non-asthmatic controls were vitamin D insufficient with 50% being vitamin D deficient. Children with asthma had lower median 25-hydroxyvitamin D serum levels (36 nmol/l, range 3–83) as compared to age-matched non-asthmatic controls (48 nmol/l, range 25–72) (p=0.03). There was a positive correlation between serum 25-hydroxyvitamin D levels and asthma symptoms (ACT) (r=0.49, p<0.001) and per cent predicted forced expired volume in 1 s (FEV1) (r=0.3, p=0.04). Serum 25-hydroxyvitamin D levels were significantly inversely associated with FeNO50 (r=0.6, p=0.001) and ICS usage (r=0.4, p=0.02). In children with STRA, a positive correlation was also noted between serum 25-hydroxyvitamin D levels and BAL levels of the anti-inflammatory cytokine interleukin (IL)-10 (r=0.51, p=0.03). No significant relationship between serum 25-hydroxyvitamin D levels and BAL neutrophils and eosinophils. Conclusion In children with STRA reduced vitamin D levels are associated with more symptoms lower lung function, more inflammation and greater ICS usage. There is a need for an intervention study, supplementing vitamin D in Vitamin D deficient children who have severe asthma.