Vitamin D and markers of airway inflammation in asthma

Abstract

Background

Vitamin D plays a role in the pathogenesis of asthma as it has a potent immunomodulatory effect acting on the cells of innate immunity. In asthmatic children low vitamin D levels are associated with poor asthma control, reduced lung function, increased medication intake, and exacerbations. Little is known about vitamin D in adult asthma patients or its association with asthma control and inflammatory markers of asthma.

Objective

To establish the relationship between vitamin D serum levels, pulmonary function, asthma control, IgE level and exhaled FE_No.

Methods

This study comprised 55 subjects (15 healthy volunteers, 40 asthmatic patient) who underwent history taking, HRCT, pulmonary function test, FE_NO, total serum IGE level and serum 25(OH)D₃ level.

Results

Vitamin D deficiency and insufficiency were observed in uncontrolled asthmatic patients. Patients with vitamin D deficiency and insufficiency had lower pulmonary function, higher serum IgE level, FE_NO and higher number of exacerbations in the last year. Total serum IgE level, FE_NO, and number of exacerbations showed a negative correlation with serum 25(OH) vitamin D. Serum 25(OH)vitamin D showed a significant positive correlation with pulmonary function in asthmatic patients.

Conclusion

The lower the vitamin D level deficiency or insufficiency, the more the asthma exacerbation, the less the asthma control, the higher the serum level of IgE and higher FE_NO. Also low vitamin D associated with airway remodeling is presented by small airway affection and HRCT findings.