Elevated exhaled nitric oxide (NO) in asymptomatic asthmatics taking bronchodilators on demand with controlled body composition.

OBJECTIVE

Fractional Exhaled Nitric Oxide (FENO) is a recently introduced non invasive marker to measure inflammation and oxidative stress in the lung. This study aimed to measure FENO in Saudi asthmatic adult patients who had mild to moderate persistent asthma, on inhaled short-acting? 2 agonists and compared them to healthy individuals matched for body composition without any evidence of obstructive airway disease.

METHODS

As per selection criteria 61 subjects were selected. 30 subjects were known asthmatic and 31 were healthy individuals matched for age, height, weight, BMI and body composition. Forced expiratory volume in 1 s (FEV1), FVC, FEV1/ FVC, PEF, FEF25, FEF50 and FEF75 were measured by standard methods. FENO measurements were performed according to the ATS (American Thoracic Society) recommendations.

RESULTS

Ventillatory function parameters FEV1 (p = 0.0020), FVC (p = 0.0030), PEF (p = 0.0121), FEF25 (p = 0.0241), FEF50 (p = 0.0240) and FEF75 (p = 0.1824) were significantly lower in asthmatic subjects compared to matched healthy control group. FENO was significantly higher (82.51 +/- 39.26) in asthmatic subjects compared to control group (23.03 +/- 8.56) p < 0.0000)

CONCLUSION

FENO levels are increased in patients with bronchial asthma with mild to moderate symptoms taking bronchodilators on demand only. It may be suggestive of the need for more accurate evaluation and early intervention with anti inflammatory drugs in a significant proportion of these patients.