title: Alveolar nitric oxide and asthma control in mild untreated asthma.
abstract: BACKGROUND
  The role of the peripheral airways in asthma is increasingly being recognized as a potential target for the achievement of optimal control of the disease. We postulated that the inflammatory changes of the small airways are implicated in the lack of asthma control in mild asthma.
  
  
  OBJECTIVE
  To test this hypothesis, we measured the alveolar fraction of exhaled NO (CalvNO) in patients with mild asthma with different levels of control of symptoms.
  
  
  METHODS
  Seventy-eight patients with asthma (35 men, age, 37 ± 15 years; FEV1 percentage of predicted, 100% ± 9%) were studied. Asthma control was assessed by using the Asthma Control Test (ACT). Measurements of exhaled NO at multiple constant flows were performed.
  
  
  RESULTS
  Bronchial NO concentrations were 27.1 ± 20 nL/min, [corrected] and CalvNO levels were 5.7 ± 3.4 ppb. The ACT score was 20 ± 4.2. The level of asthma control was not associated with bronchial NO concentrations (rs = 0.16, P = .15). However, a significant correlation was found between the ACT score and CalvNO (rs = 0.25, P = .03). Moreover, CalvNO was significantly higher in patients with uncontrolled asthma than in patients with controlled/partially controlled asthma (6.7 ± 2.6 ppb vs 4.9 ± 2.6 nL/min, [corrected] respectively, P = .02). In the subgroup of patients with asthma who underwent extrafine inhaled corticosteroid treatment, the magnitude of the inhaled corticosteroid-induced improvement in asthma control positively correlated with baseline CalvNO at 1 month (rs = 0.39, P = .003) and at 3 months (rs = 0.49, P < .0001).
  
  
  CONCLUSIONS
  The alveolar component of exhaled NO is associated with the lack of asthma control in patients with mild, untreated asthma. This observation supports the notion that abnormalities of the peripheral airways are implicated in the mildest forms of asthma.
authors: Dipartimento Biomedico di Medicina Interna e Specialistica, Sezione di Pneumologia, University of Palermo, Palermo, Italy. nicola.scichilone@unipa.it
authors: Nicola
authors: N
authors: Scichilone
authors: Salvatore
authors: S
authors: Battaglia
authors: Salvatore
authors: S
authors: Taormina
authors: Viviana
authors: V
authors: Modica
authors: Elena
authors: E
authors: Pozzecco
authors: Vincenzo
authors: V
authors: Bellia
mesh_terms: D000328:Adult; D001249:Asthma / Q000378:metabolism* / Q000503:physiopathology / Q000517:prevention & control*; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide; D012129:Respiratory Function Tests; D055815:Young Adult
chemical_list: D009569:Nitric Oxide