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Correlations between exhaled nitric oxide levels and pH-metry data in asthmatics with gastro-oesophageal reflux
Silvestri M, Mattioli G, Defilippi AC, Fregonese B, Battistini E, Jasonni V, Rossi GA.
BACKGROUND: In gastro-oesophageal reflux (GER), micro-aspirations of gastric fluid may damage the epithelial surface of the airways, an important source of endogenous nitric oxide (NO).
OBJECTIVES: The aim of the study was to evaluate the possible influence of GER on fractional exhaled nitric oxide (FE(NO)) release.
METHODS: FE(NO) levels were compared in two age-matched groups of allergic children: (1) 20 with mild asthma, responding to standard anti-asthma pharmacologic therapy (asthmatic children) and (2) 12 with mild 'asthma-like symptoms' and GER.
RESULTS: No differences in pulmonary functions parameters (FEV(1), FVC and FEF(25-75%)) were found between the two groups of children (p > 0.1); FE(NO) levels were higher in asthmatic children compared with GER children (p = 0.0001).
GER children underwent 24-hour oesophageal pH-metry, and possible correlations between pH-metry data, pulmonary functions and FE(NO) levels were evaluated.
No correlations were found between pulmonary functions and pH-metry data (p > 0.05, each correlation).
In contrast, correlations were observed between FE(NO) levels and pH-metry data, including (1) percentage of study time with pH < 4 (r = -0.80, p = 0.008), (2) number of episodes with pH < 4 (r = -0.76, p = 0.012), and (3) number of episodes >5 min with pH < 4 (r = -0.69, p = 0.02).
CONCLUSIONS: Thus, FE(NO) levels are lower in allergic children with 'asthma-like symptoms' and GER as compared to asthmatic children.
The correlations between FE(NO) levels and pH-metry data suggest that inhalation of acid gastric content may interfere with NO production in the airways.
Respiration. 2004 Jul-Aug;71(4):329-35.
Correlations between exhaled nitric oxide levels and pH-metry data in asthmatics with gastro-oesophageal reflux.
Silvestri M, Mattioli G, Defilippi AC, Fregonese B, Battistini E, Jasonni V, Rossi GA.
Pulmonary Department, G. Gaslini Institute, Genoa, Italy. |
