Transient or persistent asthma-like symptoms and lung growth over 2-year follow-up in pre-adolescent children.

BACKGROUND The main purpose of this study was to assess the effect of transient and continued asthma-like symptoms on lung function growth in preadolescent children. METHODS The follow-up respiratory health survey has been conducted on the sample of 1,129 children aged 9 years over 2 years follow-up. The basic health end-points were the occurrence of asthma-like symptoms and slower lung function growth (SLFG), which was defined as the lung function gain over 2 years within the lowest quintile of the distribution of a given spirometric test. RESULTS Adjusted odds ratios (OR) for SLFG [forced vital capacity (FVC)] were significantly higher only in the children having continued symptoms [OR = 3.39: 95% confidence interval (CI) = 1.39-8.27]. There was a consistent trend of adjusted ORs for SLFG [forced expiratory volume (FEV,) with the category of symptoms, where OR was 2.00 (95% Cl = 1.17-3.42) in children with transient symptoms: while 4.10 (95% Cl = 1.71-9.86) in children who had persistent symptoms. The corresponding ORs for SLFG [maximal mid-expiratory flow (FEF25_75c)] were 2.27 (95% Cl = 1.37-3.76); and 5.43 (95% Cl = 2.38-12.40). DISCUSSION The association between asthma-like symptoms and lung function gain in preadolescent children confirmed the clinical significance of the symptoms in question. The observed slower lung function gain in preadolescence may have implications for the development of chronic lung disease later in adulthood.