No relationship between lung function and high-sensitive C-reactive protein in adolescence

Introduction: Several studies on adults have indicated that lower spirometric lung function may be associated with increased systemic inflammation, but no studies have investigated if this association is already present in adolescence. Objective: We explored the temporal relationship between changes in lung function and concentrations of plasma C-reactive protein (CRP) in a population-based cohort study at ages 14 and 20 years using a high-sensitivity CRP assay. Methods: CRP measurements were performed in a total of 420 subjects at mean age of 13.9 years. Of these, 262 subjects (62%) participated in the follow-up investigation at mean age of 20.1 years. Results: Levels of log-CRP at age 14 were not significantly associated with forced expiratory volume (FEV(1)) or FEV(1)/ forced vital capacity (FVC) ratio at age 20, nor with the change in FEV(1), FVC or FEV(1)/FVC ratio between 14 and 20 years after controlling for body mass index (BMI), airway hyperresponsiveness (AHR), eosinophil cationic protein (ECP), asthma, smoking, sex, and height at 14 years, and change in height between 14 and 20 years. Sex, BMI, AHR, ECP and change in height between 14 and 20 years were identified as independent factors associated with the change in FEV(1), FVC and FEV(1)/FVC ratio in adolescence. Conclusion: We did not find an association between CRP levels at age 14 and change in lung function by age 20; whereas, sex, change in height, BMI, AHR and ECP were associated with lung function change in adolescence. Our findings indicate that systemic inflammation is of less importance for change in lung function in adolescence. Please cite this paper as: Nybo M, Hansen HS, Siersted HC and Rasmussen F. No relationship between lung function and high-sensitive C-reactive protein in adolescence. The Clinical Respiratory Journal 2010; 4: 230-236.