Obesity promotes a low-grade systemic inflammatory state that may act on the lung to exacerbate asthma. There is little information on the relationship between systemic inflammation and lung function in children and adolescents.
Methods:
178 adolescents (boys and girls) were involved, four groups were divided according to their diagnosis: non-obese and non-asthmatic controls (n=38), non-obese asthmatics (n=31), obese non-asthmatics (n=62), obese asthmatics (n=47). The levels of PAI-1 and fibrinogen were determined in blood samples. The lung function was evaluated by measuring forced expiratory flow in 1-second (FEV1) and forced vital capacity (FVC1).
Results:
Compared to healthy controls, obese adolescents with or without asthma showed higher levels of fibrinogen (328.4±54.9, 324.9±68.9 and 289.2±61.5 mg/dL, respectively) and PAI-1 (36.0±17.3, 53.2±22.3 and 52.6±24.7ng/ml, respectively) and reduced FEV1/FVC ratio (87.7±7.7, 81.6±8.6 and 81.7±6.9, respectively). In the whole studied subjects, FEV1/FVC ratio showed significant inverse correlation with PAI-1 (r=-0.185), fibrinogen (r=-0.157), BMI (r=-0.303), insulin(r=-0.198) and HOMA (r=-0.173). In the 78 asthmatic subjects, FVC correlated positively with BMI, no significant correlation was observed between FEV1/FVC ratio and BMI, HOMA, PAI-1 or fibrinogen.
Conclusions:
Our data demonstrated that the degree of systemic inflammation and the degree of obesity in the whole studied groups correlated to the reduced lung function. Further studies are needed to identify the pathophysiologic mechanism for such association.