Relationship between plasma copeptin levels and complications of community-acquired pneumonia in preschool children

High plasma copeptin level has been associated with clinical outcomes after acute illness. The present study was undertaken to investigate the plasma copeptin concentrations in preschool children with community-acquired pneumonia (CAP) and to analyze the correlations of copeptin with CAP-related complications and pleural effusion. Plasma copeptin concentrations of 100 healthy children and 165 preschool children with CAP were measured. 35 children (21.2%) presented with complicated CAP and 28 children (17.0%) presented with pleural effusion. The admission copeptin levels were significantly increased in all patients (49.7 ± 21.4 pmol/L), children with complicated CAP (73.0 ± 16.9 pmol/L), those with uncomplicated CAP (43.4 ± 17.8 pmol/L), those with pleural effusion (70.9 ± 17.4 pmol/L) and those without pleural effusion (45.3 ± 19.5 pmol/L) compared with healthy control individuals (9.0 ± 2.7 pmol/L, all P < 0.001). Multivariate logistic regression analysis showed that plasma copeptin levels were independently related to CAP-related complications (odds ratio 1.214, 95% confidence interval 1.104–1.872, P < 0.001) and pleural effusion (odds ratio 1.226, 95% confidence interval 1.109–1.917, P < 0.001). A receiver operating characteristic curve analysis showed plasma copeptin level better predicted CAP-related complications (area under curve 0.876, 95% confidence interval 0.815–0.922) and pleural effusion (area under curve 0.831, 95% confidence interval 0.765–0.885). Thus, plasma copeptin level may represent a novel biomarker for predicting CAP-related complications in preschool children.