Objective To explore the correlations of serum interleukin-4 (IL-4), leptin and chemerin levels with severity of asthma in obese children and their predictive values for asthma control.

Methods A total of 102 obese children with asthma were selected as study group, and another 102 healthy obese children were selected as control group. The serum levels of IL-4, leptin and chemerin were compared between the two groups. The study group was divided into mild (n=34), moderate (n=42) and severe (n=26) asthma groups based on severity of disease, and the serum levels of IL-4, leptin and chemerin were compared among different groups. The correlations of serum IL-4, leptin and chemerin with disease severity were analyzed. After 4 weeks of treatment, the 102 children with asthma were divided into controlled group (n=82) and uncontrolled group (n=20) based on asthma control status. Clinical data and serum levels of IL-4, leptin and chemerin were compared between the two groups, and their impacts on asthma control were analyzed. The predictive values of serum IL-4, leptin and chemerin levels for asthma control were evaluated.

Results The serum levels of IL-4, leptin and chemerin showed significant gradual increase trends among controlled children, mild asthma children, moderate asthma children, and severe asthma children (P < 0.001). Spearman correlation analysis showed positive correlations of serum IL-4, leptin and chemerin with disease severity (P < 0.001). The serum levels of IL-4, leptin and chemerin in the uncontrolled group were significantly higher than those in the controlled group (P < 0.001). Logistic regression analysis showed that serum IL-4 (OR=1.514, 95%CI, 1.117 to 2.051), leptin (OR=1.534, 95%CI, 1.234 to 1.907), and chemerin (OR=1.418, 95%CI, 1.026 to 1.959) after adjusting for disease duration were still the independent risk factors for asthma control (P < 0.05). The areas under the curve (AUC) for predicting asthma control by single and combined detections of serum IL-4, leptin and chemerin were 0.807 (95%CI, 0.717 to 0.879), 0.801 (95%CI, 0.711 to 0.874), 0.834 (95%CI, 0.748 to 0.901) and 0.932 (95%CI, 0.864 to 0.972), respectively. The AUC for combined prediction was significantly better than that for individual predictor (P < 0.05).

Conclusion The serum levels of IL-4, leptin and chemerin in obese children with asthma are positively correlated with disease severity, and they are independent risk factors for asthma control. Combined detection of these three indicators has a higher predictive value for asthma control.