Relationship Between Body Mass Index And Lung Function And Exhaled Nitric Oxide In Children With Asthma

Objective:The aim of this study was to investigate the effect of body mass index on lung function and fractional exhaled nitric oxide and treatment efficacy in children with asthma and provid a certain reference for individualized treatment.Methods:Patients with mild acute exacerbation asthma who were first come to our hospital from 09/2020 to 09/2022 were screened and enrolled after stabilization with inhaled glucocorticoids and bronchodilators.114 patients were finally included in the study.Another 40 healthy physical examination children were selected as the healthy control group;and patient information was collected through the hospital information system.The information included age,gender,height,weight and other general information,and body mass index was calculated.Other information included lung function,fractional exhaled nitric oxide,Childhood asthma control score.Children with asthma were divided into the normal weight group(n=43),overweight group(n=24)and obese group(n=47)according to BMI;statistical methods such as t-test,ANOVA,non-parametric rank sum test,chi-square test or Fisher exact test,linear correlation analysis or rank correlation analysis were used to combine the data characteristics.The relationship between body mass index and lung function and fractional exhaled nitric oxide in children with asthma was analyzed and the effect of body mass index on the effectiveness of conventional inhalation therapy for asthma was explored.Results:1.Comparison of baseline informationA total of 114 children with asthma and 40 healthy control children(with normal BMI)were included in this study,including 43 cases in the normal weight group,24 cases in the overweight group and 47 cases in the obese group.In the normal weight group,there were 29 males and 14 females,with a mean of(6.19±1.76)years;in the overweight group,there were 18 males and 6 females,with a mean of(6.96±2.27)years;in the obese group,there were 33 males and 14 females,with a mean of(6.26±1.64)years;The differences were not statistically significant(P>0.05)when comparing the gender composition and age of the groups.The differences were not statistically significant(P>0.05)when comparing the general information on history of allergic diseases(rhinitis,eczema,atopic dermatitis,food allergy,etc.),family history of asthma,allergen positivity and eosinophil ratio of the asthma groups,and the differences were statistically significant(P<0.001)when comparing the BMI of the asthma groups.2.Comparison of pre-treatment pulmonary function indicators between groups of childrenThe differences in FVC,FEV1,FEV1/FVC,PEF and MMEF were statistically significant(P<0.05);the FVC,FEV1 and FEV1/FVC of children in the obese group were all lower than those in the normal weight group,and the differences were statistically significant(P<0.05);FVC,FEV1,FEV1/FVC,PEF and MMEF were all higher in the healthy control group than in the asthmatic normal weight group,the overweight group and the obese group,and the differences were statistically significant(P<0.05),The differences were statistically significant(P<0.05).Comparison of the indicators between the overweight group and the normal weight group,as well as the obese group,were not statistically significant(P>0.05).3.Comparison of FeNO values in children with asthma in three groupsThe differences were not statistically significant when comparing FeNO in each group(P>0.05).4.Correlation between BMI and pulmonary function indicators and FeNO in the asthma groupBMI was negatively correlated with FEV1,FEV1/FVC and MMEF in children with asthma(P<0.05),but not with FeNO,FVC and PEF(P>0.05).There was no correlation between FeNO and all indicators of lung function(P>0.05).5.Comparison of pulmonary function indicators after treatment in asthma groupsThe differences in FVC,FEV1,FEV1/FVC and MMEF of children in the three groups after treatment were statistically significant(P<0.05);In the comparison between groups,FVC,FEV1,FEV1/FVC and MMEF of children in the obese group were all lower than those in the normal weight group,and the differences were statistically significant(P<0.05).In the obese group,FEV1,FEV1/FVC and MMEF were all lower than those in the overweight group,and the difference was statistically significant(P<0.05).FVC and FE V1 of children in the overweight group were lower than those of the normal weight group,and the difference was statistically significant(P<0.05).The difference was not statistically significant when comparing the PEF of each group(P>0.05).6.Comparison of pulmonary function indicators before and after treatment in asthma groupsAfter treatment,FVC,FEV1,FEV1/FVC,PEF and MMEF of children in the normal weight group were all higher than before,and the difference was statistically significant(P<0.05).After treatment,FEV1,FEV1/FVC,PEF and MMEF of children in the overweight group were all higher than before,and the difference was statistically significant(P<0.05).When comparing the FVC before and after treatment,the difference was not statistically significant(P>0.05).In the obese group,FVC,FEV1,FEV1/FVC,PEF and MMEF were all higher after treatment compared to before,and the difference was statistically significant(P<0.05).7.Comparison of C-ACT scores and asthma control in children with asthma between groupsThe difference between the C-ACT scores of children in the three groups was statistically significant(P<0.05).As BMI increased,the proportion of poorly controlled asthma increased and the difference was statistically significant(P<0.05).8.Correlation analysis of BMI and C-ACT scores in the asthma groupThere was a negative correlation between BMI and C-ACT score(r=-0.204 P=0.029),suggesting that the higher the BMI,the lower the level of effective asthma control.Conclusions:1.BMI can affect some of the indicators of lung function in children with asthma.2.BMI in asthmatic children was negatively correlated with pulmonary ventilation function and not significantly correlated with FeNO.3.BMI of children with asthma was negatively correlated with asthma control level.