The Effect of Obesity on the Level of Fractional Exhaled Nitric Oxide in Children with Asthma

Abstract

Background: Several studies have demonstrated a relationship between asthma and obesity. However, the results have been conflicting with regard to the relationship between fractional exhaled nitric oxide (FeNO), used as a marker of airway inflammation in asthmatic patients, and obesity. We aimed to evaluate the association of FeNO with obesity and obesity-related metabolic complications in asthmatic and nonasthmatic children. Methods: The study population included children aged between 6 and 17 years and consisted of 4 groups: obese asthmatics (n = 52), normal-weight asthmatics (n = 49), obese nonasthmatics (n = 51) and normal-weight nonasthmatics (n = 42). FeNO measurement and spirometry were performed for all patients. To evaluate the metabolic complications, serum lipids, glucose and insulin levels were measured. Insulin resistance (IR) was estimated by the homeostasis model assessment, HOMA-IR. All participants were evaluated for the presence of metabolic syndrome (MS). Results: The mean age for the 194 subjects participating in the study was 11.6 ± 2.5 years. The FeNO level of asthma patients with MS was not different from those without MS (14.5 ± 8.0 and 16.7 ± 8.7, respectively, p = 0.449). In the nonasthmatic group, subjects with MS had a higher FeNO level than subjects without MS (12.5 ± 5.1 and 17.3 ± 8.3, respectively, p = 0.014). Spearman's rank correlation coefficients revealed a positive correlation between FeNO and body mass index (BMI; p = 0.049, r²: 0.204) in the nonasthmatic group and after multivariate regression analysis, BMI still persisted as an independent risk factor for FeNO. Conclusion: We found a positive correlation between BMI and FeNO level which suggests a link between obesity and increased airway inflammation in nonasthmatic children.

Distinct Metabolic Profile of Inhaled Budesonide and Salbutamol in Asthmatic Children during Acute Exacerbation

“…Other studies found that children with a high body mass index had an increased risk of asthma [39]. However, a recent population-based study showed that asthmatic children experience higher rates of insulin resistance than those without asthma [40]. Conversely, children with asthma during acute exacerbation were often prescribed glucocorticoids and beta2 agonists.…”

Body mass index, asthma and exhaled nitric oxide in U.S. Adults, 2007–2010

“…Two of them reported results for persons with asthma, with one finding no association [14] and the other a negative association [15]. Several other more recent studies have issued similarly inconsistent findings [18][19][20].…”

Pediatric Obesity-Related Asthma: The Role of Metabolic Dysregulation

“…Furthermore, FeNO was not associated with asthma among obese children, 109 and a significant association between BMI and FeNO was observed only among nonasthmatic children. 110 It is hypothesized that these disparate reports either support heterogeneity in the pathophysiology of obesity-related asthma 116 or are reflective of inherent differences in disease severity. 108 As noted in normal-weight asthma, although classic asthma is atopic, involving eosinophils and Th2 cells, severe asthma, even among normal-weight individuals, is nonatopic, mediated by neutrophils.…”