The effect of obesity on the level of fractional exhaled nitric oxide in children with asthma.
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, r(2): 0.204) in the nonasthmatic group and after multivariate regression analysis, BMI still persisted as an independent risk factor for FeNO.


CONCLUSIONS
We found a positive correlation between BMI and FeNO level which suggests a link between obesity and increased airway inflammation in nonasthmatic children.
Department of Pediatric Allergy and Immunology, Ankara Children's Hematology Oncology Education and Research Hospital, Ankara, Turkey.
Mustafa
M
Erkoçoğlu
Ayşenur
A
Kaya
Celal
C
Ozcan
Ayşegül
A
Akan
Emine
E
Vezir
Dilek
D
Azkur
Ozlem
O
Kara
Fatma
F
Demirel
Tayfur
T
Ginis
Ersoy
E
Civelek
Can Naci
CN
Kocabaş
D000293:Adolescent; D001249:Asthma / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D045853:Exhalation; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000378:metabolism*; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism*
D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D009569:Nitric Oxide