Obesity can influence children's and adolescents' airway hyperresponsiveness differently.

Original research article

Bruno Sposato, Marco Scalese, Maria Giovanna Migliorini, Maria Piera Riccardi, Massimo Tosti Balducci, Luigi Petruzzelli and Raffaele Scala

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Multidisciplinary Respiratory Medicine 2013, 8:60  

Published: 12 September 2013

Abstract (provisional)

Background

Literature is still arguing about a possible relationship between airway hyperresponsiveness (AHR) and body mass index (BMI). This study aimed at evaluating the influence of BMI on AHR and pulmonary function in children and adolescents that performed a methacholine test for suggestive asthma symptoms.

Methods

799 consecutive children/adolescents (535 M; mean age: 15 +/- 3 yrs; median FEV1% predicted: 101.94% [93.46-111.95] and FEV1/FVC predicted: 91.07 [86.17-95.38]), were considered and divided into underweight, normal, overweight and obese. Different AHR levels were considered as moderate/severe (PD20 <= 400mug) and borderline (PD20 > 400mug).

Results

536 children/adolescents resulted hyperreactive with a median PD20 of 366mug [IQR:168--1010.5]; 317 patients were affected by moderate/severe AHR, whereas 219 showed borderline hyperresponsiveness. Obese subjects aged > 13 years showed a lower (p = 0.026) median PD20 (187mug [IQR:110--519]) compared to overweight (377mug [IQR:204--774]) and normal-weight individuals' values (370.5mug [IQR:189--877]). On the contrary, median PD20 observed in obese children aged <= 13 years (761mug [IQR:731--1212]) was higher (p = 0.052) compared to normal-weight children's PD20 (193mug [IQR:81--542]) and to obese adolescents' values (aged > 13 years) (p = 0.019). Obesity was a significant AHR risk factor (OR:2.853[1.037-7.855]; p = 0.042) in moderate/severe AHR adolescents. Females showed a higher AHR risk (OR:1.696[1.046-2.751] p = 0.032) compared to males. A significant relationship was found between BMI and functional parameters (FEV1, FVC, FEV1/FVC) only in hyperreactive females.

Conclusions

Obesity seems to influence AHR negatively in female but not in male adolescents and children. In fact, AHR is higher in obese teenagers, in particular in those with moderate/severe hyperresponsiveness, and may be mediated by obesity-associated changes in baseline lung function.

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