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 ≤ 400 μg) and borderline (PD20 > 400 μg).
Results: 536 children/adolescents resulted hyperreactive with a median PD20 of 366 μg [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 (187μg [IQR:110-519]) compared to overweight (377 μg [IQR:204-774]) and normal-weight individuals' values (370.5 μg [IQR:189-877]). On the contrary, median PD20 observed in obese children aged ≤ 13 years (761 μg [IQR:731-1212]) was higher (p = 0.052) compared to normal-weight children's PD20 (193 μg [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.
BMI can influence adult males' and females' airway hyperresponsiveness differently.Multidiscip Respir Med. 2012 Nov 17;7(1):45. doi: 10.1186/2049-6958-7-45. Multidiscip Respir Med. 2012. PMID: 23157852 Free PMC article.
Small airway impairment and bronchial hyperresponsiveness in asthma onset.Allergy Asthma Immunol Res. 2014 May;6(3):242-51. doi: 10.4168/aair.2014.6.3.242. Epub 2014 Feb 11. Allergy Asthma Immunol Res. 2014. PMID: 24843800 Free PMC article.
Smoking and Obesity Increase Airway Hyperesponsiveness Risk in the Elderly.Curr Aging Sci. 2016;9(4):284-294. doi: 10.2174/1874609809666160413113604. Curr Aging Sci. 2016. PMID: 27071476
Screening and Interventions for Childhood Overweight [Internet].Rockville (MD): Agency for Healthcare Research and Quality (US); 2005 Jul. Agency for Healthcare Research and Quality (US). 2005. PMID: 20722132 Free Books & Documents. Review.
[Simple obesity in children. A study on the role of nutritional factors].Med Wieku Rozwoj. 2006 Jan-Mar;10(1):3-191. Med Wieku Rozwoj. 2006. PMID: 16733288 Review. Polish.
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Obesity and asthma.J Allergy Clin Immunol. 2018 Apr;141(4):1169-1179. doi: 10.1016/j.jaci.2018.02.004. J Allergy Clin Immunol. 2018. PMID: 29627041 Free PMC article. Review.