Obesity disproportionately impacts lung volumes, airflow and exhaled nitric oxide in children.

Tsung-Chieh Yao,Su-Ching Chang,Ming-Han Tsai,Man-Chin Hua,Ren-Hua Chung,Kuo-Wei Yeh,Wan-Chen Lin,Sui-Ling Liao,Hui-Ju Tsai,Yu-Lun Tseng,Su-Wei Chang,Jing-Long Huang,Shen-Hao Lai,Jing-Ya Hsu,Li-Chen Chen,Yang-Ching Chen

doi:10.1371/journal.pone.0174691

Abstract

BackgroundThe current literature focusing on the effect of obesity and overweight on lung function and fraction of exhaled nitric oxide (FeNO) in children, particularly among healthy children of non-European descent, remains controversial. Furthermore, whether the relationship of obesity and overweight with lung function and FeNO in children is modified by atopy is unclear. The objective of this study was to examine the effect of excess weight on lung function parameters and FeNO among Asian children, with a particular focus on exploring the potential effect modification by atopy.MethodsWe investigated the effect of excess weight on lung function and FeNO in a population sample of 1,717 children aged 5 to 18 years and explored the potential modifying effect of atopy.ResultsThere were positive associations of body mass index (BMI) z-score with forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF), and forced expiratory flow at 25–75% (FEF25-75) (all P<0.001), after controlling for confounders. The beta coefficient for FEV1 (0.084) was smaller than that for FVC (0.111). In contrast, a negative association was found between BMI z-score and FEV1/FVC ratio (P<0.001) and FeNO (P = 0.03). A consistent pattern of association for lung function variables was observed when stratifying by atopy. There was a negative association of BMI z-score with FeNO in atopic subjects (P = 0.006), but not in non-atopic subjects (P = 0.46).ConclusionsExcess weight disproportionately impacts lung volumes and airflow in children from the general population, independent of atopic status. Excess weight inversely affects FeNO in atopic but not in non-atopic children.

Highlights

Excess weight represents a major global health challenge because of the established health risks and substantial increase in prevalence of overweight and/or obesity in children and adults worldwide, both in developed and developing countries [1,2,3]
The major finding of the current study is that increasing body mass index (BMI) disproportionately impacts lung volumes and airflow among children in a population setting which is reflected by increase in forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and peak expiratory flow (PEF), and FEF25-75, but decrease in FEV1/FVC ratio, independent of atopic status
We found that FVC, a measure of lung volume, increased linearly with increasing BMI; on the other hand, FEV1 and PEF, measures of airflow limitation, increased linearly with increasing BMI

Summary

Introduction

Excess weight represents a major global health challenge because of the established health risks and substantial increase in prevalence of overweight and/or obesity in children and adults worldwide, both in developed and developing countries [1,2,3]. Taiwan has experienced a substantial increase in the prevalence of childhood overweight and obesity, from 5.7% to 14.2% for overweight and from 7.9% to 17.4% for obesity in male students; and from 11.1% to 13.4% for overweight and from 3.1% to 4.1% for obesity in female students during the study period of 1991 and 2003 [3]. Whether the relationship of obesity and overweight with lung function and FeNO in children is modified by atopy is unclear. The objective of this study was to examine the effect of excess weight on lung function parameters and FeNO among Asian children, with a particular focus on exploring the potential effect modification by atopy

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Conclusion