Gender-Modified Effect of Body Mass Index on Decline in Lung Function: A Pooled Analysis

We investigated whether obesity is associated with airway hyperresponsiveness in otherwise healthy humans and, if so, whether this correlates with a restrictive lung function pattern or a decreased number of sighs at rest and/or during walking. Lung function was studied before and after inhaling methacholine (MCh) in 41 healthy subjects with body mass index ranging from 20 to 56. Breathing pattern was assessed during a 60-min rest period and a 30-min walk. The dose of MCh that produced a 50% decrease in the maximum expiratory flow measured in a body plethysmograph (PD50MCh) was inversely correlated with body mass index ( r2 = 0.32, P < 0.001) and waist circumference ( r2 = 0.25, P < 0.001). Significant correlations with body mass index were also found with the maximum changes in respiratory resistance ( r2 = 0.19, P < 0.001) and reactance ( r2 = 0.40, P < 0.001) measured at 5 Hz. PD50MCh was also positively correlated with functional residual capacity ( r2 = 0.56, P < 0.001) and total lung capacity ( r2 = 0.59, P < 0.001) in men, but not in women. Neither PD50MCh nor body mass index correlated with number of sighs, average tidal volume, ventilation, or breathing frequency. In this study, airway hyperresponsiveness was significantly associated with obesity in otherwise healthy subjects. In obese men, but not in women, airway hyperresponsiveness was associated with the decreases in lung volumes.

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Body mass index status and peripheral airway obstruction in school-age children: a population-based cohort study

Thorax ◽

10.1136/thoraxjnl-2017-210716 ◽

2018 ◽

Vol 73 (6) ◽

pp. 538-545 ◽

Cited By ~ 12

Author(s):

Sandra Ekström ◽

Jenny Hallberg ◽

Inger Kull ◽

Jennifer L P Protudjer ◽

Per Thunqvist ◽

...

Keyword(s):

Body Mass Index ◽

Lung Function ◽

Airway Obstruction ◽

Body Mass ◽

Overweight And Obesity ◽

School Age Children ◽

Childhood And Adolescence ◽

Small Airways ◽

Cross Sectional ◽

The Impact

BackgroundFew large prospective studies have investigated the impact of body mass index (BMI) on lung function during childhood.MethodsUsing data collected between 2002 and 2013, we analysed associations between BMI status and lung function (assessed by spirometry) from 8 to 16 years, as well as cross-sectional associations with small airway function (impulse oscillometry) at 16 years in the BAMSE cohort (n=2889). At 16 years, cross-sectional associations with local and systemic inflammation were investigated by analysing FENO, blood eosinophils and neutrophils.ResultsOverweight and obesity at 8 years were associated with higher FVC, but lower FEV1/FVC ratio at 8 and 16 years. In boys, but not girls, obesity at 8 years was associated with a further reduction in FEV1/FVC between 8 and 16 years. In cross-sectional analyses, overweight and obesity were associated with higher frequency dependence of resistance (R5–20) and larger area under the reactance curve (AX0.5) at 16 years. Increased blood neutrophil counts were seen in overweight and obese girls, but not in boys. No association was found between BMI status and FENO. Persistent, but not transient, overweight/obesity between 8 and 16 years was associated with higher R5–20 and AX0.5 and lower FEV1/FVC (−2.8% (95% CI −4.1 to −1.2) in girls and −2.7% (95% CI −4.4 to −1.1) in boys) at 16 years, compared with persistent normal weight.ConclusionIn childhood and adolescence, overweight and obesity, particularly persistent overweight, were associated with evidence of airway obstruction, including the small airways.

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Age and body mass index affect fit of spirometry GLI references in schoolchildren

10.1101/2021.10.07.21264678 ◽

2021 ◽

Author(s):

Rebeca Mozun ◽

Cristina Ardura-Garcia ◽

Eva S. L. Pedersen ◽

Jakob Usemann ◽

Florian Singer ◽

...

Keyword(s):

Body Mass Index ◽

Lung Function ◽

Body Mass ◽

Clinical Decision Making ◽

Clinical Care ◽

Normal Weight ◽

Linear Regression Models ◽

Cross Sectional ◽

Mean Values ◽

Z Scores

AbstractBackgroundReferences from the Global Lung Function Initiative (GLI) are widely used to interpret children’s spirometry results. We assessed fit for healthy schoolchildren.MethodsLuftiBus in the school (LUIS) is a population-based cross-sectional study done from 2013-2016 in the canton of Zurich, Switzerland. Parents and children aged 6-17 years answered questionnaires about respiratory symptoms and lifestyle. Children underwent spirometry in a mobile lung function lab. We calculated GLI-based z-scores for FEV1, FVC, FEV1/FVC, and FEF25-75 for healthy White participants. We defined appropriate fit to GLI references by mean values ±0.5 z-scores. We assessed if fit varied by age, body mass index, height, and sex using linear regression models.ResultsWe analysed data from 2036 children with valid FEV1 measurements of which 1762 also had valid FVC measurements. The median age was 12.2 years. Fit was appropriate for children aged 6-11 years for all indices. In adolescents aged 12-17 years, fit was appropriate for FEV1/FVC (mean: -0.09; SD: 1.02) z-scores, but not for FEV1 (mean: -0.62; SD: 0.98), FVC (mean: -0.60; SD: 0.98), and FEF25-75 (mean: -0.54; SD: 1.02). FEV1, FVC, and FEF25-75 z-scores fitted better in children considered overweight (means: -0.25, -0.13, -0.38) than normal weight (means: -0.55, -0.50, -0.55; p-trend: <0.001, 0.014, <0.001). FEV1, FVC, and FEF25-75 z-scores depended on both age and height (p interaction: 0.034, 0.019, <0.01).ConclusionGLI-based FEV1, FVC, and FEF25-75 z-scores do not fit White Swiss adolescents well. This should be considered when using reference equations for clinical decision making, research and international comparison.Take home messageOur study suggests GLI-based FEV1, FVC, and FEF25-75 z-scores over detect abnormal lung function in Swiss adolescents, and more so among slimmer adolescents, which has important implications for clinical care, research, and international comparisons.

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