The Effects of Asthma on the Association Between Pulmonary Function and Obesity: A 16-Year Longitudinal Study

Ying-Jhen Huang; Yi-Chi Chu; Hung-Ling Huang; Jing-Shiang Hwang; Ta-Chien Chan

doi:10.2147/JAA.S299186

The Effects of Asthma on the Association Between Pulmonary Function and Obesity: A 16-Year Longitudinal Study

J Asthma Allergy. 2021 Apr 8:14:347-359. doi: 10.2147/JAA.S299186. eCollection 2021.

Authors

Ying-Jhen Huang¹, Yi-Chi Chu¹, Hung-Ling Huang^{2

3

4}, Jing-Shiang Hwang⁵, Ta-Chien Chan^{1

6}

Affiliations

¹ Research Center for Humanities and Social Sciences, Academia Sinica, Taipei, Taiwan.
² Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan.
³ Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
⁴ Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
⁵ Institute of Statistical Science, Academia Sinica, Taipei, Taiwan.
⁶ Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan.

Abstract

Background: Asthma and obesity are important public health issues around the world. Obesity is considered a risk factor associated with the severity and incidence of asthma. We investigated the relationships between poor pulmonary function (defined by forced vital capacity (FVC) and percentage of predicted FVC (FVC%)) and obesity.

Methods: This is a retrospective longitudinal study using the MJ health examination database in Taiwan from 2000 to 2015. There were 160,609 participants aged ≥20 years with complete obesity indicators and lung function data, and having at least two visits. A generalized estimation equation (GEE) model was applied to estimate the association between lung function and obesity.

Results: BMI was the best indicator to predict poor pulmonary function for our participants. Results of BMI are presented as an example: Obesity (body mass index (BMI) ≥27.0 kg/m²) is significantly associated with lower FVC [adjusted coefficients (β) for asthmatics: -0.11 L (95% CI: -0.14, -0.08); adjusted β for non-asthmatics: -0.08 L (-0.09, -0.08)] and FVC% [adjusted β for asthmatics: -1.91% (95% CI: -2.64, -1.19); adjusted β for non-asthmatics: 1.48% (-1.63, -1.33)]. Annual change of BMI (ΔBMI/year) is an independent risk factor for decreased FVC [adjusted β for asthmatics: -0.030 L (-0.048, -0.013); adjusted β for non-asthmatics: -0.019 L (-0.022, -0.016)] and FVC% [adjusted β for non-asthmatics: -0.603% (-1.063, -0.142); adjusted β for non-asthmatics: -0.304% (-0.393, -0.214)], and is significantly associated with accelerated FVC decline [adjusted β of ΔFVC/year and ΔFVC %/year for asthmatics: -0.038 L (-0.054, -0.022) and -0.873% (-1.312, -0.435); adjusted β of ΔFVC/year and ΔFVC %/year for non-asthmatics: -0.033 L (-0.042, -0.024) and -0.889% (-1.326, -0.452)].

Conclusion: Obesity is significantly associated with decreased lung function, and asthmatics had a higher risk than non-asthmatics.

Keywords: BMI; FVC; asthma; obesity; pulmonary function.

Grants and funding

This research was supported by a grant titled “Obesity and asthma severity: interactions among health behaviors, genetic polymorphism, and environmental exposure” (grant number: AS-PH 109-01-2) from Academia Sinica. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.