Journal of Asthma and Allergy (Apr 2021)
The Effects of Asthma on the Association Between Pulmonary Function and Obesity: A 16-Year Longitudinal Study
Abstract
Ying-Jhen Huang,1 Yi-Chi Chu,1 Hung-Ling Huang,2– 4 Jing-Shiang Hwang,5 Ta-Chien Chan1,6 1Research Center for Humanities and Social Sciences, Academia Sinica, Taipei, Taiwan; 2Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan; 3Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; 4Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; 5Institute of Statistical Science, Academia Sinica, Taipei, Taiwan; 6Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, TaiwanCorrespondence: Ta-Chien ChanResearch Fellow, Research Center for Humanities and Social Sciences, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 115, TaiwanTel +886 2-2785-7108 ext. 312Email [email protected]: 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: asthma, obesity, BMI, pulmonary function, FVC
