The Relationship Between BMI and Lung Function in Populations with Different Characteristics: A Cross-Sectional Study Based on the Enjoying Breathing Program in China

Abstract

Xingyao Tang,1– 4 Jieping Lei,2,3,5,6 Wei Li,1– 3,5 Yaodie Peng,1,7 Chen Wang,1– 3,5 Ke Huang,1– 3,5,* Ting Yang1– 3,5,* 1Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, 100029, People’s Republic of China; 2National Center for Respiratory Medicine, Beijing, 100029, People’s Republic of China; 3National Clinical Research Center for Respiratory Diseases, Beijing, 100029, People’s Republic of China; 4Capital Medical University, Beijing, 10069, People’s Republic of China; 5Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, Beijing, 100029, People’s Republic of China; 6Department of Clinical Research and Data Management, Center of Respiratory Medicine, China-Japan Friendship Hospital, Beijing, 100029, People’s Republic of China; 7Peking University Health Science Center, Beijing, 10029, People’s Republic of China*These authors contributed equally to this workCorrespondence: Ke Huang; Ting Yang, China-Japan Friendship Hospital, Beijing, 100029, People’s Republic of China, Tel [phone], Email [email protected]; [email protected]: To analyze the relationship between body mass index (BMI) and lung function, which may help optimize the screening and management process for chronic obstructive pulmonary disease (COPD) in the early stages.Patients and Methods: In this cross-sectional study using data from the Enjoying Breathing Program in China, participants were divided into two groups according to COPD Screening Questionnaire (COPD-SQ) scores (at risk and not at risk of COPD) and three groups based on lung function (normal lung function, preserved ratio impaired spirometry [PRISm], and obstructive lung function).Results: A total of 32,033 subjects were enrolled in the current analysis. First, in people at risk of COPD, overweight and obese participants had better forced expiratory volume in one second (FEV1; overweight: 0.33 liters (l), 95% confidence interval [CI]: 0.27 to 0.38; obesity: 0.31 L, 95% CI: 0.22 to 0.39) values than the normal BMI group. Second, among people with PRISm, underweight participants had a lower FEV1 (− 0.56 L, 95% CI: − 0.86 to − 0.26) and forced vital capacity (FVC; − 0.33 L, 95% CI: − 0.55 to − 0.11) than participants with a normal weight, and obese participants had a higher FEV1 (0.22 L, 95% CI: 0.02 to 0.42) and FVC (0.16 L, 95% CI: 0.02 to 0.30) than participants with a normal weight. Taking normal BMI as the reference group, lower FEV1 (− 0.80 L, 95% CI: − 0.97 to − 0.63) and FVC (− 0.53 L, 95% CI: − 0.64 to − 0.42) were found in underweight participants with obstructive spirometry, and better FEV1 (obesity: 0.26 L, 95% CI: 0.12 to 0.40) was found in obese participants with obstructive spirometry.Conclusion: Being underweight and severely obese are associated with reduced lung function. Slight obesity was shown to be a protective factor for lung function in people at risk of COPD and those with PRISm.Keywords: body mass index, lung function, preserved ratio impaired spirometry, chronic obstructive pulmonary disease

Keywords

• body mass index
• lung function
• preserved ratio impaired spirometry
• chronic obstructive pulmonary disease