Impact of BMI on exacerbation and medical care expenses in subjects with mild to moderate airflow obstruction

Yong Suk Jo,1 Yee Hyung Kim,2 Jung Yeon Lee,3 Kyungjoo Kim,4 Ki-Suck Jung,5 Kwang Ha Yoo,6 Chin Kook Rhee4 1Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kyung Hee University Hospital, Seoul, Republic of Korea; 2Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea; 3Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Konkuk University Chungju Hospital, Chungju, Republic of Korea; 4Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, College of Medicine, Seoul St Mary’s Hospital, The Catholic University of Korea, Seoul, Republic of Korea; 5Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Republic of Korea; 6Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea Background and objective: The rate of obesity is increasing in Asia, but the clinical impact of body mass index (BMI) on the outcome of chronic obstructive pulmonary disease (COPD) remains unknown. We aimed to assess this impact while focusing on the risk of exacerbation, health-care utilization, and medical costs. Methods: We examined 43,864 subjects registered in the Korean National Health and Nutrition Examination Survey (KNHANES) database from 2007 to 2012, and linked the data of COPD patients who had mild to moderate airflow obstruction (n = 1,320) to National Health Insurance (NHI) data. COPD was confirmed by spirometry. BMI was used to stratify patients into four categories: underweight (BMI