The Effect of Low Body Mass Index on the Development of Chronic Obstructive Pulmonary Disease and Mortality

Abstract

Background: Sarcopenia may worsen disease progression and lead to poor outcomes in chronic obstructive pulmonary disease (COPD). However, its effect on the development of COPD is unclear. Methods: We enrolled 437,584 participants registered in the physical health check-up cohort database of the Korean National Health Interview Survey from 2002 to 2003, after exclusion of participants older than 65 years and those previously diagnosed with COPD confirmed by ICD-10 code and prescribed medication. We classified participants according to smoking duration and BMI at baseline. COPD development and mortality were checked for 13 years. Findings: Participants in the low BMI group (<18.5 kg/m2) had a significantly higher rate of COPD development for 13 years (7.6%) than those in other groups (3.4-4.1%; P < .0001). Among never or light smokers, COPD development in the low BMI group (5.6–6.7%) was significantly higher than those in other groups (2.8–4.7%). Similarly, among participants with a smoking history of ≥30 years, same trend was observed (20.1% versus 8.4-12.4%). On multivariable analysis, normal or higher than normal body weight was significantly protective against the development of COPD (hazard ratio [HR], 0.609–0.739; P < .0001) compared to low BMI. It also shows better COPD-free-survival (HR, 491–0.622; P < .0001) and overall survival (HR, 0.440–0.585; P < .0001) compared to low BMI. Interpretation: Low BMI is an important risk factor for COPD development and mortality. Maintaining normal or higher than normal body weight may reduce the risk for COPD development and mortality. Funding Statement: None Declaration of Interests: None Ethics Approval Statement: This study was approved by the Institutional Review Board of Gangnam Severance Hospital (number: 3-2018-0034). The requirement for informed consent was waived considering the retrospective nature of this study.