Article Abstract

Body mass index of patients with chronic obstructive pulmonary disease is associated with pulmonary function and exacerbations: a retrospective real world research

Authors: Zhenchao Wu, Dong Yang, Zhengwei Ge, Mengdie Yan, Nan Wu, Yi Liu

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is prevalent in China. The role of body mass index (BMI) in COPD progression and prognosis is unclear. We analyzed the association between BMI and pulmonary function, inflammation levels and exacerbation in Chinese COPD patients.
Methods: Our retrospective real world research included 744 patients with COPD diagnosed by spirometry and hospitalized from January 1st, 2014 to December 31st, 2016. The indicators were gathered from hospital records database and frequency of exacerbation in the three years were followed up. All 744 patients were divided into four groups by BMI grades. We analyzed the association between BMI and pulmonary function, inflammation levels and exacerbation by Spearman bivariate correlations, Kruskal-Wallis test, Mann-Whitney U test and logistic regression.
Results: The singly proportion (median of BMI) of these patients in underweight, normal weight, overweight and obesity was 7.80% (17.54), 45.97% (22.12), 27.96% (27.00) and 18.28% (31.25) respectively. With increasing of BMI grades, the values of forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF), forced expiratory flow (FEF25/50/75) and diffusing capacity of carbon monoxide (DLCO) were correspondingly increasing; the percentage of neutrophils and C-reactive protein (CRP) presented significant declining trend while the trend of the percentage of eosinophils was negative; the dose of systemic corticosteroid and length of stay present decreasing tendency; the frequency of exacerbation and hospitalization were decreasing. These were similar results in gender, smoking status COPD subgroups.
Conclusions: In our study, BMI was moderately correlated with pulmonary function positively and exacerbations negatively. To some extent, BMI might be a useful indicator to predict the prognosis of COPD patients and for long-term management.