BMI but not central obesity predisposes to airway closure during bronchoconstriction.

Autor: Peters U; Division of Pulmonary and Critical Care Medicine, Vermont Lung Center, University of Vermont Larner College of Medicine, Burlington, VT, USA., Subramanian M; Division of Pulmonary and Critical Care Medicine, Vermont Lung Center, University of Vermont Larner College of Medicine, Burlington, VT, USA., Chapman DG; Division of Pulmonary and Critical Care Medicine, Vermont Lung Center, University of Vermont Larner College of Medicine, Burlington, VT, USA.; Translational Airways Group, University of Technology, Sydney, NSW, Australia.; Airway Physiology and Imaging Group, Woolcock Institute of Medical Research, Sydney, NSW, Australia., Kaminsky DA; Division of Pulmonary and Critical Care Medicine, Vermont Lung Center, University of Vermont Larner College of Medicine, Burlington, VT, USA., Irvin CG; Division of Pulmonary and Critical Care Medicine, Vermont Lung Center, University of Vermont Larner College of Medicine, Burlington, VT, USA., Wise RA; Department of Medicine, Johns Hopkins University, Baltimore, MD, USA., Skloot GS; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA., Bates JHT; Division of Pulmonary and Critical Care Medicine, Vermont Lung Center, University of Vermont Larner College of Medicine, Burlington, VT, USA., Dixon AE; Division of Pulmonary and Critical Care Medicine, Vermont Lung Center, University of Vermont Larner College of Medicine, Burlington, VT, USA.
Jazyk: angličtina
Zdroj: Respirology (Carlton, Vic.) [Respirology] 2019 Jun; Vol. 24 (6), pp. 543-550. Date of Electronic Publication: 2019 Jan 29.
DOI: 10.1111/resp.13478
Abstrakt: Background and Objective: Obesity produces restrictive effects on lung function. We previously reported that obese patients with asthma exhibit a propensity towards small airway closure during methacholine challenge which improved with weight loss. We hypothesized that increased abdominal adiposity, a key contributor to the restrictive effects of obesity on the lung, mediates this response. This study investigates the effect of body mass index (BMI) versus waist circumference (WC) on spirometric lung function, sensitivity to airway narrowing and closure, and airway closure during bronchoconstriction in patients with asthma.
Methods: Participants underwent spirometry and methacholine challenge. Sensitivity to airway closure and narrowing was assessed from the dose-response slopes of the forced vital capacity (FVC) and the ratio of forced expiratory volume in 1 s (FEV 1 ) to FVC, respectively. Airway closure during bronchoconstriction (closing index) was computed as the percent reduction in FVC divided by the percent reduction in FEV 1 at maximal bronchoconstriction.
Results: A total of 116 asthmatic patients (56 obese) underwent methacholine challenge. Spirometric lung function was inversely related to WC (P < 0.05), rather than BMI. Closing index increased significantly during bronchoconstriction in obese patients and was related to increasing BMI (P = 0.01), but not to WC. Sensitivity to airway closure and narrowing was not associated with BMI or WC.
Conclusion: Although WC is associated with restrictive effects on baseline lung function, increased BMI, rather than WC, predisposes to airway closure during bronchoconstriction. These findings suggest that obesity predisposes to airway closure during bronchoconstriction through mechanisms other than simple mass loading.
(© 2019 Asian Pacific Society of Respirology.)
Databáze: MEDLINE
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