Asthma typically has an allergic basis that develops early in life. By contrast, many obese asthmatics have late-onset, non-atopic (LONA) asthma that is specific to their obese state. Furthermore, this LONA phenotype is frequently unresponsive to conventional steroid therapy. This leaves these subjects with few treatment options other than major weight loss, which is rarely achieved. There is thus a critical need to develop alternative approaches to asthma therapy in obese patients. Our preliminary data lead us to hypothesize that the airways hyperresponsiveness of LONA obese asthma occurs in those individuals who are particularly prone to experience closure of their small airways following bronchial challenge at the reduced lung volumes characteristic of obesity. Our computational modeling studies further show that increased closure can be explained by these individuals having airways that are more compliant and/or thicker than average, causing them to experience the symptoms of asthma in the setting of obesity when lung volume becomes chronically reduced as a result of excess weight. Our goal is to test this hypothesis in LONA asthmatics by assessing airway wall compliance as reflected in lung impedance measured with the forced oscillation technique, ventilation heterogeneity measured by nitrogen washout, and airway compliance and wall thickness determined by comparing CT images taken at total lung capacity and at functional residual capacity. We will also establish the efficacy of elevating lung volume with positive end-expiratory pressure (PEEP) as a means of resolving an asthma attack once it starts (i.e. as a rescue therapy), and for reducing the likelihood of having an asthma attack in the first place (i.e. as a controller therapy). Again, lung impedance and nitrogen washout will be used as the key outcome measures reflective of the effects that PEEP has on lung function. The increasing incidence of asthma in the US has been linked to increasing obesity, adding significantly to the already huge public health burden created by the obesity pandemic. By defining the utility and efficacy of volume elevation in obese asthma we anticipate being able to bring about an important change in the way therapies are administered to a large patient population that currently has few treatment options.

Public Health Relevance

Obesity is a major risk factor for asthma, altering the nature of the disease and its response to therapy. There is a critical need to understand the pathophysiology of asthma in obesity and to develop new treatments. The goal of this proposal is to understand mechanisms contributing to airway hyperresponsiveness in obesity and to develop a customized new therapy for this disease.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL130847-02
Application #
9243305
Study Section
Special Emphasis Panel (ZRG1-CVRS-G (02))
Program Officer
Noel, Patricia
Project Start
2016-03-15
Project End
2020-02-29
Budget Start
2017-03-01
Budget End
2018-02-28
Support Year
2
Fiscal Year
2017
Total Cost
$577,979
Indirect Cost
$199,507
Name
University of Vermont & St Agric College
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405
Nyenhuis, Sharmilee M; Dixon, Anne E; Ma, Jun (2018) Impact of Lifestyle Interventions Targeting Healthy Diet, Physical Activity, and Weight Loss on Asthma in Adults: What Is the Evidence? J Allergy Clin Immunol Pract 6:751-763
Dixon, Anne E; Peters, Ubong (2018) The effect of obesity on lung function. Expert Rev Respir Med 12:755-767
Peters, Ubong; Dixon, Anne E; Forno, Erick (2018) Obesity and asthma. J Allergy Clin Immunol 141:1169-1179
Kanagalingam, S; Shehab, S S; Kaminsky, D A et al. (2018) Effect of obesity on sinonasal disease in asthma. J Asthma 55:525-531
Peters, Ubong; Suratt, Benjamin T; Bates, Jason H T et al. (2018) Beyond BMI: Obesity and Lung Disease. Chest 153:702-709
Wellman, Tyler J; MondoƱedo, Jarred R; Davis, Gerald S et al. (2018) Topographic distribution of idiopathic pulmonary fibrosis: a hybrid physics- and agent-based model. Physiol Meas 39:064007
Qian, Xi; Aboushousha, Reem; van de Wetering, Cheryl et al. (2018) IL-1/inhibitory ?B kinase ?-induced glycolysis augment epithelial effector function and promote allergic airways disease. J Allergy Clin Immunol 142:435-450.e10
Kaminsky, David A; Wang, Lucy L; Bates, Jason H T et al. (2017) Fluctuation Analysis of Peak Expiratory Flow and Its Association with Treatment Failure in Asthma. Am J Respir Crit Care Med 195:993-999
Dixon, Anne E; Castro, Mario; Gerald, Lynn B et al. (2017) Effect of intranasal corticosteroids on allergic airway disease in asthma. J Allergy Clin Immunol Pract 5:1125-1128.e3
Dixon, Anne E; Suratt, Benjamin T (2017) Chair's Summary: Obesity and Associated Changes in Metabolism, Implications for Lung Diseases. Ann Am Thorac Soc 14:S314-S315

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