Obese asthmatics may have dysfunction in distal airways at baseline that worsens with methacholine
Written By : Medha Baranwal
Medically Reviewed By : Dr. Kamal Kant Kohli
Published On 2023-05-01 03:45 GMT | Update On 2023-05-01 06:12 GMT
USA: Researchers have found in a new study that people with asthma and obesity have significant dysfunction in the distal airways at baseline that worsens with methacholine. The study was published in the CHEST journal on January 04, 2023.The study showed that this subgroup reported increased asthma exacerbations and increased symptoms, suggesting this distal airway dysfunction is...
Login or Register to read the full article
USA: Researchers have found in a new study that people with asthma and obesity have significant dysfunction in the distal airways at baseline that worsens with methacholine. The study was published in the CHEST journal on January 04, 2023.
The study showed that this subgroup reported increased asthma exacerbations and increased symptoms, suggesting this distal airway dysfunction is clinically significant. Many obese people without asthma also develop distal airway dysfunction in response to moderate doses of methacholine.
Anne E. Dixon from the University of Vermont in Burlington, VT, and colleagues aimed to investigate physiological phenotypes of asthma in obesity.
They addressed the question of physiological responses during bronchoconstriction, differentiated different groups of asthma in patients with obesity, and differentiated responses related to obesity.
For this purpose, they performed a cross-sectional study of obese patients (22 without lung disease and 31 with asthma). Participants underwent methacholine challenge testing with spirometry measurement and respiratory system impedance by oscillometry.
The study revealed the following findings:
· People had class III obesity (BMI, 46.7 ± 6.6 kg/m2 in control and 47.2 ± 8.2 kg/m2 in asthma patients).
· Most participants had remarkable changes in peripheral airway impedance in response to methacholine. In control subjects, there was an increase in resistance at 5 Hz measured by oscillometry by 45% ± 27% and area under the reactance curve (AX) by 268% ± 236% in response to 16 mg/mL methacholine; in asthma patients, there was an increase in resistance at 5 Hz measured by oscillometry by 52% ± 38% and AX by 361% ± 295% in response to provocation concentration producing a 20% fall in FEV1 dose of methacholine. These responses indicate that obesity predisposes to peripheral airway reactivity.
· Two distinct asthma groups emerged based on respiratory system impedance: one with lower reactance and more concordant bronchoconstriction in central and peripheral airways, the other with high reactance and discordant bronchoconstriction responses in central and peripheral airways.
· The high reactance asthma group included only women and reported significantly more gastroesophageal reflux disease, worse chest tightness, more wheezing, and more asthma exacerbations than the low reactance group.
"Oscillometry testing can reveal a physiological phenotype of asthma in obesity that may be linked with more severe disease and worse symptoms, and also reveal subclinical abnormalities in obese people, but without clinically diagnosed lung disease," the researchers conclude.
Reference:
Dixon, A. E., Poynter, M. E., Garrow, O. J., Kaminsky, D. A., Tharp, W., & Bates, J. H. (2023). Peripheral Airway Dysfunction in Obesity and Obese Asthma. Chest, 163(4), 753-762. https://doi.org/10.1016/j.chest.2022.12.030
Our comments section is governed by our Comments Policy . By posting comments at Medical Dialogues you automatically agree with our Comments Policy , Terms And Conditions and Privacy Policy .
Disclaimer: This site is primarily intended for healthcare professionals. Any content/information on this website does not replace the advice of medical and/or health professionals and should not be construed as medical/diagnostic advice/endorsement/treatment or prescription. Use of this site is subject to our terms of use, privacy policy, advertisement policy. © 2024 Minerva Medical Treatment Pvt Ltd