Seminar: Asthma, Obesity and the Mechanics of the Airways

Speaker: Professor Jason Bates, University of Vermont, USA

Asthma is a common pathologic syndrome characterized by excessive narrowing of the airways of the lung. The underlying abnormality in asthma remains poorly understood, and indeed there may be a number of disparate causes, but obesity appears to be one of them. The recent obesity epidemic has brought to light a group of individuals who are clinically diagnosed as adults as having a kind of asthma that is not associated with atopy, and which resolves when they lose weight after receiving bariatric surgery. We hypothesize that these individuals have airways that are more compliant than normal, which predisposes their lungs to becoming collapsed when their operating lung volumes are reduced by the weight of adipose tissue in and around the thorax. Measurements of respiratory system impedance versus lung volume made with the forced oscillation technique, as well as multi-breath nitrogen washout data, support this view. In particular, both techniques reveal that obese late-onset non-atopic asthmatic subjects, in contrast to non-asthmatics, experience dramatic levels of lung derecruitmentas they expire down to functional residual capacity. These findings suggest that altered airway mechanics play an important role in the growing phenotype of obese asthma.

Brief Biography
Jason H.T. Bates obtained his B.Sc. in Physics at the University of Canterbury, New Zealand in 1977, his Ph.D. in Medicine from the University of Otago, New Zealand in 1981, and a D.Sc from Canterbury University in 1994. He is currently Professor of Medicine, Molecular Physiology & Biophysics, and Electrical & Biomedical Engineering at the University of Vermont. Dr. Bates is also Deputy Editor for the Journal of Applied Physiology, a Fellow of The American Institute for Medical & Biological Engineering, a Fellow of the Biomedical Engineering Society, and a Senior Member of IEEE-EMBS. Dr. Bates’ research focuses on the mechanical properties of the lung in health and disease.