Effect of bariatric surgery on airway response and lung function in obese subjects with asthma.
BACKGROUND
Obesity is a risk factor for self-reported asthma and makes asthma management more difficult. The effects of bariatric surgery on asthma in severely obese subjects remain to be documented.


METHODS
In this prospective study, 12 asthmatic patients with severe obesity were evaluated before, 6 and 12 months after bariatric surgery. Each had methacholine inhalation tests, measures of expiratory flows and lung volumes, measurements of C-reactive protein and questionnaires on asthma medication, asthma symptoms and co-morbid conditions. Eleven severely obese patients with asthma (considered as controls) underwent the same evaluations. Primary endpoint was airway responsiveness to methacholine and secondary endpoints were lung volumes and markers of systemic inflammation.


RESULTS
Mean body mass index decreased from 51.2 to 34.4 kg/m(2) twelve months post-surgery. Mean PC(20) methacholine improved from 0.84 to 6.2 mg/ml (P < 0.001); FEV(1), FVC, FRC, FRC/TLC and ERV all improved (P ≤ 0.006). C-reactive protein decreased from 8.6 to 1.7 mg/L (P < 0.001) Asthma symptoms total score was significantly reduced (P = 0.03) and asthma medication needs decreased, ten patients being able to stop all asthma drugs. No significant changes of these parameters from baseline were observed in asthmatic controls. Improvements in airway responsiveness and lung volumes happened in parallel and correlated with reductions of body mass index (r = 0.58, P = 0.049), C-reactive protein levels (r = -0.74, P = 0.004).


CONCLUSIONS
Airway responsiveness, lung volumes and asthma severity/control markedly improved with weight loss following bariatric surgery in severely obese patients.
Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Canada. lpboulet@med.ulaval.ca
Louis-Philippe
LP
Boulet
Hélène
H
Turcotte
Julie
J
Martin
Paul
P
Poirier
D000328:Adult; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology; D050110:Bariatric Surgery; D015992:Body Mass Index; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents; D002097:C-Reactive Protein / Q000378:metabolism; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications* / Q000601:surgery*; D011446:Prospective Studies; D015656:Respiratory Mechanics / Q000502:physiology; D015431:Weight Loss / Q000502:physiology; D055815:Young Adult
D018927:Anti-Asthmatic Agents; D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride; D002097:C-Reactive Protein