Impact of Bariatric Surgery on Pulmonary Function and Nitric Oxide in Asthmatic and Non-Asthmatic Obese Patients

Carlo Lombardi M.D.a, Sabrina Gargioni M.D.a, Angelo Gardinazzi M.D.b, Giorgio Walter Canonica M.D.c & Giovanni Passalacqua M.D.*ca Allergy Unit, Department of Internal Medicine, Sant'Orsola-Poliambulanza Hospital, Brescia, Italyb Department of General Surgery, Sant'Orsola-Poliambulanza Hospital, Brescia, Italyc Allergy & Respiratory Diseases, Department of Internal Medicine, University of Genoa, Genoa, Italy*Corresponding author: Giovanni Passalacqua, M.D., Allergy & Respiratory Diseases, Department of Internal Medicine, Padiglione Maragliano, L.go R. Benzi 10, 16132 Genoa, Italy; Tel: +39 10 3538908; Fax: +39 10 3538904; E-mail: passalacqua@unige.itBackground. Asthma is an important co-morbidity of obesity. This study evaluated the impact of bariatric surgery on respiratory function in obese patients and compared the outcomes in asthmatic and non-asthmatic subjects. Methods. The study was observational and prospective and included subjects on waiting list for bariatric surgery. Pulmonary function, symptoms, and exhaled nitric oxide were assessed before surgery and 1 year after. Results. Twenty-nine severe obese subjects (age range: 25–66 years) with a mean body mass index of 44.8 ± 4.7 kg/m2 were included. Fourteen of them had also intermittent to moderate asthma. In the whole population, the body mass index decreased from 44.8 ± 4.7 to 41.1 ± 3.9 kg/m2 (p = .0001) and the forced vital capacity increased from 3.05 ± 0.83 to 3.50 ± 0.81 L (p = .043). No change was seen in forced expiratory volume and oxygen saturation. These results remained valid also analyzing asthmatics and non-asthmatics separately. Concerning nitric oxide, the decrease at 1 year was significantly different between the two populations, since in asthma patients exhaled nitric oxide decreased by 4.86 ppb after bariatric surgery and increased by 0.27 ppb in non-asthmatics (p = .04). Conclusions. Bariatric surgery significantly reduces the intake of inhaled corticosteroids and the levels of exhaled nitric oxide, thus bronchial inflammation, in asthmatics.