Mauro Maniscalco1, Anna Zedda2, Stanislao Faraone2, Stefano Cristiano3, Matteo Sofia4, Andrea Motta5. 1. Section of Respiratory Medicine, S. Maria della Pietà Hospital, Casoria, Naples, Italy. Electronic address: mauromaniscalco@hotmail.com. 2. Section of Respiratory Medicine, S. Maria della Pietà Hospital, Casoria, Naples, Italy. 3. Department of Surgery, S. Maria della Pietà Hospital, Casoria, Naples, Italy. 4. Department of Respiratory Medicine, Monaldi Hospital, University Federico II of Naples, Italy. 5. Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, Naples, Italy.
Abstract
BACKGROUND: Fractional concentration of exhaled nitric oxide (FeNO) is a recognized biomarker of the lower respiratory tract, where it is produced by the proximal conducting airways and the expansible peripheral bronchoalveolar compartment. We have previously shown that large increase in body mass decreases FeNO. Here we evaluated bronchial and alveolar components of the NO output of the lower respiratory tract in subjects with severe uncomplicated obesity (OB). METHODS: Fifteen OB subjects (BMI 45.3 ± 5.6 kg/m(2)), 15 healthy controls (HC) (BMI 22.4 ± 2.4 kg/m(2)) and 10 obese subjects who experienced weight loss after bariatric surgery (OBS) (BMI 31.2 ± 3.4 kg/m(2)), were examined. Anthropometry and respiratory lung tests were performed. Exhaled NO was assessed using multiple single-breath NO analysis at different constant expiratory flow rates. From the fractional NO concentration measured at each flow-rate, the total NO flux between tissue and gas phase in the bronchial lumen (J'awNO), and the alveolar NO concentration (CANO) were extrapolated. RESULTS: Measured FeNO levels at 50 mL/s were lower in OB compared with HC and OBS (11.6 ± 2.8 ppb, 18.0 ± 4.1 ppb and 17.6 ± 2.9 ppb, respectively, p < 0.05). In OB, both J'awNO and CANO resulted significantly lower than OBS and HC values. CONCLUSIONS: Respiratory NO output is decreased in severe uncomplicated obesity for the reduction of both large/central airway maximal NO flux and alveolar NO concentration. The pathophysiological relevance of airway NO abnormalities in severe obese phenotype remains to be investigated.
BACKGROUND: Fractional concentration of exhaled nitric oxide (FeNO) is a recognized biomarker of the lower respiratory tract, where it is produced by the proximal conducting airways and the expansible peripheral bronchoalveolar compartment. We have previously shown that large increase in body mass decreases FeNO. Here we evaluated bronchial and alveolar components of the NO output of the lower respiratory tract in subjects with severe uncomplicated obesity (OB). METHODS: Fifteen OB subjects (BMI 45.3 ± 5.6 kg/m(2)), 15 healthy controls (HC) (BMI 22.4 ± 2.4 kg/m(2)) and 10 obese subjects who experienced weight loss after bariatric surgery (OBS) (BMI 31.2 ± 3.4 kg/m(2)), were examined. Anthropometry and respiratory lung tests were performed. Exhaled NO was assessed using multiple single-breath NO analysis at different constant expiratory flow rates. From the fractional NO concentration measured at each flow-rate, the total NO flux between tissue and gas phase in the bronchial lumen (J'awNO), and the alveolar NO concentration (CANO) were extrapolated. RESULTS: Measured FeNO levels at 50 mL/s were lower in OB compared with HC and OBS (11.6 ± 2.8 ppb, 18.0 ± 4.1 ppb and 17.6 ± 2.9 ppb, respectively, p < 0.05). In OB, both J'awNO and CANO resulted significantly lower than OBS and HC values. CONCLUSIONS: Respiratory NO output is decreased in severe uncomplicated obesity for the reduction of both large/central airway maximal NO flux and alveolar NO concentration. The pathophysiological relevance of airway NO abnormalities in severe obese phenotype remains to be investigated.
Authors: Njira Lugogo; Cynthia L Green; Noah Agada; Siyi Zhang; Susanne Meghdadpour; Run Zhou; Siyun Yang; Kevin J Anstrom; Elliot Israel; Richard Martin; Robert F Lemanske; Homer Boushey; Stephen C Lazarus; Stephen I Wasserman; Mario Castro; William Calhoun; Stephen P Peters; Emily DiMango; Vernon Chinchilli; Susan Kunselman; Tonya S King; Nikolina Icitovic; Monica Kraft Journal: J Allergy Clin Immunol Date: 2017-06-15 Impact factor: 10.793