Body mass index is associated with reduced exhaled nitric oxide and higher exhaled 8-isoprostanes in asthmatics

• Authors: Sushma Cribbs, Emory University; Sumita Khatri, Case Western; Joel Mermis, Emory University; Samira Savill, Emory University; Shireen Haque, Emory University; Mauricio Rojas, Emory University; Lou Brown, Emory University; Gerald W Teague, Emory University; Fernando Holguin, Emory University
• Journal Title: Respiratory Research
• Volume: Volume 8, Number 1
• Publisher: BioMed Central | 2007-04-16, Pages 32-32
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1186/1465-9921-8-32
• Subjects: Health Sciences, General; Health Sciences, Health Care Management
• Keywords: Science & Technology; Life Sciences & Biomedicine; Respiratory System; RESPIRATORY SYSTEM; OXIDATIVE STRESS; AIRWAY INFLAMMATION; NATIONAL-HEALTH; OBESITY; LEPTIN; ADIPONECTIN; WOMEN; SEVERITY; CHILDREN; MEN

Abstract

Background: Recently, it has been shown that increasing body mass index (BMI) in asthma is associated with reduced exhaled NO. Our objective in this study was to determine if the BMI-related changes in exhaled NO differ across asthmatics and controls, and to determine if these changes are related to increased airway oxidative stress and systemic levels of leptin and adiponectin.Methods: Observational study of the association of BMI, leptin, and adiponectin with exhaled nitric oxide (NO) and exhaled 8-isoprostanes in 67 non-smoking patients with moderate to severe persistent asthma during baseline conditions and 47 controls. Measurements included plasma levels of leptin, adiponectin, exhaled breath condensates for 8-isoprostanes, exhaled NO, pulmonary function tests, and questionnaires regarding asthma severity and control.Results: In asthmatics, BMI and the ratio of leptin to adiponectin were respectively associated with reduced levels of exhaled NO (β = -0.04 [95% C.I. -0.07, -0.1], p < 0.003) and (β = -0.0018 [95% C.I. -0.003, -0.00034], p = 0.01) after adjusting for confounders. Also, BMI was associated with increased levels of exhaled 8-isoprostanes (β = 0.30 [95% C.I. 0.003, 0.6], p = 0.03) after adjusting for confounders. In contrast, we did not observe these associations in the control group of healthy non-asthmatics with a similar weight distribution.Conclusion: In adults with stable moderate to severe persistent asthma, but not in controls, BMI and the plasma ratio of leptin/adiponectin is associated with reduced exhaled NO. Also, BMI is associated with increased exhaled 8-isoprostanes. These results suggest that BMI in asthmatics may increase airway oxidative stress and could explain the BMI-related reductions in exhaled NO. © 2007 Komakula et al; licensee BioMed Central Ltd.