title: Body mass index is associated with reduced exhaled nitric oxide and higher exhaled 8-isoprostanes in asthmatics.
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 (beta = -0.04 [95% C.I. -0.07, -0.1], p < 0.003) and (beta = -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 (beta = 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.
  
  
  CONCLUSIONS
  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.
authors: Department of Medicine, Emory University, Atlanta, USA. skomaku@emory.edu
authors: Sushma
authors: S
authors: Komakula
authors: Sumita
authors: S
authors: Khatri
authors: Joel
authors: J
authors: Mermis
authors: Samira
authors: S
authors: Savill
authors: Shireen
authors: S
authors: Haque
authors: Mauricio
authors: M
authors: Rojas
authors: LouAnn
authors: L
authors: Brown
authors: Gerald W
authors: GW
authors: Teague
authors: Fernando
authors: F
authors: Holguin
mesh_terms: D052242:Adiponectin / Q000097:blood; D000328:Adult; D000368:Aged; D001249:Asthma / Q000097:blood / Q000503:physiopathology*; D015992:Body Mass Index; D045853:Exhalation; D005260:Female; D006801:Humans; D028421:Isoprostanes; D020738:Leptin / Q000097:blood; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide; D012720:Severity of Illness Index
chemical_list: D052242:Adiponectin; D028421:Isoprostanes; D020738:Leptin; D009569:Nitric Oxide