Abstract

Afef Chouchane, Hanène Miâdi-Messaoud, Wafa Ben Turkia, Sonia Rouatbi, Zouhair Tabka, Abdel Aziz Ben-Jebria

Obesity and asthma are associated disorders but the mechanisms responsible for this relationship are unclear. Exhaled nitric oxide has been proposed as a non invasive marker of airway inflammation in asthma. The aim of this study was to investigate the relationship between exhaled nitric oxide, body mass index (BMI) and airway hyper-responsiveness to methacholine. Fifty two (21 lean and 31 obese) healthy women were recruited and examined in the Clinical Laboratory of Physiology located in the Medical School of Sousse. The average ages (± s.e.) of the two groups of lean and obese were 35.6±2.1 and 37.4±1.9 years, respectively. Their corresponding mean BMI (± s.e.) were 22.1±0.3 and 37.7±1.2 kg.m¯², respectively. Pulmonary function tests, exhaled NO and airway hyper-responsiveness were investigated in the two groups. Our data indicate that: (1) exhaled NO levels were significantly correlated BMI (r=0.85; p<0.001) as well as with the efficacy of the MCH agonist promoting the maximal response (r=0.45; p=0.001); and 2) the mean of exhaled NO was significantly higher in obese than in lean group (p<0.001). We concluded that obesity induced airway hyper-reactivity in obese women through airway inflammation as evidenced by the significant association between exhaled NO and BMI.