The association between exhaled nitric oxide and sleep apnea: The role of BMI - 09/08/14

Doi : 10.1016/j.rmed.2014.05.010

Seyyed JalilMirmohammadi ^a, Amir Houshang Mehrparvar ^a,^b, Sara Safaei ^a,^⁎ , Ehsan Samimi ^a, Mona Torab Jahromi ^a
^a Department of Occupational Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
^b Industrial Diseases Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran

^∗Corresponding author. Department of Occupational Medicine, Shahid Rahnamoun Hospital, Farrokhi ave., Yazd, Iran. Tel.: +98 3516229193; fax: +98 3516229194.

Summary

Background

Obstructive sleep apnea syndrome is associated with airway inflammation. Measurement of exhaled nitric oxide is a non-invasive method for evaluation of airway diseases. It seems that obesity is an exacerbating factor for airway inflammation. We aimed to evaluate the changes of exhaled nitric oxide after sleep in patients suffering from OSA regarding BMI.

Method

In 54 patients referred for polysomnography, exhaled nitric oxide measurements were performed before and after sleep. Subjects were divided into three categories: normal, obese with sleep apnea and non-obese, based on polysomnographic recordings and BMI.

Results

47 subjects had abnormal apnea/hypopnea index (AHI mean = 39.7) and 7 were normal regarding AHI (AHI mean = 3.0). BMI was significantly correlated to AHI, number of desaturations and hypoxia. Among those with apnea, 31 subjects were obese and 16 were non-obese. Exhaled nitric oxide levels in normal and OSA subjects showed no significant change, but a significant increase was found in obese patients with apnea (14.7 pre-sleep mean, 20.0 post-sleep mean).