Measurement of exhaled nitric oxide in healthy Egyptian population: normal ranges and factors affecting

Abstract Background Nitric oxide is an important regulatory mediator throughout the body. Naturally, the diagnostic applicability of fraction of exhaled nitric oxide (FeNO) depends on the availability of reference values that adequately take into account the major factors affecting FeNO. FeNO values are strongly influenced by several intraindividual factors, including age, atopy, high immunoglobulin E, height, weight, sex, and smoking habits. This study aimed to address the normal ranges of FeNO in healthy Egyptian adults and its relation to other personal factors. Materials and methods A total of 211 healthy Egyptian individuals were selected from pulmonary outpatient clinics and the Chest Department of University Hospital during the period between January 2014 and September 2014. Pulmonary function tests, FeNO measurement, and laboratory tests were carried out. The participants’ demographic data were also recorded. Results There was significant negative correlation between measured FeNO and age, weight, BMI, and smoking index. A positive correlation was found between FeNO and height. Female participants had significantly lower levels of FeNO (20.4 ± 9.9) compared with male nonsmokers (28.2 ± 12.4). Conclusion FeNO is affected by sex, BMI, weight, height, and current smoking. The reference ranges for FeNO in healthy Egyptian adults were similar to those of the Caucasian population. In general, values of more than 50 parts per billion (ppb) in male participants and 40 ppb in female participants are considered abnormal in Egyptian populations.