Correlation of fraction of exhaled nitric oxide with asthma control test and asthma severity in diagnosed cases of asthma

Abstract

BackgroundFraction of NO in exhaled air (FENO) has emerged as a simple, non-invasive, sensitive marker of airway inflammation in asthma diagnosis and management. Correlation studies of FENO with clinical grades of asthma and symptom burden are sparse, more so in Indian population. Hence, this study was carried out in Indian subjects to evaluate FENO correlation with asthma severity. MethodsThe study was performed on 52 proven cases of asthma in the age group of 17–90 years in period of December 2016 to May 2018. All the subjects had assessment in the form of Asthma Control Test (ACT)questionnaire, FENO parts per billion measurement with a portable NO analyzer (NIOX MINO Airway Inflammation Monitor; Aerocrine) and spirometry. Statistical analysis was presented in the form of percentage (%) and mean. ResultsOf a total of 52 asthma cases, 27 (51.9%) were male cases while 25 (48.1%) were female cases. Study population ranged from 17 to 82 years. Subjects categorized into 03 categories of asthma severity based on their treatment step. ACT score of ranged between 11 and 25 with a mean value of 20.27 and standard deviation of 3.73. No significant correlation was found between FENO and ACT (r) = −0.177, P-value = 0.210 (>0.05). Significant correlation between FENO and different grades of asthma severity was found with p-value 0.032 (<0.05). ConclusionAsthma severity as assessed by the step of treatment is correlated well with FENO value in an asthmatic individual to maintain the controlled asthma status. FENO and ACT were found to have no correlation.