Association Between Pulmonary Function Parameters and Apnea Hypopnea Index in Asthmatic Children Living at High Altitude.

INTRODUCTION

Obstructive sleep apnea (OSA) has been associated with poorer asthma outcomes in children, including reduced disease control and a greater risk of exacerbation. However, little is known about the relationship between sleep-disordered breathing severity and pulmonary function in pediatric patients residing at high altitude.

METHODS

We conducted a cross-sectional study including children aged 3-12 years with physician-diagnosed asthma who underwent overnight polysomnography at a referral center in Bogotá, Colombia (2640 m above sea level), between 2012 and 2017. Clinical characteristics, spirometric measurements, oscillometry parameters, and polysomnographic variables were collected and analyzed. Associations between pulmonary function indices and apnea-hypopnea measures were evaluated using Spearman correlation analysis.

RESULTS

Sixty-four children were included, of whom 59.4% had moderate-to-severe asthma and 59.4% had uncontrolled disease. In oscillometry, airway resistance at 5 Hz (R5) demonstrated an inverse correlation with AHI before bronchodilator administration (r = -0.440, p < 0.05) and after bronchodilator administration (r = -0.491, p < 0.05). Similar inverse correlations were observed between R5 and OAHI. Among spirometric variables, postbronchodilator FEV1 was negatively correlated with OAHI (r = -0.329, p < 0.05). No significant associations were found between OSA severity and asthma severity, body mass index, or nocturnal oxygen saturation.

CONCLUSIONS

Our findings revealed an association between the AHI and VEF1 in asthmatic children residing in a tropical city at high altitude. However, the results regarding the relationship between AHI and R5 were contradictory.