Obstructive Sleep Apnea in Bronchial Asthma Patients: Assessment of Prevalence and Risk Factors

Sleep-related breathing disorders are group of respiratory disease among them obstructive sleep apnea (OSA) is highly prevalent and seen among those having recognized risk factors. Recent studies have shown that asthma and OSA contribute bi directional relationship where each disorder adversely influences the other one. This study was planned to assess OSA among bronchial sthma patients.

This study was conducted at Sleep lab of our department among adult patients of bronchial asthma after institutional ethical committee approval. Eligible and willing to participate patients were subjected to clinical assessment protocol that included history, clinical examination, measurement of Sleep Score, BMI, neck circumference etc followed by overnight Level 1 polysomnography.

50 patients with age range 30 to 68 years constituted the study population with mean age of 48.16 years. 70% patients were female with male female ratio of 1:2.3. The prevalence of OSA in asthma patients was 46%. 12% patients had mild OSA, 14% had moderate while 20% were having severe OSA. Mean BMI in our study was 27.87 Kg/m2 . OSA patients were associated with more BMI compared to patients without OSA (42% vs. 30%) (p value 0.04). Asthma patients who were smokers had more OSA symptoms compared to non-smokers (p value 0.002). Asthma patients with OSA were also associated with higher neck circumference and more snoring at night time as compared to non OSA population. Uncontrolled asthma was seen in 18 patients and 16 of them were having OSA (p=0.001). Most common co morbid illness in patients with OSA was GERD (78.26%) followed by allergic rhinitis (56%). Most of these patients (82%) were not having associated major local anatomical defect.

:OSA is not uncommon in asthma patients. Careful assessment of sleep related symptoms and demographic parameters of asthma patients are essential to suspect diagnosis of OSA. Additional factors like smoking, obesity, GERD and allergic rhinitis are important contributing factor for higher risk of OSA among asthma patients. Early diagnosis of OSA in asthma patients by polysomnography may have a clinical benefit in the management of both diseases.