For ten years, children and adults with asthma and other respiratory disorders have attended my AsthmaCare courses in Ireland and abroad. One striking observation is the number of patients who attend for asthma but who also reported suffering from snoring, sleep apnoea, and chronic fatigue. This is not surprising given the physiological effects from chronic hyperventilation that contribute to narrowing of the airways and sleepdisordered breathing. Breathing volume is greater when asthma is severe, poorly controlled or unstable. This will have a knock-on effect by increasing the severity of snoring and sleep apnoea.
This section examines the relationship between asthma and sleep-disordered breathing, which includes snoring and sleep apnoea.
It is estimated that there are 300 million people worldwide with asthma, and its prevalence increases by 50% every decade. The relationship between asthma, snoring, and sleep apnoea is significant, with one researcher claiming that “approximately 74% of asthmatics experience nocturnal symptoms of airflow obstruction secondary to reactive airways disease.” From a study of 244 asthmatic patients, Teodorescu et al. found that “37% snored habitually and 40% demonstrated high OSA (obstructive sleep apnoea) risk.” A high risk of OSA was determined by asthma severity, reflux and use of an inhaled steroid medication.
Julien et al. tested the hypothesis that the prevalence and severity of sleep apnoea is greater among patients with severe asthma compared with moderate asthma and controls without asthma. Comparisons were made between 26 patients with severe asthma, 26 patients with moderate asthma, and 26 patients without asthma of similar age and body mass index. The study found that 88% of patients in the severe asthma group, 58% of patients in the moderate asthma group, and 31% of patients in the controls without asthma group had more than 15 apnoeic events per hour. The paper concluded that “Obstructive sleep apnoea-hypopnea was significantly more prevalent among patients with severe compared with moderate asthma, and more prevalent for both asthma groups than controls without asthma.”
Researchers investigated whether asthma can promote obstructive sleep apnoea by examining the prevalence of OSA among patients with asthma that is difficult to control. The paper, published in The Journal of Asthma, concluded that the “study showed an unexpectedly high prevalence of OSA among patients with unstable asthma receiving long-term chronic or frequent burst of oral corticosteroid therapy.”
Similar findings were published in a paper entitled, “Association of Obstructive Sleep Apnoea Risk With Asthma Control in Adults,” which found from a study of 472 asthmatic patients that poorly controlled asthma resulted in a threefold increase in the risk of obstructive sleep apnoea. The paper concluded “that there is a higher risk of OSA in patients with not well controlled asthma independent of known asthma aggravators.”
In a paper entitled, “Obstructive sleep apnoea syndrome and asthma: what are the links?” Alkhalil et al. noted that several studies confirm that asthmatics are more prone to developing obstructive sleep apnoea. The paper further noted that symptoms in common for asthma and OSA included nasal obstruction, a decrease in the pharyngeal cross sectional area, and an increase in upper airway collapsibility.