Oral appliance therapy vs. nasal CPAP in obstructive sleep apnea: an award-winning study on psychological distress
Editor’s note: Dr. Ghizlane Aarab is a research committee member of the American Academy of Dental Sleep Medicine (AADSM) and was recently selected as a recipient of an AADSM Clinical Research Award for 2014.
Obstructive sleep apnea (OSA) is characterized by recurrent obstruction of the upper airway, often resulting in oxygen desaturation and arousal from sleep. Common symptoms include excessive daytime sleepiness, snoring, and reduced ability to concentrate or focus. Additionally, some OSA patients report symptoms of psychological distress, such as depression and anxiety.
ADDITIONAL READING |Prospective multicenter cohort study of obstructive sleep apnea (OSA) patients treated with a custom-made mandibular repositioning device (MRD)
Although continuous positive airway pressure (CPAP) has been proposed as the most effective treatment for severe OSA patients, another option — mandibular advancement devices (MADs) — are also being considered as a primary treatment option for those with mild and moderate OSA or those who do not tolerate CPAP.
ADDITIONAL READING |Dental professionals can help screen for sleep apnea
MADs reposition the mandible and tongue, which improves upper airway patency during sleep by enlarging the upper airway and decreasing upper airway collapsibility. For example, titratable MADs are designed to gradually protrude the mandible by a mechanical advancing mechanism, until an effective protrusive position is achieved.
The therapeutic effects of MADs on respiratory and subjective symptoms (e.g., daytime sleepiness and quality of life) when compared with those of CPAP were proven to be satisfactory in several randomized controlled trials, but before our study no randomized, placebo-controlled trials were performed that compared the effects of an objectively titrated MAD and CPAP on psychological distress symptoms. Therefore, the aim of this study was to compare the effects of a titrated MAD with those of nasal CPAP on psychological distress symptoms.
Our study was part of a randomized, placebo-controlled trial in which different treatment effects of a titrated MAD were compared with those of nasal CPAP and an intraoral placebo appliance. Sixty-four patients, with mild to moderate OSA and an average age of 52 years, were randomly assigned to one of the three groups (titrated MAD, nasal CPAP, or intraoral placebo appliance). All patients filled out a symptom checklist that was designed to measure symptomatic psychological distress over the prior week (e.g., depression and anxiety) before and after their six-month treatments.
All three groups showed higher-than-average values of psychological distress at the baseline, which included items such as somatization, insufficiency of thinking and acting, agoraphobia, anxiety, and sleeping problems, among others, than the reported averages for the Dutch population. The changes in the different dimensions from baseline to therapy evaluation were not significantly different between the three groups, while the pooled data of the three groups showed significant improvements over time in the aforementioned dimensions.
Our team concluded from this study that there is no significant difference between the titrated MAD and nasal CPAP in their beneficial effects on psychological distress symptoms. Furthermore, the placebo effects probably play an important role in the significant improvements of psychological distress symptoms with these therapies.
