Treatment for SDB
Positive airway pressure (PAP) therapy is the first-line treatment for most patients with obstructive sleep apnea. The most common is continuous PAP, which provides a constant airflow that is used to “pneumatically splint” the vulnerable portions of the nasopharyngeal airway by having air blown into the patient’s nose and/or mouth using a nasal or full face mask, nasal pillows, or nasal prongs. Bilevel PAP provides 2 pressure levels—one during inhalation and a lower one during exhalation. The pressure drop during exhalation increases comfort for patients who have difficulty in exhaling against the incoming airflow. The automatic self-adjusting PAP uses computer-controlled flow variations to determine and supply optimal pressure. Finally, noninvasive positive pressure ventilation devices provide ventilatory assist. These devices are similar to bilevel PAP; however, the rate of oscillation between the two pressures is specified.
Overall, continuous PAP is extremely safe and very effective in patients with SDB, and its benefits are well sustained. Patients who received continuous PAP and conservative therapy (sleep hygiene and weight loss) had decreased sleepiness and improved quality of life compared with patients who received only conservative therapy.2 Similarly, in a randomized, double-blind, placebo-controlled study, patients who received therapeutic continuous PAP had less sleepiness and better quality of life than patients who received subtherapeutic continuous PAP.3 However, negative study results have also been reported.4
Comorbid psychiatric illnesses
Studies show a higher prevalence of psychiatric conditions in patients with SDB. Using Department of Veterans Affairs administrative databases, we compared patients with and without SDB. A high prevalence of psychiatric comorbid conditions was seen in more than 100,000 patients with this diagnosis (Table 3). Similar results have been found in non-veteran populations.5,6
Mood disorders. Depressive symptoms are frequently reported in patients with obstructive sleep apnea. However, the association between depression and obstructive sleep apnea remains controversial. Findings from our study as well as those from others indicate a higher prevalence of depressive symptoms in patients who have obstructive sleep apnea.5-7In contrast, other studies cast doubt on such a relationship.8