Patients with obstructive sleep apnea can be grouped into distinct clinical subtypes that differ in response to positive airway pressure treatment, according to two studies published in the March issue of the journal Sleep.
In the first study, investigators evaluated whether patients in different clinical clusters responded differently to positive airway pressure (PAP) treatment. Authors identified 706 patients with moderate to severe obstructive sleep apnea (OSA) from the Icelandic Sleep Apnea Cohort. All patients completed a sleep study prior to starting PAP treatment, and completed questionnaires to assess symptoms. Patients were grouped into one of three clusters based on symptomatology: disturbed sleep, minimally symptomatic, or sleepy, wrote Grace W. Pien, MD, of the division of pulmonary and critical care medicine at Johns Hopkins University, Baltimore, and her coauthors.
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Patients in the minimally symptomatic cluster reported symptoms at lower rates than patients in the other clusters at baseline, and they remained relatively asymptomatic at follow-up, the authors noted. By comparison, patients in the sleepy group reported the highest Epworth Sleepiness Scale scores at baseline (16.0 plus or minus 3.4), which fell by five points at follow-up (mean change, −5.3; 95% confidence interval, −5.8 to −4.8). Also, patients in the sleepy group reported higher rates of drowsy driving (37.8%) at baseline, which dropped to 8.1% at follow-up (odds ratio, 0.06; 95% CI, 0.03-0.14).