CPAP benefits extend to mild OSA patients

Jul 20 2012

By Lucy Piper

The use of continuous positive airway pressure (CPAP) treatment, an effective option for severe obstructive sleep apnea (OSA), should be extended to sleepy patients with milder OSA, say US researchers.

They found that patients with mild and moderately severe OSA had greater functional improvement after 8 weeks of CPAP therapy compared with sham CPAP.

"The improvements we saw were highly significant and clinically relevant," said lead researcher Terri Weaver (University of Illinois at Chicago College of Nursing) in a press statement.

"In addition, our study was conducted at both large and smaller clinical practice sites, making our results highly generalizable."

In all, 239 participants, aged an average of 50 years, with newly diagnosed mild OSA (apnea-hypopnea index [AHI] with 3% desaturation 5-30 events/hour) and self-reported daytime sleepiness (Epworth Sleepiness Scale [ESS] score >10) were randomly assigned to receive CPAP or sham CPAP for 8 weeks.

During the 8 weeks of treatment, total score on the Functional Outcomes of Sleep Questionnaire (FOSQ) increased from an average of 13.92 to 14.89 in the 121 patients receiving active CPAP, whereas it fell from an average of 14.41 to 14.27 in the 118 patients receiving sham treatment.

After taking into account clinical center and different clinical and demographic characteristics, analyses showed a mean increase in FOSQ score of 0.98 following active treatment and a mean decrease of 0.06 after sham treatment.

The group difference in mean changes in FOSQ from baseline to week 8 was 0.95, corresponding to an effect size of 0.41.

Ninety-one patients initially received sham CPAP then crossed over to receive 8 weeks of active CPAP treatment, and for these patients the mean improvement in FOSQ total score from baseline was 1.73, corresponding to an effect size of 0.69.

Active CPAP treatment also resulted in significant improvements in ESS scores, Physical Component scores on the Short-Form 36 Health Outcomes Survey, and Total Mood Disturbance scores on the Profile of Mood States scale.

"The improvement we found in functional status in sleepy patients with milder OSA is consistent with studies of those with more severe disease and supports the application of CPAP therapy as standard in patients with milder OSA who have symptoms of daytime sleepiness," the team concludes in the American Journal of Respiratory and Critical Care Medicine.

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