Researchers in Europe have found that continuous positive airway pressure (CPAP) can reduce daytime sleepiness in sufferers of obstructive sleep apnea (OSA), even if their symptoms are minimal.
It has also shown effectiveness in improving the quality of life of such people.
"Treatment with CPAP clearly reduces daytime sleepiness and improves quality of life in patients with very limited symptoms, at a rate of about half the improvement seen in patients with more severe symptoms," said Sonya Craig, research fellow at Churchill Hospital, Oxford.
Researchers observed 341 patients with proven OSA but insufficient current symptoms. They randomised patients to receive CPAP for six months or no treatment.
The Epworth Sleepiness Score, a standard scoring system used in sleep studies, was used to determine the change in daytime sleepiness measured at the start of the study and again at after six months.
Wakefulness and sleepiness were also measured using a second test, called the Oxford Sleep Resistance Test (OSLER), and quality of life was assessed using a standard questionnaire.
After six months of the treatment, CPAP significantly reduced daytime sleepiness and increased wakefulness compared to the standard treatment group.
"The magnitude of the improvement in sleepiness and quality of life scores was greater than expected, particularly given that the patients were considered to have only very mild symptoms when assessed in clinic," she said.
The study will be presented at the ATS 2011 International Conference in Denver.