A new study provides evidence that obstructive sleep apnea (OSA) is highly prevalent in people with multiple sclerosis (MS), and it suggests that OSA may be a contributor to the fatigue that is one of the most common and debilitating symptoms of MS. Results show that one-fifth of MS patients surveyed in a large tertiary MS practice carried a diagnosis of OSA, and more than half were found to have an elevated risk for OSA based on a validated screening tool. Further analysis showed that OSA risk was a significant predictor of fatigue severity, even after adjusting for potential confounders such as age, gender, body mass index (BMI), sleep duration, and depression.

“OSA may be a highly prevalent and yet under-recognized contributor to fatigue in persons with MS,” says lead author and principal investigator Tiffany J. Braley, MD, MS, an Assistant Professor of Neurology from the University of Michigan Multiple Sclerosis and Sleep Disorders Centers in Ann Arbor, in a release. “Our study suggests that clinicians should have a low threshold to evaluate MS patients for underlying sleep disturbances.”

The study results appear in the February 15 issue of the Journal of Clinical Sleep Medicine, which is published by the American Academy of Sleep Medicine (AASM).

“Obstructive sleep apnea is a chronic illness that can have a destructive impact on your health and quality of life,” says AASM president Dr M. Safwan Badr. “People with multiple sclerosis who are found to have a high risk of OSA should be referred to a board certified sleep medicine physician for a comprehensive sleep evaluation.”

Braley and her colleagues, Benjamin M. Segal, MD (Director of the University of Michigan Multiple Sclerosis Center), and Ronald D. Chervin, MD, MS (Director of the University of Michigan Sleep Disorders Center), studied 195 MS patients who completed a sleep questionnaire and four validated instruments designed to assess daytime sleepiness, fatigue severity, insomnia severity, and OSA risk. Medical records also were accessed to examine clinical characteristics that may predict fatigue or OSA risk.

According to the authors, the cross-sectional design of the study did not allow for an examination of cause-and-effect relationships. However, the results suggest that a substantial portion of MS-related fatigue could be eliminated by the diagnosis and successful treatment of OSA in patients with MS.