A new study by researchers at the University of Michigan Multiple Sclerosis and Sleep Disorders Centers, Ann Arbor, Mich, provides evidence that obstructive sleep apnea (OSA) is highly prevalent in people with multiple sclerosis (MS), and it may be a contributor to fatigue – one of the most common and debilitating symptoms of MS.

These findings are based on a study published in the Journal of Clinical Sleep Medicine, which is produced by the American Academy of Sleep Medicine (AASM).

According to investigators with the study, 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,” said 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, Mich. “Our study suggests that clinicians should have a low threshold to evaluate MS patients for underlying sleep disturbances.”

“Obstructive sleep apnea is a chronic illness that can have a destructive impact on your health and quality of life,” said M. Safwan Badr, MD, president of the AASM. “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.