MedicalResearch.com Interview with:
Ken M. Kunisaki , MD
Associate Professor of Medicine
Pulmonary, Allergy, Critical Care and Sleep Medicine
University of Minnesota
Medical Research: What is the background for this study? What are the main findings?
Dr. Kunisaki : Obstructive sleep apnea (OSA) is a very common condition that is the result of recurrent complete or partial closure of the upper airway during sleep. OSA leads to poor sleep quality and excessive daytime sleepiness.
A previous study suggested that OSA is more common in the winter, but there were no vitamin D measurements in that study, which seemed potentially relevant since many people have lower vitamin D levels in the winter, due to less sunlight exposure in the winter. Several studies have also shown that people with low vitamin D levels have worse muscle function. Since muscles are partially responsible for keeping the upper airway open during sleep, we wondered whether people with low vitamin D levels might have weaker upper airway muscles and therefore be more prone to having OSA.
In our study, we found that indeed, persons with OSA had lower vitamin D levels than those without OSA, but this was explained by obesity. In other words, the low vitamin D levels seen in OSA patients is likely just a marker of obesity and not likely related to the presence or absence of OSA.
Medical Research: What should clinicians and patients take away from your report?
Dr. Kunisaki : Our data would suggest that checking vitamin D levels and/or taking vitamin D supplements likely has no impact on the development or severity of OSA.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Kunisaki : Like almost all studies, our study had some important limitations. Our study participants were generally healthy, older (mean age was 76.4 years), Caucasian (92.2%) men. As such, we have to be careful to say our results may not apply to other groups such as women, younger people, and non-Caucasians. We also had very few people with profoundly low vitamin D levels (such as <12 ng/mL) where there may be the strongest effects on muscle problems; therefore, we can’t say much about that particular group. Future research might look at other populations like women, non-Caucasians, and those with very low vitamin D levels, to see if vitamin D has any potential relationship to OSA in those patients.
Authors: Umesh Goswami1 , Kristine E. Ensrud1,2, Misti L. Paudel2 , Susan Redline3,4, Eva S. Schernhammer3,4, James M. Shikany5 , Katie L. Stone6 , Ken M. Kunisaki2,1 for the Osteoporotic Fractures in Men (MrOS) Study Research Group.
American Thoracic Society (ATS) December 2015
Ken M. Kunisaki , MD (2015). Vitamin D Level Likely Has No Impact on Sleep Apnea