A study involving 302 older women (mean age 82) has found that those with moderate to severe sleep apnea were at twice the risk of having problems in performing basic functions associated with independent living.
http://www.eurekalert.org/pub_releases/2014-11/jhub-oww111214.php
Spira, A. P., Stone, K. L., Rebok, G. W., Punjabi, N. M., Redline, S., Ancoli-Israel, S., & Yaffe, K. (2014). Sleep-Disordered Breathing and Functional Decline in Older Women. Journal of the American Geriatrics Society, 62(11), 2040–2046. http://doi.org/10.1111/jgs.13108