Electroencephalographic sleep in the healthy "old old": a comparison with the "young old" in visually scored and automated measures.

This report extends the normative study of sleep into healthy 80-year-olds and compares them with healthy 70- and 60-year-olds. We observed stability of sleep efficiency and rapid eye movement sleep across three decades of late life, but a slight decline of slow-wave sleep in the 80-year-olds (decreased total delta wave counts). Women showed better preservation of slow-wave sleep than men. Automated EEG period analysis of this phenomenon demonstrated higher rates of delta wave production in the first NREM sleep period of women compared to that of men, a finding associated with longer REM sleep latencies in women. Unexpectedly, 80-year-old women showed decay in sleep maintenance, while 80-year-old men demonstrated stability of sleep maintenance, relative to their respective 60- and 70-year-old counterparts. Implications for the understanding of sleep and its regulation in health and aging are discussed.