Neurodegenerative disease and Decline in Deep Sleep
This article in SLEEP indicates a relationship between declining REM and delta (Stage N3) sleep. The researchers went back to 2004-2007 and looked at polysomnogram (PSG) sleep studies with a special eye on baseline REM and delta percentages among middle age adults, mostly men, who were disease free at the time. Then going forward, they retested these individuals at various levels of followup, on average 12 years later, and then compared findings between those who developed neurodegenerative diseases and those who did not. The pattern in this graphic shows the obvious decline in REM and delta with the gold and black lines in the right column. Thus, neurodegenerative diseases were clearly associated with less REM and Delta sleep as well those with more awakenings.