Interestingly, the glymphatic cleanrance occurs during the NREM sleep, and more specifically the NREM SWS sleep.[29][30][32] As seen previously, it is a sleep stage that decreases in normal aging.[30] So there is less glymphatic clearance and an increase in AB burden that will form the AB plaques.[32][29][30] Therefor, in AD sleep disturbances will amplify this phenomenon.

^ Keckeis, Marietta; Lattova, Zuzana; Maurovich-Horvat, Eszter; Beitinger, Pierre A.; Birkmann, Steffen; Lauer, Christoph J.; Wetter, Thomas C.; Wilde-Frenz, Johanna; Pollmächer, Thomas (2010). Finkelstein, David (ed.). "Impaired Glucose Tolerance in Sleep Disorders". PLoS ONE. 5 (3): e9444. doi:10.1371/journal.pone.0009444. PMC 2830474. PMID 20209158.

There are many possible causes of restless legs syndrome, including kidney failure, nerve disorders, vitamin and iron deficiencies, pregnancy, and some medications (such as antidepressants). Recent studies have shown a strong genetic link and researchers have been able to isolate a gene that may be responsible for at least 40% of all cases of the disorder.
A systematic review found that traumatic childhood experiences (such as family conflict or sexual trauma) significantly increases the risk for a number of sleep disorders in adulthood, including sleep apnea, narcolepsy, and insomnia.[17] It is currently unclear whether or not moderate alcohol consumption increases the risk of obstructive sleep apnea.[18]
The natural internal clock that controls our 24-hour cycle of sleep and waking, circadian rhythms are easily upset by changes in schedule, and they're greatly affected by light and darkness. Jet lag is the best known circadian rhythm disorder, but this sensitive inner clock can also be disrupted by changes in routine resulting in an erratic sleep schedule.