People Who Achieve REM Sleep Later Might Be Experiencing Early Symptom of Alzheimer Disease

Image credit: Pixel-Shot | stock.adobe.com

Research published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association demonstrated that people who take longer to start rapid eye movement (REM) sleep may be experiencing an early symptom of Alzheimer disease (AD) and AD and related dementias (ADRD). The authors note that additional intervention trials are needed to determine if targeting REM latency can modify one’s risk for AD or ADRD.¹

Sleep disturbances, according to the authors, are common in patients with dementia and have become increasingly associated with AD and ADRD. Additionally, they note that growing evidence has indicated a potential association of sleep duration, sleep quality, or excessive daytime sleepiness with amyloid beta (Aβ) deposition assessed by positron emission tomography (PET) scans or cerebrospinal fluid (CSF) measures in older adults.¹

“The delay in REM sleep disrupts the brain’s ability to consolidate memories by interfering with the process that contributes to learning and memory,” Yue Leng, PhD, associate professor in the Department of Psychiatry and Behavioral Sciences and the Weill Institute for Neurosciences at University of California San Francisco, said in a news release. “If it is insufficient or delayed, it may increase the stress hormone cortisol. This can impair the brain’s hippocampus, a critical structure for memory consolidation.”²

For this study, the investigators evaluated associations between polysomnography (PSG)-assessed sleep architecture—particularly focusing on REM sleep and its features—as well as the following plasma-based biomarkers: phosphorylated tau at threonine 181 (p-tau 181); neurofilament light (NfL); brain-derived neurotrophic factor (BDNF); and Aβ PET. A total of 128 middle- to older-aged participants (mean age: 70.8 ± 9.6 years) with AD (n = 64), mild cognitive impairment (n = 41), or normal cognition (n = 23) were enrolled in the study. All participants underwent PSG, Aβ PET, and plasma biomarker analysis.¹

The researchers observed that those who achieved REM earlier did so under 98 minutes after falling asleep, whereas those who achieved REM later took over 193 minutes. Additionally, those with AD were more likely to have relayed REM sleep and approximately 16% more amyloid and 29% more tau compared with those who achieved REM faster.²

The findings also showed that, after adjusting for demographics (eg, age, sex, smoking, body mass index, and others), apolipoprotein E ε4 status, cognition, and comorbidities, the highest tertile of REM latency was associated with a higher Aβ burden (β = 0.08, 95% CI: 0.03 to 0.13, p = .002), elevated p-tau181 (β = 0.19, 95% CI: 0.02 to 0.13, p = .002), and reduced BDNF levels (β = -0.47, 95% CI: –0.68 to –0.13, p = .013), compared with the lowest tertile.¹

Further, the investigators also observed that lower REM and slow-wave sleep percentages were associated with higher levels of p-tau181, but there was no significant association between other sleep measures, including total sleep time, sleep efficiency, and sleep onset latency, as well as AD and ADRD biomarkers. Additionally, there were no significant non-linear relationships detected between REM latency and the biomarkers.¹

“Future research should study the effects of certain medications that influence sleep patterns, as these may modify disease progression. This includes treating conditions like sleep apnea and avoiding heavy drinking, since both can interfere with a healthy sleep cycle,” Dantao Peng, MD, from the department of neurology at the China-Japan Friendship Hospital in Beijing, said in the news release. “Patients taking certain antidepressants and sedatives that reduce REM sleep should discuss their concerns with their doctor, if they are worried about AD.”²

Another study published in August 2024 demonstrated poor sleep quality has a direct link to mortality risk as well as probable dementia and cognitive impairment. The study also showed that there were affects on memory for both short sleep durations and sleep disturbances.³

Health care professionals, notably pharmacists, can be key in helping patients achieve REM sleep. They can recommend that patients take over-the-counter supplements, such as melatonin, or prescribe treatments to help patients reach this level of sleep faster and gain more restful sleep. Additionally, other methods may be effective, such as reducing screen time, maintaining a healthy diet, exercising, and partaking in activities that keep the brain active, such as reading.^1,3

REFERENCES

1. Jin J, Chen J, Cavaillès C, et al. Association of rapid eye movement sleep latency with multimodal biomarkers of Alzheimer's disease. A&D. 2025;e14495. doi:10.1002/alz.14495

2. University of California — San Francisco. Delayed REM sleep could be an early sign of Alzheimer’s. News release. January 27, 2025. Accessed January 28, 2025. https://www.eurekalert.org/news-releases/1071382

3. McGovern, G. Poor Sleep Quality and Dementia Linked With Mortality Risk. Pharmacy Times. October 3, 2024. Accessed January 28, 2025. https://www.pharmacytimes.com/view/poor-sleep-quality-and-dementia-linked-with-mortality-risk