It is estimated that < 50% of Americans get the recommended 7-8 hours of sleep each night. Many of those that achieve 8 hours require sleep aids to get that precious sleep. There are many reasons that sleep eludes us. Insomnia is one of the constant complaints that I see in my patients. And it contributes to many of the medical issues they face.
Perimenopause, for example, disrupts sleep patterns. The low progesterone during this period delays sleep onset and shortens sleep periods. As estrogen declines, night sweats cause nighttime awakening. For my male patients, BPH and nocturia can present a problem. When stress is present and the mind starts cycling, getting back to sleep can be next to impossible. Daily life is stressful and it is our sleep that suffers.
Consequences of Insomnia
What are the consequences of this sleep deficit? Previous studies from the medical literature have shown that sleep flushes toxic molecules and waste from the brain (1,2). A recent study from Nature shows that sleep protects us from atherosclerosis aka “hardening of the arteries”. Interrupted sleep led to higher number of monocytes in the blood and larger plaques in the arteries (3). A monocyte is a white blood cell (WBC). Multiple studies link higher numbers of circulating WBC to the development of atherosclerosis. This can lead to heart attacks and strokes.
LInks to Alzheimer Disease
Another team demonstrated in mice that sleep depletes levels of amyloid-beta and tau – 2 proteins that are linked to Alzheimer disease (AD). This finding was corroborated in human cerebrospinal fluid (fluid around the brain and spinal column). Death of brain cells was slowed down in mice who had uninterrupted sleep. This was published in Science in February 2019 (4).
Take Home message on Insomnia?
Take home message: Inadequate or fragmented sleep can predispose people to atherosclerosis and Alzheimer Disesase. So get your ZZZ’s to protect both your brain and your heart. Look for my next blog on ways to optimize your sleep!
- NEJM Journal Watch Gen Med Aug 21 2018
- Nature 2018;560:185
- McAlpine CS et al. Sleep modulates haematopoiesis and protects against atherosclerosis. Nature 2019 Feb 21;566:383.
- Holth JK eet al. The sleep-wake cycle regulates brain interstitial fluid tau in mice and CSF in humans. Science 2019 Feb 22;363:880