Counting Sheep: Who’s Helping Us Optimize our Sleep?
We spend one-third of our life sleeping.
Yet, seldom do we treat our sleep with the respect it deserves. Even in medical school, I can only recall one lecture about sleep, despite concrete evidence that poor sleep leads to morbidity and mortality. Sleep is an attractive market for digital health companies given its important health implications. So, which companies are helping us count sheep?
A Good Night’s Sleep
The average American spends 200,000 hours—one-third—of their life sleeping. You would think that humans spending so much time sleeping would make learning about sleep a high priority in medical school. However, out of the 100+ medicine lectures I’ve sat—not slept—through, I can only recall one that was about sleep.
So, I’ve taken the initiative to do my own scholarly research into sleep and its effects on our different systems. Here’s a quick summary:
- Cardiovascular: Too little sleep is associated with hypertension, likely due to autonomic dysregulation. Additionally, sleep apnea leads to poor quality sleep and, therefore, increased sympathetic tone (higher blood pressure and heart rate). With sleep apnea, you’re constantly waking yourself up throughout the night without even realizing, essentially activating a stress response over and over again. The downstream effects of prolonged, uncontrolled hypertension are heart failure, stroke and nephropathy, to name a few.
- Psych: Perhaps the most noticeable effects of sleep are on our psyche. Sleep is responsible for memory consolidation, whether this is procedural memory, rote memory, or emotions experienced throughout the day. Therefore, it shouldn’t be surprising that impaired sleep may lead to depression, anxiety, attention and memory problems. This relationship is also bidirectional, in that depression and anxiety can also lead to poor sleep.
- Musculoskeletal: Muscle repair, protein synthesis and tissue growth occur during sleep. Poor sleep quality and quantity downregulate important proteins needed for muscle repair, leading to decreased contractility. Hence, Ironman athlete Lionel Sanders makes sure he sleeps on average eight hours per night.
- Nervous: During sleep, immune cells in the nervous system clear misfolded proteins. Therefore, sleep deprivation impairs such protein clearance, leading to the build-up of neurotoxins like amyloid beta and alpha synuclein which are implicated in neurodegenerative diseases like Alzheimer’s and Parkinson’s.
- Endocrine: Poor sleep acutely increases our cortisol levels, leading to elevated heart rate and blood pressure. Over time, this leads to systemic inflammation and hormonal imbalances. High cortisol levels are important in the short term, stimulating alertness and vigilance, and raising heart rate and blood pressure, but over time it can cause systemic inflammation and disrupt our hormonal balance. For example, insufficient or too much sleep can disrupt glucose metabolism, leading to diabetes.
- Immune: Many of the above system-based problems from poor sleep stem from sleep’s effect on the immune system. Sleep promotes our body’s defense against infection and inflammation. So, when sleep deprived, our innate and adaptive immune systems essentially go haywire, leading to chronic inflammatory states, increasing the risk for infection, cardiovascular disease, cancer and neurodegenerative disorders.
The key concept to remember is U: too little sleep and too much sleep lead to morbidity—seven to eight hours of high-quality sleep is the Goldilocks Zone.
Digital Health Cos Tackling Sleep
There are many digital health companies tackling sleep.
In my opinion, WHOOP and Oura Ring are the two prominent wearables devices analyzing sleep data and turning it into actionable insight. WHOOP is a fitness ban that you wear 24/7–there’s no need to remove the ban because the charger slides right on top of it. Oura is similar to WHOOP, but instead of a fitness ban, it’s a ring. Here’s what the analytics look like below.
You can see both track time awake and time in light sleep, deep sleep and REM sleep. As your activity and fitness levels change, so will the need to spend more time in certain stages of sleep. For example, an athlete with successive nights of poor sleep will eventually experience REM rebound, where they spend more time in the REM stage of sleep with increased intensity and frequency.
Both WHOOP and Oura Ring will advise you on when to sleep to ensure optimal recovery.
While Apple Watch can track the different stages of sleep, I find it inferior to WHOOP and Oura. The main reason is Apple Watch has poor battery life and often requires people to charge it overnight while sleeping. Therefore, data is often captured infrequently.
Eight Sleep is a fascinating, non-invasive piece of technology. They offer a (very) smart mattress and mattress cover.
The smart mattress/cover automatically adjusts the bed’s temperature throughout the night based on your sleep habits. You can also manually set your bed temperature (for both sides of the bed). What makes the technology very smart is its ability to link with your smart home devices like Nest, Philip Hue smart lights and Alexa. The mattress’s core feature includes tracking heart rate variability, resting heart rate, respiratory rate and body temperature. Like WHOOP and Oura ring, Eight Sleep provides you with a sleeping score to help you understand your quality of sleep. Unlike WHOOP and Oura ring, Eight Sleep doesn’t require you wear anything for data.
Similarly, Withings has an under-mattress sleep tracker which analyzes changes in pressure (movement) and noise. No wearable is required. Withings provides the same type of data as Eight Sleep, WHOOP and Oura Ring, with the addition of a snoring report for sleep apnea detection.
Crescent is an app-based, sleep coaching startup on the come up offering health tracking features and concierge sleep support. The company aims to help you discover how your daily habits affect your sleep and tweak those habits accordingly to optimize them.
The company is quite new, and still in the beta stages. You can request early access here. I’m curious to see how this company performs and will be tracking them over the next several months!
Around one-third of the U.S. population reports getting the necessary eight hours of sleep per night. Another one-third reports six hours or less, which is likely an underestimate of current numbers, given the study was from two decades ago. Perhaps most astonishing is that people in Western countries sleep on average 1.5 hr less than a century ago. This is a problem.
For example, it’s estimated that sleep-related absence from work accounts for the loss of ten million working hours annually in the U.S., costing employers between $1,300 to $3,000 per employee.
Sleep is critical to performing optimally at work and in athletics. As such, poor sleep leads to poor performance in all aspects of life and affects health and the economy. I discussed above how sleep affects your own health. But how about doctors taking care of you? Physician residents are notoriously sleep-deprived. Follow any resident on Twitter, and you’ll see how miserable it is for them, and their patients, to be working non-stop.
In the 1980s, an over-worked, sleep-deprived resident was accused of misdiagnosing serotonin syndrome in a young woman, leading to her death. A lawsuit ensued and the Libby Zion Law was enacted, limiting residents to working 80-hour work weeks. Still, you will find residents working 24-hour+ shifts. Throw one of these wearable devices on a resident, and I’m sure the data will be astonishing.
Overall, digital health companies, whether they be wearables, smart mattresses or coaching apps are potential solutions to address poor sleep to improve health and productivity. But, truly addressing the sleep deprivation problem will require an entire shift in work culture.