How Sleep Deprivation Affects Your Heart

When it comes to health, we know that the way we live is a big determinant. How we eat, sleep, and exercise plays a role in how healthy we are. Either too little, or too much, in any of these categories is problematic and can result in various health conditions. If you eat too little or too much, if you sleep too little or too much, if you exercise too little or too much, there are physical repercussions. But did you know that too much or too little sleep (sleep deprivation) can cause problems with your heart specifically?

Cultural Sleep Deprivation

Although too much sleep applies in a small number of cases, its opposite, sleep deprivation, is at epidemic proportions. A lack of sleep is quite common in our modern society with lots of stress, long workdays, and pressure to manage multiple responsibilities. In general, our culture encourages performance and hard work, and it can lead to sleep problems that interfere with both the amount of sleep and the quality of the sleep you get.

In Japanese culture, they have a name for working yourself literally to death, Karoshi. They have an excruciatingly long work week and have been experiencing people who literally drop dead from too much work and not enough sleep.

Life works best in balance, and so does your heart. It needs enough sleep, but not too much, in order to function properly. Since Americans are routinely getting about 6.8 hours of sleep, nearly 1.5 hours less than 100 years ago, it is having an effect. Let’s see what it is doing to our hearts and how it might be playing into the increase in heart disease.

Lack of Sleep and the Heart

Sleep deprivation is strongly linked to certain disorders of the heart like hypertension (HT), coronary heart disease (CHD), and heart failure (HF) from diabetes mellitus. It affects the heart directly and indirectly. Directly, a lack of sleep results in high blood pressure, which will manifest the next day and is usually accompanied by elevated nervous system activity as well. Blood pressure naturally falls at night as part of healthy heart regulation. With shortened or interrupted sleep, the heart may not have enough time at the lowered level it needs to ensure proper functioning. In simple terms, the heart rests while you sleep, and it needs enough rest in order to be healthy.

The more we know about sleep, the more we understand that there is an ideal amount of it. Between 7 and 9 hours per night is what is required, and both more or less than that range, can disrupt heart health. If you need 7 to 9 hours of sleep to be healthy, then that is also what works for your heart. Studies show that less than 6 hours a night can increase the risk for cardiovascular disease by 48%. Conversely, sleeping too much, 9 hours or more, can increase the risk by 38%. Sleep duration, or lack thereof, definitely has the greatest negative impact on the heart.

Further, lack of sleep affects the heart indirectly. It is a contributing factor in obesity and type II diabetes, which can both promote heart disease. Lack of sleep alters hormones which can influence both cortisol levels and the part of the brain that controls hunger. These changes in hormone level may result in insulin resistance which can develop into type II diabetes or contribute directly to weight gain.

Further, lowered sleep amounts can result in larger amounts of plaque in the arteries. Both too much sleep and too little sleep can cause higher levels of calcium, one of the primary ingredients, along with fat and cholesterol, that deposit themselves in the blood vessels making plaque. This plaque can lead to cardiovascular disease through the narrowing or blockage of blood vessels.

What is Sleep Deprivation Exactly?

So, we know that dysregulated sleep, in particular sleep deprivation, can lead to heart maladies, but what defines sleep deprivation? As mentioned, sleep deprivation is defined as too little sleep, but there are many forms of too little sleep. Let’s say you went to bed and slept without interruption for a solid 6 hours. You would have a form of sleep deprivation that would be fairly straightforward and easy to quantify. However, many types of sleep disorders result in forms of irregular sleep that is far more nuanced.

For example, if you have insomnia, you might be up and down throughout the night, and it may be difficult to track amounts. This kind of erratic sleep also prevents the deep restorative REM states that the body needs to be healthy. Other sleep disorders, like sleep apnea, don’t allow for deep or consistent sleep either and can cause sleep deprivation. To sum this up, sleep deprivation can be missed hours of sleep, interrupted sleep, and a lack of deep sleep.

How Can I Improve Sleep?

Lack of sleep affects your heart, and this alone should be a motivator to improve sleep. Sleep hygiene has become a science with best practices that can increase sleep quality and duration. In short, the following are recommended.

• Get sunlight early in the day and reduce artificial light in the evening.
• Don’t eat after dinner, or very light food no later than two hours before bed.
• No screen time at least 2 hours before bed including, iPad, TV, or phone.
• Maintain a consistent sleep schedule, go to bed and get up at the same time every day.
• Get regular exercise.
• Do something relaxing before bed like taking a bath or reading in bed.
• Sleep in a dark, quiet, cool room, using room darkening curtains if necessary.

Summary

Sleep deprivation affects various bodily functions that can directly and indirectly lead to heart disease. It can increase blood pressure, affect hormones, and increase plaque. Sleep deprivation can cause weight gain, obesity, and diabetes, which are all factors in heart disease. Conversely, enough good quality sleep can improve heart health. Consider incorporating some good sleep practices to improve both the quality and quantity of your sleep.