Can Lack of Sleep Cause Heart Disease?

Life in a big city is hectic with everyone hurrying somewhere, always being late and getting stressed due to the lack of time. This causes people to sleep much less than the necessary 8 hours a day which leads to a number of health risks.

A lot of articles online claim that lack of sleep causes various cardiovascular diseases. But is this true? And if it is true, why does this happen?

Is it true that lack of sleep causes heart disease?

Yes. A 10-year study conducted by The Harvard University tracked health and sleep habits of over 70,000 women. The researchers accounted for factors such as weight, age, and bad habits, and then looked at how much the person was sleeping on average. It appeared that women who slept less than 5 hours per day were 40% more likely to suffer from heart disease than women who slept 8 hours per day. However, this research has also shown that oversleeping is equally harmful. Women who slept more than 9 hours per night were 37% more likely to suffer from heart disease.

It appears that chronic sleep deprivation also increases the likelihood of diabetes and obesity. Not enough sleep can also affect the lining of the arteries causing low-grade inflammation and increasing the risk of atherosclerosis.

How does sleep deprivation increase the likelihood of obesity?

Everyone knows the importance of sleep. Insufficient sleep decreases your ability to react, slows you down, and even kills your sex drive. Not many people realize that lack of sleep can also increase the risk of obesity.

This can be attributed to the fact that sleep deprivation decreases the levels of leptin which is the hormone which suppresses appetite and increases metabolism and increases levels of ghrelin, the hormone which stimulates appetite.


Leptin is a hormone produced by white adipose tissue that regulates the person’s appetite and metabolism. It increases your satiety and changes your metabolism by influencing the thyroid gland through the hypothalamus.

During sleep, leptin is being synthesized to tell your body that it has enough energy. However, if the person does not get enough sleep, the leptin levels do not return to the normal levels. This causes your body to think that it needs more energy which, in turn, increases hunger. This can cause you to feel hunger while youare actually full. Additionally, low levels of leptin slow down your metabolism, since the body thinks that it needs to conserve energy.

Another thing that can decrease leptin levels is hunger. There is a saying among athletes: “The best way to gain weight is to go hungry for a while.” And this is true, since severe calorie restriction decreases the leptin levels, slowing down your metabolism and increasing base hunger, which makes you gain weight very quickly.


Ghrelin is another hormone that regulates your hunger and metabolism. This hormone is synthesized by ghrelin cells in your gastrointestinal tract and has the opposite function of leptin. Like leptin, it also regulates the rate of use and distribution of energy. Ghrelin is secreted when the stomach is empty, and it’s secretion is stopped when the walls of the stomach are stretched. It acts on the hypothalamus and increases hunger, gastric acid secretion, and motility, in order to prepare the person for another meal. Ghrelin is one of the key hormones that regulate the perception of reward by influencing the ventral tegmental area (a site which processes the development of addictions and sexual desire).

During sleep, the levels of ghrelin decrease, and if the person is not getting enough sleep, the levels of ghrelin remain too high, which makes the person hungry.

Additional Factors

Aside from changes in the levels of leptin and ghrelin, sleep deprivation also causes the levels of stress hormones to rise and increases the person’s insulin resistance. Not only does this cause you to gain weight, it also may increase the risk of diabetes.

Alcohol consumption before bed can also lead to hormonal changes which result in weight gain. This is caused by the fact that alcohol disrupts the normal sleep cycles and decreases the amount of REM sleep. Sleep medications essentially do the same thing.


A sufficient amount of sleep is absolutely necessary for the well-being of a person. Not only does sleep affect the person’s ability to concentrate and learn, it also influences a person’s health. If you wish to be fit and have a healthy heart, then it is absolutely necessary to get a good night’s sleep.


1.  “We Are Chronically Sleep Deprived,” Vol. 18 No. 10. Sleep Medicine, Kryger, Meir, et al., Third Edition. 2000.

2.  “Health Care Utilization in the 10 Years Prior to Diagnosis in Obstructive Sleep Apnea Syndrome Patients,” Vol. No. 22. Journal of Clinical Hypertentions, Vol. 4 No. 6. Journal of the American Board of Family Practice, Vol. 15 No. 2.

3.  “Effect of Nasal Continuous Positive Airway Pressure Treatment on Blood Pressure in Patients with Obstructive Sleep apnea,” Vol. 107. News release