It’s no secret that heart disease is America’s number one killer. More than 600,000 people die from heart disease each year, according to the CDC, and plaque buildup from a poor diet isn’t the only reason. It turns out that lack of sleep actually contributes to heart disease too. And one’s Health, age, and fitness level make no difference.

The relation between sleep and heart health

A person’s body goes into repair mode during sleep. Cells produce more proteins that heal damage to muscle and tissue. Stress levels, blood pressure, and inflammation are lowered as well.

When adults sleep less than 7 hours each night, though, they’re likely to experience more health problems that increase the risk of heart disease, according to the CDC. These risk factors include:

  • High blood pressure
  • Stroke
  • Obesity or being overweight
  • Stress and inflammation
  • Sleep disorders (sleep apnea, insomnia)
  • Type 2 diabetes

Many of these conditions and risk factors are linked. Sleep disorders can cause high blood pressure just like stress, and people who are overweight often develop sleep apnea.

Lack of sleep and blood pressure

High blood pressure is one of the biggest culprits for strokes and heart disease. When people enter deep stages of sleep, their blood pressure and heart rate go down. Interrupted sleep cycles cause the body to release chemicals that stop this from happening.

Without deep periods of rest, the heart might get overworked, and it can lead to high blood pressure over time. That’s why people with sleep apnea have a higher risk of heart disease and stroke.

Sleeping less may cause weight gain

Being overweight is a major factor in the development of heart disease. While exercise and a good diet help maintain a healthy weight, sleep is just as important.

Ghrelin and leptin are important hormones that help decrease hunger; they assist with appetite regulation and prevent overeating. Sleep deprivation can interfere with their production and cause bad eating habits, like eating more unhealthy foods that clog arteries. Children who don't get enough quality sleep are also at risk for weight gain, as it interferes with the function of the hypothalamus, a section of the brain that helps control energy and appetite.

Less sleep increases the risk of type 2 diabetes

Increased blood sugar levels are linked to lack of sleep. People who don’t get enough quality, deep sleep are in danger of developing insulin resistance, according to Web MD. Insulin resistance causes glucose to build up in a person’s bloodstream, and it’s the leading cause of type 2 diabetes. Type 2 diabetes damages blood vessels and nerves, which increases the odds of having a stroke or heart attack.