Updated: May 31, 2019
Cardiovascular disease (CVD) is a severe public health threat in the US. American Heart Association reports that every third American dies from CVD. Coronary heart disease is the most common and accounts for 43 % of deaths. Another terrifying fact is that every 40 seconds, an American has a heart attack.
In the 2010 study on links between sleep duration and cardiovascular disease, Japanese researchers noted that in the 1980s many Japanese laborers died from what is called “karoshi,” a death from overwork,” and that a vast number of these deaths “involved acute cardiovascular events.”
Taking into account that only 37% of Americans work 40 hours a week while everyone else puts in significantly more than that (both in and outside the workplace), it is useful to look at how lack of sleep affects the hearts of the busiest among us.
Dr. Nieca Goldberg explains the difference between Heart disease and Cardiovascular Disease:
Heart disease is any disease that affects the heart, including coronary artery disease (CAD), arrhythmia, heart failure, and others.
Cardiovascular disease (CDV) is a disease of the heart or blood vessels. The most prevalent of its kind are peripheral artery disease, stroke, and high blood pressure.
The Importance of Adequate Sleep
The human body is a sophisticated machine, impacted by the most subtle changes. The inconvenient truth is that one solely night of 3.6 hour-sleep, increases blood pressure in healthy adults. It results in a higher heart rate even if the physical activity is entirely excluded.
The evidence shows no difference between chronic and short-term sleep deprivation when it comes to its adverse impact on the heart. A partial night sleep loss increases the risk of cardiovascular disease and speeds up its progression in those who already struggle with it just the same as habitual sleep restriction does.
In the Alameda County Study, researchers found that subjects who got 8 hours of shuteye per night were at a lower risk of heart disease, heart attack, cancer, and stroke. On the other hand, participants who slept 6 hours or less, or 9 hours or more per night were more prone to suffer from these conditions.
Jama Internal Medicine Journal published similar findings. The research looked at ladies and their sleeping patterns. The women who slept 5 hours were as likely to be affected by heart disease as those who slept 9. However, those who slept 8 hours were at the lowest risk of being affected by coronary events.
Sleep deficiency and oversleeping have similar harmful effects on cardiovascular health. Lack of sleep impairs glucose and insulin levels in the blood, which ultimately leads to weight gain and diabetes. Doctors warn about the evidence surrounding the detrimental consequences of excessive sleep. Prolonged slumber is not always a sign of poor health, but conversely, the health conditions emerge in long sleepers. A misalignment in circadian rhythm leads to metabolic dysfunction and has viscous ramifications on the heart and overall health.
These astonishing results highlight the significance of getting adequate sleep.
Disordered sleep and heart disease: a dangerous duo
A large body of evidence shows connections between insomnia, obstructive sleep apnea, and heart disease. Statistics say that sleep disorder is found in 47%-83% of cardiovascular patients. 35% of patients with a sleep disorder have high blood pressure, and 12%-53% have other types of heart problems.
Obstructive Sleep Apnea
Obstructive Sleep Apnea (OSA) occurs when throat muscles relax during sleep and block the airways. Therefore breathing is interrupted, which makes the individual snore and wake up, gasping for air. People who suffer from sleep apnea experience up to 30 pauses in breathing during a single night. They wake up tired, wrestle with daytime fatigue, and are at higher risk of having problems with arrhythmia, high blood pressure, and heart failure.
Dr. Atul Malhotra, associate professor at Harvard Medical School and sleep specialist at Brigham and Women's Hospital notes that "Over time, OSA exposes the heart and circulation to harmful stimuli that may cause or contribute to the progression of most cardiovascular diseases."
When you fight for your breath during sleep, the body gets into a state of stress. Its functions are on high alert as it releases adrenaline and cortisol (stress hormones) to tackle the shortage of oxygen. When this continually occurs, the levels of adrenaline don’t drop, resulting in high blood pressure.
Studies corroborated that treating OSA reduces the risk of cardiovascular disease.
Moreover, research supports the correlation between insomnia and the risk of heart disease. Shifts in sleep duration have a significant impact on developing heart disease.
Insomnia is a type of sleep disturbance characterized by difficulty in falling asleep, staying asleep, or the absence of restorative sleep (REM sleep). Insomniacs are at a 45% higher risk of suffering and dying from cardiovascular disease compared to those who don’t struggle with this type of sleep disorder.
Chronic sleep loss leads to a metabolic and chemical imbalance in the body. It is associated with elevated levels of inflammatory substances which the body releases in the urge to boost the weakened immune system due to sleep restriction and lack of recovery sleep. Doctors caution that impairment of metabolic hormones and an overflow of stress hormones increase the risk of cardiovascular disease.
While low-quality sleepers are more likely to suffer from heart disease, the silver lining is that the quality and quantity of sleep patterns are indeed, impacted by a range of cultural, social, physiological, and environmental influences. This powerful reflection leaves the space for altering lifestyle to introduce the changes necessary to improve the quality of sleep, bolster health, extend longevity, and fuel cognitive performance.