Sleep is an essential time for the body to recuperate. During the non-rapid eye movement (NREM) sleep stages, heart rate slows, blood pressure drops by around 10-20% (nocturnal dipping), and breathing stabilises. These changes reduce stress on the heart, allowing it to recover from strain that occurs during waking hours. Some evidence even indicates that improving sleep may reduce the likelihood of heart attacks or other cardiovascular problems in people who are otherwise at high risk.

Without sufficient nightly sleep, a person doesn’t spend enough time in the deep stages of NREM sleep that benefit the heart. The same problem can affect people whose sleep is frequently interrupted. As a result, chronic sleep deprivation has been linked to numerous heart problems including high blood pressure, high cholesterol, heart attack, obesity, diabetes, and stroke.

How Poor Sleep Negatively Impacts Cardiovascular Health

  • Research has found that sleep deprivation contributes to atherosclerosis, where plaque forms as a consequence of inflammation and collects in the arteries and cause them to harden.

  • The impact of sleep deprivation on coronary heart disease is also believed to be influenced by sleep’s effects on blood pressure. Hypertension strains the arteries, making them less effective at bringing blood to the heart and as a result contributing to heart disease. The link between lack of sleep and high blood pressure is highest in middle-aged adults. People who work long hours in high-stress jobs and people with other risk factors for hypertension are more likely to have raised blood pressure after chronic poor sleep.

  • Poor sleep, including abrupt awakenings, can generate a sharp uptick in heart rate. Research has also found that people with sleeping problems are more likely to complain of an irregular heartbeat. For these reasons, lack of sleep may be tied to heart palpitations. In addition, a study in older adults found that people who have frequent nightmares were considerably more likely to report having an irregular heartbeat.

  • Research suggests that sleep deprivation heightens the risk of heart attacks. In one study, people sleeping less than six hours per night had a 20% higher chance of a heart attack.

  • An observational study of over 400,000 people found strong associations between sleeping problems and heart failure. In that study, people who slept less than seven hours per night had an elevated risk of heart failure. Heart failure was also more common in people who had other indicators of unhealthy sleep including insomnia symptoms, daytime sleepiness, snoring, and being an evening person. The more of these signs of unhealthy sleep that one person had, the higher their likelihood of heart failure.

  • Obstructive sleep apnea (OSA) is a breathing disorder that is linked to heart disease, obesity, diabetes, stroke, and high blood pressure. People with OSA have lapses in breathing during sleep when their airway gets blocked.

  • Insomnia, sleep apnea, and other sleep difficulties affect many pregnant women, and these issues have been associated with a higher risk of cardiovascular problems both during and after pregnancy.

  • A study published in the journal Sleep found that newly hired early-morning shift workers may see an increased risk of cardiovascular disease as they transition to their earlier work schedules and that the risk for developing cardiovascular issues may increase the longer someone stays on shift work.

Sources: The Sleep Foundation | Wikipedia | National Library of Medicine