Sleep is the single most effective way to reset our brain and body health each day. Sleep is a foundational element of human biology and is a requirement for life. We spend roughly one-third of our lives asleep. A famous quote is, “Happiness is nothing more than getting enough sleep”. Sleep disturbance is a common condition in modern society, with evidence showing that people sleep on average 1.5 hr less than a century ago. one-third of the general population suffers from sleep-related problems And now, we better understand the relationship between poor sleep and poor health, especially cardiovascular health. Just a couple of months ago, the American heart association added Sleep to the essential pillars of cardiovascular health. And in this episode, we will discuss sleep and heart health, what is good sleep, what is bad sleep, what’s the risk of poor sleep, and we will end up with some advice on how to improve your sleep for a stronger heart. First, is there a relationship between the number of hours slept and CV health? Yes, we have clear data on this relationship Sleeping for less than six hours is associated with a 70% increase in mortality Sleeping 5 hr or less per night had a 2.3-fold greater risk of AMI Sleeping for less than four hours is associated with a 2.8 times increase in mortality Sleeping for nine hours or more was also associated with a 70% increase in mortality The ideal duration of sleep is between seven hours and eight hours because this has been associated with the best survival. During normal, healthy sleep, blood pressure drops by around 10-20%. This is known as nocturnal dipping, and research highlights its role in cardiovascular health. When we sleep, the blood pressure comes down, and the heart rate also goes down. This helps to unload the circulatory system and give rest to the heart. Poor sleep, whether from a lack of sleep or sleep disruptions, is associated with non-dipping, meaning that a person’s blood pressure doesn’t go down at night. Studies have found that elevated nighttime blood pressure is related to overall hypertension (high blood pressure). Not only hypertension but sleep disruption is also associated with an increased risk of diabetes, coronary atherosclerosis, and myocardial infarction. Add to that obesity risk; we can remember that we are more likely to feel hungry when we don’t get enough sleep. All these conditions are increased with sleeping less than six hours or with sleeping more than nine hours. It is a U-shaped relation. We've understood the impact of sleep quantity on health, but what is the impact of poor sleep quality on health? We also know that difficulty falling asleep, nightmares, easily awakening from sleep, use of sleeping pills, and walking up tired are markers of poor sleep. Poor sleep quality was associated with subclinical cardiovascular disease and increased risk of cardiovascular disease. Sleep apnea, where there is airway obstruction resulting in loud snoring and apnea, is a well-established risk for resistant hypertension, heart failure, coronary disease, and atrial fibrillation. What’s the mechanism linking sleep and poor cardiometabolic health? There are several potential mechanisms. Data show that a lack of sleep may increase sympathetic nervous system activity the next day; sleep deprivation also results in an inflammatory state and in increased salt intake, elevated cortisol levels, and insulin resistance. These changes all culminate in poor cardiometabolic health resulting in a cascade or a package of cardiovascular diseases. How to improve your sleep? First: Identify your ideal sleep duration The general rule is 7-8 hours of daily sleep. But because this may vary, you can measure your own needed sleep hours this way… Try to get into bed at the time where you fall asleep within about 15 minutes, and wake up without an alarm clock, feeling rested, and having enough energy to carry you through the day. On average, the amount of sleep you get this way is probably the right amount of sleep for you. The American heart association elected to add sleep duration as an eighth metric to the formal definition of CVH. Metric: Average hours of sleep per night Scoring:
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