Poor sleep affects heart health in several ways. And heart patients shouldn’t set their thermostat too low this winter. Cardiologist Thomas Phillips explains why.
The Belgian Heart League is worried about the Belgian’s sleep. More than one in two Belgians (54%) say in a survey that they do not get enough sleep. For example, insomnia, hypersomnia (excessive daytime sleepiness), and parasomnia (disturbances during sleep, such as sleepwalking) are conditions that can significantly affect sleep quality, the league warns.
In particular, obstructive sleep apnea syndrome (OSAS) that is difficult to recognize has long-term consequences for the heart and blood vessels. This sleep disorder affects one in five adults (to varying degrees). During sleep, the sleeper stops breathing uncontrollably for more than ten seconds, more than five times per hour. As a result, an alarm bell rings in the brain and the patient wakes up without realizing it and never enters a deep, restful sleep.
How exactly does a poor night’s sleep increase the risk of cardiovascular disease?
Thomas Phlips (cardiologist-electrophysiologist at the Jessa hospital in Hasselt): ‘In recent years, a lot of research has been done on the link between disturbed sleep and the heart. There are a number of mechanisms that can play a role. One is that with obstructive sleep apnea, the oxygen tension in the blood decreases and the heart has to pump harder to get more oxygen. As a result, blood pressure rises. In episodes of obstructive apnea, pressure in the chest and therefore in the heart also increases. This puts pressure on the structures of the heart. The anterior chamber of the heart, in particular, is less muscular and will therefore be under pressure, which can cause arrhythmias such as atrial fibrillation. The drop in oxygen tension also affects the autonomic nervous system, which can also trigger atrial fibrillation via certain triggers. We see that a form of sleep apnea is very often hidden in patients with atrial fibrillation, which is more or less the case in up to 50% of patients. Poor sleep can also increase the risk of hypertension, obesity and type 2 diabetes. These in turn can lead to cardiovascular problems and arrhythmias. ‘
A cooler home isn’t a problem for healthy young people, but it’s not healthy for cardiovascular patients.
Thomas Phillips, cardiologist
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A major disadvantage of sleep apnea is that it is so difficult to recognize. The Belgian Cardiological League estimates that 80% of people with sleep apnea are undiagnosed. How can you, as a patient, recognize the condition?
Phillips: ‘There are three forms of sleep apnea, of which the obstructive form is the most frequent. It is often related to being overweight. The weight in the neck hinders the epiglottis so that it no longer opens properly and you start snoring. However, this is not to say that every person who snores will also have sleep apnea. Due to the growing number of obesity cases, sleep apnea is on the rise in our society. If you don’t have a partner who points out your snoring, you often don’t notice. Some people also complain of tiredness or irritability during the day or have difficulty concentrating. Others develop sleep problems or depression without realizing that there is an underlying problem with sleep apnea. Do you recognize these complaints? Do not hesitate to consult a doctor. There are many resources nowadays to investigate what problems occur during sleep and what causes them. ‘
How do you know if you are sleeping badly?
Symptoms are the same for most sleep disorders: dry mouth upon waking, headache in the morning, attention problems or irritability.
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It’s right? Does shift work increase the risk of cardiovascular disease?
Phillips: ‘Shift workers run a slightly higher risk, but the difference with regular employees is not that great. The question is what the underlying reason is. Shift work is often accompanied by certain habits, such as improper eating or smoking. This leads to obesity and possibly even sleep apnea. A healthy way of sleeping is therefore related to a healthy lifestyle. Shift workers should pay more attention to a healthy lifestyle, even more than other people. ‘
Will the switch to winter time soon pose a risk for cardiovascular patients?
Phillips: ‘When we switch to solar time, we can sleep an extra hour and there are no obvious negative effects. But with the transition to summer time – where we lose an hour of sleep – there are some more cardiovascular problems at the population level. In the weeks following the switch there is a slight increase in heart attacks, strokes and possibly more arrhythmias. One less hour of sleep means additional stress for the body. This once again demonstrates the importance of a healthy and restful sleep. ‘
Can sleeping too much be harmful to the heart?
Phillips: ‘The optimal amount of sleep is six to eight hours. Some people need nine hours. Sleeping longer can also affect heart health. But this is rather an indirect consequence. People who sleep much longer may exercise less or have poorer eating habits. This is why a certain regularity in sleep is certainly not an unnecessary luxury. Going to sleep at about the same time every night, obviously without making it an obsession. Feel free to sleep a little longer on the weekend. ‘
This winter, many people will turn down their heat or not turn it on at all due to high energy prices. Is such a cold house good for the heart?
Phillips: ‘A cooler home isn’t a problem for healthy young people, but it’s not healthy for cardiovascular patients. Heart patients are at no greater risk of heart attack if they set the thermostat one degree lower than normal this winter, but drastically lowering the temperature to just 16 degrees in the living room causes physical stress. Blood pressure increases in hypertensive patients, and even people with a reduced pumping function of the heart do not benefit from such a low ambient temperature. Heart patients therefore have an interest in a stable temperature at home. With sudden changes in temperature in winter, people with coronary artery stenosis may experience chest pain due to vasospasm. In the bedroom, however, it could be a little cooler. This promotes good sleep. You are well hidden and your metabolism will work slower. ‘
A few simple tips will help deal with the decline in sleep quality:
1. Do not drink caffeinated beverages (tea, coffee, cola, fizzy drinks) during the four or six hours before bedtime
2. Do not smoke immediately before going to bed and when you are awake at night
3. Avoid alcohol at dinner
4. Keep your bedroom quiet and dark
5. Avoid extreme temperatures in the bedroom
6. Get rid of the problems of the day and those that remain to be solved well before bedtime
7. Prefer a light dinner but don’t go to bed hungry
8. Practice regular physical activity in the late afternoon or early evening
9. Position the alarm so that you cannot see it
10. Do relaxing activities at least an hour before bed to prepare for sleep
Further information: Belgian Cardiological League
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