Poor sleep impacts your heart health in several ways. And heart patients should not set their thermostat too low this winter. Cardiologist Thomas Phillips explains why.
The Belgian Cardiological League is concerned about the sleep of the Belgian. More than one in two Belgians (54 percent) say in a survey that they do not get enough sleep. For example, insomnia, hypersomnia (excessive daytime sleepiness) and parasomnia (disorders during sleep, such as sleepwalking) are conditions that can significantly affect the quality of sleep, the league warns.
In particular, the difficult-to-recognize obstructive sleep apnea syndrome (OSAS) has long-term consequences for the heart and blood vessels. This sleep disorder affects one in five adults (to varying degrees). While sleeping, the sleeper stops breathing uncontrollably for more than ten seconds, more than five times an hour. As a result, an alarm bell rings in the brain and the patient wakes up without realizing it and never goes into deep, restorative 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 into the link between disturbed sleep and the heart. There are a number of mechanisms that may play a role. One is that with obstructive sleep apnea, the oxygen tension in the blood drops and the heart has to pump harder to get more oxygen. As a result, blood pressure rises. In obstructive apnea episodes, the pressure in the chest and thus 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 come 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 roughly the case in up to 50 percent of patients. Poor sleep can also increase the risk of high blood pressure, obesity and type 2 diabetes. These in turn can lead to cardiovascular problems and arrhythmias.’
A cooler house is not a problem for young, healthy people, but it is not healthy for cardiovascular patients.
An important disadvantage of sleep apnea is that it is so difficult to recognize. The Belgian Cardiological League estimates that 80 percent 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 rising number of obesity cases, sleep apnea is increasing in our society. If you don’t have a partner to point out your snoring, you are often not aware of it. Some people then complain of tiredness or irritability during the day or have trouble concentrating. Others develop sleep or depression problems without realizing that there is an underlying problem of sleep apnea. Do you recognize these complaints? Do not hesitate to consult a doctor. Nowadays there are many resources to investigate which problems occur during your sleep and what causes them.’
How do you know if you are sleeping badly?
The symptoms are the same for most sleep disorders: dry mouth on waking, headache in the morning, problems with attention or irritability.
Is it right that shift work increases 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 unhealthy eating or smoking. This leads to obesity and possibly also sleep apnea. A healthy way of sleeping is therefore related to a healthy way of life. Shift workers should pay extra attention to a healthy lifestyle, even more than other people.’
Will switching to winter time soon pose a risk for cardiovascular patients?
Phillips: ‘When we switch to winter time, we can sleep an hour longer and there is no clear negative effect. But with the switch to daylight saving time – where we miss an hour of sleep – there are some more cardiovascular problems at the population level. In the weeks after the switch there is a slight increase in infarcts, strokes and possibly more arrhythmias. An hour less sleep means extra stress for the body. That proves once again the importance of a healthy, refreshing sleep.’
Can too much sleep be bad for the heart?
Phillips: ‘The optimal amount of sleep is six to eight hours. Some people need nine hours. Sleeping longer can also affect your heart health. But that is rather an indirect consequence. People who sleep much longer may exercise less or have poorer dietary habits. That is why a certain regularity in the sleeping pattern is certainly not an unnecessary luxury. Go to sleep at more or less the same time every night, without making it an obsession of course. Feel free to sleep in a little longer at the weekend.’
This winter, many people will lower their heating or not turn it on at all because of high energy prices. Is such a cold house healthy for the heart?
Phillips: ‘A cooler house is not a problem for young, healthy people, but it is not healthy for cardiovascular patients. Heart patients run no greater risk of a heart attack if they set their thermostat one degree lower than normal this winter, but drastically lowering the temperature to just 16 degrees in the living room causes physical stress. It raises blood pressure in hypertensive patients and even people with a reduced pumping function of the heart do not benefit from such a low room temperature. Heart patients therefore have an interest in a stable temperature in the house. With sudden temperature changes in winter, people with coronary artery stenosis may experience chest pain from vasospasm. In the bedroom, on the other hand, it may be a bit cooler. This promotes good sleep. You are nicely tucked in and your metabolism then turns less quickly.’
A few simple recommendations will help address the decline in sleep quality:
1. Do not drink caffeinated drinks (tea, coffee, cola, soda) during the four to six hours before bedtime
2. Don’t smoke right before bed and when you are awake at night
3. Avoid alcohol with dinner
4. Keep your bedroom quiet and dark
5. Avoid extreme temperatures in the bedroom
6. Get rid of the problems of the day by and those that remain to be solved well before bedtime
7. Prefer a light evening meal but don’t go to bed hungry
8. Practice regular physical activity late in the afternoon or early evening
9. Place your alarm clock so you can’t see it
10. Have relaxing activities at least one hour before bedtime to prepare for sleep
More info: Belgian Cardiological League