A new study has finally confirmed what has been known for a long time and the answer lies in our body’s internal clock.
In an asthma attack, the airways in the lungs start to close, which makes breathing difficult and causes coughing and makes people gasp. Many asthmatics report a peculiarity in the attacks – which usually be stronger at night – and there is now a study that explains why.
A 2005 study found that nearly 75% of asthmatics had more severe attacks at night, and a survey of London hospitals in the 1970s found that attacks at night or early in the morning had a most likely to be fatal.
Scientists had many theories, between sleep being the cause, sleeping position, possible allergens in bedding, or ciclo circadiano, that is, our body’s clock that regulates hormones, the heartbeat and the immune system every 24 hours and is influenced by external factors such as light and mealtime. However, the reason remained unknown, until now.
Published in September in Proceedings of the National Academy of Sciences, a study showed how the circadian cycle can become “immune” to these factors that influence it and contribute to asthma, writes Wired.
The sample consisted of 17 asthmatic participants, who had to check their lung function at home four times every day with a respirometer, which measures how much air they can pull out of their lungs in a single second. Participants also recorded their symptoms and noted every time they had to use the pump.
They were then placed in two different experiments while living in dimly lit rooms. In the first one, called “constant routine protocol“, the participants sat on a bed for 38 hours without being able to sleep, get up to go to the bathroom or make any physical effort. Every two hours they ate the same meal – a small tuna or peanut butter and jelly sandwich.
The aim is test the body’s internal clock, since in these rooms without clocks or windows that show sunlight and without the normal working hours of the participants, it seemed that time did not exist and there was no way of knowing when it’s time to eat or sleep or if it was day or night.
Participants were also hooked up to thermometers that monitored their temperatures and every two to four hours, nurses collected blood and urine samples and measured airway resistance. These tests served to understand the circadian rhythm without the influence of behavioral and environmental cues.
The second experience, called “forced desynchrony protocol“, served to understand how behavioral cycles can affect asthma. This time, participants had to live in the same dimly lit rooms for eight days, but instead of having their routine activities – such as eating, bathing or sleeping – programmed for a 24-hour cycle, they were planned for one day. 28 hours.
This time, they could get up and walk a little around the room, but could not go out or do any kind of demanding exercise. Every two or four hours, they were retested.
All these experiences came to a conclusion: each person’s circadian cycle contributes to a worsening of asthma. When the body clock thinks it’s night and bedtime, the participants used the bomb four times more. In case the sleep coincided with the circadian night, the tension in the airways also increased.
Steven Shea, one of the authors of the study, claims that these experiments succeeded once and for all show that the circadian rhythms affect asthma, regardless of other factors, but remember that other factors also have an impact. “The circadian clock is always ticking, but we do things all the time too, and we really need to know how all this accumulates”, he concludes.