While we are sleeping in bed, some parts of our body are working at high pressure: the immune system is hunting for pathogens, the liver breaks down the toxins and converts the nutrients, our brain stores just learned in long-term preservation.
If we sleep too little, it makes us moody and unconcentrated, more susceptible to infections and our risk of serious health problems is increasing: for example, sleep deprivation promotes the development of obesity and hypertension and increases the risk of premature birth in pregnant women.
Now the researchers have discovered another effect that sleep deprivation has on our body: it interferes with the "management" of the body's water balance and ensures that we wake up dehydrated.
Those who sleep little are dehydrated more often
Asher Rosinger scientists from Pennsylvania State University analyzed urine samples from 25,000 subjects in China and the United States who had previously provided sleep patterns. They specifically looked for biomarkers in the urine that indicate dehydration.
The result: participants in the study, the sleeping on average six hours or less per night were on average more dehydrated as subjects who get around eight hours of sleep a night.
According to the researchers, the key role in this context plays the so-called antidiuretic hormone. The task of this hormone is to maintain a sufficient level of fluids in the body. This hormone is released mainly during sleep, mainly in the last hours of sleep. Those who wake up too early lose the window of opportunity in which the body is hydrated. The antidiuretic hormone makes it by drawing water from the urine and returning it to the body.
The glass of water in the morning fills the reservoir with liquids
According to the authors of the study, dehydration can help us feel so hurt after a sleepless night. They advise you to start the day with a glass of warm water after a few nights – this refills the liquids. Cold water is less suitable because the body has an extra job to heat the water at body temperature.
Rosinger, Asher Y., et al. (2018): Short sleep duration is associated with inadequate hydration: intercultural tests of US and Chinese adults in: Sleep.