There are various scientific studies that demonstrate the importance of night rest. In fact, sleeping little and badly can compromise our health from various points of view. If you don’t get enough sleep, for example, your risk of heart attack and stroke increases. In the past, research had focused on possible damage to the functioning of the heart. A study, published in the journal The Physiological Society’s Experimental Physiology (April 2019), explains why.
A group of researchers from the University of Colorado in Boulder in USA (CU Boulder), led by Christopher DeSouza – professor of Integrative Physiology – have discovered the causes. From the results of this new investigation, it appears that individuals who sleep less than 7 hours a night have blood levels lower than three physiological regulators. These are microRNAs that influence the expression of genes and play an important role in the health of the vascular system. These are small molecules (capable of suppressing the gene expression of specific cellular proteins) on whose function the scientific world is paying particular attention, also with regard to other diseases, including the development of anti-tumor drugs.
The researchers analyzed blood samples taken from 24 healthy adults (men and women) between the ages of 44 and 62. Participants were asked to fill out questionnaires regarding their sleep-related habits. The researchers thus found that half of the participants slept from 7 to 8.5 hours a night, while the other half slept from 5 to 6.8 hours every night. In addition, the levels of nine microRNAs, already associated with inflammatory status, immune function, and vascular health, were measured. The data showed that those who sleep little have 40-60% lower levels of miR- 125A, miR-126 and miR-146a (molecules capable of suppressing inflammatory proteins), compared to those who sleep well.
This is the first study that investigated the impact that sleep can have on the blood levels of microRNAs. A previous study, on the other hand, had shown that adult men who sleep less than 6 hours a night have dysfunction in endothelial cells (the cells that line blood vessels). It is a condition that does not allow a good dilation of the arteries, compromising the vascular function.
In the United States, 40% of the population sleeps too little, with an average duration of 6.8 hours per night; despite the instructions of the American Heart Association to sleep at least 7-9 hours. Why 7-8 hours is the “magic” number of hours of sleep is still unclear. The most truthful hypothesis is that the minimum number of seven hours of sleep per night guarantees to maintain the right levels of important physiological regulators, such as microRNAs. CU Boulder researchers are already at work in their laboratories, with new investigations that allow them to determine if it is possible to restore blood levels of microRNA, with the ensuing benefits, thanks to the simple restoration of healthy habits related to sleep with a duration of 7-8 hours. In any case, using the blood levels of microRNA as a marker of cardio-vascular diseases, it is possible to identify the risk factors in patients who sleep little, thanks to the use of non-invasive tests, which involve a simple blood sampling, instead of the invasive methods currently used. A new investigation mechanism through which to understand how sleep affects general physiology and heart health.
