A new study has found a link between a lack of sleep and an elevated risk for illness.
The new study builds on previous studies that found that a lack of sleep impacts that activation of the immune system, inflammation, carbohydrate metabolism and the hormones that regulate appetite. Now Finnish researchers at the University of Helsinki have found that sleep loss also influences cholesterol metabolism.
The new study examined the impact of cumulative sleep deprivation on cholesterol metabolism in terms of both gene expression and blood lipoprotein levels.
Using state-of-the-art methods, a small blood sample can yield information about the activation of all genes, as well as the amounts of hundreds of different metabolites, researchers noted. This means it is possible to seek new regulating factors and metabolic pathways that participate in a particular function of the body, they said.
“In this case, we examined what changes sleep loss caused to the functions of the body and which of these changes could be partially responsible for the elevated risk for illness,” said doctoral student Vilma Aho, a researcher from the Sleep Team Helsinki research group.
The study found genes that help regulate cholesterol transport are less active in people suffering from sleep loss than in those getting sufficient sleep. This was found both in a laboratory-induced sleep loss experiment and in a Finnish population study, according to the researchers.
For the study, researchers analyzed data from three different studies, including an experiment conducted in cooperation with the Finnish Institute of Occupational Health under strictly controlled laboratory conditions, simulating a work week with restricted sleep.
It also used data from the Dietary, Lifestyle and Genetic determinants of Obesity and Metabolic syndrome (DILGOM) study, a subset of the national FINRISK population study.
Lastly, it used data from the Cardiovascular Risk in Young Finns Study, a Finnish population study that followed the lifestyles and heart health of participants from childhood. The new study used data from 2007, when participants were between the ages of 30 and 45, according to researchers.
While analyzing the different metabolites, researchers found that in the population-level data, people suffering from sleep loss had fewer high-density HDL lipoproteins, commonly known as the good cholesterol transport proteins, than people who slept sufficiently.
These results help explain the higher risk of cardiovascular disease in sleep-deprived people and help understand the mechanisms through which lack of sleep increases this risk, according to the researchers.
“It is particularly interesting that these factors contributing to the onset of atherosclerosis, that is to say, inflammatory reactions and changes to cholesterol metabolism, were found both in the experimental study and in the epidemiological data,” Aho said.
The results highlight the health impact of good sleep, researchers add.
They advise that health education should focus on the significance of good, sufficient sleep in preventing common diseases, in addition to healthy food and exercise.
“The experimental study proved that just one week of insufficient sleep begins to change the body’s immune response and metabolism,” Aho said. “Our next goal is to determine how minor the sleep deficiency can be while still causing such changes.”
Source: University of Helsinki