Saturday, November 17, 2018 09:31:30 AM
Life Desk :
People with disrupted sleep are often tired, and their body prioritizes storing fat over maintaining muscle strength which may simultaneously increase obesity risk
Lack of sleep makes it harder to process blood sugar, thereby increasing type 2 diabetes risk
Poor sleep or working night shifts may lead to excessive weight gain, reports a new study. The findings of the study are published in the scientific journal Science Advances.
In a new study, researchers at Uppsala University now demonstrate that one night of sleep loss has a tissue-specific impact on the regulation of gene expression and metabolism in humans. This may explain how shift work and chronic sleep loss impairs our metabolism and adversely affects our body composition.
'People who suffer from chronic sleep loss or who carry out night shift work are more likely to put on weight. Disrupted sleep can alter the metabolism and increases the body's ability to store fat.'
Epidemiological studies have shown that the risk for obesity and type 2 diabetes is elevated in those who suffer from chronic sleep loss or who carry out shift work. Other studies have shown an association between disrupted sleep and adverse weight gain, in which fat accumulation is increased at the same time as the muscle mass is reduced - a combination that in and of itself has been associated with numerous adverse health consequences.
Researchers from Uppsala and other groups have in earlier studies shown that metabolic functions that are regulated by, e.g., skeletal muscle and adipose tissue are adversely affected by disrupted sleep and circadian rhythms. However, until now it has remained unknown whether sleep loss per se can cause molecular changes at the tissue level that can confer an increased risk of adverse weight gain.
In the new study, the researchers studied 15 healthy normal-weight individuals who participated in two in-lab sessions in which activity and meal patterns were highly standardized.
In randomized order, the participants slept a normal night of sleep (over eight hours) during one session and were instead kept awake the entire night during the other session. The morning after each night-time intervention, small tissue samples (biopsies) were taken from the participants' subcutaneous fat and skeletal muscle. These two tissues often exhibit disrupted metabolism in conditions such as obesity and diabetes.
At the same time in the morning, blood samples were also taken to enable comparison across tissue compartments of a number of metabolites. These metabolites comprise sugar molecules, as well as different fatty and amino acids.
The tissue samples were used for multiple molecular analyses, which first of all revealed that the sleep loss condition resulted in a tissue-specific change in DNA methylation, one form of mechanism that regulates gene expression.
DNA methylation is a so-called epigenetic modification that is involved in regulating how the genes of each cell in the body are turned on or off, and is impacted by both hereditary as well as environmental factors, such as physical exercise.
"Our research group were the first to demonstrate that acute sleep loss in and of itself results in epigenetic changes in the so-called clock genes that within each tissue regulate its circadian rhythm.
Our new findings indicate that sleep loss causes tissue-specific changes to the degree of DNA methylation in genes spread throughout the human genome. Our parallel analysis of both muscle and adipose tissue further enabled us to reveal that DNA methylation is not regulated similarly in these tissues in response to acute sleep loss," said Jonathan Cedernaes who led the study.
"It is interesting that we saw changes in DNA methylation only in adipose tissue, and specifically for genes that have also been shown to be altered at the DNA methylation level in metabolic conditions such as obesity and type 2 diabetes.
Epigenetic modifications are thought to be able to confer a sort of metabolic "memory" that can regulate how metabolic programmes operate over longer time periods. We, therefore, think that the changes we have observed in our new study can constitute another piece of the puzzle of how chronic disruption of sleep and circadian rhythms may impact the risk of developing for example obesity," notes Jonathan Cedernaes.
Further analyses of, e.g., gene and protein expression demonstrated that the response as a result of wakefulness differed between skeletal muscle and adipose tissue. The researchers say that the period of wakefulness simulates the overnight wakefulness period of many shift workers assigned to night work.
A possible explanation for why the two tissues respond in an observed manner could be that overnight wakefulness periods exert a tissue-specific effect on tissues' circadian rhythm, resulting in misalignment between these rhythms. This is something that the researchers found preliminary support for also in this study, as well as in an earlier similar but smaller study.
"In the present study, we observed molecular signatures of increased inflammation across tissues in response to sleep loss. However, we also saw specific molecular signatures that indicate that the adipose tissue is attempting to increase its capacity to store fat following sleep loss, whereas we instead observed signs indicating a concomitant breakdown of skeletal muscle proteins in the skeletal muscle, in what's also known as catabolism.
We also noted changes in skeletal muscle levels of proteins involved handling blood glucose, and this could help explain why the participants' glucose sensitivity was impaired following sleep loss. Taken together, these observations may provide at least partial mechanistic insight as to why chronic sleep loss and shift work can increase the risk of adverse weight gain as well as the risk of type 2 diabetes," said Jonathan Cedernaes.
The researchers have only studied the effect of one night of sleep loss, and therefore do not know how other forms of sleep or disruption of circadian misalignment would have affected the participants' tissue metabolism.
"It will be interesting to investigate to what extent one or more nights of recovery sleep can normalize the metabolic changes that we observe at the tissue level as a result of sleep loss. Diet and exercise are factors that can also alter DNA methylation, and these factors can thus possibly be used to counteract adverse metabolic effects of sleep loss," said Jonathan Cedernaes.
US Vice-President Mike Pence expressed the Trump administration's strongest condemnation about Myanmar's treatment towards Rohingya Muslims. He told Aung San Suu Kyi that "persecution" by Myanmar's military was "without excuse" in a meeting with her on November14. Mr Pence also pressed Suu Kyi to pardon two Reuters journalists who were ...
AFP, Zagreb :Spain passed up the chance to seal progress to the Nations League finals as they were beaten 3-2 by Croatia on Thursday, undone by a 93rd-minute winner from Tin Jedvaj.Jedvaj's late strike leaves Group 4 wide open ahead of its final fixture between England and Croatia on Sunday. ...
Deepika Padukone and Ranveer Singh got married at the picturesque locale of Lake Como in Italy. The much-in-love duo got married in a traditional Konkani wedding ceremony on November 14 and today solemnised their wedding as per Sindhi tradition. After managing to keep their wedding pictures well-guarded, the couple has ...
Reuters, London : British Prime Minister Theresa May was fighting for survival on Friday after a draft divorce deal with the European Union provoked the resignations of senior ministers and mutiny in her party.More than two years after the United Kingdom voted to leave the EU, it is still unclear how, ...
THE countrywide 'Income Tax Fair -2018' has already drawn a huge crowd. The authorities hope more people would be brought under tax net this year too. Finance Minister AMA Muhith while inaugurating the fair said out of country's 16 crore population, the number of taxpayers is around one crore. There ...
AP, Washington :The United States military has "lost its edge" and could potentially lose a war against Russia or China, a report by a bipartisan panel established by Congress says.The report by the National Defense Strategy Commission on November 14 said U.S. military superiority has "eroded to a dangerous degree" ...
Shraddha Kapoor commences the shoot of her upcoming film Chhichhore. Shraddha took to her twitter handle on Wednesday morning and announced, “Time to get back in to it! Excited to start a new journey. Day 1 for me on #Chhichhore?? @NGEMovies @niteshtiwari22 @itsSSR.” Earlier, The first look poster of Chhichhore ...
Entertainment Report :Jaya Ahsan has already proved herself as an actress not only in Bangladesh but also in Kolkata. Now she is one of the busiest actors in Indian Bangla cinema whose commitment to her craft has taken her places including a circus. Jaya’s latest Bangladeshi film Debi, which also ...
Sheikh Arif Bulbon :Bijori Barkatullah was one of the popular TV actresses of her generation. She is not only an actress but also a dance artiste, model and host. Today is her birthday. She takes break on her birthday. Before birthday she also worked. Bijori informed that yesterday she took ...
AFP, Burton-On-Trent :Wayne Rooney will make his final farewell as England's greatest ever goalscorer in a friendly against the United States on Thursday, but is excited at what a young squad can achieve under "fearless" coach Gareth Southgate in the years to come.Rooney, 33, made the last of his 119 ...
Agency :Windies suffered a big blow as captain Jason Holder was ruled out of the Bangladesh tour with a shoulder injury. Holder is said to have suffered the injury during the recent tour of India, and will need at least four weeks to recover from the setback."Jason has a partial ...
THE Bangladesh Bank's role as the custodian of the production and distribution of money and credit in the economy has been eroded by the finance ministry in the past decade. It's not a common people's remark. Rather, it came from a Director of the central bank while addressing a meeting ...