Lack of sleep affects fat metabolism
September 16, 2019
Science Daily/American Society for Biochemistry and Molecular Biology
A restricted-sleep schedule built to resemble an American work week made study participants feel less full after a fatty meal and altered their lipid metabolism. One night of recovery sleep helped, but didn't completely erase the effects of sleep restriction.
We're all a little short on sleep during the work week. A new study adds to the mounting evidence about just how harmful lack of sleep can be. In the Journal of Lipid Research, researchers at Pennsylvania State University report that just a few days of sleep deprivation can make participants feel less full after eating and metabolize the fat in food differently.
Sleep disruption has been known to be have harmful effects on metabolism for some time. Orfeu Buxton, a professor at Penn State and one of the senior authors of the new study, contributed to a lot of the research demonstrating that long-term sleep restriction puts people at a higher risk of obesity and diabetes. However, Buxton said, most of those studies have focused on glucose metabolism, which is important for diabetes, while relatively few have assessed digestion of lipids from food.
Kelly Ness, now a postdoctoral fellow at the University of Washington, ran the study when she was a graduate student in Buxton's lab. After participants spent a week getting plenty of sleep at home, she said, the 15 healthy men in their 20s checked into the sleep lab for the ten-night study. For five of those nights the participants spent no more than five hours in bed each night.
During the study, Ness said, she and other researchers collected data but also spent time, "interacting with the subjects, playing games with them, talking with them -- helping to keep them awake and engaged and positive."
To find out how the uncomfortable schedule affected metabolism, the researchers gave participants a standardized high-fat dinner, a bowl of chili mac, after four nights of sleep restriction. "It was very palatable -- none of our subjects had trouble finishing it -- but very calorically dense," Ness said. Most participants felt less satisfied after eating the same rich meal while sleep deprived than when they had eaten it well-rested.
Then researchers compared blood samples from the study participants. They found that sleep restriction affected the postprandial lipid response, leading to faster clearance of lipids from the blood after a meal. That could predispose people to put on weight. "The lipids weren't evaporating -- they were being stored," Buxton explained.
The simulated workweek ended with a simulated Friday and Saturday night when participants could spend ten hours in bed catching up on missed shut-eye. After the first night, they ate one last bowl of chili mac. Although participants' metabolic handling of fat from food was slightly better after a night of recovery sleep, they didn't recover to the baseline healthy level.
This study was highly controlled, which makes it an imperfect model for the real world, Ness said. It focused on healthy young people, who are usually at a lower risk of cardiovascular disease, and all of the participants were men. The researchers also wondered whether giving more recovery time would change the magnitude of recovery they observed.
Nonetheless, according to Buxton, the study gives worthwhile insight into how we handle fat digestion. "This study's importance relies on its translational relevance. A high-fat meal in the evening, at dinnertime -- and real food, not something infused into the vein? That's a typical exposure. That's very American."
https://www.sciencedaily.com/releases/2019/09/190916114020.htm
Only 12 percent of American adults are metabolically healthy
Trends help sound alarm for efforts to lower associated risk of types 2 diabetes, heart disease and other complications
November 28, 2018
Science Daily/University of North Carolina at Chapel Hill
The prevalence of metabolic health in American adults is 'alarmingly low,' even among people who are normal weight, according to a new study. Only one in eight Americans is achieving optimal metabolic health. This carries serious implications for public health since poor metabolic health leaves people more vulnerable to developing Type 2 diabetes, cardiovascular disease and other serious health issues.
This study, published Nov. 28 in the journal Metabolic Syndrome and Related Disorders, presents the most updated U.S. data on metabolic health, which is defined as having optimal levels of five factors: blood glucose, triglycerides, high-density lipoprotein cholesterol, blood pressure, and waist circumference, without the need for medications.
For the study, researchers examined National Health and Nutrition Examination Survey data from 8,721 people in the United States between 2009 and 2016 to determine how many adults are at low versus high risk for chronic disease. Data revealed that only 12.2 percent of American adults are metabolically healthy, which means that only 27.3 million adults are meeting recommended targets for cardiovascular risk factors management.
In the last decade the thresholds for common health measures, for example those that are used to determine if someone has high blood pressure or blood sugar levels, have been lowered by respected professional medical societies. These more restrictive guidelines may mean that a smaller proportion of people are meeting the optimal levels for the cardiovascular risk factors.
"The study fills a gap. We wanted to know how many American adults really meet the guidelines for all of these risk factors and are within optimal levels for disease prevention and health," said Joana Araujo, postdoctoral research associate in nutrition and the study's first author. "Based on the data, few Americans are achieving metabolic health, but the most disturbing finding was the complete absence of optimal metabolic health in adults who had obesity, less than a high school education, were not physically active and were current smokers. Our findings should spur renewed attention to population-based interventions and widely accessible strategies to promote healthier lifestyles."
The data showed that being more physically active, female, younger, more educated and a nonsmoker were factors associated with being more metabolically healthy. Whereas, being non-Hispanic black or having a higher body mass index meant people were less likely to be metabolically healthy.
The research team looked at how health-related behaviors might play into metabolic health and how the proportion of people who are metabolically healthy changes when BMI, physical activity or smoking rates are higher or lower. They found that less than 1 percent of obese adults are metabolically healthy. On the other hand, people who exercise more appear to have higher levels of metabolic health.
The authors call for further study to understand the mechanisms of risk factor development, with a focus on people of normal weight as well as heavier adults.
https://www.sciencedaily.com/releases/2018/11/181128115045.htm
When fathers exercise, children are healthier, even as adults
October 22, 2018
Science Daily/Ohio State University Wexner Medical Center
Most parents know that the diet and exercise habits of a pregnant woman impacts the health of her baby, but little is known about how a father's health choices are passed to his children. A new study finds that lifestyle practices of fathers prior to conception may have a major impact on the lifelong health of their children.
In a new study led by Kristin Stanford, a physiology and cell biology researcher with The Ohio State University College of Medicine at the Wexner Medical Center, paternal exercise had a significant impact on the metabolic health of offspring well into their adulthood.
Laurie Goodyear of the Joslin Diabetes Center and Harvard Medical School co-led the study, published today in the journal Diabetes.
"This work is an important step in learning about metabolic disease and prevention at the cellular level," said Dr. K. Craig Kent, dean of the Ohio State College of Medicine.
Recent studies have linked development of type 2 diabetes and impaired metabolic health to the parents' poor diet, and there is increasing evidence that fathers play an important role in obesity and metabolic programming of their offspring.
Stanford is a member of Ohio State's Diabetes and Metabolism Research Center. Her team investigated how a father's exercise regimen would affect his offspring's metabolic health. Using a mouse model, they fed male mice either a normal diet or a high-fat diet for three weeks. Some mice from each diet group were sedentary and some exercised freely. After three weeks, the mice bred and their offspring ate a normal diet under sedentary conditions for a year.
The researchers report that adult offspring from sires who exercised had improved glucose metabolism, decreased body weight and a decreased fat mass.
"Here's what's really interesting; offspring from the dads fed a high-fat diet fared worse, so they were more glucose intolerant. But exercise negated that effect," Stanford said. "When the dad exercised, even on a high-fat diet, we saw improved metabolic health in their adult offspring."
Stanford's team also found that exercise caused changes in the genetic expression of the father's sperm that suppress poor dietary effects and transfer to the offspring.
"We saw a strong change in their small-RNA profile. Now we want to see exactly which small-RNAs are responsible for these metabolic improvements, where it's happening in the offspring and why," Stanford said.
Previous studies from this group have shown that when mouse mothers exercise, their offspring also have beneficial effects of metabolism.
"Based on both studies, we're now determining if both parents exercising has even greater effects to improve metabolism and overall health of offspring. If translated to humans, this would be hugely important for the health of the next generation," Goodyear said.
The researchers believe the results support the hypothesis that small RNAs could help transmit parental environmental information to the next generation.
"There's potential for this to translate to humans. We know that in adult men obesity impairs testosterone levels, sperm number and motility, and it decreases the number of live births," Stanford said. "If we ask someone who's getting ready to have a child to exercise moderately, even for a month before conception, that could have a strong effect on the health of their sperm and the long-term metabolic health of their children."
Other Ohio State researchers involved in the study were Lisa Baer, Adam Lehnig and Joseph White.
Funding from the National Institutes of Health supported this research.
https://www.sciencedaily.com/releases/2018/10/181022085844.htm