Posts tagged with "University of Colorado-Boulder"

Don’t ‘sleep in’ on Saturday or Sunday

March 1, 2019

Wake up, America! A study conducted at the University of Colorado–Boulder has found that trying to catch up on shut-eye over the weekend may not be such a good idea—for either your waistline or your health, CNN reported on February 28.

“Weekend catch-up sleep is not protective,” Dr. Vsevolod Polotsky, director of Sleep Research at the Johns Hopkins University School of Medicine, told the cable news network, adding, “The bottom line of this study is that even if you sleep longer on weekends, if you continue to sleep poorly, you will still eat too much, and you will still gain weight.”

Study author Kenneth Wright, Jr., who directs the Sleep Lab at the UC-Boulder, agrees. “Sleeping in on weekend doesn’t correct the body’s inability to regulate blood sugar, if that weekend is followed by a workweek or [a]school week full of insufficient sleep,” he told CNN.

The study by Wright and his colleagues—published in the journal Current Biology—assigned 36 healthy young men and women to three groups that prescribed different sleep requirements over a total of 10 days. None of the participants had newborns in the home or any health impairments that would affect the quality of their sleep.

The first group had the opportunity to sleep for nine hours each night for the 10 days. The second group was restricted to only five hours of sleep a night for the same duration, while the third was restricted to five hours Monday through Friday but allowed to sleep as long as they wanted on the weekend and go to bed as early as they liked on Sunday night. Come Monday, that third group was put back on the deprived sleep schedule of only five hours a night.

Both of the sleep-deprived groups snacked more after dinner and gained weight during the study—men, much more than women, CNN reports. The sleep-deprived men showed an overall 2.8% increase in their weight, while women’s body size went up by only 1.1%. By comparison, men who slept in on the weekend showed a 3% increase in weight, while women’s body size went up 0.05%

Gaining weight while sleep-deprived isn’t surprising, Wright said. “One of the things we and others have found in the past is that when people don’t sleep enough, they tend to eat more, partly because their body is burning more calories. But what happens is that people eat more than they need and therefore gain weight.

That could be in part, Polotsky told the news outlet, because hunger hormones are affected by a chronic lack of sleep. “The hormone leptin decreases appetite, while the hormone ghrelin increases appetite,” explained Polotsky, who was not involved in the study. “We know from previous research that sleep deprivation causes leptin to drop and ghrelin to rise, so you’re hungry.”

What was surprising to the researchers is what happened to the group who slept in on the weekends. “Even though people slept as much as they could, it was insufficient,” Wright said. “As soon as they went back to the short sleep schedules on Monday, their ability of their body to regulate blood sugar was impaired.”

Why? One of the reasons the weekend group may have been more affected is because their circadian rhythm, or biological clock, had been altered, depriving the body of certain hormones.

“If you catch up during weekends, you habitually eat later, because the circadian clock is shifting,” Polotsky said. “Add in after-dinner snacks; the sleep-deprived eat much more after dinner, as well.”

Not only that, but the weekend recovery group showed increased sensitivity to insulin in both their muscles and their livers, a result not found in the second group on restricted sleep. That’s important, Wright explained to CNN, because the muscle and liver are two of the most important tissues that take up blood sugar after eating.

“That helps us understand why is it that when we don’t get enough sleep, we have an increased risk for things like diabetes,” he added, because “short, insufficient sleep schedules will lead to an inability to regulate blood sugar and increases the risk of metabolic disease in the long term.”

Metabolic syndrome is an array of symptoms such as fat around the waist, abnormal cholesterol, high blood sugar, and high blood pressure—all of which can raise the risk of heart disease, stroke and diabetes.

“And when we go back to getting too little sleep again,” Wright told CNN, “we’re doing things that could be negative for our health long-term.”

The American Academy of Sleep Medicine recommends at least seven hours of sleep each night for adults and much more for children.

Research contact: kenneth.wright@colorado.edu

Coming clean: Your showerhead is spritzing bacteria on your naked body

November 7, 2018

Do you want to know “the real dirt” on showers? A study conducted at the University of Colorado-Boulder has found that showerheads are covered with bacteria-filled slime that could make us sick.

The researchers used high-tech instruments and lab methods to analyze roughly 50 showerheads from nine cities—among them, New York City, Chicago, and Denver—in seven states nationwide.

They concluded that—while we believe we are getting invigorating relief and a good daily cleansing, about 30% of the showerheads we use instead are covering our naked bodies with significant levels of Mycobacterium avium. That’s a pathogen linked to pulmonary disease that most often infects people with compromised immune systems; but which occasionally can infect healthy people, said CU-Boulder Distinguished Professor Norman Pace, lead study author.

 “If you are getting a face full of water when you first turn your shower on, that means you are probably getting a particularly high load of Mycobacterium avium, which may not be too healthy,” he said.

Showering may cleanse our bodies of sweat and dirt, but over time, our showerheads develop scum—also known as biofilm—due to the warm, wet conditions in the stall or tub.

Many of the bacteria in the scum are not harmful, but the team did find traces of nontuberculous mycobacteria (NTM) in showerheads across the United States. NTM is particularly prevalent in parts of Southern California, Florida, and New York — all areas with higher reported incidences of NTM lung disease, the study authors note. They believe showerheads may transmit the disease.

Symptoms of the infection include coughing up blood, shortness of breath, persistent coughing, fatigue and fever, according to the American Lung Association. Not everyone develops the condition after exposure to NTM, and doctors aren’t sure why only some people get sick. However, those who already have lung problems,  as well as older adults and people with weak immune systems are at greater risk. The infection is treated with antibiotics, according to WebMD.

The team also found that NTM is more common in metal showerheads, as well as U.S. households that use municipal water over well water. Mycobacteria are resistant to the chlorine found in municipal water, so they have more room to grow after other the chlorine kills off other bacteria.

According to study co-author Noah Fierer, more research should be done to determine whether our water treatments could put us at risk.

“There is a fascinating microbial world thriving in your showerhead and you can be exposed every time you shower,” Fierer said in a statement. “Most of those microbes are harmless, but a few are not, and this kind of research is helping us understand how our own actions—from the kinds of water treatment systems we use to the materials in our plumbing—can change the makeup of those microbial communities.”

What does all this mean for you? You definitely shouldn’t stop showering, but you might want to think about cleaning your showerhead every now and then. Using vinegar, which has been shown to kill many types of mycobacteria, is a good bet.

Research contact: matthew.gebert@colorado.edu