Monday, April 29, 2013

MRI scanners may be able to detect visual images in dreams

During sleep studies, I can tell when someone is in dream sleep. However, I can't determine what they dreaming about. Here is an article about research done in Japan showing that an MRI may be able to predict what you are dreaming about. They studied three men in early stages of sleep with an MRI. This showed the researchers what area of the brain was activated during dreaming. The researchers woke the subjects up and had them describe what they were dreaming about. They correlated the visual dream description with the location that lit up on the MRI. Then, when the men dreamed again in the MRI, researchers were able to predict about 70% of the time, what the person was dreaming about by noting the location of the brain that had lit up on the MRI. Pretty cool, huh?

Friday, April 26, 2013

Type 2 diabetes linked to low melatonin levels

Melatonin is the hormone produced in your brain when the sun goes down. It is the signal that says it's time for sleep soon. This article talks about a study that showed that people with low amounts of melatonin at night were twice as likely to develop type 2 diabetes.

It will be interesting to see if taking melatonin would prevent people who are at risk from developing diabetes. Research also needs to be done to figure out how and why melatonin is related to diabetes. I wonder if people with type 1 diabetes also have low melatonin levels at night.

Wednesday, April 24, 2013

Sleep apnea may impair kids behavior and adaptive functioning

Studies have shown that kids with obstructive sleep apnea (OSA) can have behavioral difficulties that affect school and home. Some will present to their pediatrician with symptoms of attention deficit-hyperactivity disorder (ADHD) - but in reality, the cause is underlying OSA. This study in the Journal Sleep looked at how kids with OSA have increased risk of behavior and adaptive functioning difficulties. Adaptive functioning refers to how these kids "negotiate social situations, engage in self-care to meet his or her own needs, and apply skills learned in school."

Researchers studied 263 kids starting at ages 6-11 years old. They had the kids and parents fill out questionnaires about behavior and functioning. They had the kids do home sleep studies. Then 5 years later, they repeated the questionnaires and sleep studies.

The results showed that the highest rate of impairment occurred in those kids diagnosed with OSA, particularly those that had it on both sleep studies (5 years apart). Researchers note, however, that some behaviors, like aggression and conduct problems, were accounted for by sociodemographic variables, rather than the OSA. And kids who had OSA on both sleep studies were 3-7 times more likely to have learning problems and lower grades than in kids who never had OSA.

Monday, April 22, 2013

CPAP may reduce inflammation associated with sleep apnea

Obstructive sleep apnea (OSA) causes inflammation - both local and systemic. Researchers think that the local inflammation is from trauma from snoring. Systemic inflammation may occur because of repetitive drops in blood oxygen levels and / or sleep fragmentation from OSA. This study did a meta-analysis to see if CPAP reduces three markers of systemic inflammation - CRP, IL-6, and TNF-alpha. The data showed that CPAP use did significantly reduce levels of CRP and TNF-alpha. It lowered levels of IL-6, but not enough to be statistically significant.

The bottom line is that untreated OSA is associated with systemic inflammation, which may raise the risk for cardiovascular disease. Treating OSA with CPAP can reduce some of the markers of inflammation - this may lower the risk of developing cardiovascular disease.

Friday, April 19, 2013

Sleep apnea may increase risk of brain tumor

Obstructive sleep apnea (OSA) can cause repetitive dips in blood oxygen levels, which can then cause chronic inflammation. Some researchers think this chronic inflammation may increase risk of cardiovascular disease, lowered immunity, and increased risk of tumors. This study showed an increase risk of brain tumors in patients with sleep apnea. The article does not describe the OSA severity - is it only in severe OSA sufferers? Or is there risk increased even with mild OSA? Does it depend on how the researchers defined apnea events - with oxygen level dip and/or arousal in brain wave monitoring? More questions than answers at this point.

Wednesday, April 17, 2013

Sleeping position may affect pregnancy outcome

I was always taught that pregnant women should avoid sleeping on their back. This is especially true as you get closer to term date. As the baby gets bigger, it and the uterus can compress the inferior vena cava, the main vein that brings blood back to the mom's heart. Less blood into the heart means less blood out of the heart, which can harm the baby.

Here is a article about a study that showed that sleeping on the back while pregnant was associated with stillbirth. Researchers think that the stillbirths occurred because the babies were low birth weight - possibly due to reduced blood flow to the placenta during back sleeping. Researchers speculate that sleeping on the sides may reduce rates of stillbirth.

Monday, April 15, 2013

Kids can sleep right through a fire alarm

Here is a video story about how kids can sleep through a fire alarm. Most parents know that kids sleep deeply. In this video story, the reporter set up an experiment demonstrating that three young boys slept right through the ear-piercing fire alarm in their home. But there is hope - one company is trying to improve the fire alarm but changing the noise it produces - instead of the beeping, it will be the parents voice telling the kids to get up.

Friday, April 12, 2013

Dr. Oz gets sued for insomnia treatment recommendation

This has received lots of press. Here is an article that discusses what happened. Apparently, Dr. Oz recommended a home remedy to sleep better - putting heated rice in your socks at night to warm your feet. This makes no sense to me. It sounds like Dr. Oz is trying to cool the body by drawing blood to the feet, which then loses the heat. One of his viewers has diabetic neuropathy, and has reduced sensation in his feet. The viewer put on socks with rice in them and suffered 3rd degree burns. That viewer is suing Dr. Oz's show, saying he should have warned viewers about the risk of getting burned.

I understand what Dr. Oz was trying to accomplish - people find it easier to sleep when their bodies are cooler. However, there are safer ways to do that than the heated-rice-in-your-socks method.

Wednesday, April 10, 2013

Home schooled teens get more sleep

There has been much criticism of school start times. Elementary school children start the latest and high school students start the earliest. But this goes against our sleep biology - young children get up earliest and teenagers sleep later. Here is a study showing that home schooled teens get about 1.5 hours more sleep per night than those students in public or private schools. In fact 55% of home schooled teens got enough sleep versus 25% of public / private school teens.

Monday, April 8, 2013

Sleep deprivation may lead to overeating

Another study about eating behavior and sleep. This time, researchers studied young, healthy people in a controlled sleep lab for two weeks straight. They restricted half of them to 5 hours per night for 5 nights, then let them sleep up to 9 hours per night. The other half slept up to 9 hours per night for 5 nights, then were restricted to 5 hours per night. When the participants were only sleeping 5 hours per night, they burned more calories, but they also ate more. And the tended to eat more of their calories closer to bedtime than the well-rested group. Interestingly, appetite controlling hormone levels were not altered as expected during the sleep deprivation phase. The researchers concluded that sleep loss does not make you overweight and getting more sleep will not make you lose weight. I wish weight loss was that easy. It still boils down to eating less calories, regardless of how many hours you sleep.

Friday, April 5, 2013

Some sleep aids may boost memory by changing sleep

When I perform sleep studies on my patients, one way I have of knowing that a patient is in a certain stage of sleep is by one of their brain wave patterns. One such pattern that is commonly associated with light, non-dream sleep is sleep spindles. Sleep researchers have discovered that certain disorders that can affect memory, like Alzheimer's and schizophrenia, have a reduce amount of sleep spindles. And certain medications can increase the number of spindles. So researchers did a test to see if taking one of these medicine to increase the spindle frequency improved memory. One of the medications was Ambien. The results showed an increase in spindles and an improvement in verbal memory. And the improvement was better than plain sleep. This is exciting, as it may allow us to improve memory in certain people.

Wednesday, April 3, 2013

Sleep disruption may signal future Alzheimer's Disease

Alzheimer's patients sleep poorly at night and often nap multiple times in the daytime. They can get their days and nights so mixed up, they end up sleeping only in the daytime and are up all night wandering. Sleep problems are a common reason for putting people with Alzheimer's Disease in nursing homes. Here is a study showing that broken up sleep and daytime napping were more likely in people with pre-clinical Alzheimer's Disease - meaning before there is any memory loss. Researchers determined their sleep quality with home based sleep testing and sleep diaries. They determined pre-clinical Alzheimer's Disease with results from a spinal tap. These findings are interesting as a disruption in sleep quality may mean that the person is at risk for developing a cognitive disorder.

Monday, April 1, 2013

Insomnia can increase risk of developing heart failure

Here is a study that got lots of press. Researchers studied over 54,000 Norwegians who were initially free of heart failure. The researchers asked the respondents how many times per week they have difficulty falling asleep, staying asleep, or woke unrefreshed. The results showed that in those that reported difficulty falling and staying asleep almost every night, and waking unrefreshed at least once a week, had a three fold increase in chance of developing heart failure. The researchers adjusted for factors that could affect the results, such as age, sex, marital status, education, shift work, blood pressure, cholesterol, diabetes, body mass index, physical activity, smoking, alcohol, any previous heart attack, depression and anxiety.

Now, before you panic, step back for a minute. These results support an association between insomnia and heart failure, but not that insomnia causes heart failure. Also, these patients were not examined before by sleep physicians and did not have sleep studies. Obstructive sleep apnea (OSA) could cause insomnia, and OSA is known to increase the risk of heart failure. So the insomnia reported by these study participants could be just a marker for undiagnosed OSA. This could explain the increased risk of heart failure, not the insomnia itself. And the study researchers did not adjust for OSA or other sleep related breathing disorders.

The authors theorize that if insomnia is linked to heart failure, then treating the insomnia may reduce risk of developing heart failure. I agree, as long as the cause of the insomnia is evaluated first.