Wind farm noise may disrupt sleep

In this article, researchers surveyed the sleep quality of people living near and far from farm turbines. The results showed that the closer a person live to the wind farm, the more disrupted their sleep, secondary to the noise generated by the turbine. Persons close to the turbine also had poorer mental health. My first thought was that perhaps the difference in self-reported sleep and mental health was due to being lower socioeconomic status, but the study authors said they controlled for that.

Weight loss may improve sleep quality

This article discusses research showing that modest weight loss (about 15 pounds) may improve self-reported sleep quality by 20%. I've seen this happen in my clinic, and the results can be impressive. Researchers think that belly fat may be responsible for sleep disruption, and losing the belly fat may be what helps improve sleep.

Insomnia increases cardiovascular risk?

Many of my patients with insomnia are understandably worried about the physical effects of insomnia. They are concerned that their insomnia will lead to cardiovascular disease (heart attack or stroke, for example) or death. To date, no studies have convincingly shown that primary insomnia increases risk of physical problems - it has been shown to increase rates of depression.

Here is an article about a study trying to link insomnia to increased risk of heart attack and stroke. However, the study authors did not separate the different types of insomnia, meaning the results are difficult to interpret. More specifically, they did not separate the effects of primary insomnia from secondary insomnia (as from sleep apnea) and even people who just decide to get too little sleep. Since the last two categories of insomnia can increase cardiovascular risk, it could make all insomnia seem risky, but this is artificial.

Young children with cystic fibrosis at risk for obstructive sleep apnea

This article discusses how young patients with cystic fibrosis, a chronic lung disease, are at increased risk for obstructive sleep apnea.

Chronic sleep loss in rats

Studies and news reports keep coming about how sleep loss / sleep deprivation is associated with obesity and type 2 diabetes - but the studies are far from conclusive. One problem is that it is difficult to control diet and sleep behavior in humans over a long period of time. Animal studies may help us understand the link between sleep and obesity, since animals can be controlled in the lab. Animal studies in the past have shown links between sleep loss and metabolic changes, but this is usually weight loss and could be due the stress of forced wake time.

Vetrivelan et al have performed an interesting study on rats published in this month's Sleep Journal. They produced brain lesions in the hypothalamic regions of rats as an animal model for chronic, partial sleep loss, and they followed the rats for 2 months (relatively long time for a rat).

Results showed that on average, the brain lesions resulted in 40% reduced sleep compared to normal rats - equivalent to reducing sleep from 8 hours to 4.8 hours per night in humans. However, the rats with brain lesions did not become obese or develop metabolic syndrome. In fact, there was a decrease in blood glucose, cholesterol, and triglycerides!

The authors are not sure why there is a different response in rats and humans to sleep deprivation. When humans voluntarily go without sleep, their food intake increases and are less active. However, the rats in this study did not consume more food and were more active than control rats. The authors concluded that chronic sleep loss per se does not lead to obesity or the metabolic syndrome, at least in rats.

General anesthesia similar to sleep

This article discusses research discussing how general anesthesia may cause deep sleep. Researchers studied the brains of mice under anesthesia and found that the anesthetics turn off wake-promoting neurons and turned on sleep-promoting neurons. However, anesthesia is still not normal sleep. But general anesthesia can allow anesthesiologists to identify individuals at risk for obstructive sleep apnea - I get frequent referrals for this very problem, since the anesthesiologist is "watching them sleep" for hours!

Electronic nose may be able to detect sleep apnea

Although I did not even know they existed, electronic noses have been developed to diagnose certain medical disorders. This article, researchers discusses a study to determine if an electronic nose could detect obstructive sleep apnea (OSA), by measuring volatile compounds in the patinents' breath. It's not clear how the researchers determined if the participants had OSA, as the article mentions only "sleep examinations." If that means sleep studies, then that would be more accurate. The results did show that the electronic nose did predict OSA. They concluded that the electronic nose could help determine who needs a sleep study and who does not.

Obstructive sleep apnea and heart attack protection?

This article discusses a study showing that patients with obstructive sleep apnea (OSA) may have less heart muscle damage during a non-fatal heart attack. These results contradict other studies showing an increased risk of heart attack with untreated OSA.

Some of the doctors in the study urge caution saying that perhaps the chronically low level of oxygen in OSA sufferers may protect some heart attack victims. Also, the study showed that the frequency of heart attacks was not decreased by OSA, just the damage to the heart muscle from the heart attack. Interesting study and more studies will be needed to sort this out.

Electronic devices, sleep duration, and childhood obesity

This article discusses research about pediatric obesity, sleep duration, and electronic devices in the bedroom. Not surprisingly, the more electronic devices (cell phone, TV, video games) were in the bedroom, the more likely the kid would be obese. Also, for each additional hour of sleep, obesity risk was reduced.

It's not clear from the article what contributes to what. I am convinced that screen time affects kids and adult sleep. Getting these devices out of the bedroom can improve sleep quality and duration. I am not convinced that just getting more sleep will reduce childhood obesity. More sleep may improve mood and academic performance, both of which can be negatively affected by insufficient sleep.

Short sleep, blood sugar, and hormone regulation

Lots of hoopla in the news about relationship between short sleep and obesity. Studies are showing that reduced sleep leads to more eating. In this month's Sleep Journal, St-Onge et al did a study to test the effects of sleep duration on hormones and metabolites involved in energy balance regulation.

They studied normal weight, health men and women in the sleep lab. They had them sleep for 4 hours per night x 3 nights and then three weeks later let them sleep 9 hours per night x 3 nights. During each three night portion, their food intake was strictly controlled and monitored.

Results showed no effect of short sleep on glucose, insulin, or leptin levels, as previously shown in other studies. The authors point out that those other studies allowed participants to eat at will, rather than the limited eating allowed in the current study. It may be that overeating in the other studies is what produced the blood glucose changes seen.

In this study, short sleep caused increases in ghrelin in men, but not in women. Ghrelin can increase appetite. Women had reduced levels of GLP-1, but men did not. GLP-1 is known to increase satiety. So men and women may overeat for different reasons in context of short sleep duration if allowed to eat whenever and as much as they want.

It is difficult to extrapolate these results to overweight individuals, who may be metabolically different than the healthy participants in this study.

Tension Tamer before bed may improve sleep

This article discusses research showing that using visualization and abdominal breathing for 10 minutes before bed may improve insomnia.

Getting elbowed at night may mean you have obstructive sleep apnea

Here is article that confirms what we see daily in clinical practice - that is that people who get woken up by their bedpartner via their elbow for snoring and/or stopping breathing are more likely to have obstructive sleep apnea (OSA). But don't be reassured if you think you don't have OSA just because you don't get elbowed at night. While it's easy to hear snoring, it's more difficult to notice pauses in breathing, as those are not usually loud or disruptive to your bedpartner. Better thing to do is talk with your doctor about getting an evaluation for OSA.

Sleep deprivation increases risk of athletic injury in teens

I've blogged about how sleep can affect athletic performance. This article discusses a study showing that teenager athletes were more prone to an athletic injury if they slept less than 8 hours. I remember not sleeping more than 6 hours per night for most of my high school years, so I imagine kids get that much or even less nowadays with all the technological gadgets available.

Video game playing and sleep fragmentation

Playing video games before bed can disrupt sleep and often reduce available sleep time, leaving kids and many adults sleep deprived. This article is about a study showing that the longer a child played video games before bed, the more broken up their sleep. It could be the light from the screen suppressing melatonin secretion and/or more stimulation from playing more. Either way, limit your child's screen time.

Red blood cell distribution width and obstructive sleep apnea

Red blood cell distribution width (RDW) is a blood test that measures the variability of the size of red blood cells, and is usually reported in common blood work to check for anemia. In the October edition of the Journal of Clinical Sleep Medicine is an article about RDW and obstructive sleep apnea (OSA) - researchers theorize that inflammation, low oxygen levels, and/or sleep fragmentation from OSA could increase the RDW. In this study, researchers studied 108 patients with OSA. Results did show a positive correlation between RDW and OSA severity. However, the numbers are hard for me to interpret. They did not include RDW values for patients without OSA. The RDW values for mild, moderate, and severe OSA are as follows: 13.15 +/- 1.7, 13.10 +/- 2.3, and 14.67 +/- 2.5. I'm no hematologist, but those values seem pretty similar, especially the ones for mild and moderate OSA. There is too much overlap in the values for me to understand the clinical significance. The study authors state that the RDW could not be used as a screening tool because it could be affected by various independent variables. They state that the RDW may be used to give earlier appointments to patients with high RDW values so that they may be treated eariler, since their OSA severity may be worse. I'm not so sure and home sleep studies may be a better and more specific screening and / or diagnostic tool.

Dolphins may sleep with only half of their brains at a time

I used to love that show Flipper when I was a kid. They don't make good dolphin-centered programs anymore. This article discusses how dolphins appear to be staying awake as long as 15 days. The researchers think that dolphins may sleep with only one-half of their brain at a time. This allows them to stay awake and alert continuously.

Sleep deprivation and fat cell insulin resistance

This article discusses research about the effect of sleep deprivation on fat cells. They studied young, healthy people - allowing some to sleep only 4.5 hours per night and the other to sleep 8 hours for a few days. They examined each groups fat cells and determined that the short sleepers had more resistance to insulin. They concluded that sleep deprivation may impair our fat cells' ability to respond to insulin, which may lead to diabetes.

These findings are interesting, but there are some problems with the conclusions, as pointed out in the article. For example, most people do not get only 4.5 hours per night, more like 6 hours. Do they have the same effect. Also, most do not deprive for only a few days, but for months / years. Does our body adapt and do the fat cells than have normal insulin sensitivity? More research is definitely needed.

More sleep helps children in school

Here is an article about how more sleep helps kids - seems obvious but at least here is some scientific evidence. For kids that got more sleep, they were less emotional, better focused, and better behaved. There are some good tips in the article for parents as well - monitor for sleepiness, which should be relatively low at a elementary age if they are getting enough sleep.

Newer sleep aids are associated with falls in elderly

Older sleep aids that are related to Valium have been shown to increase falls in elderly patients, especially those with dementia. This article shows how elderly people are at much higher risk of falls with the newer sleep aids like Ambien.

CPAP use and high blood pressure.

It's well known that obstructive sleep apnea (OSA) is linked to high blood pressure (HTN). However, it's less clear that CPAP reduces HTN. In the October edition of Journal of clinical Sleep Medicine is a study attempting to show just that. Researchers studied veterans with known OSA who also had HTN and diabetes (DM). They monitored their CPAP use and followed them for upto one year.

Results showed that both systolic and diastolic blood pressure decreased significantly with CPAP use. This effect was most prominent with African-American patients, but still present in European-Americans. Interestingly, CPAP use did not reduce the subjects fasting blood sugar levels or long term blood sugar control as measured by their hemoglobin A1C.

Obstructive sleep apnea and coronary atherosclerosis

This article discusses research about obstructive sleep apnea (OSA) and coronary artery plaques, which are blockages in the arteries supplying the heart with blood. The softer the plaque, the more dangerous it is. The results showed that more severe OSA was associated with more soft plaque formation. Also, the more severe the OSA, the greater chance of having more than one artery with plaque. This was a small study, and more research needs to be done to determine if CPAP reduces the atherosclerosis.

Non-sleep aids being used to treat insomnia

This article discusses a concerning trend in the treatment of insomnia - physicians are prescribing less traditional sleep aids in favor of using non-traditional medications that are sedating, like anti-epilepsy and anti-psychotic medications. Although these medications can be safe when used for their indicated diseases, there is very little data to support their use in insomnia. The results highlight the difficulty in treating it with medications. Usually, physicians will start with the typical sleep aids like Ambien. When those stop working, other medications are tried such as the ones listed above. However, for long term treatment of insomnia, cognitive behavioral therapy (CBT) has been shown to be superior. The problem is that too few doctors know how to do CBT and it is much more difficult to implement than just taking a pill.