Sunday, September 30, 2012

Men who co-sleep may have lower testosterone at night

This article discusses research showing that in men who co-sleep with their baby have lower testosterone levels at night than man who do not co-sleep. The researchers do not know why this happens or even the significance. One theory is that the lower testosterone levels may help men be more responsive to their babies.

Saturday, September 29, 2012

Restless legs syndrome and soap

I saw this article titled "Can a bar of soap cure your nighttime leg cramps?" and wanted to comment. I think the author is confusing two separate disorders - restless legs syndrome and nocturnal leg cramps. They say that a bar of soap under the mattress may improve restless legs syndrome, but the title implies nocturnal leg cramps. The confusing part is that both conditions may respond to magnesium, which purportedly is given off by soap - I don't know if that is true. But it seems that if magnesium was given off by soap, how would putting it under your mattress help? Also, they mentioned lavender soap may help, as the lavender can help sleep. Maybe, but why not just use lavender aromatherapy? If you have leg cramps or restless legs, see your doctor first.

Friday, September 28, 2012

Obstructive sleep apnea common in women

This article discusses research about the prevalence of obstructive sleep apnea (OSA) in women. I was taught that men are about two times more likely to have OSA than women until women reach menopause. Than the prevalence is about equal for both men and women. But this study showed that about half of the women in their sample had some form of OSA, with 14% having severe OSA. Hopefully the word will get out and women will talk to their doctor or a sleep physician about getting evaluated.

Thursday, September 27, 2012

Wednesday, September 26, 2012

Snoring is linked to behavioral problems in toddlers

This article reviews research showing that toddlers who snore on a regular basis are more prone to behavioral problems. This could be because chronic snoring is often a marker for obstructive sleep apnea (OSA). And treating the snoring (and underlying OSA) could improve a child's behavior. If your child snores regularly, you may want to have him or her evaluated by an ear, nose, and throat doctor (an ENT) or a sleep physician.

Tuesday, September 25, 2012

This article discusses research showing that the light from tablets close to bedtime can lead to sleeplessness. I have seen this in some of my patients. The light can suppress Melatonin, the hormone that gets secreted when it is dark. My patients have used filters to block out blue light or a software program called f.lux.

Monday, September 24, 2012

Exercise training improves daytime functioning in sleep apnea patients

Exercise may improve obstructive sleep apnea (OSA) severity, even in the absence of weight loss. The less severe the OSA, the better patients may feel in the daytime. This article in the August edition of the Journal of Clinical Sleep Medicine is about a study done to see if exercise training can improve daytime functioning even without reducing OSA severity.

In the study, they had a group of people do supervised exercise for 12 weeks versus the control group that did only stretching for 12 weeks. The two groups of participants were similar with the exception of their baseline sleepiness scores, with the exercise group reporting a little more sleepiness than the stretching group.

The results of the study showed that at the end of the 12 weeks, the OSA severity was 25% lower in the exercise group. The exercise group also had less depressive symptoms, less fatigue, and more vigor than the stretching group. Exercise training caused a lowering if subjective sleepiness, but this was not statistically significant. Exercise training improved physical functioning, vitality, and mental health as measured by questionnaires. Interestingly, there was no difference in participants performance on tests of cognition with exercise versus stretching.

Now you may say that the improvements in exercise were due to OSA severity reduction, not because of the exercise itself as the authors proposed. But, only improvement in fatigue was linked to reduction in OSA severity in the exercise group. All of the other improvements occurred in the exercise group even when the OSA severity remained the same.

These findings are exciting, because not everyone feels better on CPAP. Perhaps exercise may improve their functioning, even though they still have OSA.

Sunday, September 23, 2012

Obstructive sleep apnea, sleeping problems, and special education

This article discusses research showing that children with obstructive sleep apnea or sleeping problems are more likely to need special education classes.

Saturday, September 22, 2012

Overactive bladder and obstructive sleep apnea

This article discusses research showing a link between overactive bladder and obstructive sleep apnea (OSA) in women. This fits with my experience, as untreated OSA can contribute to nighttime urination, and CPAP often helps.

Friday, September 21, 2012

Stomach sleeping and erotic dreaming

This article describes research showing that in people who slept more on the their stomach, reported dream content that was more sexual in nature, including being tied and locked up. Dreams were also more likely to be about being persecuted in stomach sleepers. The researchers speculated that sleeping on your stomach may deprive your brain temporarily of oxygen which could result in the type of dream content reported by the subjects. I'm not sure about the decreased oxygen levels with sleeping on your stomach. However, it could be that some patients inadvertently bury their face in the pillow which could been be misinterpreted by their sleeping brain as being tied up or locked up. Also, I am not convinced you can control the content of your dream by the position that you sleep in. It may be better just to sleep in a position that is most comfortable.

Thursday, September 20, 2012

Obstructive sleep apnea, stroke, obesity, and type 2 diabetes

Obstructive sleep apnea (OSA), stroke, elevated weight, and type 2 diabetes often exist together. Sorting out what contributes to what is difficult to do. The authors of the study in the Sleep Journal studied how OSA severity is related to cardiovascular disease (CVD) in obese type 2 diabetics. The subjects were studied with home sleep tests and asked subjectively about CVD.

The results showed that the risk of stroke increased with the OSA severity. However, OSA severity did not correlate with increased risk of other CVD like coronary heart disease or heart attack. The authors concluded that moderate to severe OSA could further increase stroke risk in obese type 2 diabetics. Of course, more studies will be need to see if treating OSA in those patients reduces stroke risk.

Wednesday, September 19, 2012

Sandpipers that sleep less mate more and have more offspring

This article describes research findings that a certain type of Sandpiper that sleeps less was able to mate more and have more offspring. The scientists involved in the study are not sure about why the birds get less sleep but the birds did not appear to have any negative effects from the sleep loss. Researchers are hoping to study the birds brains in order to understand the role of sleep and the effects of sleep loss. Unfortunately, many studies have shown that sleep loss in humans does affect her performance. Perhaps by studying these birds brains, we can figure out how to improve performance in humans who have endured sleep loss.

Tuesday, September 18, 2012

Sleep apnea can increase risk for type 2 diabetes

This article discusses research showing that obstructive sleep apnea (OSA) may increase risk for type 2 diabetes - which is typically adult onset and often linked to obesity. However, researchers studied healthy young men and measured their insulin sensitivity and insulin levels. In those men with OSA, they showed signs of reduced insulin sensitivity and increased insulin levels, which are precursors to diabetes. Now the article does not state whether the patients with OSA were treated.

Monday, September 17, 2012

Snoring and carotid artery blockages

Snoring has been linked to blockages in carotid arteries in animals, but it's not clear if snoring contributes to blocked arteries in humans. In the August edition of the Sleep journal, researchers perform the study on subjects that had had strokes or mini strokes (TIAs). They had the patient's complete questionnaires about snoring and they graded the degree of carotid artery narrowing by ultrasound.

The results showed no association between snoring and carotid artery narrowing. However this study did not assess for obstructive sleep apnea which could increase the risk of stroke. Therefore, in patients who have had strokes, or mini strokes, it can be helpful to have them assessed for obstructive sleep apnea.

Friday, September 14, 2012

Obstructive sleep apnea is linked to decreased insulin resistance.

This article describes research showing that children with obstructive sleep apnea have decreased sensitivity to insulin. Decreased sensitivity to insulin can be seen in diabetes. The researchers hypothesized that oxygen level decreases seen in obstructive sleep apnea could be responsible for the decreased sensitivity to insulin. Results of this study suggest that it is important to screen patients with diabetes or who are prediabetic for obstructive sleep apnea.

Thursday, September 13, 2012

Learning while asleep

This article discusses research showing that some learning can occur during sleep. In this study, researchers exposed subjects to a sound paired with a certain smell that affects breathing during sleep. They did this enough times so that the subjects had the breathing reaction just to the sound alone, even when the smell did not accompany it (think Pavlovian response).

The researchers then tested the subjects when awake and found that they reacted to the sound alone, even when there was no smell along with it. This means that the learning occurred while asleep, as the subjects had no memory of either the sound or smell. Pretty cool, huh?

Wednesday, September 12, 2012

Patients having bariatric surgery may not report symptoms of obstructive sleep apnea

This article discusses research showing that in patients undergoing bariatric surgery, they often do not report symptoms of obstructive sleep apnea (OSA) as often. This is despite a rather high incidence of OSA in this population. The results of this study are consistent with my clinical experience. I often get patients referred from bariatric surgeons who otherwise would not come to a sleep disorders clinic. Because untreated obstructive sleep apnea is dangerous for patients undergoing bariatric surgery, it may be beneficial to screen all patient's undergoing potential weight loss surgery for obstructive sleep apnea. Since patients report less symptoms, the screening used may be better if it is objective rather than relying on patient reports. Of course, I understand that patient's thinking about bariatric surgery may see this as one more obstacle in their path to achieving weight loss. However, due to the perioperative risk it would be beneficial to get screened for sleep apnea, whether they experience symptoms or not.

Tuesday, September 11, 2012

Monday, September 10, 2012

Smoking linked to more severe obstructive sleep apnea.

This article is about house smoking may increase the severity of obstructive sleep apnea (OSA). The authors explain that the correlation between smoking and OSA has not been studied in detail. The results of this study showed that smokers were more likely to have moderate to severe OSA, whereas nonsmokers were more likely to have mild OSA. The severity of OSA was particularly increased in those smokers who smoked at least 1 pack per day for 10 years.

They concluded that the results suggest smoking thikens the lining of the back of the throat, which causes narrowing of the air passages. This then leads to a worsening of the OSA.

So if you are smoker, this study provides yet another reason to give up the habit.

Friday, September 7, 2012

Violent cartoons disrupt sleep of preschoolers

This article discusses research showing that violent cartoons, meant for older children, can disrupt the sleep of preschoolers. This makes sense to me, as younger children can not understand what they are watching. The researchers recommend age-appropriate shows for pre-schoolers.

Thursday, September 6, 2012

Short sleep duration and breast cancer

This article discusses research showing an association between post-menopausal women with short sleep durations and aggressive breast cancer. There was no association between the aggressiveness of the cancer and sleep duration in pre-menopausal women. The researchers obtained sleep duration by asking the women how long they slept on average, and this method is not the most accurate. It's not clear why the link between short sleep duration and aggressiveness of breast cancer - it could be that insufficient sleep causes our bodies to be in a chronically inflamed state, which perhaps may be more advantageous for certain tumors. More studies are needed to see if better or more sleep could reduce the aggressiveness of breast and other cancers.

Wednesday, September 5, 2012

Insomnia, obstructive sleep apnea, or daytime sleepiness is linked to insulin resistance

This article discusses research showing that patients with insomnia, obstructive sleep apnea (OSA), or excessive daytime sleepiness are more likely to have insulin resistance. This is no surprise to me, as research has shown a link between OSA and diabetes before. But this research may prompt primary care physicians to test their patients for diabetes if they also experience insomnia or daytime sleepiness, or have known OSA.

Tuesday, September 4, 2012

Sleep researcher idenitifies area of brain that wakes you up when oxygen levels drop

This article discusses how a sleep researcher demonstrates the area of the brain affected by low oxygen levels at night when sleep apnea occurs. The area is called the parabracheal nucleus (PBN) and is responsible for waking your brain up if your oxygen level gets too low. That's a good thing, so that people with obstructive sleep apnea keep breathing when asleep. The results also showed that a neurotransmitter called GABA can reduce the PBN's ability to wake the brain up. This is important because some sleeping pills enhance GABA - and could therefore reduced the PBN's effectiveness!

Monday, September 3, 2012

Sleep duration and response to Hepatitis B Vaccination

There has been a lot of press about this, so I thought I would review this article published this month in the Sleep Journal. The premise of the article is that sleep deprivation has been shown to affect the immune system. But this study set out to determine if sleep duration would predict if patients would respond to Hepatitis B vaccinations.

Researchers studied 125 healthy subjects aged 40-60 years old. They had the patients record sleep diaries and rated their sleep quality for 3 days before and after each of three Hep B vaccination injections. After the study was started, they did measure 104 patients sleep with a home sleep test, called an actigraph.

The researchers broke up sleep into three categories - less than 6 hours, 6-7 hours, and more than 7 hours. The results showed that the shorter the sleep duration, the lower the response to the vaccinations. The findings were independent of age, sex, and BMI, which apparently have beeen shown to affect vaccination response. Only sleep duration, not sleep quality or sleep efficiency, was correlated with vaccination response.

The researchers did not measure daytime sleepiness. So it is not known if the subjects who got 6 hours but were not sleepy also had a decreased immune response. In other words, this study does not tell us if sleep deprivation (needing 8 hours, but only getting 6 hours) or just getting 6 hours or less is associated with the decreased immune response. Some people are short sleepers, needing only 4-6 hours of sleep per night. Do they really have lowered immune response? My intuition is that sleep deprived individuals would have the lowered immune response, not short sleepers. Perhaps experiements should be done on those who sleep 8 hours, but need to sleep 10 hours. So it may not be the absolute number of hours of sleep, just the number of hours obtained relative to the number hours needed to feel rested.