Friday, June 29, 2012

Women with polycystic ovarian syndrome and obstructive sleep apnea more likely to have prediabetes

This article discusses how women with a condition called polycystic ovarian syndrome (PCOS) and obstructive sleep apnea (OSA) are at increased risk of being prediabetic. See my other blogpost about OSA and PCOS.

Thursday, June 28, 2012

Infants Sleep Environments More Important Than Genetics

Here is an article about a study confirming what I already knew - that establishing a pro-sleep environment early in a child's life will help them sleep better.

Tuesday, June 26, 2012

Obstructive Sleep Apnea and Diabetic Neuropathy

This article discusses study results showing that obstructive sleep apnea (OSA) is linked to diabetic neuropathy. Researchers think it may be due to the repetitive oxygen level drops during OSA that increases the risk of neuropathy. It would interesting to note if treating the OSA reduces the neuropathy risk.

Monday, June 25, 2012

CPAP Use and Glucose Tolerance in Obstructive Sleep Apnea

This article reports on findings by Dr. Weinstock and others in the May edition of the Journal Sleep. Impaired glucose tolerance (IGT) is a precursor to diabetes. Studies have shown a link between obstructive sleep apnea (OSA) and IGT as well as diabetes. But there are few studies about the effects of treating OSA and the impact on IGT or even diabetes. Dr. Weinstock studied 50 individuals with at least moderate OSA and IGT, but not full blown diabetes. They treated the participants with real CPAP for 2 months and then fake CPAP for two more months. The results showed that in IGT was reduced only in those with severe OSA and obesity. In fact, for every hour of increased CPAP use, there was a significant improvement in glucose tolerance. There was also an effect seen in those with excessive sleepiness, regardless of weight or OSA severity - however there were not enough participants in this category to be statistically significant.

The study authors concluded that for those with obesity and mild to moderate OSA, 8 weeks of CPAP is not helpful in improving glucose tolerance. Eight weeks of CPAP did improve glucose tolerance (although it did not normalize it) in those with severe OSA regardless of obesity. Therefore, it may be helpful to screen patients with IGT for sleep disordered breathing and to especially treat those with severe OSA. This may reduce the chance of those patients going on to develop full blown diabetes. Of course, more studies are needed to demonstrate that effect.

Friday, June 22, 2012

Obesity and Depression Linked to Excessive Sleepiness

This article confirms something I have been seeing more and more in my clinic - people who struggle with obesity are feeling excessively sleepy, and it's not due to disrupted sleep or obstructive sleep apnea. Since OSA does cause sleepiness, and is strongly associated with obesity, it's difficult for me to tell which obese people are sleepy from OSA versus from obesity without a sleep study.

The article also discusses research that shows that people who are depressed can be excessively sleepy from the depression itself, rather than from a separate sleep disorder like OSA. I see this too in my sleep clinic, but less often, and it's still important to rule out sleep disorders like OSA.

Bottom line: If you're feeling sleepy in the daytime, despite getting enough sleep, talk to your doctor or a sleep physician.

Thursday, June 21, 2012

Untreated Sleep Apnea Affects Teenagers Development

This article is about research showing that teenagers who have untreated obstructive sleep apnea (OSA) have higher rates of emotional, social, and academic problems. Researchers controlled for age, body mass index, ethnicity, and race. These finding are understandable if you think about how OSA disrupts sleep on a nightly basis - and good sleep is important to the normal development of children and teenagers.

Wednesday, June 20, 2012

Hospital Noises May Disrupt Sleep

This article talks about research showing that noises in hospitals can disrupt sleep. In this study, 12 healthy people were studied outside of the hospital and "hospital" noises were pumped in - like IV machine beeps and talking. Frequently, these sounds briefly disrupted sleep, sometimes without the person's knowledge and sometimes causing brief increases in heart rate. The authors suggest making hospitals less noisy, which may improve sleep, and may help patient's heal faster.

Tuesday, June 19, 2012

Sleepiness in NFL Players Associated With Staying With the Team

This article discusses research findings presented at the Sleep Meeting in Boston. Dr. Winter has shown an association between recently-drafted NFL players' subjective sleepiness and their likelihood of staying with team. The conclusion is that finding out the reason for the sleepiness, and treating it, may help in retaining that player.

Monday, June 18, 2012

Daytime Sleepiness and Obesity

Obstructive sleep apnea (OSA) can cause excessive daytime sleepiness, and many patients with OSA are obese. However, some obese patients with OSA are still sleepy despite regular treatment with CPAP. Several studies have linked excessive sleepiness with obesity in patients without OSA. Clinically, I see both conditions often enough, and sleep researchers do not understand exactly why these patients are sleepy. Drs. Panossian and Veasey at the University of Pennsylvania published a review article in the May edition of the Journal Sleep about this topic.

The article describes how patients with OSA who undergo bariatric surgery sometimes have a dramatic improvement in subjective sleepiness a few weeks after the surgery. I have seen this in my clinic as well, even though the patients may still have OSA. Again, the reason for the improvement in sleepiness is not known.

Food can affect sleepiness too. The article describes a complicated system of hormones and other bloodstream chemicals that are released in response to food ingestion that can inhibit our alertness.

There is a group of cells in a deep part of the brain called the hypothalamus, and these cells are involved in maintaining our wakefulness. In narcolepsy, these cells die off, resulting in excessive daytime sleepiness. Some studies are showing that these cells can stop functioning normally in the context of obesity, and this could contribute to sleepiness.

The authors conclude by stating that in patients who are obese, OSA is a common enough disorder that it should be ruled out if the patient is sleepy. If there is no OSA to explain the sleepiness, than it could be due to a combination of the obesity itself and dietary influences. How we treat that sleepiness is still up in the air - for now it appears that weight loss may improve alertness. Easier said than done.

Sunday, June 17, 2012

Treating Obstructive Sleep Apnea May Improve Depression

This article discusses research that shows that treating obstructive sleep apnea (OSA) may improve depressive symptoms. This has been by experience clinically and other studies have shown this. However, I have some concerns about this study. The researchers screened for depression by using a tool called the PHQ-9. It is a good tool, but some of the questions are related to fatigue and poor sleep, which can be seen in patients with untreated OSA without depression. In other words, patients with untreated OSA can seem depressed on a PHQ-9 test from the sleep disruption due to the OSA, not from depression. In this study, the patients with depression who were the most sleepy, benefited the most from treatment of their OSA. This makes me wonder again if the PHQ-9 scores were improved only because sleepiness improved, not because depression improved.

Saturday, June 16, 2012

CPAP May Improve Erectile Dysfuntion

Untreated obstructives sleep apnea (OSA) is known to contribute to erectile dysfunction (ED) in men and decreased libido in both men and women. This article discusses research showing that CPAP can improve erectile dysfunction in men. I have observed this clinically in my younger male patients and they are quite happy about it!

I always thought that OSA could lead to ED by the repeat oxygen level drops, but the study author suggests another cause. All men have erections in dream sleep and OSA disrupts dream sleep the most - this may lead to the ED seen in untreated OSA.

The article talks about how the CPAP mask is not sexy (see my post about CPAP masks), and that is something I joke about sometimes with my younger patients. It is a real concern of my younger patients, especially those that are single. But snoring, which is almost always present with OSA, is definitely NOT sexy. Since the CPAP treats the snoring, this will allow your bedpartner to sleep better and that may improve his or her libido!

Friday, June 15, 2012

Insomnia and Fear of the Dark

This article presents research from the Sleep Meeting at Boston. In those who slept poorly, half were reported they were afraid of the dark. In those that slept well, only a quarter reported being afraid of the dark. Researchers also demonstrated an increased startle response in those that were afraid of the dark, pointing to a potentially increased startle response. This is interesting research, as I wouldn't expect many adults to feel afraid of the dark - certainly not as many as reported in this study. And sleeping with the light on may help reduce the fear, but also may make sleeping more difficult.

Thursday, June 14, 2012

Sleep Deprivation and Stroke Risk

This article discusses research presented at the Sleep Meeting in Boston. Researchers discovered that patients who slept less than six hours, per their own self-report, were more likely to have stroke symptoms than those that slept longer. This increased risk occurred despite being normal weight and researchers controlled for other factors associated such as high blood pressure, high cholesterol, and sleep apnea. The effect was greatest in African Americans, which could explain how this racial group is more prone to having stroke than other races.

Wednesday, June 13, 2012

Sleep Deprivation and Anxiety

This article is about more research presented at the Sleep Meeting in Boston. It describes how sleep deprivation could increase anxiety in those already prone to anxiety. Researchers sleep deprived participants and showed them emotionally upsetting images. Those sleep deprived participants, especially those prone to anxious reactions, had stronger responses to the images than those that were not sleep deprived. This research is interesting, and I conclude that getting as much sleep as possible my help people with anxiety disorders function better. However, patients with anxiety disorders usually have some insomnia already, putting them in a catch-22. Perhaps treating the anxiety would allow them to sleep better, which would then reduce their tendency to be anxious. More studies are needed for sure.

Tuesday, June 12, 2012

Sleep Deprivation and Junk Food

Here is an article about research showing that participants were more likely to respond to images of junk food when sleep deprived. When the participants slept 9 hours, they did not respond more to junk food. The researchers conclude that sleep deprivation may contribute to poor eating habits, perhaps as a way to increase energy. This study used powerful imaging technology to look at brain regions involved in reward, so there was no data on hormonal changes that may have impacted food type choice.

Monday, June 11, 2012

Characteristics of Long Sleep Duration

Studies have shown that people who say they sleep less than six hours or more then 8 hours have higher amounts of adverse health outcomes like cardiovascular disease, diabetes, and obesity. But studies that actually measure how long someone sleeps have not shown an association of documented longer sleep times and adverse health. And few studies have looked at potential abnormalities in self reported long sleepers.

Dr. Patel and others analyzed subjective and objective sleep data from older (at least 65 years old) men that were part of a larger study on osteoporosis, and the results are published in the May edition of the Sleep Journal. The researchers compared data from men who were classified as long vs normal duration sleepers. Sleep duration was defined as normal if the men said they slept 7-8 hours per night and long if they slept 9 or more hours per night. The results showed that self reported long sleepers were older, more likely to have diabetes, and the have worse cognitive functioning. There was a trend (but it did not reach statistical significance) showing more cardiovascular disease and depression in the self-reported long sleepers. In fact, antidepressant use was twice that in the self reported normal sleep duration group. There was no difference in smoking rates, alcohol use, caffeine intake, sedative use, or pain medicine use between the two groups.

As you might expect, the self reported long sleepers actually did sleep longer than the men who reported they slept normal amounts. On average, the long sleepers slept 20-43 minutes more than normal duration sleepers, depending on the way sleep was measured. Also, self-reported long sleepers tended to overestimate their sleep duration to a greater extent than self-reported normal sleepers. In other words, these men did sleep longer than normal sleepers, but not as long as they thought they were sleeping. Sleep quality, sleep stages, and daytime sleepiness was not different between the two groups either. Finally, there was no difference in the rates of sleep disordered breathing (like sleep apnea), periodic limb movement disorder (similar to restless legs syndrome), or awakenings at night between the two groups.

Bottom line: Those who report sleeping longer do in fact sleep longer, but it does not appear to be caused by a sleep abnormality or other health characteristic.

Sunday, June 10, 2012

Alcohol can Shorten Overall Amount of Sleep

Here is an article about how drinking alcohol close to bedtime can shorten the overall amount of time the drinkers slept. This is new information, as studies have only shown that alcohol disrupts sleep. This study was also unique in that it measured sleep over many nights in the participants' homes.

Friday, June 8, 2012

Dopamine Receptors and Sleep Deprivation

Here is an article about how sleep deprivation affects dopamine receptors and possibly interacts with adenosine

Thursday, June 7, 2012

Insomnia Linked to High Blood Pressure

Here is an article about research that is going to be presented at next week's Sleep Meeting in Boston. It details how researchers have shown a link between insomnia and high blood pressure. It makes sense, as some insomniacs are thought to have chronically elevated nervous systems.

Obstructive Sleep Apnea in a New Animal Model Shows Damage to Brain Arteries

Here is an article about how scientists have developed a new model of obstructive sleep apnea (OSA) in animals. They used this new model to study the affects of OSA on brain arteries. After one month of moderate OSA, there was visible damage to the arteries in the animals brains. The researchers concluded that this vessel damage could contribute to the increased risk of stroke seen in patients with untreated OSA.

Tuesday, June 5, 2012

Sleep Quality and Bedpartners

Interesting article in the Wall Street Journal about a study showing sleep quality can be better in couples that sleep together vs single people.

Restless Legs Syndrome Symptom Descriptions

Restless legs syndrome (RLS) symptoms are often difficult for patients to describe to me. The condition is not usually painful, but is uncomfortable and undesired. Here is an article about a study done that attempted to come up with the most appropriate words to describe RLS symptoms.

Monday, June 4, 2012

Risk Factors of Poor Sleep

Studies show that insomnia varies widely in the population, from 8-40%, depending on how the researcher defines insomnia. Dr. Fernandez-Mendoza has differentiated poor sleep from an insomnia disorder in past studies. In a recent study published in the May edition of the Journal Sleep, Dr. Fernandez-Mendoza and others examined the risk factors of poor sleep in a large sample of a Pennsylvania population using both subjective and objective information.

The study participants had a complete sleep history and physical examination along with a sleep study at baseline, and were then followed for an average of 7.5 years. The researchers defined sleep quality as normal, poor sleep (meaning one or more insomnia symptoms, but not enough to qualify for an insomnia disorder), or chronic insomnia. Patients with chronic insomnia at baseline were excluded from the study, as the researchers were studying poor sleep risk factors, not chronic insomnia risk factors.

The results showed that at any time during the study, 18% of participants were poor sleepers. Risk factors for this population included having ulcers (presumably stomach ulcers, although not explicitly defined in the paper), depression, obesity, moderate to severe sleep apnea, and smoking. Interestingly, alcohol consumption did not pose an increased risk. Of note, obesity was an independent risk factor for poor sleep, even in those without sleep apnea. The researchers suggest that metabolic abnormalities from obesity could play a role in development of poor sleep.

Thirty-nine percent were persistently poor sleepers. Risk factors for this population was having a heart "disorder" (type of disorder not specified in this paper), having an ulcer, being middle age, and having allergy/asthma.

Seventeen percent went from being poor sleepers to having chronic insomnia. Risk factors for this population were being female, age less than 40, depression, smoking, fewer physical health conditions, shorter objective sleep duration (as measured by the sleep study), and a family history of sleep problems. The authors point out that the short sleep duration finding could mean that elevated nervous system arousal could be responsible for this and may increase risk of medical problems with this type of insomnia, in contrast to chronic insomnia with a normal objective sleep duration. I wonder if these patients have less of a physiologic insomnia, and instead they could be naturally "short" sleepers (perhaps needing 6 hours of sleep or less per night). They would then develop insomnia by trying to make themselves sleep 8 hours each night.

Finally, 44% went from poor sleep to normal sleep during the study, demonstrating that poor sleep can resolve. It's not clear why, but could be due to improvement in underlying physical condition(s) that were driving the poor sleep to begin with.