Monday, August 26, 2013

CPAP water chambers and chronic sinus symptoms

Many of my patients ask if using CPAP can contribute to sinus problems. It is rare that CPAP use increases sinus problems. Much more common is that CPAP use reduces sinus symptoms.

Most people who use a CPAP use a water chamber to increase the moisture content in the air. Distilled water is supposed to be used and the water chamber is cleaned weekly. However, bacteria can still live in the chamber (called colonization). This study in the Journal of Clinical Sleep Medicine investigated whether bacterial colonization of the water chambers was associated with chronic sinus symptoms.

Researchers swabbed the water chambers and different types of bacteria did grow. Overall, almost 50% of the water chambers tested grew bacteria. However, there was no association between bacterial colonization of the water chamber and chronic sinus problems. The researchers concluded that bacterial colonization of the water chambers seems to be of no clinical significance.

Monday, August 19, 2013

Exercise and insomnia

I was taught that regular exercise can improve sleep quality. My patients have told me that sometimes they sleep better if they are "worn out" from exercise or just physical exertion. Exercising upon awakening can help regulate your body clock, giving it a routine. This study in the Journal of Clinical Sleep Medicine studied 11 women with an average age of 61 years. They had the women wear actigraphs, which measure sleep at home. The women also did moderate aerobic exercise 3-4 times per week. The results showed that exercise duration did not correlate with sleep improvements. But sleep duration did correlate with exercise duration - the shorter the total sleep time, the shorter the exercise duration the next day. This makes sense to me. From my own experience, if I get little sleep while on call, I am less likely to exercise the next morning.

Friday, August 16, 2013

Insomnia may affect thinking tests

Insomnia is a very common disorder. It's hard to diagnose and sleep studies are often not helpful. Primary insomnia (PI) means the insomnia is not caused by another disorder. PI is also common. Studies have not shown that patients with PI suffer any objective neurocognitive (thinking performance) deficits.

Here is an interesting study in the Journal Sleep. Dr. Edinger discusses subtypes of insomniac - those who sleep a normal amount versus those who are short sleepers, and those who are alert in the daytime vs those who are sleepy. In this study, sleep duration was measured with overnight sleep studies. Level of daytime sleepiness was measured with a daytime sleepiness test.

Physiologic hyperarousal is a common problem with insomniacs. This refers to elevated nervous system activity - think adrenaline. This can disrupt nighttime sleep but also allow sleep deprived people to be alert in the daytime. The results of this study showed that insomniacs with hyperarousal had lower neurocognitive test scores. Of note, people who were sleepy but not insomniacs also had lower neurocognitive test scores.

As mentioned in the commentary on this article, this study has real world implications. Insomniacs with hyperarousal may respond, at least in part, to biological treatments to lessen hyperarousal. And those insomniacs that do not have hyperarousal may respond more to psychological treatments like cognitive behavioral therapy.

Wednesday, August 14, 2013

Obstructive sleep apnea linked to glaucoma

Glaucoma is an eye disease that can lead to blindness. This article discusses research that patients with obstructive sleep apnea (OSA) are at risk of developing glaucoma. And this study showed that OSA is an independent risk factor for developing glaucoma and that OSA is not just a marker of poor health, which also could lead to glaucoma. So if you have OSA, see your eye doctor if you are having any problems with your eyes.

Monday, August 12, 2013

Sleep not to blame for all fatigue

Many of my patients feel that fatigue is due to how long they sleep. In some cases it can be. But fatigue has many causes. This article discusses research showing no link between self reported sleep duration and fatigue. Unfortunately, certain sleep disorders may be occurring without the persons awareness, like obstructive sleep apnea (OSA). OSA can cause fatigue, and treatment of OSA can help. So before concluding that your fatigue is not related to your sleep quality, talk to your doctor.

Friday, August 9, 2013

Week of camping can reset sleep schedule

Research has shown that our modern lifestyle can make it hard to get to bed early enough. Not just indoor lighting, but the screens from electronic devices used close to bedtime can delay sleep. This article discussed a study about the effects of light on sleep. Researchers took volunteers who normally slept after midnight and 8 am. They had them sleep in tents outdoors for one week with no external lighting of any kind, and no cell phones. After a week, the volunteers had shifted their sleep schedules two hours earlier. Researchers said the participants melatonin levels changed, being secreted earlier.

The headline of this article is misleading, however. The week of camping won't have a lasting affect when the volunteers go back home to their routines. They would have to restructure their time so that their homes are relatively dark and to not use electronic devices close to bed.

Wednesday, August 7, 2013

Lunar cycle may impact sleep

The moon has been implicated in changes in human behavior. Here is an article about a study about how the lunar cycle may affect sleep. Researchers studied volunteers that slept two nights in a completely dark bedroom where they could not see the moon. The results showed that around the full Moon, brain activity related to deep sleep dropped by nearly a third. Melatonin levels also dipped. The volunteers also took five minutes longer to fall asleep and slept for 20 minutes less when there was a full Moon. I don't have access to the actual article, so I am not sure if the volunteers subjectively reported that they felt their sleep was different. And in my experience, most of my patients with insomnia do not report any association with lunar cycle and sleep quality. Of course, women sometimes have subjective changes in sleep quality due to menstrual cycle, but that is not correlated with lunar cycle.

It would be interesting to see how the same experiment done over the entire lunar cycle.

Monday, August 5, 2013

Obstructive sleep apnea may reduce exercise capacity

This article discusses research showing a link between obstructive sleep apnea (OSA) and decreased exercise capacity. Specifically, the results showed that severe OSA was associated with reduced functional aerobic capacity, impaired heart rate recovery after exercise, and higher resting, peak, and post-exercise blood pressure. The study did not determine if treating the OSA improved exercise capacity.

Friday, August 2, 2013

Sleep deprivation may contribute to prejudice and stereotyping

Here is an interesting article about research on sleep deprivation. The researcher did three studies, where she sleep deprived students and assessed their prejudice and stereotyping of others. Her results suggest that sleep deprivation may negatively impact people's expression of prejudice and stereotypes. It's not clear how sleep deprived the students were during the experiment - was it a total night of sleep loss, or chronic partial sleep loss?

In the article, the researcher is quoted saying, "In our research, we found that sleep functions as a self-regulatory resource that, when depleted, leaves people less able to control their thoughts, attitudes and behaviors in a non-prejudicial manner." And, she is quoted saying, "By having a good night's sleep and being well-rested, individuals are more likely to be able to act appropriately in situations."

Of course, being sleep deprived is no excuse for behaving inappropriately, no matter how tired we may be.