Wednesday, September 30, 2015

CPAP use, obstructive sleep apnea, and cardiac function

Studies have shown that obstructive sleep apnea (OSA) can negatively impact cardiac function, especially if the OSA is severe. And studies have shown that treating severe OSA with CPAP can improve cardiac function. However, studies have not shown clearly that treating milder cases of OSA provides significant cardiac benefit.

This study looked at patients with mild-to-moderate OSA with mild cardiac dysfunction. Patients were minimally symptomatic with regards to OSA as well. Patients were either given CPAP for 6 months or given no CPAP. Compliance with CPAP was determined based on the CPAP download. The results did not show any convincing change in cardiac function or structure after 6 months of CPAP usage. There was no dose response effect with CPAP usage either, meaning that there still was no change in cardiac function in those that used CPAP the longest per night.

The researchers concluded that CPAP use in patients with mild OSA and mild cardiac dysfunction may not be as helpful as traditional cardiac dysfunction treatments like blood pressure medications.

Wednesday, September 23, 2015

Obstructive sleep apnea may disrupt the blood brain barrier

The blood brain barrier is like a wall that has holes in it. It allows good substances to cross from the blood vessels into the brain. At the same time, it keeps out harmful substances like bacteria and some toxins. According to this article, researchers think that some illnesses may result from the breakdown of the blood brain barrier.

The article discusses a research study showing that untreated obstructive sleep apnea (OSA) can breakdown the blood brain barrier. The researchers think that the low oxygen levels associated with OSA are responsible for the breakdown. But the breakdown may be what causes some of the symptoms of OSA, such as memory or mood problems. The researchers also think that repairing the blood brain barrier may improve these symptoms in patients with OSA. I also wonder if treating the OSA repairs the blood brain barrier - more studies will be needed to figure that out.

Wednesday, September 9, 2015

Magnetic stimulation may improve nighttime bedwetting

Nighttime bedwetting, also called nocturnal enuresis, can cause family problems and embarrassment to the person suffering with it. Obviously all of us start out life as a bedwetter, but most develop nighttime control at around 5 or 6 years of age. The causes of enuresis are variable, with some cases being the result of obstructive sleep apnea (OSA). Treating the OSA improves the nocturnal enuresis.

This study evaluated the effect of magnetic stimulation on nocturnal enuresis. Researchers put the magnet over the subjects lower back, just above the tailbone. The magnet was turned off and on rapidly 5 times per week. The results showed significant reduction in nocturnal enuresis frequency. Sham magnetic stimulation also showed a reduction in nocturnal enuresis frequency that was almost as large as the real magnetic stimulation. However, the frequency of enuresis returned to baseline after the sham magnetic therapy was stopped. In the real magnetic stimulation group the effect persisted a month after therapy was stopped.

Wednesday, August 26, 2015

Sleep-related breathing disorders, functional disorders, and anxiety disorders

Here is a fascinating article (at least to me) about a possible link between sleep-related breathing disorders like obstructive sleep apnea and other disorders. The other disorders are classified as "functional", meaning no etiology is agreed upon, such as fibromyalgia, chronic fatigue syndrome, and migraines. The other disorders include anxiety disorders like panic attacks and post-traumatic stress disorder (PTSD).

The researcher that is discussed in article is Dr. Gold at Stony Brook University and has published research studies on this topic. His theories about how mild OSA disorders can worsen functional and anxiety disorders is not without controversy. However, if further research confirms his theories, treatment for OSA may also help these difficult-to-treat disorders.

Wednesday, August 19, 2015

Sleep and memory

Research has shown that sleep is connected to memory. This article discusses research about that topic. I don't have access to the original research study, only the summary article provided in the link. The study setup had participants learn made-up words prior to a night of sleep or the same amount of time awake. The participants were then asked to recall the words after a period of sleep or wakefulness.

The results showed that when compared to wakefulness, sleep helped the participants recall forgotten words. One of the researchers concluded that "sleep almost doubles our chances of remembering previously unrecalled material. The post-sleep boost in memory accessibility may indicate that some memories are sharpened overnight. This supports the notion that, while asleep, we actively rehearse information flagged as important."

Wednesday, August 5, 2015

Sleep and long distance running

This article isn't just about sleep. It's about a runner who does ultra-marathons - typically 50k or 100k races. This runner broke the unofficial record for completing the Appalachian Trail. He finished the 2189 mile journey in only 46 days - this comes out to be 47.5 miles per day! I've ran a marathon and have done many 3-5 night backpacking trips in the Smoky Mountains, but I can't imagine walking or running 47.5 miles per day. What an amazing feat.

The reason I am blogging about this, though, is because the article mentions how the runner only got 4-5 hours of sleep per night. On the last few days, he only got 1-2 hours per night! So this elite athlete could continue to function at his high level even with very little sleep. This fact is interesting because some studies show that athletes perform better when they get plenty of rest. The article doesn't say how much sleep the runner typically gets when not racing. It may be that he only sleeps 5-6 hours on a regular night - so 4-5 hours of sleep would not be that much deprivation.

Wednesday, July 29, 2015

Sleeping with your phone

This article discusses survey data about cell phone use. The results showed that 71% of those surveyed sleep with their cell phone near them. Most have it on their nightstand, but some have it on the bed or even in their hand. The article reports that only 24% of those surveyed keep their phone in a separate room, which is consistent with good sleep hygiene.

I don't agree that keeping your cell phone out of your bedroom is good sleep hygiene. I keep mine next to my nightstand every night. For me, my phone serves as my pager for when I am on call but also as my alarm. The problem with having a cell phone in your bedroom occurs when you use the phone to help you fall asleep, rather than learning to fall asleep on your own. Or if you get texts, email alerts, or calls all night from friends and family - this will disturb your sleep. But just having the phone next to you is not necessarily a problem.