Wednesday, July 16, 2014

Sleep loss and psychosis

Sleep deprivation has interesting affects on our mental and physical functioning. For example, sleep deprivation tends to temporarily improve the mood of patients with depression. In fact, too little sleep can result in a manic episode in patients with bipolar disorder. This study showed that one full night of sleep depression can produce symptoms that resemble psychosis. Psychosis is a mental disorder where the person "breaks" with reality, and is part of the disorder called schizophrenia. The most common symptoms are hallucinations and delusions. The results of the study about sleep deprivation are remarkable because the psychotic symptoms occurred after only one night of sleep loss. But don't worry, the psychotic symptoms resolved completely after sleeping the next night. The researchers theorize that psychosis from sleep loss may possibly be used to study mental illness and medications used to treat mental illness.

Wednesday, July 9, 2014

Insomnia and high blood pressure

Primary insomnia means difficulty sleeping not due to another medical or sleep disorder. It's a common problem but has not been conclusively linked with increased risk of medical illness. It has been shown to increase risk of depression. Part of what I do when I treat chronic insomnia is to explain that insomnia by itself is not medically dangerous. The studies that have shown links between insomnia and medical problems have not distinguished primary from secondary insomnia. Insomnia secondary to obstructive sleep apnea (OSA) can increase risk for cardiovascular (CV) disease, but it's the OSA, not the insomnia that is raising the CV risk.

Here is an article confirming what's already known about primary insomnia and high blood pressure. The results showed no link between insomnia and high blood pressure, even for 'severe' insomnia.

Wednesday, July 2, 2014

Positional therapy for obstructive sleep apnea

A subset of my patients with obstructive sleep apnea (OSA) have it only on their back. By this, I mean that I've documented with a sleep study that a patient has OSA when sleeping on their back, but no OSA when on their sides. In my experience, this type of OSA is rare and usually only in patients with normal weight. But these patients have a treatment option that does not work in a majority of OSA patients - positional therapy. This means that if the patient can sleep on their sides or stomach only, they greatly reduce their snoring and sleep apnea. The trick is to not sleep on their back - something hard to do if they are asleep! I usually advocate using pillows behind the back to keep the person from rolling onto their side.

The FDA has just cleared an interesting device for positional OSA. It's called Night Shift by Advanced Brain Monitoring. It's a small device worn around the neck at night. It detects position (probably by gyroscope) and causes mild vibrations when the wearer is on their back. The vibrations help the user roll over, but stay asleep. The device vibrates more vigorously if the person is not responding. Their have been some studies on this device and they report improvement in sleep quality, reduction of snoring volume, and reduction of OSA.

Wednesday, June 25, 2014

Human growth hormone and sleep quality

Human growth hormone (HGH) is popular amongst some athletes who use it for performance enhancement. A significant amount of HGH is secreted at night when asleep. Sleep deprivation can reduce HGH levels. HGH levels also naturally decrease with age. HGH can be used to treat certain medical conditions, like Prader-Willi Syndrome, which can cause sleep problems. I've not seen it used however in otherwise healthy people to improve sleep quality.

This study did just that - subjects took HGH at bedtime and reported significant improvement in time to fall asleep. They also had less time awake in the middle of the night and woke more rested in the morning. No reason for why HGH may improve sleep quality is given. Perhaps scientists will discover a novel mechanism of action to help those with reduced sleep quality.

Wednesday, June 18, 2014

Sleeping pills and heart failure

Patients with heart failure are at increased risk of having sleep difficulties. Sleep-related breathing difficulties like sleep apnea are also more common in heart failure patients. Here is a study that looked at sleeping pills and heart failure patients. Specifically, the researchers investigated the relationships between drugs prescribed at hospital discharge, going back into the hospital, and cardiovascular events in heart failure patients.

The results showed that sleeping pills increase the risk of cardiovascular events in heart failure patients by 8-fold. The type of sleeping pills that were most risky were the benzodiazepines like valium. At the end of the article, the researchers speculate that benzodiazepine sleep aids could reduce cardiac function or cause respiratory depression, and this could worsen any underlying sleep-related breathing disorders. The latter is certainly possible and underscores the importance of heart failure patients getting evaluated for sleep apnea. Prior to prescribing sleep aids, it's best to rule out sleep-related breathing disorders. If sleep apnea is present, that needs to be treated, rather than just giving sleep aids.

Wednesday, June 11, 2014

Sleep apnea and cardiovascular effects

Obstructive sleep apnea (OSA) is associated with high blood pressure and cardiac arrhythmias. When someone has a sleep apnea event, their heart rate typically slows down. Heart rate then speeds up during the subsequent recovery breaths. It's this repetitive slow-fast cycle during the night that is thought to contribute to arrhythmia. And research has shown that the more oxygen levels decrease during sleep apnea, the greater the risk to the heart and blood vessels. This study was done in a rat model of OSA. The results showed that the low oxygen levels from OSA damaged vital neurons in the rats' brains that regulate blood pressure and heart rate. This could explain why OSA increases risk of high blood pressure and cardiac rhythm problems. More research will be needed to determine if treating OSA can reverse the damage to those neurons.

Wednesday, June 4, 2014

Yawning may cool the brain

I sometimes get asked why we yawn and I am not sure. I was taught that it was to increase oxygen supply to the blood, but research has not demonstrated that definitively. This study showed that yawning may be a way that the brain gets cooled. Specifically researchers studied contagious yawning - that type of yawning which occurs when you see another person yawn. This is in contrast to spontaneous yawning. The results showed that contagious yawning was more common at warm temperatures. However, it was not more common at very hot temperatures, such as in Arizona in the summer.