Drying up the HIV reservoir

Wnt is one of those funky developmental signaling pathways that gets re-used over and over again, whether it’s in the early embryo, the brain or the Read more

Overcoming cardiac pacemaker "source-sink mismatch"

Instead of complication-prone electronic cardiac pacemakers, biomedical engineers at Georgia Tech and Emory envision the creation of “biological Read more

Hope Clinic part of push to optimize HIV vaccine components

Ten years ago, the results of the RV144 trial– conducted in Thailand with the help of the US Army -- re-energized the HIV vaccine field, which had been down in the Read more

Emory Sleep Center

Take heart, Goldilocks — and get more sleep

Sleeping too little or too much increases the risk of cardiovascular events and death in those with coronary artery disease, according to a new paper from Emory Clinical Cardiovascular Research Institute.

Others have observed a similar U-shaped risk curve in the general population, with respect to sleep duration. The new study, published in American Journal of Cardiology, extends the finding to people who were being evaluated for coronary artery disease.

Arshed Quyyumi, MD and colleagues analyzed data from a registry of 2846 patients undergoing cardiac catheterization at Emory. The “sweet spot” appeared to be those who report sleeping between 6.5 and 7.5 hours per night.

39 percent of patients with coronary artery disease reported that they slept fewer than 6.5 hours per night, and 35 percent slept longer than 7.5 hours. For the next few years, both groups had higher risks of all-cause mortality: elevated risk of 45 percent and 41 percent, respectively. Patients were followed for an average of 2.8 years.

The extreme ends of sleep duration both had even higher risk: people who reported less than 4.5 hours per day had almost double mortality risk (96 percent), and those more than 8.5 hours had 84 percent higher mortality risk.

Patients with short sleep durations also had higher cardiovascular mortality (48 percent), but adjusting for cardiovascular risk factors attenuated the association between long sleep duration and CV risk.

A detailed assessment of someone’s sleep can require PSG (polysomnography). In this study,  researchers were able to get information by simply asking about sleep duration.

The participants in the Emory study were simply asked: “How many hours of sleep do you usually get each night (or when you usually sleep)?” This question may not always be answered accurately, since time in bed isn’t necessarily time asleep. Still, the broad strokes show that the sleep-CV health relationship is robust.

“What is most stunning to me are that these data were collected from cardiac patients about to undergo an invasive procedure, who still reported an aspect of their sleep that was meaningful and predictive of future survival,” says Donald Bliwise, PhD, a specialist in sleep and aging research who is a co-author on the Emory study. “Often, epidemiologic studies collect data far away from a clinic setting, where anxiety is less and estimations may be sharper. We have here in this clinical study beautiful evidence that estimates made ‘from the gurney’ may be just as meaningful as those collected in the field.”

Quyyumi says if patients with heart disease are sleeping poorly, it’s important to recognize that they are at higher risk and counsel them regarding getting more sleep, as well as factors that can disrupt sleep, such as caffeine, alcohol and looking at screens late in the day.

More specific treatments may depend what is interfering with high-quality sleep in a given patient. Several conditions can lead to difficulty sleeping, such as sleep apnea, restless leg syndrome, as well as depression, all of which have been linked with heart disease. Physiologically, several mechanisms are probably exerting their effects, such as weakening circadian rhythms and sleep fragmentation with aging, and obesity/metabolic syndrome driving inflammation. Read more

Posted on by Quinn Eastman in Heart Leave a comment

Gabbing about GABA — implications for hypersomnia treatments

Anesthesiologist Paul Garcia and his colleagues are presenting two posters at the Society of Neuroscience meeting this week, whose findings may raise concerns about two non-stimulant drugs Emory sleep specialists have studied for the treatment of hypersomnia: flumazenil and clarithromycin.

For both, the data is in vitro only, so caution is in order and more investigation may be needed.

With flumazenil, Garcia and colleagues found that when neurons are exposed to a low dose for 24 hours, the cells increase expression of some GABA receptor forms.

This could be part of a mechanism for tolerance. I heard some anecdotes describing how flumazenil’s wake-promoting effects wear off over time at the Hypersomnia Foundation conference in July, but it’s not clear how common the phenomenon is.

Flumazenil’s utility in hypersomnia became known after the pioneering experience of Anna Sumner, who has reported being able to use the medicine for years. See this 2013 story in Emory Medicine. Read more

Posted on by Quinn Eastman in Neuro Leave a comment

Hypersomnia update: clarithromycin study

Screen Shot 2015-07-01 at 4.25.58 PM

From Emory Medicine, Spring 2013

A small clinical study of clarithromycin for the sleep disorder hypersomnia shows that the antibiotic can combat patients’ subjective experience of sleepiness, but it does not seem to improve reaction time measured in a video-game-type vigilance task.

The effects of clarithromycin in hypersomnia were first observed by Emory doctors when a pioneering patient (Anna Sumner, whose story is told in this Emory Medicine article) unexpectedly experienced sleeplessness when taking it for a respiratory infection.

The results of the study were published online by Annals of Neurology on June 10.

Lynn Marie Trotti, MD, David Rye, MD, PhD and colleagues from the Department of Neurology and Emory Sleep Center conducted the study, which involved 23 patients.

Advantages of clarithromycin:

  1. It’s inexpensive and widely available.
  2. It’s an option for people dealing with hypersomnia for whom other medications, such as modafinil, are not helpful or tolerable.
  3. It represents an alternative to flumazenil, the benzodiazepine antidote that has been shown to help some hypersomnia patients. Flumazenil used to be very scarce, and shortages occur (Hypersomnia Foundation/American Society of Health System Pharmacists).

Disadvantages of clarithromycin:

  1. It’s an antibiotic, so it probably changes intestinal bacteria.
  2. Chronic use could promote the growth of antibiotic-resistant bacteria.
  3. Most patients reported an altered sense of taste or smell. Some describe this as a metallic mouth sensation.

Read more

Posted on by Quinn Eastman in Neuro Leave a comment

Hypersomnia update: beyond subject one

It’s not sleep apnea. It’s not narcolepsy. Hypersomnia is a different kind of sleep disorder. There’s even an “apples and oranges” T-shirt (see below) that makes that point.

This weekend, your correspondent attended a patient-organized Living with Hypersomnia conference. One of the main purposes of the conference was to update sufferers and supporters on the state of research at Emory and elsewhere, but there was also a lot of community building — hence the T-shirts.

The story of how sleep took over one young lawyer’s life, and how her life was then transformed by flumazenil, a scarce antidote to sleeping pills she was not taking, has received plenty of attention.

Now an increasing number of people are emerging who have a condition similar to Anna Sumner’s, and several questions need answers. Read more

Posted on by Quinn Eastman in Neuro 7 Comments

Getting a good night’s sleep is key to health

Sleep expert David Schulman, MD, MPH, assistant professor of medicine, pulmonary, Emory School of Medicine, and medical director for the Emory Sleep Disorders Laboratory, talks with Emory patients every day about how to get a good night’s sleep.

Get more sleep than a cat nap

Here, in his own words, Schulman discusses the topic of sleep:

There is growing evidence that sleeplessness can contribute to illness such as diabetes or heart disease, and many problems can arise when someone has not gotten a good night’s sleep – such as falling asleep while driving or while on the job. We all want to be as healthy as we can – eating right, exercising – and I can tell you that getting a good night’s sleep is just as important to overall health. If you have regular sleep problems, discussing this problem with your doctor may be the first step to finding a solution.

Read more

Posted on by Jennifer Johnson in Uncategorized Leave a comment