Light-treatment Device To Improve Sleep Quality In The Elderly

Sleep disturbances increase as we age. Some studies report more than half of seniors 65 years of age or older suffer from chronic sleep disturbances. Researchers have long believed that the sleep disturbances common among the elderly often result from a disruption of the body’s circadian rhythms — biological cycles that repeat approximately every 24 hours.

In recent years, scientists at Rensselaer Polytechnic Institute’s Lighting Research Center and elsewhere have demonstrated that blue light is the most effective at stimulating the circadian system when combined with the appropriate light intensity, spatial distribution, timing, and duration. A team at the Lighting Research Center (LRC) has tested a goggle-like device designed to deliver blue light directly to the eyes to improve sleep quality in older adults.

“Light and dark patterns are the major synchronizer of circadian rhythms to the 24-hour solar day,” said Mariana Figueiro, Ph.D., Lighting Research Center Light and Health Program director and principal investigator on the project. “Light stimulus travels through the retina, the light-sensitive nerve tissue lining the back wall of the eye, to reach the master clock in the brain. However, a combination of age-related changes in the eye and a more sedentary lifestyle may reduce the amount of light stimulus reaching an older person’s retina, therefore reducing the amount of light for the circadian system.”

As we age, the lens in the eye thickens and the pupil shrinks, reducing the amount of light passing through to the retina. Making matters worse, in some cases, such as with persons with Alzheimer’s disease, the circadian system may require a stronger light stimulus due to deteriorating neural processes in the brain. These physical and neural changes can lead to muted signals to the circadian system. Factor in environmental influences, such as an indoor lifestyle with less access to daylight, and you have a perfect scenario for the development of irregular sleep-activity patterns, according to Figueiro.

The research team explains that a marked increase in daytime lighting levels can counteract the age-dependent losses in retinal light exposure by providing a stronger signal to the circadian system. However, the color and intensity of commercially available lighting systems, like those used in senior residences, assisted-living facilities, and nursing homes, are designed for visual effectiveness and minimal energy use and not necessarily efficacious for generating light to stimulate the older circadian system.

Commercially-available “white” light sources advertised to treat circadian-related sleep disorders are usually very bright light and can cause glare and compromise compliance.

In this project, the light-treatment prototype tested by Figueiro’s team was developed by Topbulb.com, LLC, based on prior LRC light and health research. The device offers an alternative approach using specially designed goggles that deliver blue light spectrally tuned for optimum circadian response.

VIA : Sciencedaily

Daytime sleepiness provides red flag for cardiovascular disease

Clinicians should be alert to patients reporting "excessive" day time sleepiness (EDS), says the European Society of Cardiology, after a French study found healthy elderly people who regularly report feeling sleepy during the day have a significantly higher risk of dying from cardiovascular disease.

The Three City study, published in Stroke, by the American Heart Association(Thursday, February 26), found that elderly people who reported excessive day time sleepiness have a 49 % relative risk increase of cardiovascular death (from cerebrovascular disease, myocardial infarction and heart failure) , compared to those who do not report sleepiness.

"Based on this study asking patients the simple question of whether they feel sleepy during the day, is a useful way of identifying a subgroup of elderly patients at higher risk of cardiovascular disease who require a more thorough follow up," said Professor Guy DeBacker, from the Division of Cardiology at the University of Gent, Belgium, and former chair of the European Society of Cardiology Joint Prevention Committee.

Professor Torben Jorgensen, from the Research Centre for Prevention and Health, Glostrup, Denmark, commented: "The study offers the opportunity to practice prevention by investigating the underlying causes of patient's sleep problems, and then introducing lifestyle changes with the intention of preventing later cardiovascular complications."

The Three City study represents the largest yet investigation exploring the prospective association between EDS and mortality in the community dwelling elderly, and the only study yet to have been conducted in Europe - all the other studies were undertaken in North America. Criticisms of the study include a low responder rate (37%) that could introduce an element of bias, and the fact that it lacked objective measures of day time sleepiness (such as polysomnography readings), instead using self reported patient responses.

"The subjects with EDS were less educated and had a lower income so there were differences between the two groups in "socioeconomic status", which was not accounted for in the multivariate analysis. SES is a strong independent predictive factor for total and for cause specific mortality, and it might be that the difference between the two groups is just the effect of socioeconomic differences," said DeBacker.

Both DeBacker and Jorgensen say the results are "hypothesis generating", and that the data needs to be confirmed in other large scale studies in different populations before any changes should be made to existing guidelines.

VIA : Physorg

‘Wake Up’ To Health Risks Of Heavy Snoring

Heavy snoring can be far from a nuisance. It can be a sign of obstructive sleep apnea, a condition where an individual briefly stops breathing during the night which raises the risk of heart failure and strokes.

“Sleep apnea or sleep disordered breathing is one that we’re getting more and more interested in because we see a very strong association with strokes, heart attacks and other cardiovascular problems,” says Melvyn Rubenfire, M.D., director of Preventative Cardiology at the University of Michigan Health System’s Cardiovascular Center.

The cardiovascular risk factors that most often come to mind are smoking, diabetes, high blood pressure, high cholesterol and family history. But it’s important to be aware of the possible health risks of heavy snoring.

Snoring is caused by a blockage in the back of the throat. What you hear is the tongue forced to the back of the throat when a person is lying on their back.

When people snore they don’t always stop breathing, but there are chemicals in the brain that should trigger breathing that are not stimulated when a person snores. Without the stimulation the person will often stop breathing.

When a person obstructs at night and stops breathing, oxygen levels drop dramatically and hormones and adrenaline surge. Those hormones contribute to high blood pressure, irregularities of the heart and can trigger heart attacks

People who snore do not necessarily have obstructive sleep apnea but the relationship is pretty strong.

And the relationship between snoring and cardiovascular problems goes both ways. Those with heart problems are more likely to have sleeping disorders. For example, heart failure can lead to water retention – water buildup in legs, lungs and tissues in the back of the throat.

VIA : Sciencedaily

Molecule Helps Sleep-deprived Rebound Mentally

Sleep experts know that the mental clarity lost because of a few sleepless nights can often be restored with a good night’s rest. Now, UT Southwestern Medical Center researchers have identified a key molecular mechanism that regulates the brain’s ability to mentally compensate for sleep deprivation.

Working with mice, they found that a molecule called an adenosine receptor is necessary for sleep-restricted animals to attain adequate levels of slow-wave activity in the brain once normal sleep resumes. It is this increase in slow-wave activity, or SWA, during rebound sleep that helps restore normal working memory and attention skills to the sleep-deprived, the scientists report in the Feb. 4 issue of the Journal of Neuroscience.

“Normal society pushes people to burn candles at both ends — going to bed late, getting up early, and somehow performing mentally with lack of adequate sleep,” said senior author Dr. Robert Greene, professor of psychiatry at UT Southwestern. “We need to have our adenosine receptors intact to do that.”

Adenosine receptors on nerve cells, including brain cells, are akin to docking points for the molecule adenosine. Adenosine levels increase in the brain with each hour of waking activity, and “docking” of the molecule with its receptor is shown in this study to help promote the slow-wave activity of sleep. Scientists have known that recovery from sleep deprivation involves not only an increase in sleep time, or rebound sleep, but also an elevation in this slow-wave activity.

To investigate how adenosine receptors and SWA might be linked, Dr. Greene and his team engineered mice that lacked a receptor to pair up with adenosine.

Sleep-restricted mice were kept awake by being placed on a moving treadmill. Researchers then electronically monitored sleep and waking activity of both normal and genetically engineered mice, including monitoring electronically the brain waves of the animals. The mice also traveled a maze with eight paths, each with a piece of chocolate at the end of it.

VIA : sciencedaily