Light-Treatment Device to Improve Sleep Quality in the Elderly

June 1, 2009

Science Daily/Rensselaer Polytechnic Institute

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.

“The goal of this phase of the development project was to create a device in a smaller form factor or envelope that allowed for social inclusion and end-user mobility, while still delivering the required dose of light,” said Topbulb.com Senior Developer Philip H. Bonello, Ph.D.

The device was worn by eleven subjects between the ages of 51 and 80 years of age. Each subject was exposed to two levels of blue light (about 50 lux and 10 lux) from the personal light-treatment device for 90 minutes on two separate nights.  Blood and saliva samples were collected at prescribed times to assess levels of nocturnal melatonin, a hormone used as a marker for the circadian clock, with high levels at night when a person is in a dark environment and low levels during the day.

After only one hour of light exposure, the light-induced nocturnal melatonin suppression level was about 35 percent for the low light level and about 60 percent for the high light level. In addition, the higher level of blue light suppressed nocturnal melatonin more quickly, to a greater extent over the course of the 90-minute exposure period, and was maintained after 60 minutes.

Having demonstrated its stimulation effect on the circadian system, the researchers believe the device could be subsequently used to increase sleep consolidation and efficiency in older subjects when worn for a prescribed duration at an appropriate time.

“The study suggests that the light goggles might be a practical, comfortable, and effective way to deliver light treatment to those suffering from circadian sleep disorders. The next steps are to conduct field studies where we will be testing the effectiveness of this personal light-treatment device on those suffering from circadian-related sleep disorders, while also verifying the acceptance of the device among the test groups,” said Figueiro.

http://www.sciencedaily.com/releases/2009/05/090529112605.htm

Use of Bright Lighting May Improve Dementia Symptoms for Elderly Persons

June 11, 2008

Science Daily/JAMA and Archives Journals

The use of daytime bright lighting to improve the circadian rhythm of elderly persons was associated with modest improvement in symptoms of dementia, and the addition of the use of melatonin resulted in improved sleep, according to a new study.

"In elderly patients with dementia, cognitive decline is frequently accompanied by disturbances of mood, behavior, sleep, and activities of daily living, which increase caregiver burden and the risk of institutionalization," the author write. These symptoms have been associated with disturbances of the circadian rhythm (the regular recurrence, in cycles of about 24 hours, of biological processes or activities).

"The circadian timing system is highly sensitive to environmental light and the hormone melatonin and may not function optimally in the absence of their synchronizing effects. In elderly patients with dementia, synchronization may be [diminished] if light exposure and melatonin production are reduced."

Melatonin reduced the time to fall asleep by a relative 19 percent and increased total sleep duration by 6 percent, but adversely affected caregiver ratings of withdrawn behavior and mood expressions. The addition of bright light improved the adverse effect on mood. In combination with bright light, melatonin reduced aggressive behavior by a relative 9 percent.

"In conclusion, the simple measure of increasing the illumination level in group care facilities [improved] symptoms of disturbed cognition, mood, behavior, functional abilities, and sleep. Melatonin improved sleep, but its long-term use by elderly individuals can only be recommended in combination with light to suppress adverse effects on mood.

The long-term application of whole-day bright light did not have adverse effects, on the contrary, and could be considered for use in care facilities for elderly individuals with dementia," the authors write.

http://www.sciencedaily.com/releases/2008/06/080610161247.htm

Insomnia May Perpetuate Depression in Some Elderly Patients

April 4, 2008

Science Daily/American Academy of Sleep Medicine

In addition to being a risk factor for a depressive episode, persistent insomnia may perpetuate the illness in some elderly patients, and especially in those receiving standard care for depression in primary care settings, according to a new study.

According to the results, patients with persistent insomnia were 1.8 to 3.5 times more likely to remain depressed, compared with patients with no insomnia. The findings were more robust in patients receiving usual care for depression than in patients receiving enhanced care. The findings were also stronger in subjects who had major depressive disorder as opposed to those with dysthymia alone.

"Even when depression was identified and treated in the primary care setting, the older adults in this study were more likely to remain depressed if they also exhibited persistent insomnia.

The finding that this risk was higher in the usual-care group suggests that enhanced depression care may partially mitigate the perpetuating effects of insomnia on depression," said Dr. Pigeon.

"While the findings make intuitive sense, until relatively recently insomnia was often considered a symptom that dissipated without active intervention once a primary condition like depression was treated, instead of being considered a distinct clinical entity that might affect a primary disorder. This study has several limitations, not the least of which are that it is not a causal study nor does it unequivocally answer the question of whether insomnia that presents with depression is a symptom or a co-morbid disorder. What seems most likely is that insomnia is indeed simply a symptom in some cases, but clearly a disorder requiring its own treatment focus in other cases."

Not sleeping well can lead to a number of problems. Older adults who have poor nighttime sleep are more likely to have a depressed mood, attention and memory problems, excessive daytime sleepiness, more nighttime falls and use more over-the-counter or prescription sleep aids. In addition, recent studies associate lack of sleep with serious health problems such as an increased risk of obesity, cardiovascular disease and diabetes.

http://www.sciencedaily.com/releases/2008/04/080401081930.htm

Daytime Dozing Linked to Increased Stroke Risk In Elderly

February 22, 2008

Science Daily/American Heart Association

Regular daytime dozing forewarns of a significantly increased risk of stroke in older Americans, researchers reported at the American Stroke Association's International Stroke Conference 2008.

Among 2,153 participants in a prospective study with an average follow-up of 2.3 years, the risk of stroke was 2.6 times greater for those classified as doing "some dozing" compared to those with "no dozing." Those in the "significant dozing" group had a 4.5 times higher risk.

After controlling for several stroke risk factors -- age, race-ethnicity, sex, education, blood pressure, diabetes, obesity and physical activity -- they found unexpectedly high stroke risks for the "some dozing" and "significant dozing" groups compared to "no dozing."

The risk of a heart attack or vascular death was higher -- 1.6 percent for the moderate dozers and 2.6 percent for the significant dozers. The findings were similar for all ethnicities and both genders.

"Given what's known now, it's worth assessing patients for sleep problems," Boden-Albala said. "And the initial assessment can be something as simple as the Epworth scale. If patients are moderately or significantly dozing, physicians need to think about sending them for further evaluation."

http://www.sciencedaily.com/releases/2008/02/080221153730.htm