Tag: light therapy

Categories : Cardiovascular DiseaseTags :

Timed Therapy with Intense Light can Benefit Cardiovascular Health

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Managing circadian rhythms through intense light and chronologically timed therapy can help prevent or treat a variety of circulatory system conditions including heart disease, according to a new study published in Circulation Research.

“The impact of circadian rhythms on cardiovascular function and disease development is well established,” said the study’s lead author Tobias Eckle, MD, PhD, professor of anaesthesiology at the University of Colorado School of Medicine.

“However, translational preclinical studies targeting the heart’s circadian biology are just now emerging and are leading to the development of a novel field of medicine termed circadian medicine.”

The senior author is Professor Tami A. Martino, PhD, distinguished chair in molecular and cardiovascular research at the University of Guelph in Ontario, Canada.

The study reviews current circadian medicine research, focusing on the use of intense light therapy following surgery, utilizsng light to treat cardiac injury, exploring how cardiovascular disease can differ between men and women and administering drugs at specific times of day to coincide with the body’s internal clock to speed healing.

It also urges more aggressive use of this therapy in humans, rather than relying on mostly animal models.

“There are literally millions of patients who could benefit from this,” Eckle said.

“The treatments are almost all low-risk. Some involve using light boxes and others use drugs that are already on the market.”

Circadian rhythms significantly influence how the cardiovascular system operates. Timing is everything. Blood pressure and heart rates follow distinct patterns, peaking during the day and ebbing at night. When this is disrupted, it leads to worse cardiovascular disease outcomes including myocardial infarction and heart failure. Light is critical in maintaining the proper balance and functioning of the body. Shift employees who may work night hours then day hours often have worse cardiac outcomes.

Eckle, who has studied circadian rhythm and health for years, said intense light can help heal the body after heart surgery while protecting it from injury during surgery, including reducing the chances of cardiac ischemia.

According to the researchers, when light hits the human eye it is transmitted to the suprachiasmatic nucleus, a structure in the brain’s hypothalamus that regulates most circadian rhythms in the body.

Intense light stabilizes the PER2 gene and increases levels of adenosine, which blocks electrical signals in the heart that cause irregular rhythms, making it cardiac protective.

Eckle has used light therapy with patients after surgery and seen positive results including lower levels of troponin, a key protein whose elevation can signal a heart attack or stroke.

Given the mounting evidence that intense light and timed drug treatments are effective, he said, it is time to move forward with more clinical trials.

“Circadian rhythms play a crucial role in cardiovascular health, influencing the timing of onset and severity of cardiovascular events and contributing to the healing process from disease,” Eckle said. “Studies in humans are clearly required. Regarding intense light therapy, chronotherapy and restricted feeding are low-risk strategies that should be tested sooner than later.”

Source: University of Colorado Anschutz Medical Campus

Categories : Neurodegenerative DiseasesTags : Leave a comment

Light Therapy may Improve Symptoms of Alzheimer’s Disease

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New meta-analysis included 15 randomised controlled trials involving 598 patients with Alzheimer’s disease and found improvements in sleep and psycho-behavioural symptoms.

Photo by Matteo Vistocco on Unsplash

Light therapy leads to significant improvements in sleep and psycho-behavioural symptoms for patients with Alzheimer’s disease, according to a new study published this week in the open-access journal PLOS ONE by Qinghui Meng of Weifang Medical University, China, and colleagues.

The cognitive decline associated with Alzheimer’s disease is often accompanied by sleep disturbances and psycho-behavioural symptoms including apathetic and depressive behaviour, agitation and aggression. Photobiomodulation is a non-pharmacological therapy that uses light energy to stimulate the suprachiasmic nucleus (SCN), a sleep modulator in the brain. Despite light therapy receiving increased attention as a potential intervention for Alzheimer’s, a systematic evaluation of its efficacy and safety has been unavailable.

In the new study, researchers searched multiple research databases to identify all randomised controlled trials related to light therapy intervention for Alzheimer’s disease or dementia. Fifteen high-quality trials with available methods and relevant outcomes were selected for further analysis. The included trials were written in English, published between 2005 and 2022, and performed in seven countries. They included a combined 598 patients.

The meta-analysis of all fifteen trials found that light therapy significantly improved sleep efficiency, increased interdaily stability (a measure of the strength of circadian rhythms), and reduced intradaily variability (a measure of how frequently someone transitions between rest and activity during the day). In patients with Alzheimer’s disease, light therapy also alleviated depression and reduced patient agitation and caregiver burden.

Given the limited sample sizes in studies included in this meta-analysis, the authors advocate for larger future studies, which could also explore if bright light exposure could cause any adverse behaviour in patients. They conclude that light therapy is a promising treatment option for some symptoms of Alzheimer’s disease.  

The authors add: “Light therapy improves sleep and psycho-behavioral symptoms in patients with Alzheimer’s disease and has relatively few side effects, suggesting that it may be a promising treatment option for patients with Alzheimer’s disease.”

Provided by PLOS One

Categories : Neurodegenerative DiseasesTags : 2 Comments

Light Therapy may Relieve Alzheimer’s Circadian Disruption

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New Alzheimer’s research suggests that enhanced light sensitivity may contribute to ‘sundowning’, which is the worsening of symptoms late in the day, thereby spurring sleep disruptions thought to contribute to the disease’s progression.

Published in Frontiers in Aging Neuroscience, these new insights from UVA Health into the disruptions of the biological clock seen in Alzheimer’s could lead to new treatments and symptom management, the researchers say. For example, caregivers often struggle with the erratic sleep patterns caused by Alzheimer’s patients’ altered circadian rhythms. Light therapy, the new research suggests, might be an effective tool to help manage that.

Better understanding Alzheimer’s effects on circadian rhythms could have implications for prevention. Poor sleep quality in adulthood is a risk factor for Alzheimer’s, as brains at rest naturally cleanse themselves of amyloid beta proteins that are thought to form harmful tangles in Alzheimer’s.

“Circadian disruptions have been recognised in Alzheimer’s disease for a long time, but we’ve never had a very good understanding of what causes them,” said researcher Thaddeus Weigel, a graduate student working with Heather Ferris, MD, PhD. “This research points to changes in light sensitivity as a new, interesting possible explanation for some of those circadian symptoms.”

Alzheimer’s hallmark is progressive memory loss, to the point that patients can forget their own loved ones, but there can be many other symptoms, such as restlessness, aggression, poor judgment and endless searching. These symptoms often worsen in the evening and at night.

Ferris and her collaborators used a mouse model of Alzheimer’s to better understand what happens to the biological clock in Alzheimer’s disease. They essentially gave the mice “jet lag” by altering their exposure to light, then examined how it affected their behaviour. The Alzheimer’s mice reacted very differently to control mice.

The Alzheimer’s mice, the scientists found, adapted to a six-hour time change significantly more quickly than the control mice. This, the scientists suspect, is the result of a heightened sensitivity to changes in light. While our biological clocks normally take cues from light, this adjustment happens gradually – thus, jet lag when we travel great distances. Our bodies need time to adapt. But for the Alzheimer’s mice, this change happened abnormally fast.

The researchers initially thought this might be because of neuroinflammation. So they looked at immune cells called microglia that have become promising targets in developing better Alzheimer’s treatments. But the scientists ultimately ruled out this hypothesis, determining that microglia did not make a difference in how quickly mice adapted. (Though targeting microglia might be beneficial for other reasons.)

Notably, the UVA scientists also ruled out another potential culprit: “mutant tau,” an abnormal protein that forms tangles in the Alzheimer’s brain. The presence of these tangles also did not make a difference in how the mice adapted.

The researchers’ results ultimately suggest there is an important role for the retina in the enhanced light sensitivity in Alzheimer’s, and that gives researchers a promising avenue to pursue as they work to develop new ways to treat, manage and prevent the disease.

“These data suggest that controlling the kind of light and the timing of the light could be key to reducing circadian disruptions in Alzheimer’s disease,” Ferris said. “We hope that this research will help us to develop light therapies that people can use to reduce the progression of Alzheimer’s disease.”

Source: University of Virginia Health System

Categories : Diseases, Syndromes and ConditionsTags : Leave a comment

Light Therapy Relieves MS Fatigue Symptoms

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Multiple Sclerosis (MS) is almost always accompanied by fatigue, a massive tiredness that is described by the vast majority of patients as the most distressing symptom. Researchers have now identified light therapy as a promising nonpharmaceutical treatment option: patients included in the study showed a measurable improvement after just 14 days of use. Their study’s results were published in the Multiple Sclerosis Journal – Experimental, Translational and Clinical.

The research team led by Stefan Seidel from the Department of Neurology at MedUni Vienna and AKH Vienna, relied not only on surveys but also on objective measurements when selecting the test persons – the first study of its kind to do so. For example, sleep-wake disorders were ruled out in the 26 participating MS patients, particularly with the assistance of various sleep medicine examinations. “In this manner, for example, we ensured that MS patients with fatigue do not suffer from sleep apnoea or periodic leg movements during sleep. Both are sleep disorders that can lead to fatigue in everyday life,” elaborated study leader Stefan Seidel.

Performance improvement

The test persons – all patients of the Neurology Department at MedUni Vienna and AKH Vienna – were equipped with commercially available light sources for self-testing at home: Half of the participants received a daylight lamp with a brightness of 10 000 lux (equivalent not to a cloudy day but not direct sunlight), while the other half received an identical lamp that emitted a red light with an intensity of <300 lux due to a filter (about the intensity of an office working environment). While the red light used by the control group showed no effect, the researchers were able to observe measurable successes in the other group after only 14 days: The participants who used their 10 000 lux daylight lamp for half an hour every day showed improved physical and mental performance after only a short period of time. In addition, the group of participants who had consumed bright light displayed less daytime sleepiness in comparison with the other group.

A nonpharmaceutical approach

Fatigue is a severe form of tiredness and fatigability that occurs in 75 to 99 percent of people with MS and is described as particularly distressing. Nerve damage triggered by MS is one possible cause. In addition to behavioural measures, such as regular rest breaks, various medications are currently available to alleviate fatigue, but some of these are associated with severe side effects. “The findings from our study represent a promising non-drug therapeutic approach,” Stefan Seidel said. However, the results still need to be confirmed in a subsequent larger-scale study. The reinvigorating mechanism of light therapy on MS patients will also be the subject of further scientific research.

Source: Medical University of Vienna