Precise timed light can reduce conditional sleep disorders and fatigue due to chemotherapy

This article is part of our special edition October 2021. Download the full edition here.

reference

WU HS, Davis Je, Chen L. Helle Licht is promising when improving sleep, depression and quality of life in women with breast cancer during chemotherapy: results of a pilot study. chronobiol int . 2021; 38 (5): 694-704.

Study goal

to find out whether treatment with light light at home that is adapted to the preference of participants for the circadian phase would influence their sleep, fatigue, their daily tiredness, their depression and quality of life during chemotherapy

draft

controlled pilot study

participant

A total of 18 women with newly diagnosed breast cancer from stadiums I to III took part in this study, 16 they completed them completely. Their age was between 29 and 68, with the majority being white/Caucasian and had a university degree. Most were treated for breast cancer in stage II. People were excluded when they had seasonal affective or psychiatric disorders, photosensitors or sleeping pills or other malignant diseases or cancer treatments, together with other exclusions.

Intervention

The investigators assigned the participants of the test condition (light blue -green light of 12,000 lux) or the control condition (weak red light of 5 lux). The participants received light therapy for 30 minutes over a light visor every day at adapted times, depending on their circadian chronotype. Evening types started the light within 30 minutes after waking up, and Morge types had the lighting between 7 and 8 p.m. Light therapy was administered on 21 consecutive days after the second cycle of chemotherapy.

study parameters evaluated

The investigators collected a variety of both subjective and objective measures. They collected initial data before the participants started their second chemotherapy cycle, and they carried out the final data collection on the day of the third chemotherapy treatment.

The patient-reported outcomes Measurement Information System (celebrities), which measures exhaustion, was one of the subjective measurements. The subjective sleep quality was evaluated with the Pittsburgh Sleep Quality Index (PSQI) and daily fatigue with the Epworth Sleepiness Scale (ESS). The patient Health Questionnaire (PHQ-9) measures depression. The quality of life was measured with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (Eortc QLQ-C30).

The sleep was objectively assessed using outpatient polysomnography (PSG).

Primary result measurements

The investigators calculated the relative change from the initial data on the data after the test for both groups. In addition, an intermediate group analysis was carried out using 2 sample test tests.

important knowledge

The test group had significant sleep improvements both subjectively and objectively. Subjectively, the falling asleep took less time - only 10 minutes in the test group compared to 20 minutes in the control group ( p = 0.045). This was confirmed by the PSG data (14 vs. 63 minutes) of the 7 participants who used the PSG at home.

Polysomnography showed a longer sleep time of 467 minutes and a higher sleep efficiency of 74 % for those who received light light, compared to 315 minutes overall sleep and only 58 % sleep efficiency in the control group. While these differences did not achieve statistical significance, the trends should be mentioned here in the short period of time of the study.

There was a relative decline in depression by 30 % for those in the group with light light and a relative increase of 24 % in the controls, but these also did not achieve statistical significance.

The quality of life was less negatively influenced by chemotherapy in the intervention group, whereby the symptom intensity (as indicated in the results of the Eortc questionnaire) increased by 33 % compared to 166 % in the control group. The fatigue did not change due to the light therapy despite apparently better sleep.

practice implications

In view of the fact that fatigue and sleep disorders affect a large part of the breast cancer patients, this approach could have a significant impact on a large population of women if it is validated. Light therapy is relatively inexpensive and easy to carry out and, if at all, has only a few negative side effects. Light therapy is currently being used to treat sleep wax disorders of the circadian rhythm and seasonal affective disorder. Maybe we can add this list to chemotherapy?

The sleep improvements that were observed with light therapy in this study were quite astonishing, with more than 2 hours more sleep per night and 16 % higher sleep efficiency in the test group. For the individual cancer patient (and other patients), improved sleep can lead to a better daily function. Adults are recommended to sleep between 7 and 9 hours every night. 1 The light therapy group reaches this goal after 21 treatment days.

This study was unique in the use of the chronotype of the participants to determine the time of day for intervention.

A poor sleep quality or duration leads to several impairments from performance to mood to health measures. Remarkably, the sleep stages percentages remained abnormally in both the control and test group, with 78 % sleep in stage 2 (increased compared to the normal value of around 50 %) and reduced percentages of the REM and stage 3 sleep. It may be that the fatigue level has not changed in some cases because the REM and stage 3 sleep was reduced compared to normal condition.

This study was unique in the use of the chronotype of the participants to determine the time of day for intervention. Our chronotype is an inherent feature that is defined by the nucleus suprachiasmatic in the hypothalamus and reinforced by the watch gene in each cell. ^{2 with light therapy (and easily by melatonin supplement) the Zirkadian phase can be manipulated. However, as soon as light therapy is ended, the person returns to their natural phase preference. Therefore, a third examination of cancer patients after the treatment period would be helpful to determine whether changes recorded during active light therapy remain (and if so, for how long) or whether light therapy must be continued.}

It is interesting that the treatment group was not separated into the 2 treatment states: light in the morning versus light at night. Light at these different times of the day has significantly different effects on our circadian system. 3 Light in the evening suppresses the evening melatonin production and shifts the circadian rhythm back, while Licht has the opposite effect in the morning by shifting the Zirkadian rhythm earlier and strengthening the nightly melatonin peak of the next night. The researchers deliberately adapted the timing of light therapy to put the participants into a more neutral circadian phase. This promotes Dr. Sonia Ancoli-Israel, 4 that showed that light morning light prevented that both the quality of life and the tiredness during chemotherapy.

In addition, people in the past were exposed to light light in the past, but not in the evening. Our circadian system has developed in accordance with this pattern in the color and brightness of light in the natural environment. It is known that artificial light can have negative effects on human health at night, including the risk of cancer. The International Agency for Cancer Research came to the conclusion that the night shift is a probable carcinogen (carcinogenic in group 2a). ^{5 Other research reports have shown that women who work night shifts have increased breast cancer. to carry out.}

In future studies with more participants, it would be interesting to see the morning and evening treatment groups separately. In addition, the ambient lighting conditions of the control group were not mentioned in their houses and lifestyles, so it is not known how much light they got at during the intervention. The control group may have been under bright (or blue light) conditions in its home environment.

This pilot study gives hope that light therapy, relatively simple and inexpensive treatment, sleep and quality of life can improve women who receive chemotherapy against breast cancer. Stay on how this approach develops.