Effects of differences in the availability of light upon the circadian rhythms of institutionalized elderly

The bright and dark side of blue-enriched light on sleep and activity in older adults

Low indoor light in urban housing can disrupt health and wellbeing, especially in older adults who experience reduced light sensitivity and sleep/circadian disruptions with natural aging. While controlled studies suggest that enhancing indoor lighting may alleviate the negative effects of reduced light sensitivity, evidence for this to be effective in the real world is lacking. This study investigates the effects of two light conditions on actigraphic rest-activity rhythms and subjective sleep in healthy older adults (≥ 60 years) living at home. Two photon-matched lights were compared; a control white light (4000 K) and a blue-enriched white light (17000 K) at two different intensities (300-450 lx and 1100-1200 lx respectively). Participants (n = 36, 25 female) completed an 11-week randomized, cross-over study, comprising 1 week of baseline, 3 weeks of self-administered light exposure (2 h in the morning and 2 h in the evening), and 2 weeks of washout for each light condition. Participants completed sleep diaries, wore a wrist actigraph and a light sensor necklace, and collected urine to measure 6-sulphatoxymelatonin. Longer duration of morning blue-enriched light significantly improved rest-activity rhythm stability and decreased sleep fragmentation. More time spent above 2500 lx increased actigraphy amplitude, daytime activity, and advanced bedtime. Evening light exposure, however, increased sleep latency and lowered sleep efficiency. Our findings show morning blue-enriched light is beneficial whereas evening light should be avoided. Optimal timing of self-administered light interventions thus may offer a promising strategy to improve sleep and rest-activity rhythms in older adults in real-world settings.

Postoperative cognitive dysfunction: spotlight on light, circadian rhythms, and sleep

Postoperative cognitive dysfunction (POCD) is a neurological disorder characterized by the emergence of cognitive impairment after surgery. A growing body of literature suggests that the onset of POCD is closely tied to circadian rhythm disruption (CRD). Circadian rhythms are patterns of behavioral and physiological change that repeat themselves at approximately, but not exactly, every 24 h. They are entrained to the 24 h day by the daily light-dark cycle. Postoperative CRD affects cognitive function likely by disrupting sleep architecture, which in turn provokes a host of pathological processes including neuroinflammation, blood-brain barrier disturbances, and glymphatic pathway dysfunction. Therefore, to address the pathogenesis of POCD it is first necessary to correct the dysregulated circadian rhythms that often occur in surgical patients. This narrative review summarizes the evidence for CRD as a key contributor to POCD and concludes with a brief discussion of how circadian-effective hospital lighting can be employed to re-entrain stable and robust circadian rhythms in surgical patients.

Multidimensional Environmental Factors and Sleep Health for Aging Adults: A Focused Narrative Review

The timing, amount, and quality of sleep are critical for an individual's health and quality of life. This paper provides a focused narrative review of the existing literature around multidimensional environments and sleep health for aging adults. Five electronic databases, Scopus, Web of Science, PubMed/Medline; EBSCOhost, PsycINFO (ProQuest), and Google Scholar yielded 54,502 total records. After removing duplicates, non-peer reviewed academic articles, and nonrelevant articles, 70 were included for review. We were able to categorize environmental factors into housing security, home environment, and neighborhood environment, and, within each environmental category, specific elements/aspects are discussed. This paper provides a comprehensive map connecting identified levels of influence (individual, home/house, and neighborhood-level) in which subfactors are listed under each level of influence/category with the related literature list. Our review highlights that multidimensional environmental factors can affect aging adults' sleep health and eventually their physical, mental, and cognitive health and that sleep disparities exist in racial minorities in socioeconomically disadvantaged communities in which cumulative environmental stressors coexist. Based on this focused narrative review on the multidimensional sleep environments for aging adults, knowledge gaps are identified, and future research directions are suggested.

[Positive effect of bright light therapy on mood and sleep quality in institutionalized older people]

INTRODUCTION

Bright light exposure during the day has a positive effect on health and its deficit can cause multiple physiological and cognitive disorders, including depression. The aim of this study was to evaluate the effect of bright light therapy (BLT) on the quality of sleep and mood emotional state; cognitive status, global deterioration and quality of life in institutionalized elderly.

MATERIAL AND METHODS

This is a study with repeated measures design. Thirty-seven older people admitted to a nursing home. The study lasted 3 weeks. The first week, the reference values were established with the Oviedo Sleep Questionnaire, Yesavage Depression Scale, Mini-Mental, Global Scale of Impairment and European Quality of Life Questionnaire. During the second week, they were exposed to BLT (7,000-10,000lx at eye level) between 9:30 a.m. and 11:00 a.m. During the third week, all the data were re-evaluated.

RESULTS

All variables improved significantly after the application of light therapy. Sleep (COS) pre-test 4.1±1.49, post-test 4.9±1.46, p: 0.01), mood (pre-test 3.65±2.78, post-test 2.65±2.9, p: 0.01), cognitive state (pre-test 22.72±6.53, post-test 24±5.92, p: 0.001), state of global deterioration (pre-test 3.10±1.26, post-test 2.72±5.92, p: 0.001) and health-related quality of life (pre-test 6.93±1.86, post-test 7.82±1.62, p: 0.001).

CONCLUSIONS

Sleep quality, mood, cognitive status, global deterioration status and quality of life significantly improved after the application of light bright therapy.

Does media use before bedtime affect the sleep of psychosomatic rehabilitation patients?

Objective

Media use can affect sleep. However, research regarding various populations is sparse. The objective of this study was to examine the relationship between media use directly before bedtime and various sleep parameters in patients of a psychosomatic rehabilitation clinic.

Methods

Patients from a German psychosomatic rehabilitation clinic were tested regarding subjective sleep quality and insomnia symptoms based on questionnaires such as the Pittsburgh Sleep Quality Index (PSQI). Eligible patients also completed an additional sleep log over a period of 1 week. A total of 347 insomnia patients were enrolled, with a mean age of 49.77 years (range 22–64 years; median = 52 years). 57.5% of the patients were 50 years or older.

Results

Analysis showed that media use and various sleep diary parameters such as total sleep time (r = −0.386, p = 0.042; rTST2 = 0.149) and sleep efficiency (r = −0.507, p = 0.006; rSE2 = 0.257) were significantly associated. In detail, more media consumption was associated with less total sleep time and a lower sleep efficiency. The same result was found for media use and sleep efficiency on weekdays (r = −0.544, p = 0.002; rSE2 = 0.296), but not for other sleep parameters. However, media use time and subjective sleep quality were not significantly correlated, r = −0.055, p = 0.768.

Conclusion

This study, which is the first to examine the relation between media use and sleep in patients of a psychosomatic rehabilitation clinic, suggests a significant association between media use and sleep duration as well as sleep efficiency. However, more research is needed to investigate the relationship between media use and sleep in more detail, to increase patients’ quality of life and to incorporate these findings into the daily life of clinicians and therapists as well as into sleep hygiene education and sleep trainings.

Bright Light Therapy and Circadian Cycles in Institutionalized Elders

BACKGROUND

Bright light therapy has been found to be an efficient method to improve the main parameters of circadian rhythms. However, institutionalized elders may suffer reduced exposure to diurnal light, which may impair their circadian rhythms, cognitive performance, and general health status.

OBJECTIVES

To analyze the effects of 5 days of morning exposure for 90 min to bright light therapy (BLT) applied to institutionalized elderly subjects with mild/moderate cognitive impairment.

SUBJECTS

Thirty-seven institutionalized subjects of both sexes, aged 70-93 years.

METHODS

The study lasted three consecutive weeks. During the second week the subjects were submitted to BLT (7000-10,000 lux at eye level) on a daily basis. Cognition, attention, and sleep quality were evaluated at the beginning of the first and third week. Circadian variables were recorded continuously throughout the 3 weeks. Non-invasive holders and validated tests were used to analyze the variables studied.

RESULTS

After BLT we have found significant improvements in general cognitive capabilities, sleep quality and in the main parameters of the subject's circadian rhythms. The results show that merely 90 min of BLT for five days seems to achieve a significant improvement in a constellation of circadian, sleep, health, and cognitive factors.

CONCLUSION

Bright light therapy is an affordable, effective, fast-acting therapy for age-related disturbances, with many advantages over pharmacological alternatives. We hypothesize these effects were the result of activating the residual activity of their presumably weakened circadian system.

Actigraphy for Assessing Light Effects on Sleep and Circadian Activity Rhythm in Alzheimer's Dementia: A Narrative Review

Background:

Alzheimer's Disease (AD) is often accompanied by severe sleep problems and circadian rhythm disturbances which may to some extent be attributed to a dysfunction in the biological clock. The 24-h light/dark cycle is the strongest Zeitgeber for the biological clock. People with AD, however, often live in environments with inappropriate photic Zeitgebers. Timed bright light exposure may help to consolidate sleep- and circadian rest/activity rhythm problems in AD, and may be a low-risk alternative to pharmacological treatment.

Objective & Method:

In the present review, experts from several research disciplines summarized the results of twenty-seven light intervention studies which used wrist actigraphy to measure sleep and circadian activity in AD patients.

Results:

Taken together, the findings remain inconclusive with regard to beneficial light effects. However, the considered studies varied substantially with respect to the utilized light intervention, study design, and usage of actigraphy. The paper provides a comprehensive critical discussion of these issues.

Conclusion:

Fusing knowledge across complementary research disciplines has the potential to critically advance our understanding of the biological input of light on health and may contribute to architectural lighting designs in hospitals, as well as our homes and work environments.

The effect of aromatherapy with lavender (Lavandula angustifolia) on serum melatonin levels

OBJECTIVE

Physiologically, blood melatonin levels decrease as a person ages and the older adult commonly presents with insomnia and other types of sleep disorders. Alternative therapies can be used to attenuate sleep disturbances. The aim of the present study was to analyze the effect of aromatherapy with lavender on serum melatonin levels in the noninstitutionalized older adult (OA).

DESIGN AND SETTING

A pre-experimental, quantitative study with a pre-test - post-test design was conducted on 67 OAs that included both sexes.

MAIN OUTCOME MEASURES

Serum melatonin levels were measured before and after eight sessions of aromatherapy with lavender that lasted 4 weeks. The results were expressed as mean ± standard deviation of melatonin levels (pg/ml). The differences were compared using the Student's t-test and statistical significance was set at a p ≤ 0.05.

RESULTS

Blood melatonin levels significantly increased in the total population after the intervention with aromatherapy (pg/ml): 102.3 ± 33.4 VS 132.5 ± 42.3, p = 0.000004. There were significant differences in the pre-test and post-test phases in the women and men measured as separate groups (p = 0.00005 and p = 0.026), respectively. However, those differences were not observed when the measurements were compared between the two sexes, before (p = 0.64) or after (p = 0.31) the intervention.

CONCLUSION

Aromatherapy with lavender essential oil similarly favors an increase in blood melatonin levels in both older adult men and women.