Tailored lighting intervention (TLI) for improving sleep-wake cycles in older adults living with dementia

Introduction: Sleep disturbance is a hallmark of Alzheimer's disease and related dementias, and caregiver stress caused by patients' nighttime wandering, injuries, and agitation are frequently at the root of decisions to move them to assisted living facilities, where typically dim institutional lighting can further exacerbate their sleep problems. This study explored the effects of a circadian-effective lighting intervention on actigraphic sleep measures and subjective assessments of sleep disturbance, depression, and sleep-disturbed behaviors. Methods: Fourteen older adult (≥60 years) participants (11 females, mean age = 84.1 [SD 8.9]), all diagnosed with moderate to severe dementia and sleep disturbance, were recruited from 3 assisted living and memory care facilities. Following a crossover, placebo-controlled design, 3 different lighting modes were used to deliver high levels of circadian stimulus to the participants' eyes for two 8-week intervention periods in a counter balanced order with a 4-week washout between the study's 2 conditions (dim light control vs. active intervention). Actigraphy and questionnaire data were collected over 7-day assessment periods that preceded (baseline weeks 1 and 9) and concluded (post-intervention week 9 and 22) the intervention periods. Actigraphic outcomes included sleep duration, sleep time, sleep efficiency, sleep start time, and sleep end time. Subjective assessments included the Cornell Scale for Depression in Dementia (CSDD), Pittsburgh Sleep Quality Index (PSQI), and Sleep Disorders Inventory (SDI) instruments. Results: Under the active condition, sleep duration significantly (p = 0.018) increased and sleep start time significantly (p = 0.012) advanced after the intervention compared to baseline. Also under the active condition, PSQI (p = 0.012), CSDD (p = 0.007), Sleep Disorders Inventory frequency (p = 0.015), and SDI severity (p = 0.015) scores were significantly lower after the intervention compared to baseline. Discussion: This study demonstrates that a circadian-effective lighting intervention delivering bright days and dark nights improves measures of sleep and mood in dementia patients living in controlled environments.

Factors associated with insomnia symptoms: A cross-sectional study during a Covid-19 fully restrictive lockdown

Insomnia is the most frequent sleep disorder and a public health concern that increased during the Covid 19 pandemic. Fully restrictive lockdowns during Covid are interesting periods to examine the impact of environmental and behavioural changes on the emergence of insomnia symptoms. In this cross-sectional study we aimed to (1) determine the main factors associated with insomnia symptoms during a Covid-19 fully restrictive lockdown examining the associated daily life alterations and (2) create a predictive model of insomnia symptoms. We used the data drawn from the "Covid-RythmE" study that reached volunteers from the general French population through an online survey during the last 2 weeks of the 2 month full lockdown. Associations with insomnia symptoms were tested and significant associations were entered in a Backward Stepwise Logistic Regression (BSLR) to assess the best combination to classify individuals with or without insomnia symptoms. From the 1624 participants, 50.64% suffered from mild to severe insomnia symptoms as assessed by the ISI. The best combination for explaining insomnia symptoms with 74.26% of accuracy included: age (OR = 1.15), females (OR = 1.26), smaller home sizes (OR = 0.77), environmental noises (OR = 1.59), anxiety symptoms (OR = 1.24), depressive symptoms (OR = 1.15), regularity of sleep-wake schedules (OR = 1.25), exposure to screen during the morning (OR = 1.13), and LED light during the evening (OR = 1.17). Thus, lifestyle schedule and exposure to natural synchronizers such as light, are primordial in considering in insomnia physiopathology, prevention and treatment, as well as the associated mental health status.

Sleep and circadian rhythm characteristics in individuals from the general population during the French COVID-19 full lockdown

The full 2‐month lockdown to fight the coronavirus disease 2019 (COVID‐19) pandemic in 2020 led to substantial disruption of daily life and routines. The present study aimed to comprehensively identify the lockdown’s effects on sleep, daily rhythms and emotions of the French population. A survey was published online during the last week of the 2‐month full lockdown and 1,627 individuals completed the online survey. The survey was self‐administered and included standardised questionnaires. Sleep schedules were delayed during lockdown in more than half of the participants. New severe delayed sleep phase affected 10% of participants with sleep schedules delayed by ≥3 hr during the lockdown compared to before. A significant decrease in exposure to morning (p < 0.001) and evening natural light (p < 0.001), a significant increase in screen exposure time (with a significant screen exposure >3 hr during the evening for 45% of the participants during lockdown versus 18% before lockdown, p < 0.001), an increase in substance use for one‐quarter of participants, a poorer sleep quality in 56% of participants, and less regular sleep schedules in 48% of participants were observed. We also found a poorer sleep quality in women than men during lockdown (p = 0.004). The French full lockdown had a severe impact on sleep quality, sleep–wake rhythms, and sleep behaviours. The implementation of public health strategies for the prevention and care of sleep–wake cycles during lockdown are therefore essential.

Association between sleep-wake habits and use of health care services of middle-aged and elderly adults in China

OBJECTIVE

To examine the relationship between sleep-wake habits and the use of health care services.

RESULTS

The proportions of the participants who were "early to bed" and "late to bed" were 48.7% and 51.3%, respectively. In the full sample, compared with those who were early to bed and early to rise, participants who went to bed late were more likely to report physician visits (late to bed and early to rise: OR = 1.13, 95% CI: 1.08-1.19, late to bed and late to rise: OR = 1.27, 95% CI: 1.18-1.38, respectively). We found no significant association between sleep-wake habits and the number of hospitalization.

CONCLUSIONS

Those middle-aged and elderly people who stayed up late and got up late are more likely to visit the doctors than those who went to bed early and got up early.

METHODS

We obtained data from a cohort study of retired employees in China, and 36,601 (95.59%) involved in the present study. The participants were allocated into 4 sleep-wake habits groups: Early-bed/Early-rise, Early-bed/Late-rise, Late-bed/Early-rise, and Late-bed/Late-rise. We explored the association between sleep-wake habits with the number of physician visits and hospitalizations.

Four of the six Drosophila rhodopsin-expressing photoreceptors can mediate circadian entrainment in low light

Light is the major stimulus for the synchronization of circadian clocks with day-night cycles. The light-driven entrainment of the clock that controls rest-activity rhythms in Drosophila relies on different photoreceptive molecules. Cryptochrome (CRY) is expressed in most brain clock neurons, whereas six different rhodopsins (RH) are present in the light-sensing organs. The compound eye includes outer photoreceptors that express RH1 and inner photoreceptors that each express one of the four rhodopsins RH3-RH6. RH6 is also expressed in the extraretinal Hofbauer-Buchner eyelet, whereas RH2 is only found in the ocelli. In low light, the synchronization of behavioral rhythms relies on either CRY or the canonical rhodopsin phototransduction pathway, which requires the phospholipase C-β encoded by norpA (no receptor potential A). We used norpA(P24) cry(02) double mutants that are circadianly blind in low light and restored NORPA function in each of the six types of photoreceptors, defined as expressing a particular rhodopsin. We first show that the NORPA pathway is less efficient than CRY for synchronizing rest-activity rhythms with delayed light-dark cycles but is important for proper phasing, whereas the two light-sensing pathways can mediate efficient adjustments to phase advances. Four of the six rhodopsin-expressing photoreceptors can mediate circadian entrainment, and all are more efficient for advancing than for delaying the behavioral clock. In contrast, neither RH5-expressing retinal photoreceptors nor RH2-expressing ocellar photoreceptors are sufficient to mediate synchronization through the NORPA pathway. Our results thus reveal different contributions of rhodopsin-expressing photoreceptors and suggest the existence of several circuits for rhodopsin-dependent circadian entrainment. J. Comp. Neurol. 524:2828-2844, 2016. © 2016 Wiley Periodicals, Inc.

Relationships between leisure-time energy expenditure and individual coping strategies for shift-work

A total of 13 to 14% of European and North American workers are involved in shift work. The present aim is to explore the relationships between coping strategies adopted by shift workers and their leisure-time energy expenditure. Twenty-four female and 71 male shift workers (mean +/- SD age: 37 +/- 9 years) completed an adapted version of the Standard Shift-work Index (SSI), together with a leisure-time physical activity questionnaire. Predictors of age, time spent in shift work, gender, marital status and the various shift-work coping indices were explored with step-wise multiple regression. Leisure-time energy expenditure over a 14-d period was entered as the outcome variable. Gender (beta = 7168.9 kJ/week, p = 0.023) and time spent in shift work (beta = 26.36 kJ/week, p = 0.051) were found to be predictors of energy expenditure, with the most experienced, male shift workers expending the most energy during leisure-time. Overall 'disengagement' coping scores from the SSI were positively related to leisure-time energy expenditure (beta = 956.27 kJ/week, p = 0.054). In males, disengagement of sleep problems (beta = -1078.1 kJ/week, p = 0.086) was found to be negatively correlated to energy expenditure, whereas disengagement of domestic-related problems was found to be positively related to energy expenditure (beta = 1961.92 kJ/week, p = 0.001). These relations were not found in female shift workers (p = 0.762). These data suggest that experienced male shift workers participate in the most leisure-time physical activity. These people 'disengage' more from their domestic-related problems, but less from their sleep-related problems. It is recommended that physical activity interventions for shift workers should be designed with careful consideration of individual domestic responsibilities and perceived disruption to sleep.