scholarly journals Dose–response effects of light therapy on sleepiness and circadian phase shift in shift workers: a meta-analysis and moderator analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Calvin Lam ◽  
Min-Huey Chung
Keyword(s):  
Phase Shift ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Light Therapy ◽  
Shift Workers ◽  
Random Effects Models ◽  
Circadian Phase ◽  
Medium Intensity ◽  
Circadian Phase Shift ◽  
Effect Of Light

AbstractLight therapy has been considered to be effective in mitigating sleepiness and regulating circadian phase shift in shift workers. However, the effective treatment dose of light therapy remains undetermined. We performed a meta-analysis of randomized experimental studies to determine the effect of light therapy doses on sleepiness and circadian phase shift in shift workers. An article search was performed in 10 electronic databases from inception to June 2020. Two raters independently screened and extracted data and reached consensus. Twenty-one eligible studies were included. Analyses were performed using random-effects models. Light therapy exerted significantly small to medium effects on sleepiness and large treatment effects on circadian phase shift. Moderator analyses performed with subgroup and metaregression analyses revealed that medium-intensity light therapy for a shorter duration more effectively reduced sleepiness at night, whereas higher-intensity light therapy more effectively induced phase shifting, but the required treatment duration remained inconclusive. This study provides evidence regarding the effect of light therapy in reducing sleepiness and shifting circadian phase in shift workers. Exposure to medium-intensity light for a short duration at night reduced sleepiness, whereas exposure to high-intensity light improved sleep by shifting their circadian phase.

scholarly journals Comment Concerning the Effects of Light Intensity on Melatonin Suppression in the Review “Light Modulation of Human Clocks, Wake, and Sleep” by A. Prayag et al.

2021 ◽  
Vol 3 (1) ◽  
pp. 181-188
Author(s):  
Peter Bracke ◽  
Eowyn Van de Putte ◽  
Wouter R. Ryckaert
Keyword(s):  
Phase Shift ◽  
Light Intensity ◽  
Dose Response ◽  
Light Modulation ◽  
Response Curves ◽  
Practical Applications ◽  
Circadian Phase ◽  
Melatonin Suppression ◽  
Dose Response Curves ◽  
Circadian Phase Shift

Dose-response curves for circadian phase shift and melatonin suppression in relation to white or monochromatic nighttime illumination can be scaled to melanopic weighed illumination for normally constricted pupils, which makes them easier to interpret and compare. This is helpful for a practical applications.

scholarly journals Lateral geniculate lesions block circadian phase-shift responses to a benzodiazepine.

1988 ◽  
Vol 85 (14) ◽  
pp. 5301-5304 ◽  
Author(s):  
R. F. Johnson ◽  
L. Smale ◽  
R. Y. Moore ◽  
L. P. Morin
Keyword(s):  
Phase Shift ◽  
Circadian Phase ◽  
Lateral Geniculate ◽  
Circadian Phase Shift

scholarly journals Integration of brief light flashes varying in intensity and duration by the human circadian system

2019 ◽  
Author(s):  
Daniel S. Joyce ◽  
Manuel Spitschan ◽  
Jamie M. Zeitzer
Keyword(s):  
Phase Shift ◽  
Light Exposure ◽  
Temporal Integration ◽  
Circadian System ◽  
Flash Intensity ◽  
Flash Duration ◽  
Variable Intensity ◽  
Circadian Phase ◽  
Variable Duration ◽  
Circadian Phase Shift

AbstractThe human circadian system is exquisitely sensitive to light, through a pathway connecting the melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) to the hypothalamic suprachiasmatic nuclei (SCN). ipRGCs are characterised by a delayed off-time following cessation of light exposure; we exploited this unusual physiologic property and examined how a sequence of flashes of bright light differing in intensity or duration presented in the biological night could delay the human circadian clock in vivo in healthy young participants (n=54). To understand the mechanism underlying circadian photoreception, we probed temporal integration by manipulating flash intensity and duration independently. In a 34-hour in-laboratory between-subjects design, we examined variable-intensity (3, 30, 95, 300, 950, 3000, or 9500 photopic lux; n=28 participants) flashes at fixed duration (2 ms), and variable-duration (10 μs, 100 μs, 1 ms, 10 ms, 100 ms, 1 sec, 10 sec) flashes at fixed intensity (2000 photopic lux; n=31 participants). We measured the phase shift of dim-light melatonin onset on the subsequent evening, and acute melatonin suppression and alertness during the flash sequence. In the variable-intensity study, we find a clear sigmoidal dose-response relationship for flash intensity and the induced circadian phase shift. In the variable-duration study, we find no parametric relationship between flash duration and induced circadian phase shift, indicating a relative insensitivity of the circadian system to flashes varying in duration. As the intermittent periods of darkness in our stimulation paradigm supports the recovery of extrinsic rod-cone signalling into the ipRGCs, our results strongly suggest rod-cone contributions into circadian photoreception.

scholarly journals Actigraphy-based parameter tuning process for adaptive notch filter and circadian phase shift estimation

2020 ◽  
Vol 37 (11) ◽  
pp. 1552-1564
Author(s):  
Jiawei Yin ◽  
Agung Julius ◽  
John T. Wen ◽  
Meeko M. K. Oishi ◽  
Lee K. Brown
Keyword(s):  
Phase Shift ◽  
Notch Filter ◽  
Parameter Tuning ◽  
Circadian Phase ◽  
Adaptive Notch Filter ◽  
Tuning Process ◽  
Circadian Phase Shift

scholarly journals 0641 Predicting Circadian Phase Shift: Circadian Monitoring and Regulation System

SLEEP ◽  
2018 ◽  
Vol 41 (suppl_1) ◽  
pp. A238-A238
Author(s):  
M S Rea ◽  
G Jones ◽  
P Hovareshti ◽  
D Tolani ◽  
A Bierman ◽  
...  
Keyword(s):  
Phase Shift ◽  
Regulation System ◽  
Circadian Phase ◽  
Circadian Phase Shift

Stimulation of BIT induces a circadian phase shift of locomotor activity in rats

2003 ◽  
Vol 976 (2) ◽  
pp. 194-201 ◽  
Author(s):  
Yasukazu Nakahata ◽  
Nobuaki Okumura ◽  
Hiroto Otani ◽  
Juri Hamada ◽  
Tadahiro Numakawa ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Phase Shift ◽  
Circadian Phase ◽  
Circadian Phase Shift ◽  
Stimulation Of

scholarly journals Exogenous sex hormones, menstrual and reproductive history, and risk of non-melanoma skin cancer among women: a systematic literature review and meta-analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saverio Caini ◽  
Simone Pietro De Angelis ◽  
Federica Corso ◽  
Carolina Fantini ◽  
Sara Raimondi ◽  
...  
Keyword(s):  
Sex Hormones ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Likelihood Estimation ◽  
Incidence Rates ◽  
Reproductive History ◽  
Age At Menarche ◽  
Hormonal Factors ◽  
Random Effects Models ◽  
Melanoma Skin

AbstractNon-melanoma skin cancers (NMSC) are more frequent among men, but women (especially those aged < 40 years) have experienced steeper growth in their incidence rates in recent years. Hormonal factors were hypothesized to be playing a role in modulating NMSC risk, but the studies published to date provided conflicting results. We systematically reviewed and meta-analysed the studies focusing on the association between hormone-related characteristics (use of exogenous sex hormones, and aspects of menstrual and reproductive history) and the risk of NMSC among women. We included observational and experimental studies published in PubMed and EMBASE until February 2020. We calculated summary relative risk (SRR) and 95% confidence intervals (CI) by applying random effects models with maximum likelihood estimation, and used the I2 statistics to quantify the degree of heterogeneity of risk estimates across studies. Eleven independent studies encompassing a total of over 30,000 NMSC cases were included in quantitative analyses. No evidence of an increased NMSC risk emerged among ever vs. never users of oral contraceptives (SRR 1.13, 95% CI 0.88–1.45) or hormones for menopause (SRR 1.09, 95% CI 0.87–1.37). Likewise, age at menarche or at menopause and parity were not associated with NMSC risk. Heterogeneity across studies was low, and pooled results were comparable between NMSC subtypes. We found no evidence that hormonal factors play a role in the pathogenesis of NMSC among women.

scholarly journals Positive Affect and Chronic Pain:A Preregistered Systematic Review and Meta-Analysis

2019 ◽  
Author(s):  
Anthony Ong ◽  
Felix Thoemmes ◽  
Kaylin Ratner ◽  
Kate Ghezzi-Kopel ◽  
M. Carrington Reid
Keyword(s):  
Cancer Pain ◽  
Positive Affect ◽  
Data Extraction ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Pain Severity ◽  
Random Effects Models ◽  
Study Selection ◽  
Subgroup Analyses ◽  
Lower Pain

Importance: Chronic non-cancer pain (CNCP) is a significant health burden among adults. Standard behavioral therapies typically focus on targeting negative affect and yield only modest treatment effects. Objective: To systematically review and investigate the association between positive affect (PA) and pain severity among adults with chronic non-cancer pain. Data Sources: Databases search included MEDLINE (PubMed), PsycINFO, CINAHL, ProQuest Dissertations and Theses, OLASTER, Open Grey, PeerJ, and PsyArXiv (inception to September 24, 2018). Study Selection: We analyzed studies that: 1) employed a daily diary, longitudinal, laboratory, or intervention study design; 2) enrolled individuals with CNCP (pain ≥ 12 weeks); and 3) reported full quantitative results on outcomes. Data Extraction and Synthesis: At least 2 researchers independently screened articles, extracted data, and assessed the risk of bias. The main meta-analysis was followed by subgroup analyses. All analyses were performed using random-effects models. Formal tests for heterogeneity (Q-statistic; I2) and publication bias (p-curve and p-uniform*) were performed. Main Outcome: Pain severity. Results: We analyzed 26 studies with 2702 participants. Positive affect was associated with reduced pain severity in both observational and experimental studies. In subgroup analyses, only gender demonstrated a consistent effect: Higher PA was associated with lower pain in observational studies that had higher percentages of female participants. Conclusion and Relevance: Positive affect is associated with a reduction in pain severity, with the strongest association observed among women with CNCP.

Overcoming Resistance Through Narratives: Findings from a Meta-Analytic Review

2020 ◽  
Vol 46 (4) ◽  
pp. 412-443 ◽  
Author(s):  
Chelsea L Ratcliff ◽  
Ye Sun
Keyword(s):  
Meta Analysis ◽  
Experimental Studies ◽  
Empirical Work ◽  
Effect Sizes ◽  
Future Research ◽  
Narrative Persuasion ◽  
Random Effects Models ◽  
Analytic Review ◽  
Narrative Engagement ◽  
The Relationship

Abstract To understand the mechanisms underlying narrative persuasion, a growing body of theoretical and empirical work suggests that narratives reduce audience resistance, possibly via narrative engagement. To synthesize this research, we performed a two-part meta-analysis using three-level random-effects models. Part I focused on experimental studies that directly compared narratives and non-narratives on resistance. Based on 15 effect sizes from nine experimental studies, the overall effect size was d = −.213 (equivalent r = −.107; p &lt; .001), suggesting that narratives generated less resistance than non-narratives. Part II was a synthesis of studies of the relationship between narrative engagement and resistance, consisting of 63 effect sizes from 25 studies. Narrative engagement and resistance were negatively correlated (r = −.131; p &lt; .001), and this relationship was moderated by narrative message characteristics, including genre, length, medium, and character unit. Implications of our findings and directions for future research are discussed.

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