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Author Youngstedt, S.D.; Elliott, J.A.; Kripke, D.F. url  doi
openurl 
  Title Human Circadian Phase-Response Curves for Exercise Type Journal Article
  Year 2019 Publication The Journal of Physiology Abbreviated Journal J Physiol  
  Volume (down) 597 Issue 8 Pages 2253-2268  
  Keywords Human Health; Circadian Rhythm; Exercise  
  Abstract KEY POINTS: Exercise elicits circadian phase-shifting effects, but additional information is needed. The phase-response curve describing the magnitude and direction of circadian rhythm phase shifts depending on the time of the zeigeber (time cue) stimulus is the most fundamental chronobiological tool for alleviating circadian misalignment and related morbidity. 51 older and 48 young adults followed a circadian rhythms measurement protocol for up to 5.5 days, and performed 1 h of moderate treadmill exercise for 3 consecutive days at one of 8 times of day/night. Temporal changes in the phase of 6-sulphatoxymelatonin (aMT6s) were measured from evening onset, cosine acrophase, morning offset, and duration of excretion, establishing significant PRCs for aMT6 onset and acrophase with large phase delays from 7-10 PM and large phase advances at both 7 AM and 1-4 PM. Along with known synergism with bright light, the above PRCs with a second phase advance region (afternoon) could support both practical and clinical applications. ABSTRACT: Although bright light is regarded as the primary circadian zeitgeber, its limitations support exploring alternative zeitgebers. Exercise elicits significant circadian phase-shifting effects, but fundamental information regarding these effects is needed. The primary aim of this study was to establish phase-response curves (PRC) documenting the size and direction of phase shifts in relation to the circadian time of exercise. Aerobically fit older (n = 51, 59-75 y) and young adults (n = 48, 18-30 y) followed a 90-min laboratory ultra-short sleep wake cycle (60 min wake/30 min sleep) for up to 5 (1/2) days. At the same clock time on three consecutive days, each participant performed 60 min of moderate treadmill exercise (65-75% of heart rate reserve) at one of 8 times of day/night. To describe PRCs, phase shifts were measured for the cosine-fitted acrophase of urinary 6-sulphatoxymelatonin (aMT6s), as well as for the evening rise, morning decline, and change in duration of aMT6s excretion. Significant PRCs were found for aMT6s acrophase, onset and duration, with peak phase advances corresponding to clock times of 7 AM and 1PM-4PM, delays from 7 PM-10 PM, and minimal shifts around 4 PM and 2 AM. There were no significant age or sex differences. The amplitudes of the aMT6s onset and acrophase PRCs are comparable to expectations for bright light of equal duration. The phase advance to afternoon exercise and the exercise-induced PRC for change in aMT6s duration are novel findings. The results support further research exploring additive phase shifting effects of bright light and exercise and health benefits. This article is protected by copyright. All rights reserved.  
  Address Department of Psychiatry, University of California, San Diego, CA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-3751 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30784068 Approved no  
  Call Number GFZ @ kyba @ Serial 2230  
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Author Rahman, S.A.; St Hilaire, M.A.; Gronfier, C.; Chang, A.-M.; Santhi, N.; Czeisler, C.A.; Klerman, E.B.; Lockley, S.W. url  doi
openurl 
  Title Functional decoupling of melatonin suppression and circadian phase resetting in humans Type Journal Article
  Year 2018 Publication The Journal of Physiology Abbreviated Journal J Physiol  
  Volume (down) 596 Issue 11 Pages 2147-2157  
  Keywords Human Health  
  Abstract KEY POINTS: There is assumed to be a monotonic association between melatonin suppression and circadian phase resetting induced by light exposure. We tested the association between melatonin suppression and phase resetting in humans. Sixteen young healthy participants received nocturnal bright light ( approximately 9500 lux) exposure of continuous or intermittent patterns, and different durations ranging from 12 min to 6.5 h. Intermittent exposure patterns showed significant phase shifts with disproportionately less melatonin suppression. Each and every bright light stimulus in an intermittent exposure pattern induced a similar degree of melatonin suppression, but did not appear to cause an equal magnitude of phase shift. These results suggest that phase shifts and melatonin suppression are functionally independent such that one cannot be used as a proxy measure of the other. ABSTRACT: Continuous experimental light exposures show that, in general, the conditions that produce greater melatonin suppression also produce greater phase shift, leading to the assumption that one can be used as a proxy for the other. We tested this association in 16 healthy individuals who participated in a 9-day inpatient protocol by assessing melatonin suppression and phase resetting in response to a nocturnal light exposure (LE) of different patterns: (i) dim-light control (<3 lux; n = 6) or (ii) two 12-min intermittent bright light pulses (IBL) separated by 36 min of darkness ( approximately 9500 lux; n = 10). We compared these results with historical data from additional LE patterns: (i) dim-light control (<3 lux; n = 11); (ii) single continuous bright light exposure of 12 min (n = 9), 1.0 h (n = 10) or 6.5 h (n = 6); or (iii) an IBL light pattern consisting of six 15-min pulses with 1.0 h dim-light recovery intervals between them during a total of 6.5 h (n = 7). All light exposure groups had significantly greater phase-delay shifts than the dim-light control condition (P < 0.0001). While a monotonic association between melatonin suppression and circadian phase shift was observed, intermittent exposure patterns showed significant phase shifts with disproportionately less melatonin suppression. Each and every IBL stimulus induced a similar degree of melatonin suppression, but did not appear to cause an equal magnitude of phase shift. These results suggest unique specificities in how light-induced phase shifts and melatonin suppression are mediated such that one cannot be used as a proxy measure of the other.  
  Address Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-3751 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29707782 Approved no  
  Call Number GFZ @ kyba @ Serial 1887  
Permanent link to this record
 

 
Author Portnov, B.A.; Stevens, R.G.; Samociuk, H.; Wakefield, D.; Gregorio, D.I. url  doi
openurl 
  Title Light at night and breast cancer incidence in Connecticut: An ecological study of age group effects Type Journal Article
  Year 2016 Publication The Science of the Total Environment Abbreviated Journal Sci Total Environ  
  Volume (down) 572 Issue Pages 1020-1024  
  Keywords Human Health  
  Abstract The aim of this study was to test the prediction that within the state of Connecticut, USA, communities with high nighttime outdoor light level would have higher breast cancer incidence rates. Breast cancer cases were identified from the Connecticut Tumor Registry, the oldest within the United States, for years 2005 and 2009 and geocoded to the 829 census tracts in the state. Nighttime light level (LAN) was obtained from the Defense Meteorological Satellite Program (DMSP), 1996/97 satellite image, providing a 10-year lag. Regression models were used incorporating the LAN levels and census level data on potential confounders for the whole female population of the state, and for separate age groups. Light level emerged as a significant predictor of breast cancer incidence. After taking account of several potential confounders, the excess risk in the highest LAN level census tracts compared to the lowest was about 63% (RR=1.63; 95% CI=1.41, 1.89). The association of LAN with breast cancer incidence weakened with age; the association was strongest among premenopausal women.  
  Address Department of Community Medicine, School of Medicine, University of Connecticut, Farmington, CT 06030, United States. Electronic address: gregorio@uchc.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0048-9697 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:27531467 Approved no  
  Call Number LoNNe @ kyba @ Serial 1529  
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Author Pattison, P.M.; Tsao, J.Y.; Brainard, G.C.; Bugbee, B. url  doi
openurl 
  Title LEDs for photons, physiology and food Type Journal Article
  Year 2018 Publication Nature Abbreviated Journal Nature  
  Volume (down) 563 Issue 7732 Pages 493-500  
  Keywords Lighting; Human Health; Plants; Review  
  Abstract Lighting based on light-emitting diodes (LEDs) not only is more energy efficient than traditional lighting, but also enables improved performance and control. The colour, intensity and distribution of light can now be controlled with unprecedented precision, enabling light to be used both as a signal for specific physiological responses in humans and plants, and as an efficient fuel for fresh food production. Here we show how a broad and improved understanding of the physiological responses to light will facilitate greater energy savings and provide health and productivity benefits that have not previously been associated with lighting.  
  Address Utah State University, Logan, UT, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30464269 Approved no  
  Call Number GFZ @ kyba @ Serial 2110  
Permanent link to this record
 

 
Author Zielinska-Dabkowska, K.M. url  doi
openurl 
  Title Make lighting healthier Type Journal Article
  Year 2018 Publication Nature Abbreviated Journal Nature  
  Volume (down) 553 Issue 7688 Pages 274-276  
  Keywords Commentary; Lighting; Human Health  
  Abstract Artificial illumination can stop us sleeping and make us ill. We need fresh strategies and technologies, argues Karolina M. Zielinska-Dabkowska.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2932  
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