Principal Investigator: Professor Thomas Erren
University Hospital of Cologne, Cologne, GermanyTags: 44219, cancer, Circadian, light, metabolic, perinatal, psychiatric
The human internal 24-hour timing system, termed the circadian system, facilitates alignment of 24-hour periodic physiological rhythms internally and with respect to the environment. One immediately recognisable rhythm is the sleep-wake cycle in alignment with the environmental light-dark cycle and other physiological rhythms. Indeed, daylight is a strong environmental time cue for the circadian system. There is a circadian clock in every cell in the body co-governing numerous physiological processes. If disrupted, physiological rhythms can be in misalignment. Such disruptions have been associated with psychiatric disorders, metabolic disease, and cancer.
Studies in animal models suggest daily light-dark cycles around the time of birth (perinatal) can imprint the circadian system (termed: PLICCS). Altered responsiveness to time cues have been observed in addition to differences in gene expression, metabolism, hormone rhythms, and neural chemistry.
Certain paradigms of PLICCS (e.g. less daylight hours) increase susceptibility to circadian system challenges later in life (such as shiftwork) and increase risk of developing circadian-related psychiatric disorders, metabolic disease, and cancer.
(1) We aim to test if differences in the daily light/dark cycle during the perinatal period in humans are associated affects disease risk.
(2) We aim to test if circadian system challenges in later life (such as participation in shiftwork, or latitudinal- or longitudinal-residence) co-contributes to PLICCS associated risks.
Date of birth and geographical location will be used to derive daily light/dark metrics with online solar calculators. Strength and probability of associations of PLICCS with disease will be calculated with various statistical methods. Later life factors will be tested as co-contributors to risk. The proposed duration of this project is 3 years: 24 months to clean and analyse data and 12 months to write papers and submit.
CLINICAL RELEVANCE/PUBLIC INTEREST
The potential impact of light on human health concerns everybody as light is omnipresent. Let’s assume the daily light-dark cycle during the perinatal period (around the date of birth) can increase or decrease risk of disease later in life. We can then explore how pregnant mothers or mothers and new born children might expose themselves to e.g. more intense/extended photoperiods using “daylight” bulbs to simulate optimal environmental light conditions. Overall, PLICCS is a candidate for increasing risk of developing diseases such as cancer, psychiatric disorders, and metabolic disease. Parents could potentially decrease risks such diseases developing in their children at low cost. Health and economic impact could be substantial.