Summary
This review links exposure to light at night and irregular light schedules — common in shift work — to disruption of circadian clock gene rhythms and downstream metabolic dysfunction including obesity risk. Lighting designers and healthcare environments should consider minimizing nighttime light exposure and maintaining robust light-dark contrast to protect circadian-metabolic homeostasis.
Key Findings
- Circadian misalignment between behavioral and molecular clocks is associated with increased obesity risk in both rodents and humans.
- Metabolically relevant hormones (insulin, glucagon, ghrelin, leptin, corticosterone) are released in a circadian fashion and are disrupted by light at night.
- The global rise in artificial light at night exposure parallels the increasing prevalence of obesity and metabolic disorders, suggesting a causal relationship mediated by circadian disruption.
- Mice with circadian clock gene mutations show altered feeding behavior, endocrine signaling, and dietary fat absorption, demonstrating the mechanistic link between clock genes and metabolism.
Categories
Sleep & Circadian Health: Reviews how light-dark cycles and light at night disrupt circadian rhythm entrainment, affecting molecular clock gene feedback loops.
Shift Work & Staff Wellbeing: Examines rotating shift work as a model of circadian misalignment with consequences for energy balance and metabolic health.
The Science of Light: Discusses the role of light as the primary zeitgeber for the suprachiasmatic nucleus and how artificial light at night disrupts circadian system function.
Author(s)
V Shabrish
Publication Year
2022
Related Publications
Sleep & Circadian Health
- Phototransduction by retinal ganglion cells that set the circadian clock
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- The two‐process model of sleep regulation: a reappraisal
- Melanopsin is required for non-image-forming photic responses in blind mice
- Strange vision: ganglion cells as circadian photoreceptors
Shift Work & Staff Wellbeing
- Off the clock: from circadian disruption to metabolic disease
- Endocrine regulation of circadian physiology
- Working against the biological clock: a review for the Occupational Physician
- Shiftwork and light at night negatively impact molecular and endocrine timekeeping in the female reproductive axis in humans and rodents
- Circadian Rhythms Disrupted by Light at Night and Mistimed Food Intake Alter Hormonal Rhythms and Metabolism
The Science of Light
- Phototransduction by retinal ganglion cells that set the circadian clock
- Color appearance models
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Melanopsin is required for non-image-forming photic responses in blind mice