1,720,993 research outputs found
Sex differences in sleep, circadian rhythms, and metabolism: implications for precision medicine
No full textThe number of individuals experiencing sleep loss has exponentially risen over the past decades. Extrapolation of laboratory findings to the real world suggests that females are more affected by extended wakefulness and circadian misalignment than males are. Therefore, long-term effects such as sleep and metabolic disorders are likely to be more prevalent in females than in males. Despite emerging evidence for sex differences in key aspects of sleep-wake and circadian regulation, much remains unknown, as females are often underrepresented in sleep and circadian research. This narrative review aims at highlighting 1) how sex differences systematically impinge on the sleep-wake and circadian regulation in humans, 2) how sex differences in sleep and circadian factors modulate metabolic control, and 3) the relevance of these differences for precision medicine. Ultimately, the findings justify factoring in sex differences when optimizing individually targeted sleep and circadian interventions in humans
Commentary: Melanopsin Regulates Both Sleep-Promoting and Arousal-Promoting Responses to Light
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Endogenous circadian rhythms in mood and well-being
No full textObjectives: we examined whether the endogenous circadian timing system modulates proxies of mood vulnerability and well-being.Methods: nineteen healthy participants (mean age: 26.6 years [23.0-30.2], seven females, body-mass index: 22.8 kg/m2 [21.1-25]) completed a laboratory protocol with a 32-hour Constant Routine, a stringently controlled protocol designed to isolate assessment of endogenous circadian rhythms. We assessed hourly anxiety- and depression-like mood (i.e., those typically observed in depression and anxiety) and well-being (i.e., associated with mental fatigue and physical comfort).Results: significant endogenous circadian rhythms were observed in anxiety-like and depression-like mood, as well as well-being (p values from the mixed-model analysis using false discovery rates < .001). Post-hoc comparisons revealed more anxiety-like and depression-like mood during the circadian phase 60°-75° (∼8–9 a.m.), and more mental fatigue and less physical comfort during the circadian phase 30°-60° (∼6–8 a.m.).Conclusions: our data indicate endogenous circadian rhythms in anxiety-like and depression-like mood and well-being in healthy young adults. Future studies will help establish circadian-based therapeutics for individuals experiencing mood and anxiety disorders
In a Heartbeat: Light and Cardiovascular Physiology
No full textLight impinging on the retina fulfils a dual function: it serves for vision and it is required for proper entrainment of the endogenous circadian timing system to the 24-h day, thus influencing behaviors that promote health and optimal quality of life but are independent of image formation. The circadian pacemaker located in the suprachiasmatic nuclei modulates the cardiovascular system with an intrinsic ability to anticipate morning solar time and with a circadian nature of adverse cardiovascular events. Here, we infer that light exposure might affect cardiovascular function and provide evidence from existing research. Findings show a time-of-day dependent increase in relative sympathetic tone associated with bright light in the morning but not in the evening hours. Furthermore, dynamic light in the early morning hours can reduce the deleterious sleep-to-wake evoked transition on cardiac modulation. On the contrary, effects of numerous light parameters, such as illuminance level and wavelength of monochromatic light, on cardiac function are mixed. Therefore, in future research studies, light modalities, such as timing, duration, and its wavelength composition, should be taken in to account when testing the potential of light as a non-invasive countermeasure for adverse cardiovascular events.Version of Recor
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