Neuroendocrinology of Sleep and Wakefulness

SCOPUS: ch.binfo:eu-repo/semantics/publishe

Metabolic and endocrine effects of sleep deprivation.

Sleep deprivation has multiple effects on endocrine and metabolic function. In particular, sleep restriction is accompanied by increased cortisol levels in the afternoon and early evening and a shorter quiescent period compared with extended sleep periods. Those alterations could facilitate central and peripheral disturbances that are associated with glucocorticoid excess, such as memory deficits, and are similar to those observed in aging. Thus, chronic sleep loss could contribute to acceleration of the aging process. Sleep restriction is also associated with an impairment of carbohydrate tolerance, similar to that observed in individuals with clinically significant impaired glucose tolerance. Thus, chronic sleep deprivation may increase the risk for diabetes. Finally, sleep plays an important role in energy balance. Partial sleep deprivation was found to be associated with a decrease in plasma levels of leptin and a concomitant increase in plasma levels of ghrelin; subjective ratings of hunger and appetite also increased (the appetite for protein-rich foods was not significantly affected). Moreover, a remarkable correlation was found between the increase in hunger and the increase in the ghrelin:leptin ratio. Thus, the neuroendocrine regulation of appetite and food intake appears to be influenced by sleep duration, and sleep restriction may favor the development of obesity.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Endocrino-metabolic disorders and sleep medicine

info:eu-repo/semantics/inPres

Somatomedins and steroids

Somatomedin levels measured by radioreceptor assay, competitive protein-binding assay or radioimmunoassay are normal in hypercortisolism; the decrease of somatomedin activity consistently found in this condition is due to an increase in circulating somatomedin inhibitors resulting in an inhibition of somatomedin action. Progestagens could possibly have a direct stimulatory effect on somatomedin-C (Sm-C) production. During puberty, the increase of Sm-C is correlated with the increase in plasma estradiol and testosterone. In young subjects, relatively low doses of estrogens and of testosterone enhance Sm-C secretion, and in adult menstruating women, a positive relationship is found between testosterone and Sm-C values. An inhibitory effect of estrogens on Sm-C is observed with higher doses and/or in older subjects. Thus, somatomedin levels might be modulated by variations of sex steroids.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Sleep and Hormonal Changes in Aging

Age-related sleep and endocrinometabolic alterations frequently interact with each other. For many hormones, sleep curtailment in young healthy subjects results in alterations strikingly similar to those observed in healthy old subjects not submitted to sleep restriction. Thus, recurrent sleep restriction, which is currently experienced by a substantial and rapidly growing proportion of children and young adults, might contribute to accelerate the senescence of endocrine and metabolic function. The mechanisms of sleep-hormonal interactions, and therefore the endocrinometabolic consequences of age-related sleep alterations, which markedly differ from one hormone to another, are reviewed in this article. © 2013 Elsevier Inc.SCOPUS: re.jinfo:eu-repo/semantics/publishe

DOSAGE PAR RADIOCOMPETITION DE LA PREDNISOLONE ET D'UN NOUVEAU CORTICOIDE SYNTHETIQUE

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Interactions entre le sommeil et la fonction endocrino-métabolique

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Hormonal circadian rhythms and sleep in aging

The 24-h temporal regulation of hormonal secretions results from the interaction of an endogenous circadian pacemaker and of sleep-wake homeostasis, a mechanism linking the timing and the intensity of sleep to the duration of prior wakefulness. A reduction in rhythm amplitude and an advance shifting constitute prominent age-related alterations of hormonal circadian rhythmicity. At the same time, the sleep-wake pattern undergoes major modifications, with a spectacular decrease in “restorative” sleep stage from early adulthood to mid-life, followed thereafter by sleep fragmentation and a decrease in total sleep time. Age-related sleep and endocrine-metabolic alterations frequently interact with each other.SCOPUS: ch.binfo:eu-repo/semantics/publishe

Patterns of plasma levels of prednisolone after oral administration in man

A competitive protein binding method was found suitable for the estimation of plasma prednisolone levels in men in whom endogenous steroids were suppressed by dexamethasone premedication. This method is rapid and precise and allows measurements of prednisolone in small blood samples after usual therapeutic doses of the drug. Using this technique, two preparations of the medication were compared, a conventional form and an enteric coated formulation; except for the delay due to the coating, they were completely comparable, since maximum levels reached, areas under the plasma concentration time curves, and apparent disappearance half lifes were almost identical.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Age-related Sleep Alterations: Implications for Endocrine Function

Age-related sleep and endocrine alterations frequently interact with each other. For a number of hormones, the effects of sleep curtailment in young subjects mimic those observed in healthy older adults with normal sleep schedule. Thus, voluntary sleep loss, which is experienced by a substantial proportion of people in more-developed countries, and has become a hallmark of modern society, could contribute to accelerate the senescence of endocrine and metabolic function. © 2007 Elsevier Inc. All rights reserved.SCOPUS: re.jinfo:eu-repo/semantics/publishe