Vitamin A and sleep regulation

Sleep disorders in dermatology - a comprehensive review

Sleep is a normal physiological process that accounts for approximately one third of a person's life. Disruption of the normal sleep cycle, which maintains physiological homeostasis, can lead to pathology. It is not known whether sleep disturbance causes skin disease or skin disease causes sleep impairment, but a bidirectional influence is suspected. We have compiled the data from published articles on "sleep disorders in dermatology" in PubMed Central from July 2010 to July 2022 (with the option "full text available") and provide an overview of sleep disorders associated with dermatological conditions and certain drugs used in dermatology as well as sleep disturbances for which some drugs used can cause itch or dermatological issues. Atopic dermatitis, eczema and psoriasis have been shown to be exacerbated by sleep problems and vice versa. Sleep deprivation, night-time pruritus and disrupted sleep cycles are often used to assess treatment response and quality of life in these conditions. Some medications used primarily for dermatological conditions have also been associated with alterations in the sleep-wake cycle. Addressing patients sleep disorders should be an integral part of the management of dermatological conditions. More studies are needed to further investigate the influence of sleep and skin disorders.

Vitamin a deficiency and sleep disturbances related to autism symptoms in children with autism spectrum disorder: a cross-sectional study

Background

Vitamin A deficiency (VAD) and sleep disturbances have been reported in children with autism spectrum disorder (ASD). The influence of vitamin A (VA) levels on sleep regulation and sleep disturbances in ASD has garnered concern. The present study aimed to characterize the association of VA levels with sleep disturbances in children with ASD.

Methods

This cross-sectional study compared children with ASD (n = 856) to typically developing children (TDC; n = 316). We used the Children’s Sleep Habits Questionnaire to assess sleep disturbances, Childhood Autism Rating Scale to evaluate the severity of autism symptoms, and Autism Behavior Checklist and Social Responsiveness Scale to assess autism behaviors. Serum VA levels were estimated using high-performance liquid chromatography. Multivariable linear regression and two-way analysis of variance were performed to investigate if VAD was related to sleep disturbances in children with ASD.

Results

Children with ASD had lower serum VA levels and a higher prevalence of sleep disturbances than TDC did. The incidence of VAD in ASD children with sleep disturbances was higher, and the symptoms more severe than those without sleep disturbances and TDC. Interestingly, the interaction between VAD and sleep disturbances was associated with the severity of autism symptoms.

Conclusion

VAD and sleep disturbances are associated with the core symptoms of ASD in children. Regular monitoring of sleep and VA levels may be beneficial for children with ASD.

Trial registration

Chinese Clinical Trial Registry, registration number: ChiCTR-ROC-14005442, registration date: December 9th 2014.

Phytohormone abscisic acid boosts pentobarbital-induced sleep through activation of GABA-A, PPARβ and PPARγ receptor signaling

BACKGROUND

Sleep disorders induce anxiety and forgetfulness and change habits. The chemical hypnotic drugs currently used have serious side effects and, therefore, people are drawn towards using natural compounds such as plant-based healing agents. Abscisic acid (ABA) is produced in a variety of mammalian tissues and it is involved in many neurophysiological functions.

OBJECTIVE

To investigate the possible effect of ABA on pentobarbital-induced sleep and its possible signaling through GABA-A and PPAR (γ and β) receptors, in male Wistar rats.

METHODS

The possible effect of ABA (5 and 10 µg/rat, intracerebroventricularly) on sleep onset latency time and duration was evaluated in a V-maze model of sleep. Pentobarbital sodium (40 mg/kg, intraperitoneally) was injected to induce sleep 30 min after administration of ABA. PPARβ (GSK0660, 80 nM/rat), PPARγ (GW9662, 3 nM/rat) or GABA-A receptor (bicuculline, 6 µg/rat) antagonists were given 15 min before ABA injection. Diazepam (2 mg/kg, intraperitoneally) was used as a positive control group.

RESULTS

ABA at 5 µg significantly boosted the pentobarbital-induced subhypnotic effects and promoted induction of sleep onset in a manner comparable to diazepam treatment. Furthermore, pretreatment with bicuculline significantly abolished the ABA effects on sleep parameters, while the amplifying effects of ABA on the induction of sleep onset was not significantly affected by PPARβ or PPARγ antagonists. The sleep prolonging effect of ABA was significantly prevented by both PPAR antagonists.

CONCLUSIONS

The data showed that ABA boosts pentobarbital-induced sleep and that GABA-A, PPARβ and PPARγ receptors are, at least in part, involved in ABA signaling.

Associations between dietary consumption and sleep quality in young Japanese males

PURPOSE

Poor sleep quality has been reported to be a risk factor for cardiovascular disease, diabetes, and metabolic syndrome, as well as mental disorders including depression and anxiety. However, few studies have investigated the association between sleep quality and diet in young males. We aimed to assess this association, adjusting for psychological factors.

METHODS

In this study, a total of 124 male Japanese students were analyzed. Sleep quality, diet, and psychological symptoms were assessed using self-reported questionnaires, including the Pittsburgh Sleep Quality Index (PSQI), brief-type self-administered diet history questionnaire (BDHQ), 12-item General Health Questionnaire (GHQ12), and State-Trait Anxiety Inventory (STAI) A-Trait scale.

RESULTS

Among participants, 40% exhibited a PSQI total score ≥ 6, indicating poor sleep quality. Poor sleep quality was associated with poor mental health status and higher levels of anxiety. After adjusting for covariates including these psychological factors, poor sleep quality was significantly associated with low intakes of fat, beta-carotene, retinol, alpha-tocopherol, vitamin K, vitamin B₁, daidzein, genistein, and iron. Poor sleep quality was also associated with low intake of pulses, fat and oil, as well as high intakes of sugar-sweetened beverages.

CONCLUSIONS

Our findings demonstrated that sleep quality among young Japanese males was associated with specific dietary features, independently of psychological status, which may help to elucidate the mechanisms underlying the link between sleep and sleep-related diseases.

The rhythm of retinoids in the brain

The retinoids are a family of compounds that in nature are derived from vitamin A or pro-vitamin A carotenoids. An essential part of the diet for mammals, vitamin A has long been known to be essential for many organ systems in the adult. More recently, however, they have been shown to be necessary for function of the brain and new discoveries point to a central role in processes ranging from neuroplasticity to neurogenesis. Acting in several regions of the central nervous system including the eye, hippocampus and hypothalamus, one common factor in its action is control of biological rhythms. This review summarizes the role of vitamin A in the brain; its action through the metabolite retinoic acid via specific nuclear receptors, and the regulation of its concentration through controlled synthesis and catabolism. The action of retinoic acid to regulate several rhythms in the brain and body, from circadian to seasonal, is then discussed to finish with the importance of retinoic acid in the regular pattern of sleep. We review the role of vitamin A and retinoic acid (RA) as mediators of rhythm in the brain. In the suprachiasmatic nucleus and hippocampus they control expression of circadian clock genes while in the cortex retinoic acid is required for delta oscillations of sleep. Retinoic acid is also central to a second rhythm that keeps pace with the seasons, regulating function in the hypothalamus and pineal gland.

Circadian rhythms and sleep--the metabolic connection

The circadian system coordinates mammalian physiology and behavior with the environmental light-dark cycle. It allocates sleep to the inactivity phase using various mechanisms involving neurotransmitters, nuclear receptors, and protein kinases. These pathways are related to metabolism, indicating that the circadian system and sleep are connected via metabolic parameters. This suggests that organs other than the brain may "sleep." A hypothetic view on this aspect is presented providing a different perspective on sleep regulation.

Onset of Kleine-Levin Syndrome in association with isotretinoin treatment

The synthetic retinoid isotretinoin is an effective treatment option for severe forms of acne vulgaris. However, several reports indicate that some patients experience altered central nervous system functions in association with treatment. We present here the first description of the onset of Kleine-Levin Syndrome (KLS), a rare disorder characterised by periodic hypersomnia and cognitive and behavioural symptoms, in close temporal relation to the start of isotretinoin treatment. We also discuss the biological potential of retinoids to affect sleep.

CONCLUSIONS

In light of a documented potential of retinoids to modulate sleep-wake regulation, the present case suggests that isotretinoin may rarely trigger the onset of KLS.

Towards retinoid therapy for Alzheimer's disease

Alzheimer's disease(AD) is associated with a variety of pathophysiological features, including amyloid plaques, inflammation, immunological changes, cell death and regeneration processes, altered neurotransmission, and age-related changes. Retinoic acid receptors (RARs) and retinoids are relevant to all of these. Here we review the pathology, pharmacology, and biochemistry of AD in relation to RARs and retinoids, and we suggest that retinoids are candidate drugs for treatment of AD.