The Effects of Sleep Loss on Brain Functioning

Probiotics Supplementation Attenuates Inflammation and Oxidative Stress Induced by Chronic Sleep Restriction

Background: Insufficient sleep is a serious public health problem in modern society. It leads to increased risk of chronic diseases, and it has been frequently associated with cellular oxidative damage and widespread low-grade inflammation. Probiotics have been attracting increasing interest recently for their antioxidant and anti-inflammatory properties. Here, we tested the ability of probiotics to contrast oxidative stress and inflammation induced by sleep loss. Methods: We administered a multi-strain probiotic formulation (SLAB51) or water to normal sleeping mice and to mice exposed to 7 days of chronic sleep restriction (CSR). We quantified protein, lipid, and DNA oxidation as well as levels of gut-brain axis hormones and pro and anti-inflammatory cytokines in the brain and plasma. Furthermore, we carried out an evaluation of microglia morphology and density in the mouse cerebral cortex. Results: We found that CSR induced oxidative stress and inflammation and altered gut-brain axis hormones. SLAB51 oral administration boosted the antioxidant capacity of the brain, thus limiting the oxidative damage provoked by loss of sleep. Moreover, it positively regulated gut-brain axis hormones and reduced peripheral and brain inflammation induced by CSR. Conclusions: Probiotic supplementation can be a possible strategy to counteract oxidative stress and inflammation promoted by sleep loss.

Sleep characteristics and excessive daytime sleepiness in adolescents and adults: results from the birth cohorts of three Brazilian cities - RPS Consortium

OBJECTIVE

To describe the prevalence of insufficient sleep duration, long sleep latency, terminal or maintenance insomnia, subjective sleep quality, and excessive daytime sleepiness among participants of birth cohorts conducted in three Brazilian cities, and to evaluate differences in prevalence rates within cohorts according to sociodemographic characteristics.

METHODS

Cross-sectional analyses involving adolescents and adults participating in four birth cohorts conducted in Ribeirão Preto (RP78 and RP94), Pelotas (PEL93) and São Luís (SL97/98). Sleep duration, latency, terminal or maintenance insomnia, and subjective sleep quality were obtained through the Pittsburgh Sleep Quality Index; and excessive daytime sleepiness was assessed using the Epworth Sleepiness Scale. Differences in the prevalence of the outcomes were analyzed in each cohort according to sociodemographic characteristics (skin color, marital status, socioeconomic status, study and working at the time of the interview) stratified by sex.

RESULTS

Insufficient sleep duration was the most common outcome at the four cohorts, with higher frequency among men. Long latency was more frequently reported by young adult women in RP94 and PEL93 cohorts, and insomnia by women of the four cohorts, when compared to men of the same age. Women generally suffered more from excessive daytime sleepiness and evaluated the quality of their sleep more negatively than men. In addition to sex, being a student and working were associated with the largest number of outcomes in both sexes.

CONCLUSION

Sleep disorders are more prevalent in women, reinforcing the need for greater investment in sleep health in Brazil, without disregarding gender and socioeconomic determinants.

Association of Food Intake with Sleep Durations in Adolescents from a Capital City in Northeastern Brazil

(1) Background: During adolescence, there are significant changes in food consumption, such as reducing the consumption of in natura or minimally processed foods and increasing the consumption of ultra-processed foods. Thus, eating habits can influence sleep duration and, consequently, affect the quality of life of young people. This study thus aims to estimate the association of consumption of in natura or minimally processed, processed, and ultra-processed foods with sleep durations in adolescents. (2) Methods: This is a cross-sectional study including 964 adolescents (18 to 19 years old) from the 1997 to 1998 birth cohort in São Luís, Maranhão. Food consumption was assessed using the food frequency questionnaire (FFQ) and stratified based on the NOVA classification. Sleep duration was verified using accelerometry in hours. The analysis of the association between the consumption of in natura or minimally processed, processedand ultra-processed foods with sleep durations in adolescents used crude and adjusted linear regression (by gender, age, skin color, education, economic class, work, consumption of alcohol, smoking, screen time, physical activity, use of illicit drugs, anxiety, depressive symptoms, and lean and fat mass). A directed acyclic graph (DAG) was used to determine the minimum set of adjustment factors. (3) Results: Of the 964 individuals evaluated, 52.0% were female. The mean sleep duration was 6 h (± 0.95). In the crude and adjusted analyses, no association was observed between food consumption according to the degree of processing and adolescent sleep durations. (4) Conclusion: There was no association between the consumption of in natura or minimally processed, processed, and ultra-processed foods with sleep durations.

No loss of orexin/hypocretin, melanin-concentrating hormone or locus coeruleus noradrenergic neurons in a rat model of chronic sleep restriction

Chronic sleep restriction (CSR) is common in modern society, adversely affecting cognitive performance and health. Yet how it impacts neurons regulating sleep remains unclear. Several studies using mice reported substantial losses of wake-active orexin/hypocretin and locus coeruleus (LC) noradrenergic neurons, but not rapid eye movement sleep-active melanin-concentrating hormone (MCH) neurons, following CSR. Here, we used immunohistochemistry and stereology to examine orexin, MCH and LC noradrenergic neurons in a rat model of CSR that uses programmed wheel rotation (3 h on/1 h off; '3/1' protocol). Adult male Wistar rats underwent one or four cycles of the 4-day 3/1 CSR protocol, with 2-day recovery between cycles in home cages. Time-matched control rats were housed in locked wheels/home cages. We found no significant differences in the numbers of orexin, MCH and LC noradrenergic neurons following either one- or four-cycle CSR protocol compared to respective controls. Similarly, the four-cycle CSR protocol had no effect on the densities of orexin axon terminals in the LC, noradrenergic dendrites in the LC and noradrenergic axon terminals in the frontal cortex. Body weights, however, decreased after one cycle of CSR and then increased with diminishing slope over the next three cycles. Thus, we found no evidence for loss of orexin or LC noradrenergic neurons following one and four cycles of the 4-day 3/1 CSR protocol in rats. Differences in CSR protocols and/or possible species differences in neuronal vulnerability to sleep loss may account for the discrepancy between the current results in rats and previous findings in mice.