Kfir Asraf

Bio: Kfir Asraf is an academic researcher from Max Stern Academic College of Emek Yezreel. The author has contributed to research in topics: Medicine & Psychology. The author has an hindex of 3, co-authored 10 publications receiving 46 citations.

Maternal perceptions of sleep problems among children and mothers during the coronavirus disease 2019 (COVID-19) pandemic in Israel.

Abstract: Despite the marked impact of the coronavirus disease 2019 (COVID-19) pandemic on the life of families and its possible negative implications for sleep, little is known about how sleep among parents and children has been impacted by this current crisis. In the present study, we addressed, for the first time, possible consequences of the COVID-19 crisis and home confinement on maternal anxiety, maternal insomnia, and maternal reports of sleep problems among children aged 6-72 months in Israel (N = 264). Our results revealed a high frequency of maternal clinical insomnia during the COVID-19 pandemic: 23% during the pandemic, compared to only 11% before the pandemic (retrospective reports about 1-2 months before the pandemic). About 80% of mothers reported mild-to-high levels of current COVID-19 anxiety. The majority of mothers reported no change in their child's sleep quality, duration, and sleeping arrangement. However, about 30% reported a negative change in child's sleep quality and a decrease in sleep duration, and there were also mothers who reported a positive change. These findings suggest that the changes in sleep patterns during the COVID-19 pandemic are varied and that no unified change for the worse should be expected. Further consideration of changes in sleep within the family context during this ongoing crisis is needed.

Increased physical activity improves gut microbiota composition and reduces short-chain fatty acid concentrations in older adults with insomnia

Abstract: Physical activity (PA) can improve functional abilities, well-being, and independence in older adults with insomnia. Studies have shown that PA may be linked to changes in the gut microbiota composition and its metabolites' concentrations. This association among older adults with insomnia, however, is yet to be determined. We explored the relationships between physical activity (PA) levels, gut microbiota composition, and short-chain fatty acid (SCFA) levels in this population. Forty-nine community-dwelling adults with insomnia symptoms, aged 65 and older, participated in this study. Their average daily step-count and sleep continuity measures over a two-week period were calculated based on Actigraphic recordings. Each participant provided fecal samples for the microbiome and SCFA analyses, anthropometric measures, and information via questionnaires on medical history and food consumption. The gut microbiota composition and SCFA concentrations were determined by next-generation sequencing and Gas chromatography-mass spectrometry, respectively. Participants were divided into two groups (more and less active) according to their median step/day count. We compared the microbiota abundance and SCFA concentrations between groups and performed correlation analysis between gut microbiota abundances and study variables. Different microbiota taxa in each PA group and increased SCFAs in feces of less active individuals were found. Changes in step counts were positively or negatively associated with the relative abundance of 19 ASVs, 3 microorganisms at the family level, and 11 microorganisms at the genus level. Furthermore, significant associations were discovered among physical activity, gut microbiota, SCFAs, and sleep parameters. Our findings provide new insights on the relationship between PA, gut microbiota composition, and primary metabolites in older adults with insomnia.

Associations between fecal short-chain fatty acids and sleep continuity in older adults with insomnia symptoms.

Abstract: Insomnia is a disorder characterized by difficulty falling asleep and poor sleep continuity and is associated with increased risks for physical and cognitive decline. Insomnia with short sleep duration is considered the most biologically severe phenotype of the disorder. Evidence suggests that short-chain fatty acids (SCFAs), the main byproducts of fiber fermentation in the gut, may affect sleep via gut-brain communications. This study explores associations between SCFAs and sleep continuity and compares SCFA concentrations in short vs. normal sleep insomnia phenotypes in older adults. Fifty-nine participants with insomnia symptoms (≥ 65 years), completed 2 weeks of objective sleep monitoring (actigraphy), and were divided into short and normal sleep duration phenotypes via cluster analysis. Sleep measures included total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), and wake after sleep onset (WASO). Stool samples were collected and fecal SCFA concentrations were determined by gas-chromatography-mass-spectrometry (GCMS). Higher concentrations of acetate, butyrate, and propionate, and total SCFAs, were associated with lower SE and longer SOL after controlling for Body Mass Index (BMI). Concentrations were higher in the short sleep duration phenotype. Age, BMI, TST, and SOL explained 40.7% of the variance in total SCFAs. Findings contribute to understanding pathways along the gut-brain axis and may lead to the use of SCFAs as biomarkers of insomnia phenotypes.

The Association between Lifestyle Changes and Psychological Distress during COVID-19 Lockdown: The Moderating Role of COVID-Related Stressors

Abstract: The COVID-19 pandemic and the accompanying circumstances (lockdown and social distancing) have been found to cause lifestyle habit changes. While negative changes (adopting risky behaviors) are known to be associated with high psychological distress, the effect of positive changes (adopting health-enhancing behaviors) has yet to be investigated. This study examined the association between the nature of changes and psychological distress, in addition to the moderating effect of “COVID-related stressors”. Online questionnaires, completed by 1969 participants, assessed the following: lifestyle changes due to COVID-19 with regard to cigarette smoking, alcohol consumption, physical activity, sleep quality, and eating habits; COVID-related stressors; Depression, Anxiety, and Stress Scale. Positive and negative changes were associated with higher psychological distress compared to no lifestyle change, and there was a moderating effect of COVID-related stressors in the association between COVID-related lifestyle changes and distress. In conclusion, to reduce psychological distress in overwhelming circumstances such as the COVID-19 pandemic, people should carefully consider whether to make changes in their lifestyle habits before doing so, even if these changes are perceived as positive and health-enhancing. Furthermore, efforts should be focused on reducing the perception of stress from COVID-19 by working on personal and mental perceptions of the situation.

Unity and Diversity

Abstract: This chapter summarises the content of the Brief, focussing on the key idea of the posterior distribution of the unobserved variables. It gives a chapter by chapter summary and provides a rationale for the order in which topics have been presented.