Objectively measured daytime sleepiness predicts weight change among adults: Findings from the Wisconsin Sleep Cohort Study

OBJECTIVE

Body mass index (BMI) trajectories are associated with night-time sleep, but it is not clear how they relate to daytime sleepiness in population data. This study aimed to examine longitudinal associations between levels and changes in daytime sleepiness and BMI trajectories among men and women.

METHODS

We estimated growth curve models among 827 participants in the Wisconsin Sleep Cohort Study (mean [sd] age = 55.2 [8.0] years at baseline). The outcome variable was BMI (kg/m2) and the key predictor was daytime sleepiness measured by Multiple Sleep Latency Test (MSLT) scores. Covariates included demographics, health behaviors, retirement status, stimulant use, and depressive symptoms. In sensitivity analyses, we evaluated the potential effects of cardiovascular disease, shift work status, and sleep apnea on the robustness of sleepiness and BMI associations.

RESULTS

At the between-person level, men who were sleepier had higher BMI levels. At the within-person level, age moderated the positive association between sleepiness and BMI among women. Specifically, young women who became sleepier over time gained more BMI than older women with comparable increases in sleepiness. Furthermore, while BMI tended to increase with age among women, BMI trajectories were steeper among sleepy women than among well-rested women, who experienced less increase in BMI over time.

CONCLUSION

The study suggested that levels and changes in daytime sleepiness as objectively measured by MSLT scores are associated with body mass among adults.

Associations of gut microbiome richness and diversity with objective and subjective sleep measures in a population sample

STUDY OBJECTIVES

Alterations in gut microbiota composition have been associated with several conditions, and there is emerging evidence that sleep quantity and quality are associated with the composition of the gut microbiome. Therefore, this study aimed to assess the associations between several measures of sleep and the gut microbiome in a large, population-based sample.

METHODS

Data were collected from participants in the Survey of the Health of Wisconsin from 2016 to 2017 (N = 720). Alpha diversity was estimated using Chao1 richness, Shannon's diversity, and Inverse Simpson's diversity. Beta diversity was estimated using Bray-Curtis dissimilarity. Models for each of the alpha-diversity outcomes were calculated using linear mixed effects models. Permutational multivariate analysis of variance tests were performed to test whether gut microbiome composition differed by sleep measures. Negative binomial models were used to assess whether sleep measures were associated with individual taxa relative abundance.

RESULTS

Participants were a mean (SD) age of 55 (16) years and 58% were female. The sample was 83% non-Hispanic white, 10.6% non-Hispanic black, and 3.5% Hispanic. Greater actigraphy-measured night-to-night sleep duration variability, wake-after-sleep onset, lower sleep efficiency, and worse self-reported sleep quality were associated with lower microbiome richness and diversity. Sleep variables were associated with beta-diversity, including actigraphy-measured night-to-night sleep duration variability, sleep latency and efficiency, and self-reported sleep quality, sleep apnea, and napping. Relative abundance of several taxa was associated with night-to-night sleep duration variability, average sleep latency and sleep efficiency, and sleep quality.

CONCLUSIONS

This study suggests that sleep may be associated with the composition of the gut microbiome. These results contribute to the body of evidence that modifiable health habits can influence the human gut microbiome.

Prevalence and Course of Idiopathic Hypersomnia in the Wisconsin Sleep Cohort Study

BACKGROUND AND OBJECTIVES

Idiopathic hypersomnia (IH) is a CNS disorder of hypersomnolence of unknown etiology. Due to the requirement for objective sleep testing to diagnose the disorder, there are currently no population-based estimates of the prevalence of IH nor data regarding the longitudinal course of IH in naturalistic settings.

METHODS

Subjective and objective data from the Wisconsin Sleep Cohort study were used to identify cases with probable IH from participants with polysomnography and multiple sleep latency test data. Demographic, polysomnographic, and symptom-level data were compared between those with and without IH. Longitudinal trajectories of daytime sleepiness among those with IH were assessed to evaluate symptom persistence or remission over time.

RESULTS

From 792 cohort study participants with available polysomnography and multiple sleep latency test data, 12 cases with probable IH were identified resulting in an estimated prevalence of IH of 1.5% (95% CI 0.7-2.5, p < 0.0001). Consistent with inclusion/exclusion criteria, cases with IH had more severe sleepiness and sleep propensity, despite similar or longer sleep times. Longitudinal data (spanning 12.1 ± 4.3 years) demonstrated a chronic course of sleepiness for most of the cases with IH, though pathologic somnolence remitted in roughly 40% of cases.

DISCUSSION

These results demonstrate IH is more common in the working population than generally assumed with a prevalence on par with other common neurologic and psychiatric conditions. Further efforts to identify and diagnose those impaired by unexplained daytime somnolence may help clarify the causes of IH and the mechanisms underlying symptomatic remission.

The effect of low-abundance OTU filtering methods on the reliability and variability of microbial composition assessed by 16S rRNA amplicon sequencing

PCR amplicon sequencing may lead to detection of spurious operational taxonomic units (OTUs), inflating estimates of gut microbial diversity. There is no consensus in the analytical approach as to what filtering methods should be applied to remove low-abundance OTUs; moreover, few studies have investigated the reliability of OTU detection within replicates. Here, we investigated the reliability of OTU detection (% agreement in detecting OTU in triplicates) and accuracy of their quantification (assessed by coefficient of variation (CV)) in human stool specimens. Stool samples were collected from 12 participants 22-55 years old. We applied several methods for filtering low-abundance OTUs and determined their impact on alpha-diversity and beta-diversity metrics. The reliability of OTU detection without any filtering was only 44.1% (SE=0.9) but increased after filtering low-abundance OTUs. After filtering OTUs with <0.1% abundance in the dataset, the reliability increased to 87.7% (SE=0.6) but at the expense of removing 6.97% reads from the dataset. When filtering was based on individual sample, the reliability increased to 73.1% after filtering OTUs with <10 copies while removing only 1.12% of reads. High abundance OTUs (>10 copies in sample) had lower CV, indicating better accuracy of quantification than low-abundance OTUs. Excluding very low-abundance OTUs had a significant impact on alpha-diversity metrics sensitive to the presence of rare species (observed OTUs, Chao1) but had little impact on relative abundance of major phyla and families and alpha-diversity metrics accounting for both richness and evenness (Shannon, Inverse Simpson). To increase the reliability of microbial composition, we advise removing OTUs with <10 copies in individual samples, particularly in studies where only one subsample per specimen is available for analysis.

Sense of community and mental health: a cross-sectional analysis from a household survey in Wisconsin

BACKGROUND

In the USA, one in five adults live with a mental illness, and researchers have estimated that nearly half of the population will have a mental illness over the course of their lifetime. Research has shown significant associations between social relationships and mental health outcomes at the individual and population levels. This study aims to examine whether sense of community, a type of social capital, is associated with mental health.

METHODS

In a cross-sectional analysis, multiple logistic regression models were used to examine whether sense of community was associated with symptoms of depression, anxiety and stress reported over the last week. The analysis used data from the Survey of the Health of Wisconsin collected between 2014 and 2016. A total of 1647 observations are included in the analyses.

RESULTS

Compared with those who report a positive sense of community, those with a negative sense of community had a significantly higher odds of reporting depression, anxiety and stress symptoms. Socioeconomic status is negatively associated with depression and anxiety, but not with stress. Women were more likely to experience moderate, severe, or extremely severe anxiety and stress, compared with men.

CONCLUSION

This study extends current understanding of health benefits of social capital and found that individuals' sense of community is associated with reduced symptoms of depression, anxiety and stress. Further research examining mechanisms to support improved sense of community and other types of social capital could benefit health equity research.

The genetic etiology of periodic limb movement in sleep

STUDY OBJECTIVES

Periodic limb movement in sleep is a common sleep phenotype characterized by repetitive leg movements that occur during or before sleep. We conducted a genome-wide association study (GWAS) of periodic limb movements in sleep (PLMS) using a joint analysis (i.e., discovery, replication, and joint meta-analysis) of four cohorts (MrOS, the Wisconsin Sleep Cohort Study, HypnoLaus, and MESA), comprised of 6843 total subjects.

METHODS

The MrOS study and Wisconsin Sleep Cohort Study (N = 1745 cases) were used for discovery. Replication in the HypnoLaus and MESA cohorts (1002 cases) preceded joint meta-analysis. We also performed LD score regression, estimated heritability, and computed genetic correlations between potentially associated traits such as restless leg syndrome (RLS) and insomnia. The causality and direction of the relationships between PLMS and RLS was evaluated using Mendelian randomization.

RESULTS

We found 2 independent loci were significantly associated with PLMS: rs113851554 (p = 3.51 × 10-12, β = 0.486), an SNP located in a putative regulatory element of intron eight of MEIS1 (2p14); and rs9369062 (p = 3.06 × 10-22, β = 0.2093), a SNP located in the intron region of BTBD9 (6p12); both of which were also lead signals in RLS GWAS. PLMS is genetically correlated with insomnia, risk of stroke, and RLS, but not with iron deficiency. Pleiotropy adjusted Mendelian randomization analysis identified a causal effect of RLS on PLMS.

CONCLUSIONS

Because PLMS is more common than RLS, PLMS may have multiple causes and additional studies are needed to further validate these findings.

Association between stressful life events and non-optimal lipid levels among women with hyperlipidaemia

AIMS

Psychological stress has been linked to lipid dysregulation with noticeable gender differences, but it remains unclear whether women are more susceptible to non-optimal lipid levels than men, when experiencing stressful life events. This study aims to examine the association between stressful life events and non-optimal lipid levels among persons with hyperlipidaemia and whether the association differs between men and women.

METHODS AND RESULTS

A nested case-control study was performed using data from the Wisconsin Sleep Cohort (WSC) Study from 2011 to 2015, including 224 participants with hyperlipidaemia and without a history of myocardial infarction or heart failure. Among them, 63 participants with non-optimal LDL cholesterol or triglyceride levels were identified as cases, and 161 participants with optimal LDL cholesterol and triglyceride levels were identified as controls. Cases and controls were traced back to their self-reported life events collected through the Retirement and Sleep Trajectories study during 2010-11. The association between stressful life events and non-optimal lipid levels was examined using multivariable logistic regression; confounding effects were addressed using propensity score weighting and Mahalanobis distance matching; gender differences were examined using subgroup analysis. Results showed that a higher number of stressful life events during 2010-11 was associated with greater odds of non-optimal lipid levels during 2011-15 (odds ratio = 1.45, P = 0.03) among women with hyperlipidaemia, whereas the association was not significant among men with hyperlipidaemia (P = 0.910).

CONCLUSION

Future studies are needed to examine the underlying mechanisms that explain gender differences in the association between stressful life events and non-optimal lipid levels.

REGISTRATION

ClinicalTrials.gov NCT00005557.

Psychological distress and well-being among sensory impaired individuals during COVID-19 lockdown measures

PURPOSE

Hearing and vision impairment are prevalent chronic conditions associated with poorer mental health. Limitations of in-person contacts during COVID-19-related lockdown measures may affect those with sensory impairments more severely exacerbating mental health problems. We aimed to determine whether hearing and/or visual impairment were associated with more psychological distress during a time of lockdown measures in Spring/Summer 2020 in Wisconsin.

METHODS

We included 1341(64% women, aged 20-92 years) Survey of the Health of Wisconsin COVID-19 survey participants (May 2020-July,2020). We assessed self-reported current mental health and well-being and vision and hearing impairment. Logistic regression models with sensory impairments as determinants and mental health outcomes were adjusted for age, gender, race, education, heart disease, hypertension, hyperlipidemia, and diabetes.

RESULTS

Vision impairment was associated with increased odds of generalized anxiety disorder (odds ratio = 2.10; 95% confidence interval = 1.32-3.29) and depressive symptoms (2.57;1.58-4.11), greater likelihood to report loneliness (1.65;1.00-2.64) and hopelessness (1.45;1.01-2.08). Hearing impaired individuals reported more loneliness (1.80;1.05-2.98) and hopelessness (1.42;0.99-2.03). Exploratory analyses revealed that sensory impaired individuals less often chose walking as a coping strategy during the pandemic.

CONCLUSIONS

Individuals with sensory impairment may represent a particularly vulnerable population during the COVID-19 pandemic. Future research should determine underlying reasons and interventions to mitigate this populations' disadvantages.

Cardiorespiratory Fitness Attenuates the Deleterious Effects of Sleep Apnea on Cerebral Structure and Perfusion in the Wisconsin Sleep Cohort Study

BACKGROUND

Emerging evidence suggests that age-related changes in cerebral health may be sensitive to vascular risk modifiers, such as physical activity and sleep.

OBJECTIVE

We examine whether cardiorespiratory fitness modifies the association of obstructive sleep apnea (OSA) severity with MRI-assessed measures of cerebral structure and perfusion.

METHODS

Using data from a cross-sectional sample of participants (n = 129, 51% female, age range 49.6-85.3 years) in the Wisconsin Sleep Cohort study, we estimated linear models of MRI-assessed total and regional gray matter (GM) and white matter (WM) volumes, WM hyperintensity (WMH:ICV ratio), total lesion volume, and arterial spin labeling (ASL) cerebral blood flow (CBF), using an estimated measure of cardiorespiratory fitness (CRF) and OSA severity as predictors. Participants' sleep was assessed using overnight in-laboratory polysomnography, and OSA severity was measured using the apnea-hypopnea index (AHI), or the mean number of recorded apnea and hypopnea events per hour of sleep. The mean±SD time difference between PSG data collection and MRI data collection was 1.7±1.5 years (range: [0, 4.9 years]).

RESULTS

OSA severity was associated with reduced total GM volume (β=-0.064; SE = 0.023; p = 0.007), greater total WM lesion volume (interaction p = 0.023), and greater WMHs (interaction p = 0.017) in less-fit subjects. Perfusion models revealed significant differences in the association of AHI and regional CBF between fitness groups (interaction ps < 0.05).

CONCLUSION

This work provides new evidence for the protective role of cardiorespiratory fitness against the deleterious effects of OSA on brain aging in late-middle age to older adults.

Metabolic health disparities driven by financial stress: Behavioural adaptation or modification?

Financial stress has been linked to an increased risk of metabolic syndrome, yet, it remains unclear whether suboptimal sleep duration and physical inactivity are the adaptive responses to financial stress or effect modifiers in the association between financial stress and metabolic syndrome. Hence, this study aims to examine whether physical activity and sleep duration mediate or moderate the bivariate association between financial stress and metabolic syndrome. A prospective secondary analysis was conducted using data from the Wisconsin Sleep Cohort Study (N = 445, mean [SD] age = 64 [7] years). Baseline moderation effect was examined using subgroup analysis with model constraints; prospective mediation model was examined using bias-corrected bootstrap confidence intervals. Results indicate that participants with higher financial stress were less likely to meet physical activity and sleep recommendations. Baseline moderation analysis indicates that meeting current recommendations of sleep duration and physical activity attenuated the association between financial stress and metabolic syndrome. In the prospective mediation analysis, weekly physical activity levels partially mediated the relationship between financial stress and metabolic syndrome, but sleep duration did not mediate this relationship. In conclusion, the joint effect of optimal sleep duration and physical activity disassociates financial stress from the risk of metabolic syndrome. Future interventions addressing metabolic risk might achieve better outcomes if clinicians and researchers factor in the behavioral adaptation of physical inactivity in financially stressed adults (Clinical Trial Registration: NCT00005557).

Assessing the relationship between physical activity and the gut microbiome in a large, population-based sample of Wisconsin adults

The gut microbiome is an important factor in human health and disease. While preliminary studies have found some evidence that physical activity is associated with gut microbiome richness, diversity, and composition, this relationship is not fully understood and has not been previously characterized in a large, population-based cohort. In this study, we estimated the association between several measures of physical activity and the gut microbiota in a cohort of 720 Wisconsin residents. Our sample had a mean age of 55 years (range: 18, 94), was 42% male, and 83% of participants self-identified as White. Gut microbial composition was assessed using gene sequencing of the V3-V4 region of 16S rRNA extracted from stool. We found that an increase of one standard deviation in weekly minutes spent in active transportation was associated with an increase in alpha diversity, particularly in Chao1's richness (7.57, 95% CI: 2.55, 12.59) and Shannon's diversity (0.04, 95% CI: 0.0008, 0.09). We identified interactions in the association between Inverse Simpson's diversity and physical activity, wherein active transportation for individuals living in a rural environment was associated with additional increases in diversity (4.69, 95% CI: 1.64, 7.73). We also conducted several permutational ANOVAs (PERMANOVA) and negative binomial regression analyses to estimate the relationship between physical activity and microbiome composition. We found that being physically active and increased physical activity time were associated with increased abundance of bacteria in the family Erysipelotrichaceae. Active transportation was associated with increased abundance of bacteria in the genus Phascolarctobacterium, and decreased abundance of Clostridium. Minutes in active transportation was associated with a decreased abundance of the family Clostridiaceae.

Individual Nutrition Is Associated with Altered Gut Microbiome Composition for Adults with Food Insecurity

Diet is widely recognized as a key contributor to human gut microbiome composition and function. However, overall nutrition can be difficult to compare across a population with varying diets. Moreover, the role of food security in the relationship with overall nutrition and the gut microbiome is unclear. This study aims to investigate the association between personalized nutrition scores, variation in the adult gut microbiome, and modification by food insecurity. The data originate from the Survey of the Health of Wisconsin and the Wisconsin Microbiome Study. Individual nutrition scores were assessed using My Nutrition Index (MNI), calculated using data from food frequency questionnaires, and additional health history and demographic surveys. Food security and covariate data were measured through self-reported questionnaires. The gut microbiome was assessed using 16S amplicon sequencing of DNA extracted from stool samples. Associations, adjusted for confounding and interaction by food security, were estimated using Weighted Quantile Sum (WQS) regression models with Random Subset and Repeated Holdout extensions (WQSRSRH), with bacterial taxa used as components in the weighted index. Of 643 participants, the average MNI was 66.5 (SD = 31.9), and 22.8% of participants were food insecure. Increased MNI was significantly associated with altered gut microbial composition (β = 2.56, 95% CI = 0.52−4.61), with Ruminococcus, Oscillospira, and Blautia among the most heavily weighted of the 21 genera associated with the MNI score. In the stratified interaction WQSRSRH models, the bacterial taxa most heavily weighted in the association with MNI differed by food security, but the level of association between MNI and the gut microbiome was not significantly different. More bacterial genera are important in the association with higher nutrition scores for people with food insecurity versus food security, including Streptococcus, Parabacteroides Faecalibacterium, and Desulfovibrio. Individual nutrition scores are associated with differences in adult gut microbiome composition. The bacterial taxa most associated with nutrition vary by level of food security. While further investigation is needed, results showed a higher nutrition score was associated with a wider range of bacterial taxa for food insecure vs. secure, suggesting nutritional quality in food insecure individuals is important in maintaining health and reducing disparities.

Age estimation from sleep studies using deep learning predicts life expectancy

Sleep disturbances increase with age and are predictors of mortality. Here, we present deep neural networks that estimate age and mortality risk through polysomnograms (PSGs). Aging was modeled using 2500 PSGs and tested in 10,699 PSGs from men and women in seven different cohorts aged between 20 and 90. Ages were estimated with a mean absolute error of 5.8 ± 1.6 years, while basic sleep scoring measures had an error of 14.9 ± 6.29 years. After controlling for demographics, sleep, and health covariates, each 10-year increment in age estimate error (AEE) was associated with increased all-cause mortality rate of 29% (95% confidence interval: 20-39%). An increase from -10 to +10 years in AEE translates to an estimated decreased life expectancy of 8.7 years (95% confidence interval: 6.1-11.4 years). Greater AEE was mostly reflected in increased sleep fragmentation, suggesting this is an important biomarker of future health independent of sleep apnea.

The Survey of the Health of Wisconsin (SHOW) Program: An Infrastructure for Advancing Population Health

Introduction

The Survey of the Health of Wisconsin (SHOW) was established in 2008 by the University of Wisconsin (UW) School of Medicine and Public Health (SMPH) with the goals of (1) providing a timely and accurate picture of the health of the state residents; and (2) serving as an agile resource infrastructure for ancillary studies. Today, the SHOW program continues to serve as a unique and vital population health research infrastructure for advancing public health.

Methods

SHOW currently includes 5,846 adult and 980 minor participants recruited between 2008 and 2019 in four primary waves. WAVE I (2008–2013) includes annual statewide representative samples of 3,380 adults ages 21 to 74 years. WAVE II (2014–2016) is a triannual statewide sample of 1,957 adults (age ≥18 years) and 645 children (age 0–17). WAVE III (2017) consists of follow-up of 725 adults from the WAVE I and baseline surveys of 222 children in selected households. WAVEs II and III include stool samples collected as part of an ancillary study in a subset of 784 individuals. WAVE IV consists of 517 adults and 113 children recruited from traditionally under-represented populations in biomedical research including African Americans and Hispanics in Milwaukee, Wisconsin.

Findings to Date

The SHOW resource provides unique spatially granular and timely data to examine the intersectionality of multiple social determinants and population health. SHOW includes a large biorepository and extensive health data collected in a geographically diverse urban and rural population. Over 60 studies have been published covering a broad range of topics including, urban and rural disparities in cardio-metabolic disease and cancer, objective physical activity, sleep, green-space and mental health, transcriptomics, the gut microbiome, antibiotic resistance, air pollution, concentrated animal feeding operations and heavy metal exposures.

Discussion

The SHOW cohort and resource is available for continued follow-up and ancillary studies including longitudinal public health monitoring, translational biomedical research, environmental health, aging, microbiome and COVID-19 research.

Genetic risk for subjective reports of insomnia associates only weakly with polygraphic measures of insomnia in 2,770 adults

STUDY OBJECTIVES

Subjective insomnia complaints and objective sleep changes are mostly studied outside of clinical trial studies. In this study, we tested whether 240 genetic variants associated with subjectively reported insomnia were also associated with objective insomnia parameters extracted from polysomnographic recordings in three studies.

METHODS

The study sample (total n = 2,770) was composed of the Wisconsin Sleep Cohort (n = 1,091) and the Osteoporotic Fractures in Men (n = 1,026) study, two population-based studies, and the Stanford Sleep Cohort, a sleep center patient-based sample (n = 653). Seven objective polysomnographic features related to insomnia defined outcome variables, with each variant allele serving as predictor. Meta-regression was performed, accounting for common confounders as well as variance differences between studies. Additionally, a normalized genetic risk score was generated for each subject to serve as a predictor variable in separate linear mixed models assessing objective insomnia features.

RESULTS

After correction for multiple testing, single-nucleotide polymorphisms associated with subjective insomnia were not significantly associated with 6 of 7 objective sleep measures. Only periodic limb movement index was significantly associated with rs113851554 (MEIS1), as found in previous studies. The normalized genetic risk score was only weakly associated with arousal index and duration of wake after sleep onset.

CONCLUSIONS

Our findings suggest that subjective insomnia does not have a strong genetic signature mapping onto objective (polysomnographic) sleep variables.

CITATION

Foldager J, Peppard PE, Hagen EW, et al. Genetic risk for subjective reports of insomnia associates only weakly with polygraphic measures of insomnia in 2,770 adults. J Clin Sleep Med. 2022;18(1):21-29.

Assessing the impact of storage time on the stability of stool microbiota richness, diversity, and composition

Background

New technologies like next-generation sequencing have led to a proliferation of studies investigating the role of the gut microbiome in human health, particularly population-based studies that rely upon participant self-collection of samples. However, the impact of methodological differences in sample shipping, storage, and processing are not well-characterized for these types of studies, especially when transit times may exceed 24 h. The aim of this study was to experimentally assess microbiota stability in stool samples stored at 4 °C for durations of 6, 24, 48, 72, and 96 h with no additives to better understand effects of variable shipping times in population-based studies. These data were compared to a baseline sample that was immediately stored at − 80 °C after stool production.

Results

Compared to the baseline sample, we found that the alpha-diversity metrics Shannon’s and Inverse Simpson’s had excellent intra-class correlations (ICC) for all storage durations. Chao1 richness had good to excellent ICC. We found that the relative abundances of bacteria in the phyla Verrucomicrobia, Actinobacteria, and Proteobacteria had excellent ICC with baseline for all storage durations, while Firmicutes and Bacteroidetes ranged from moderate to good. We interpreted the ICCs as follows: poor: ICC < 0.50, moderate: 0.50 < ICC < 0.75, good: 0.75 < ICC < 0.90, and excellent: ICC > 0.90. Using the Bray–Curtis dissimilarity index, we found that the greatest change in community composition occurred between 0 and 24 h of storage, while community composition remained relatively stable for subsequent storage durations. Samples showed strong clustering by individual, indicating that inter-individual variability was greater than the variability associated with storage time.

Conclusions

The results of this analysis suggest that several measures of alpha diversity, relative abundance, and overall community composition are robust to storage at 4 °C for up to 96 h. We found that the overall community richness was influenced by storage duration in addition to the relative abundances of sequences within the Firmicutes and Bacteroidetes phyla. Finally, we demonstrate that inter-individual variability in microbiota composition was greater than the variability due to changing storage durations.

Habitual sleep, sleep duration differential, and weight change among adults: Findings from the Wisconsin Sleep Cohort Study

OBJECTIVES

Assess longitudinal associations between diary-measured sleep duration and clinically assessed body mass index (BMI).

DESIGN

Multilevel growth curve analyses examined how within-person changes and between-person differences in habitual sleep duration were associated with BMI trajectories.

SETTING

Sleep diaries across 2-6 consecutive weekday and weekend nights at each data collection point, repeatedly collected at approximate 4-year intervals, for an average of 9.2 (standard deviation [SD] = 3.6) years between 1989 and 2011.

PARTICIPANTS

About 784 participants (47% women) enrolled in the Wisconsin Sleep Cohort Study (mean [SD] age = 51.1 [8.0] years at baseline).

MEASUREMENTS

The outcome variable was BMI (kg/m²). Key predictors were habitual sleep duration (defined as average weekday nighttime sleep duration) and sleep duration differential (defined as the difference between average weekday and average weekend nighttime sleep duration) at each data collection wave.

RESULTS

Men with shorter habitual sleep duration on weekdays had higher BMI than men with longer habitual sleep duration on weekdays (β = -0.90 kg/m²/hour, se = 0.34, p = .008). Participants with larger differentials between weekday and weekend sleep duration experienced more rapid BMI gain over time for both men (β = 0.033 kg/m²/year per hour differential, se = 0.017, p = .044) and women (β = 0.057 kg/m²/year per hour differential, se = 0.027, p = .036).

CONCLUSION

This study suggests that habitual short sleep is associated with higher BMI levels in men and that a larger weekday-weekend sleep differential is associated with increasing BMI trajectories among both men and women in mid-to-late life.

Associations of school night sleep duration and circadian preference with middle school-aged student attendance, tardiness, and suspension

OBJECTIVES

Research has associated both school night sleep duration (SNSD) and circadian preference (CP) with middle school-aged students' attendance and tardiness, but the interaction between these characteristics remains unexplored within this context, along with the impact of SNSD and CP on school suspension likelihood. Thus, this study investigated associations between SNSD, CP, and their interaction with middle school-aged student attendance, tardiness, and suspension, while accounting for sociodemographic characteristics.

PARTICIPANTS

About 4175 students from 12 middle schools in the Madison, Wisconsin, Metropolitan School District.

METHODS

Students completed a computer-based, sleep-related survey during class. Students reporting SNSD between 4 and 12 hours were included in the final analytical sample (N = 3860; mean age ± standard deviation = 12.0 ± 0.86 years; range = 10-16 years). CP was characterized using the single-item self-morningness/eveningness question. Linear mixed-effects regression estimated associations of SNSD and CP with tardiness and attendance. Logistic mixed-effects regression assessed associations with school suspension. Fully adjusted multilevel models included sociodemographic covariates, nesting students within schools.

RESULTS

About 3860 student responses comprised the final sample, which had a SNSD of 8.15 ± 1.37 hours and general eveningness preference. Short-and-long SNSD associated with lower attendance and increased out-of-school suspension. Greater eveningness preference was negatively associated with attendance and tardiness. No SNSD and CP interactions emerged. Associations between sociodemographic characteristics and attendance, tardiness, and suspension were observed.

CONCLUSIONS

Results support need for efforts to improve middle school-aged student sleep health and account for eveningness preference. Research clarifying the interactive influence of sleep, circadian, and sociodemographic characteristics on attendance and achievement is warranted.

Association of Rapid Eye Movement Sleep With Mortality in Middle-aged and Older Adults

Importance

Rapid eye movement (REM) sleep has been linked with health outcomes, but little is known about the relationship between REM sleep and mortality.

Objective

To investigate whether REM sleep is associated with greater risk of mortality in 2 independent cohorts and to explore whether another sleep stage could be driving the findings.

Design, Setting, and Participants

This multicenter population-based cross-sectional study used data from the Outcomes of Sleep Disorders in Older Men (MrOS) Sleep Study and Wisconsin Sleep Cohort (WSC). MrOS participants were recruited from December 2003 to March 2005, and WSC began in 1988. MrOS and WSC participants who had REM sleep and mortality data were included. Analysis began May 2018 and ended December 2019.

Main Outcomes and Measures

All-cause and cause-specific mortality confirmed with death certificates.

Results

The MrOS cohort included 2675 individuals (2675 men [100%]; mean [SD] age, 76.3 [5.5] years) and was followed up for a median (interquartile range) of 12.1 (7.8-13.2) years. The WSC cohort included 1386 individuals (753 men [54.3%]; mean [SD] age, 51.5 [8.5] years) and was followed up for a median (interquartile range) of 20.8 (17.9-22.4) years. MrOS participants had a 13% higher mortality rate for every 5% reduction in REM sleep (percentage REM sleep SD = 6.6%) after adjusting for multiple demographic, sleep, and health covariates (age-adjusted hazard ratio, 1.12; fully adjusted hazard ratio, 1.13; 95% CI, 1.08-1.19). Results were similar for cardiovascular and other causes of death. Possible threshold effects were seen on the Kaplan-Meier curves, particularly for cancer; individuals with less than 15% REM sleep had a higher mortality rate compared with individuals with 15% or more for each mortality outcome with odds ratios ranging from 1.20 to 1.35. Findings were replicated in the WSC cohort despite younger age, inclusion of women, and longer follow-up (hazard ratio, 1.17; 95% CI, 1.03-1.34). A random forest model identified REM sleep as the most important sleep stage associated with survival.

Conclusions and Relevance

Decreased percentage REM sleep was associated with greater risk of all-cause, cardiovascular, and other noncancer-related mortality in 2 independent cohorts.

Physiological sleep measures predict time to 15-year mortality in community adults: Application of a novel machine learning framework

Clarifying whether physiological sleep measures predict mortality could inform risk screening; however, such investigations should account for complex and potentially non-linear relationships among health risk factors. We aimed to establish the predictive utility of polysomnography (PSG)-assessed sleep measures for mortality using a novel permutation random forest (PRF) machine learning framework. Data collected from the years 1995 to present are from the Sleep Heart Health Study (SHHS; n = 5,734) and the Wisconsin Sleep Cohort Study (WSCS; n = 1,015), and include initial assessments of sleep and health, and up to 15 years of follow-up for all-cause mortality. We applied PRF models to quantify the predictive abilities of 24 measures grouped into five domains: PSG-assessed sleep (four measures), self-reported sleep (three), health (eight), health behaviours (four), and sociodemographic factors (five). A 10-fold repeated internal validation (WSCS and SHHS combined) and external validation (training in SHHS; testing in WSCS) were used to compute unbiased variable importance metrics and associated p values. We observed that health, sociodemographic factors, and PSG-assessed sleep domains predicted mortality using both external validation and repeated internal validation. The PSG-assessed sleep efficiency and the percentage of sleep time with oxygen saturation <90% were among the most predictive individual measures. Multivariable Cox regression also revealed the PSG-assessed sleep domain to be predictive, with very low sleep efficiency and high hypoxaemia conferring the highest risk. These findings, coupled with the emergence of new low-burden technologies for objectively assessing sleep and overnight oxygen saturation, suggest that consideration of physiological sleep measures may improve risk screening.

A Comparison of Self- and Proxy-Reported Subjective Sleep Durations With Objective Actigraphy Measurements in a Survey of Wisconsin Children 6-17 Years of Age

Children's sleep quality and duration are important to overall development, health, and wellbeing. However, measuring children's sleep is challenging, especially in situations where objective assessment is impractical. This study aimed to assess age and proxy effects in comparing subjective sleep duration with objective measures, in a community-based sample of Wisconsin children (aged 6-17 years), recruited from 2014-2017. The sample participants had a mean age of 11.4 (standard deviation, 3.3) years and 52% of them were male. We used linear mixed effects models to test for age effects in proxy- and self-report groups separately, and a quasiexperimental regression discontinuity approach to compare subjective sleep duration with objective actigraphy estimates across proxy- and self-report groups. We found evidence of systematic overestimation of sleep duration when using subjective measurements but did not find evidence of age effects in either group. Based on these analyses, we found evidence of differential overestimation by proxy- or self-report condition. Proxy reporters overestimated sleep duration by 2.3 hours (95% confidence interval: 2.2, 2.4), compared with 1.0 hour (95% confidence interval: 0.7, 1.2) for self-reporters. These findings suggest that proxy- versus self-reporting conditions are an important consideration when designing a study, and that it might be beneficial to reduce the age at which children self-report.

The Survey of the Health of Wisconsin (SHOW) Program: An infrastructure for Advancing Population Health Sciences

PURPOSE

The Survey of the Health of Wisconsin (SHOW) was established in 2008 by the University of Wisconsin (UW) School of Medicine and Public Health (SMPH) with the goals of 1) providing a timely and accurate picture of the health of the state residents; and 2) serving as an agile resource infrastructure for ancillary studies. Today SHOW continues to serve as a vital population health research infrastructure.

PARTICIPANTS

SHOW currently includes 5,846 adult and 980 minor participants recruited between 2008-2019 in four primary waves. WAVE I (2008-2013) includes annual statewide representative samples of 3,380 adults ages 21 to 74 years. WAVE II (2014-2016) is a triannual statewide sample of 1957 adults (age ≥18 years) and 645 children. WAVE III (2017) consists of follow-up of 725 adults from the WAVE I and baseline surveys of 222 children in selected households. WAVEs II and III include stool samples collected as part of an ancillary study in a subset of 784 individuals. WAVE IV consist of 517 adults and 113 children recruited from traditionally under-represented populations in biomedical research including African Americans and Hispanics in Milwaukee county, WI.

FINDINGS TO DATE

The SHOW provides extensive data to examine the intersectionality of multiple social determinants and population health. SHOW includes a large biorepository and extensive health data collected in a geographically diverse urban and rural population. Over 60 studies have been published covering a broad range of topics including, urban and rural disparities in cardio-metabolic disease and cancer, objective physical activity, sleep, green-space and mental health, transcriptomics, the gut microbiome, antibiotic resistance, air pollution, concentrated animal feeding operations and heavy metal exposures.

FUTURE PLANS

The SHOW cohort is available for continued longitudinal follow-up and ancillary studies including genetic, multi-omic and translational environmental health, aging, microbiome and COVID-19 research.

ARTICLE SUMMARY

Strengths and limitations: The Survey of the Health of Wisconsin (SHOW) is an infrastructure to advance population health sciences including biological sample collection and broader data on individual and neighborhood social and environmental determinants of health.The extensive data from diverse urban and rural populations offers a unique study sample to compare how socio-economic gradients shape health outcomes in different contexts.The objective health data supports novel interdisciplinary research initiatives and is especially suited for research in causes and consequences of environmental exposures (physical, chemical, social) across the life course on cardiometabolic health, immunity, and aging related conditions.The extensive biorepository supports novel omics research into common biological mechanisms underlying numerous complex chronic conditions including inflammation, oxidative stress, metabolomics, and epigenetic modulation.Ancillary studies, such as the Wisconsin Microbiome Study, have expanded the utility of the study to examine human susceptibility to environmental exposures and opportunities for investigations of the role of microbiome in health and disease.Long-standing partnerships and recent participation among traditionally under-represented populations in biomedical research offer numerous opportunities to support community-driven health equity work.No biological samples were collected among children.The statewide sampling frame may limit generalizability to other regions in the United States.

Longitudinal sleep characteristics and hypertension status: results from the Wisconsin Sleep Cohort Study

AIMS

Sleep characteristics such as short sleep duration or sleep-disordered breathing are established predictors of hypertension. However, few studies have used in-lab polysomnography with a longitudinal design to measure how hypertension is associated with different sleep stages over time. The purpose of this study is to examine whether hypertension is associated with the longitudinal course of sleep quality over time.

METHODS

The current study evaluated data from the Wisconsin Sleep Cohort Study, which consists of 1525 adults in a community-based population of middle-aged to older adults followed for approximately 12-25 years. Sleep characteristics were objectively measured using polysomnography and subjectively assessed using a self-report questionnaire on insomnia complaints. We used linear mixed-effects regression models and cumulative logit models to assess whether the interaction of hypertension and time is associated with objective and subjective sleep.

RESULTS

We found people with hypertension exhibited a greater decline in total sleep time in rapid eye movement sleep (%) over time than those without hypertension (P < 0.05). Individuals with hypertension had less decline in % N3 sleep over time than those without hypertension (P < 0.05). Among the subjective insomnia complaints, our findings indicate hypertensive individuals have a higher probability of having higher levels of 'difficulties in falling asleep' compared with people without hypertension.

CONCLUSION

These findings suggest that hypertension is associated with modified longitudinal changes of objective and subjective sleep characteristics.

Gender Differences in the Relationship Between Financial Stress and Metabolic Abnormalities

BACKGROUND

Financial stress is associated with higher prevalence of metabolic abnormalities and cardiovascular disease, but the extent to which this association differs by type of metabolic abnormalities or gender is unclear.

OBJECTIVES

The study aims were (a) to examine the association between financial stress and the prevalence of common metabolic abnormalities and (b) to test the association for gender differences.

METHODS

A cross-sectional secondary analysis was conducted using data from the Retirement and Sleep Trajectories study, an ancillary study of the Wisconsin Sleep Cohort study. Composite indicator structural equation alpha modeling with a stacking approach was applied in the data analysis.

RESULTS

After controlling for covariates, financial stress was positively associated with the prevalence of abdominal obesity, metabolic syndrome, and dyslipidemia, with significant gender differences. Among men, financial stress was positively associated with the prevalence of hypertriglyceridemia. Among women, financial stress was positively associated with the prevalence of prediabetes, abdominal obesity, metabolic syndrome, and dyslipidemia.

CONCLUSION

Men living with financial stress are more likely to have hypertriglyceridemia, a specific metabolic abnormality and risk factor for acute cardiovascular events. However, financial stress in women is associated with a broader array of metabolic abnormalities (e.g., dyslipidemia, prediabetes, abdominal obesity, metabolic syndrome), highlighting a potential risk of multiple chronic conditions later in life.

Polysomnographic indicators of restorative sleep and body mass trajectories in the Wisconsin Sleep Cohort Study

STUDY OBJECTIVES

Previous research suggests that reductions in restorative, slow-wave (N3), and rapid eye movement (REM) sleep are associated with weight gain and obesity in mid-to-late life. We extend prior work by examining how within-person (WP) changes and between-person (BP) differences in restorative sleep over several years are associated with body mass trajectories among participants in the Wisconsin Sleep Cohort Study (WSCS).

METHODS

We used data from 4,862 polysomnographic (PSG) sleep studies and physical exams collected from 1,187 WSCS participants over an average duration of 14.9 years. Primary measures of interest included body mass index (BMI = kg/m2) and the percentages of time spent in N3 and REM sleep. We estimated a series of linear mixed regression models to examine how WP changes and BP differences in N3 and REM sleep affected BMI trajectories, controlling for other sleep measures, demographic characteristics, and health behaviors as potential confounders.

RESULTS

Women in the WSCS experienced more rapid BMI gain than men. With some variation by sex, we found that (1) below-average N3 and REM sleep is associated with above-average BMI, and (2) within-person decreases in N3 and REM sleep over time are associated with gains in BMI. These findings persisted after adjustment for sleep duration and other potential confounders.

CONCLUSIONS

Our findings highlight the importance of PSG indices of restorative sleep in mid-to-late life, suggesting that future clinical treatments and public health policies will benefit from heightened attention to sleep quality.

Automatic detection of cortical arousals in sleep and their contribution to daytime sleepiness

OBJECTIVE

Significant interscorer variability is found in manual scoring of arousals in polysomnographic recordings (PSGs). We propose a fully automatic method, the Multimodal Arousal Detector (MAD), for detecting arousals.

METHODS

A deep neural network was trained on 2,889 PSGs to detect cortical arousals and wakefulness in 1-second intervals. Furthermore, the relationship between MAD-predicted labels on PSGs and next day mean sleep latency (MSL) on a multiple sleep latency test (MSLT), a reflection of daytime sleepiness, was analyzed in 1447 MSLT instances in 873 subjects.

RESULTS

In a dataset of 1,026 PSGs, the MAD achieved an F1 score of 0.76 for arousal detection, while wakefulness was predicted with an accuracy of 0.95. In 60 PSGs scored by nine expert technicians, the MAD performed comparable to four and significantly outperformed five expert technicians for arousal detection. After controlling for known covariates, a doubling of the arousal index was associated with an average decrease in MSL of 40 seconds (p = 0.0075).

CONCLUSIONS

The MAD performed better or comparable to human expert scorers. The MAD-predicted arousals were shown to be significant predictors of MSL.

SIGNIFICANCE

This study validates a fully automatic method for scoring arousals in PSGs.

0168 Effects of School Night Sleep Duration and Circadian Preference on Student Tardiness: An Investigation in a Middle-School Aged Sample

Introduction

Sleep and circadian factors play an important role in school attendance, academic performance, and daytime behaviors among adolescents. This investigation assessed school night sleep duration (SNSD) and circadian preference (CP) association with first period tardies (FPT) using a middle-aged sample from the Madison (Wisconsin) Metropolitan School District (MMSD), prior to implementation of a planned district-wide delay in middle school start times.

Methods

4,175 middle-school aged students from 12 MMSD schools completed a sleep survey, which included SNSD and a validated 4-level measure of CP. Self-reported SNSD between 4-and-12 hours served as final sample inclusion criterion. Mixed effects modeling was employed with students nested within school. Linear regression determined SNSD and CP effect on student tardiness. Individual, year-long FPT served as outcome variable. Inclusion of SNSD quadratic term was not statistically indicated. Full model covariates included age, sex, race, parent educational level, homelessness, free and reduced lunch, and special education status.

Results

Final sample included 3,860 students. Univariate regression determined a significant CP association with FPT [β=1.20, 95% CI (0.54, 1.86), F(1,10.41)=13.7, p=0.004), but not SNSD [β=-0.31, 95% CI (-0.70, -0.09), F(1,10.21)=2.5, p=0.14]. SNSD and CP interaction was not significant. CP significance was maintained in the full model [β=1.24, 95% CI (-0.70, -0.09), F(1,11.21)=13.7, p=0.004]. Evening preference associated with 3.72 more FPT, relative to morning preference.

Conclusion

Results suggest evening preference is associated with increased risk of tardiness among middle school students. Future research that examines the relationships between delayed school start times, circadian preference, and impact on school tardiness is indicated.

Support

This research was generously supported by a grant from the Madison Education Partnership (MEP).

0833 Midlife Sleep Health is Associated With Later-Life Depression and Anxiety

Introduction

Several aspects of sleep - collectively conceptualized as ‘sleep health’ - are associated with anxiety and depression. This study investigated whether specific components of sleep health experienced during midlife are associated with depression and anxiety symptoms in later life.

Methods

A subset of Wisconsin Sleep Cohort participants (n=616; 45% female; mean [SD] baseline age=55 [8] years) completed 4 study visits at 4-year intervals. Visits included polysomnography and questionnaires about sleep, mood, and health. Outcomes (Zung depression score, State and Trait Anxiety) were regressed on sleep health characteristics (AHI, %N3 sleep, %REM sleep, sleep efficiency, sleep latency, sleep duration, sleep debt, nap duration, insomnia symptoms, circadian preference, excessive daytime sleepiness [EDS], Epworth Sleepiness Scale [ESS]) using 2 types of linear models adjusting for age, sex, BMI, education, exercise, smoking, and caffeine consumption: 1) longitudinal models in which baseline sleep health predicted mood outcomes 12 years later (adjusting for baseline levels of the outcome variable), and 2) models in which 12-year change in sleep health predicted 12-year change in outcomes.

Results

Longer nap duration, evening circadian preference, and EDS during midlife were associated with worse depression scores in later life. 12-year increases in nap duration, EDS, and ESS were associated with 12-year worsening of depression. Longer sleep duration and greater EDS during midlife were associated with worse trait anxiety in later life. 12-year increases in sleep duration, nap duration, insomnia symptoms, EDS and ESS were associated with 12-year worsening of trait anxiety. Greater AHI and EDS during midlife were associated with worse state anxiety in later life. 12-year increases in ESS were associated with worsening state anxiety. (P&lt;0.05 for all reported results.)

Conclusion

Multiple aspects of sleep health experienced during midlife are associated with greater depression and anxiety in later life.

Support

NIH grants: National Institutes of Aging (R01AG058680; R01AG036838); National Heart, Lung, and Blood Institute (R01HL62252); National Center for Research Resources (1UL1RR025011)

0347 Aging and Retirement are Independently Associated with Reduced Social Jetlag

Introduction

Social jetlag (SJL; difference in sleep timing on freedays versus workdays) is a measure of chronic circadian misalignment due to a mismatch between preferred biological sleep timing and societal scheduling demands. Cross-sectionally, greater SJL is associated with poorer health and younger age. We assessed longitudinal changes in SJL across aging and retirement.

Methods

In 1137 participants of the Wisconsin Sleep Cohort (WSC), sleep timing was collected via sleep diaries every 4 years (2802 data points, 47% female, mean age 51 years at baseline (+/-8 SD, range 31 - 74)). In 829 participants of the Retirement and Sleep Trajectories study (REST, an ancillary study of the WSC), sleep timing and retirement status were collected in 4 annual mailed surveys (1700 data points, 55% female, mean age 59 years at baseline (range 46-81)). Midsleep was defined as the time midway between bedtime and waketime. SJL was defined as the absolute difference between midsleep on workdays/weekdays and freedays/weekends. Mixed models were used to test associations of change in sleep timing with change in age, retirement status and self-reported health.

Results

In the WSC, aging 10 years was associated with 16 minutes reduction in SJL (p&lt;.001), driven by a shift of midsleep to 7 minutes later on weekdays and 10 minutes earlier on weekends. The effect of age on SJL remained significant when tested only in employed people. In the REST study, the transition from full time employment to full time retirement was associated with ~ 1 hour shorter SJL, maintained 1, 2 and 3 years post-transition (p&lt;.001, controlling for age). Greater SJL was associated with worse self-rated health (p=.02).

Conclusion

Aging and the transition from employment to retirement are independently associated with reduced social jetlag. Greater social jetlag is associated with poorer self-reported health.

Support

This study was supported by grants from the National Institutes of Health (NIH): R01HL62252, R01AG036838, R01AG058680, and 1UL1RR02501.

0048 The Association Between REM Sleep and Risk of Mortality in Three Independent Cohorts

Introduction

Sleep disorders and sleep characteristics have been linked to higher risk of mortality. Despite the emerging evidence of a sleep-mortality association, the relationship between sleep architecture and mortality aren’t well understood. We hypothesize that reduced REM is associated with increased mortality risk.

Methods

The Osteoporotic Fractures in Men (MrOS) study is a population-based study of 2,675 older men. Cox regression was used to evaluate the association between %REM and mortality rate. Potential covariates were evaluated using 6-fold cross validation. Sensitivity analyses were performed to rule out alternative explanations. Wisconsin Sleep Cohort (WSC) and Sleep Heart Health Study (SHHS) data were used to replicate the findings.

Results

The MrOS sample mean age was 76.3 years (SD=5.51) and the median follow-up time was 12.1 years. There was a 13% higher rate of mortality for every absolute 5% reduction in REM sleep (HR=1.13, 95%CI, 1.08–1.19) after adjusting for multiple demographic, sleep, and health covariates. The association persisted for cardiovascular disease-related mortality (CVD) (HR=1.18, 95%CI, 1.09–1.28), cancer-related mortality (HR=1.14, 95%CI, 1.03–1.26), and other mortality (HR=1.19, 95%CI, 1.10–1.28). The WSC included 45.7% women. The mean age of the 1,388 individuals analyzed was 51.5 (SD=8.5); the median follow-up time was 20.8 years. The effect size for 5% reduction in REM on rate of all-cause mortality was similar in this cohort despite the younger age, inclusion of women, and longer follow-up period (HR=1.17, 95%CI, 1.03–1.34). SHHS data is still being analyzed; however the unadjusted model is consistent with the other cohorts.

Conclusion

We found an association between reduced REM and mortality in two, possibly three independent cohorts, which persisted across different causes of death and multiple sensitivity analyses. Mechanistic studies are needed and strategies to preserve REM may influence clinical therapies and reduce mortality risk.

Support

NHLBI provides funding for the MrOS Sleep ancillary study “Outcomes of Sleep Disorders in Older Men” under grant numbers: R01 HL071194, R01 HL070848, R01 HL070847, R01 HL070842, R01 HL070841, R01 HL070837, R01 HL070838, and R01 HL070839. Wisconsin Sleep Cohort was supported by R01HL62252, RR03186, and R01AG14124 from the NIH. Dr. Redline was partially supported by NHLBI R35 HL135818.

0267 School Night Sleep Duration Effect on Risk for In-and-Out of School Suspensions: An Investigation in a Middle-School Aged Sample

Introduction

Sleep plays an important role in adolescent education and development. Sleep impacts student school attendance, academic performance, and daytime behaviors. There has been limited investigation into the impact on sleep duration (SD) on school suspension risk. Given the growing public health and policy focus on altering school start times to increase SD, this study assessed SD association with school suspension risk using a middle-school aged sample from the Madison (Wisconsin) Metropolitan School District (MMSD), prior to implementation of a planned district-wide delay in middle school start times.

Methods

4,175 middle-school aged students from 12 MMSD schools completed a sleep survey, which included school-night SD (SNSD). Self-reported SNSD between 4-and-12 hours served as criterion for inclusion in final sample. Mixed effects modeling was employed with students nested within school. Logistic regression determined SNSD association with in-school (ISS) and out-of-school (OSS) suspensions. ISS and OSS were dichotomized (No ISS/OSS = 0; nonzero ISS/OSS = 1) to serve as outcome variables. Full model covariates included age, sex, race, circadian preference, parent educational level, homelessness, free and reduced lunch, and special education status.

Results

Final sample included 3,860 students. Shorter SNSD associated with greater likelihood of OSS [OR = 0.83, 95% CI (-0.28, -0.09), X2 = 16.1, p &lt; 0.0001], but not ISS [OR = 0.97, 95% CI (-0.14, -0.070), X2 = 0.44, p = 0.51]. Significance between SNSD and OSS was maintained in the full model [OR = 0.84, 95% CI (-0.27, -0.08), X2 = 13.2, p = 0.0003]. Each additional hour of sleep associated with 16% lower risk of OSS.

Conclusion

These results suggest that students with shorter SD are at increased risk for OSS, which further highlights the potential deleterious impact of short SD on adolescent educational experience.

Support

This research was generously supported by a grant from the Madison Education Partnership (MEP).

Impaired neurobehavioral alertness quantified by the psychomotor vigilance task is associated with depression in the Wisconsin Sleep Cohort study

BACKGROUND

Excessive daytime sleepiness plays an important role in the presentation and course of mood disorders. Standard objective measures of daytime sleep propensity are of little to no value in depressive illness. This study examined the psychomotor vigilance task (PVT), an objective measure of neurobehavioral alertness, and its cross-sectional and longitudinal associations with depressive symptomatology in the Wisconsin Sleep Cohort Study.

METHODS

The sample consisted of 1569 separate 10-min PVT assessments conducted in 942 unique individuals. Cross-sectional and longitudinal conditional logistic regression models were used to estimate associations between the primary outcome of depression symptomatology (adjusted Zung scale≥50) and six separate PVT variables: mean reciprocal reaction time (1/RT); total lapses (RTs≥500 msec; LAPSE); total false responses (FALSE); reciprocal of the mean of the 10% fastest (FAST) and 10% slowest (SLOW) RTs; and slope of the linear regression line for all transformed 1/RTs (SLOPE).

RESULTS

In fully-adjusted cross-sectional models, 1/RT, LAPSE, FAST, and SLOW were each significantly associated with depression, such that worse neurobehavioral alertness was associated with higher odds of depressive symptomatology. Similar, though attenuated, findings were observed in fully-adjusted conditional longitudinal models that examined within-subject changes in depression status in the subset of participants with repeated PVT assessments. FALSE and SLOPE were not associated with depression in either cross-sectional or conditional longitudinal models.

CONCLUSIONS

These findings suggest components of the PVT are associated with depressive symptomatology. Further research is indicated to clarify the role of the PVT in the assessment of hypersomnolence in mood disorders.

Urinary lead concentration and composition of the adult gut microbiota in a cross-sectional population-based sample

BACKGROUND

Lead (Pb) is a ubiquitous environmental contaminant with an array of detrimental health effects in children and adults, including neurological and immune dysfunction. Emerging evidence suggests that Pb exposure may alter the composition of the gut microbiota, however few studies have examined this association in human populations. The purpose of this study was to examine the association between urinary Pb concentration and the composition of the adult gut microbiota in a population-based sample of adults.

METHODS

Data used in this study were collected as part of the Survey of the Health of Wisconsin (SHOW) and its ancillary microbiome study. The SHOW is a household-based health examination survey of Wisconsin residents, collecting a variety of survey data on health determinants and outcomes, as well as objective measurements of body habitus, and biological specimens including urine. The ancillary microbiome study added additional questions and biological specimen collection, including stool, from participants age 18+. Pb concentration was analyzed in urine samples, and gut microbiota composition was assessed using DNA sequencing of the 16S rRNA V4 region, extracted from stool samples. Data processing and statistical analyses were performed in mothur, Python, R, and SAS.

RESULTS

Of 696 participants, urinary Pb concentration was highest in those age 70+, females, those with a high school diploma or lower, current and former smokers, and those without indoor pets. In adjusted models, increasing urinary Pb levels were associated with increases in microbial α-diversity (p = 0.071) and richness (p = 0.005). Differences in microbial β-diversity were significantly associated (p = 0.003) with differences in urinary Pb level. Presence of Proteobacteria, including members of the Burkholderiales, was significantly associated with increased urinary Pb.

CONCLUSION

These results suggest that Pb exposure is associated with differences in the composition of the adult gut microbiota in a population-based human sample. Further investigation of this association is warranted.

One-year changes in self-reported napping behaviors across the retirement transition

OBJECTIVE

To estimate associations of retirement with self-reported frequency and duration of naps.

DESIGN

Prospective cohort study.

SETTING

Population-based.

PARTICIPANTS

1359 current and former Wisconsin state employees, aged 54-69.

MEASUREMENTS

Four annual surveys mailed between 2010 and 2014 elicited employment status and nap characteristics. Changes in employment status and nap characteristics were identified from survey pairs measured 1 year apart (up to 3 survey pairs per subject). General linear mixed models with repeated measures were used to estimate changes in minutes napped per week (MNPW), weekly nap frequency, and individual nap duration as predicted by retirement transitions vs stable employment status. All models were adjusted for demographic characteristics, self-rated health, medical diagnoses, sleep problems, circadian preference, and change in nocturnal sleep duration.

RESULTS

There were 3101 survey pairs in the analytic sample. Full retirement (transition from working ≥35 h/wk to not working for pay) over a 1-year period predicted a statistically significantly larger mean change in MNPW than stable employment status: mean (95% confidence interval) = +48 (+16, +80) MNPW. Associations between staged retirement transitions (from full-time to part-time work, or from part-time work to full retirement) and 1-year changes in MNPW were not statistically significant. The MNPW changes associated with full retirement were attributable to nap frequency increase of +0.4 (+0.1, +0.8) d/wk; nap duration did not change significantly.

CONCLUSIONS

Compared with stable employment status, full retirement is associated with an average 1-year increase of +48 MNPW. This change is attributable to a frequency gain of 0.4 d/wk napped. Changes in nap duration were negligible.

The bidirectional association between physical activity and sleep in middle-aged and older adults: a prospective study based on polysomnography

Study Objectives

To examine the bidirectional association between physical activity (PA) and polysomnographically (PSG)-assessed sleep parameters characterized by total sleep time (TST), sleep onset latency (SOL), wake time after sleep onset (WASO), sleep efficiency and percentage of TST in N1, N2, and N3 stages and rapid eye movement (REM) sleep in middle-aged and older adults.

Methods

Longitudinal study based on a subsample of the Wisconsin Sleep Cohort. Self-reported PA information was used to estimate the metabolic equivalents of task (MET-minutes/week) activity and in-laboratory PSG exams provided information on sleep parameters at baseline and after 3-11 years of follow-up between 2004 and 2015. Poisson and linear regression models controlling for confounders estimated associations of sleep outcomes with changes in PA.

Results

A total of 424 participants (45.8% female; mean ± SD age 60.1 ± 7.5 years) were followed over an average of 5.0 ± 1.6 years. Compared to baseline PA of <500 MET-minutes/week (reference category), 500 to 1500 MET-minutes/week of PA was associated with lower incidences of TST <6 hours (relative risk, RR: 0.49; 95% confidence interval, CI: 0.27; 0.88), WASO >60 minutes (RR: 0.58; 95% CI: 0.41; 0.82) and sleep efficiency <80% (RR: 0.61; 95% CI: 0.39; 0.94), adjusting for sociodemographic, health behaviors and medical conditions. No significant associations were observed between baseline sleep characteristics and changes in PA through the follow-up.

Conclusion

In this prospective study, an intermediate level of PA at baseline predicted lower risk of incident short sleep time, higher WASO and lower sleep efficiency measured with PSG.

Associations Between the Apnea-Hypopnea Index During REM and NREM Sleep and Cognitive Functioning in a Cohort of Middle-Aged Adults

STUDY OBJECTIVES

Prior research has linked obstructive sleep apnea (OSA) to varied cognitive deficits. Additionally, OSA in rapid eye movement (REM) versus non-rapid eye movement (NREM) sleep has been shown to be a stronger predictor of outcomes such as hypertension. The present study aimed to investigate whether OSA-as characterized by the apnea-hypopnea index (AHI)-during REM and NREM sleep is associated with performance on a range of cognitive tasks. We also investigated whether the presence/absence of the apolipoprotein E4 allele (APOE4) modifies the associations between AHI during REM and NREM sleep and cognitive performance.

METHODS

A cross-sectional sample of 1,250 observations from 755 community-dwelling adults (mean [standard deviation] age, 62.3 [8.2] years) participating in the Wisconsin Sleep Cohort study was carried out by means of overnight polysomnography, paper-and-pencil cognitive tasks, and genetic data. Linear mixed effects models with repeated measures estimated associations of AHI during REM and NREM sleep with cognitive outcomes, stratified by APOE4 status (carrier versus noncarrier).

RESULTS

No significant associations were found between REM AHI and cognitive outcomes for either APOE4 carriers and non-carriers. Higher NREM AHI was associated with worse memory retention among APOE4 carriers; among noncarriers of APOE4, higher NREM AHI was associated with worse performance on a test of psychomotor speed, but better performance on two tests of executive function.

CONCLUSIONS

Sleep state-specific (REM, NREM) OSA may be differentially associated with varying dimensions of cognitive deficits in middle-aged to older adults, and such associations are likely to be modified by genetic factors, include APOE polymorphisms.

Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis

BACKGROUND

There is a scarcity of published data on the global prevalence of obstructive sleep apnoea, a disorder associated with major neurocognitive and cardiovascular sequelae. We used publicly available data and contacted key opinion leaders to estimate the global prevalence of obstructive sleep apnoea.

METHODS

We searched PubMed and Embase to identify published studies reporting the prevalence of obstructive sleep apnoea based on objective testing methods. A conversion algorithm was created for studies that did not use the American Academy of Sleep Medicine (AASM) 2012 scoring criteria to identify obstructive sleep apnoea, allowing determination of an equivalent apnoea-hypopnoea index (AHI) for publications that used different criteria. The presence of symptoms was not specifically analysed because of scarce information about symptoms in the reference studies and population data. Prevalence estimates for obstructive sleep apnoea across studies using different diagnostic criteria were standardised with a newly developed algorithm. Countries without obstructive sleep apnoea prevalence data were matched to a similar country with available prevalence data; population similarity was based on the population body-mass index, race, and geographical proximity. The primary outcome was prevalence of obstructive sleep apnoea based on AASM 2012 diagnostic criteria in individuals aged 30-69 years (as this age group generally had available data in the published studies and related to information from the UN for all countries).

FINDINGS

Reliable prevalence data for obstructive sleep apnoea were available for 16 countries, from 17 studies. Using AASM 2012 diagnostic criteria and AHI threshold values of five or more events per h and 15 or more events per h, we estimated that 936 million (95% CI 903-970) adults aged 30-69 years (men and women) have mild to severe obstructive sleep apnoea and 425 million (399-450) adults aged 30-69 years have moderate to severe obstructive sleep apnoea globally. The number of affected individuals was highest in China, followed by the USA, Brazil, and India.

INTERPRETATION

To our knowledge, this is the first study to report global prevalence of obstructive sleep apnoea; with almost 1 billion people affected, and with prevalence exceeding 50% in some countries, effective diagnostic and treatment strategies are needed to minimise the negative health impacts and to maximise cost-effectiveness.

FUNDING

ResMed.

Sleep Apnea and Kidney Function Trajectory: Results From a 20-Year Longitudinal Study of Healthy Middle-Aged Adults

Study Objectives

To determine whether sleep apnea, defined by polysomnography, accelerates kidney function decline in generally healthy adults not selected for sleep apnea or kidney disease.

Methods

We performed a retrospective cohort study in 855 participants from the Wisconsin Sleep Cohort Study, a large 20-year population-based study of sleep apnea, who had at least one polysomnogram and serial measurements of serum creatinine over time. Sleep apnea was defined as an apnea-hypopnea index ≥ 15 or positive airway pressure (PAP) use at baseline. We compared the slope of estimated glomerular filtration rate (eGFR) change and odds of rapid eGFR decline (>2.2 mL/minute/1.73 m2/year) for those with and without sleep apnea.

Results

The mean follow-up was 13.9 ± 3.4 years. The cohort was 50.4 ± 7.6 years, 55% male, and 97% white. The mean eGFR was 89.3 ± 13.8 mL/minute/1.73 m2 and 11% had sleep apnea. Overall, the mean eGFR change was -0.88 ± 1.12 mL/minute/1.73 m2/year. Compared with those without sleep apnea, participants with sleep apnea had a 0.2 mL/minute/1.73 m2/year slower eGFR decline though this was not statistically significant (95% CI [-0.06-0.45], p = .134). When we excluded those on PAP therapy (n = 17), eGFR decline was even slower among those with sleep apnea (0.36 mL/minute/1.73 m2/year slower, 95% CI [0.08-063], p = .012). Those with sleep apnea had lower odds of rapid eGFR decline but this was not statistically significant, even after excluding PAP users.

Conclusion

Among healthy middle-aged adults, the presence of sleep apnea at baseline did not accelerate kidney function decline compared with those without sleep apnea over time.