Preliminary investigation of the interactive role of physiological arousal and insomnia complaints in gray matter volume alterations in chronic widespread pain

STUDY OBJECTIVES

Brain regions involved in insomnia and chronic pain are overlapping and diffuse. The interactive role of physiological arousal in associations between insomnia symptoms and neural regions is unknown. This preliminary study examined whether arousal interacted with sleep in associations with gray matter volume of frontal (dorsolateral prefrontal cortex, anterior cingulate cortex) and temporal (right/left hippocampus) regions in adults with chronic widespread pain and insomnia complaints.

METHODS

Forty-seven adults with chronic widespread pain and insomnia (mean age = 46.00, standard deviation = 13.88, 89% women) completed 14 daily diaries measuring sleep onset latency (SOL), wake time after sleep onset, and total sleep time (TST), as well as Holter monitor assessments of heart rate variability (measuring physiological arousal), and magnetic resonance imaging. Multiple regressions examined whether average SOL, wake time after sleep onset, or TST were independently or interactively (with arousal/heart rate variability) associated with dorsolateral prefrontal cortex, anterior cingulate cortex, and left/right hippocampus gray matter volumes.

RESULTS

Shorter TST was associated with lower right hippocampus volume. TST also interacted with arousal in its association with right hippocampal volume, Specifically, shorter TST was associated with lower volume at highest and average arousal levels. SOL interacted with arousal in its association with anterior cingulate cortex volume, such that, among individuals with lowest arousal, longer SOL was associated with lower volume.

CONCLUSIONS

Preliminary findings highlight the interactive roles of physiological arousal and insomnia symptoms in associations with neural structure in chronic widespread pain and insomnia. Individuals with the highest physiological arousal may be particularly vulnerable to the impact of shorter TST on hippocampal volume loss. Reducing SOL may only impact anterior cingulate cortex volume in those with lower physiological arousal.

CITATION

Curtis AF, Nair N, Hayse B, et al. Preliminary investigation of the interactive role of physiological arousal and insomnia complaints in gray matter volume alterations in chronic widespread pain. J Clin Sleep Med. 2024;20(2):293-302.

Adolescent sleep mediates maternal depressive problems and parenting behaviors: daughter and son differences in a majority Black and Hispanic sample

STUDY OBJECTIVES

Parents who experience depressive symptoms are less likely to use positive parenting behaviors, in part because of sad affect and inconsistency, which can lead to disengaged parenting. Their children also are more likely to get too little sleep, get too much sleep, or have trouble sleeping, leading to increased child irritability and defiance, which may make it more difficult for a parent to use clear rules and result in more harsh parenting behaviors. The current study examined whether adolescent sleep (too little, too much, trouble sleeping) mediated the relation between maternal depression and parenting behaviors (harsh parenting, positive parenting, clear rules). Further, child gender was examined as a moderator (i.e., moderated mediation).

METHODS

The sample (N=318) consisted of mothers reporting on adolescents aged 16-18 (M=16.89, SD=.429; 53.4% female) from the 10th wave of the Schools and Families Educating Children Study (SAFE). Measures included the Child Behavior Checklist (CBCL), Center for Epidemiologic Studies Depression Scale (CESD), and the Parenting Practices Questionnaire (PPQ).

RESULTS

Too little sleep mediated the relation between maternal depressive problems and clear rules in the overall sample (β = .05), and between maternal depressive problems and positive parenting (β = .11), clear rules (β = .13), and harsh parenting (β = .14) for only sons. Too much sleep mediated the relation between maternal depressive problems and harsh parenting in the overall sample (β = .03), but no mediation occurred for sons and daughters separately. Trouble sleeping did not serve as a mediator in the overall sample but mediated the relation between maternal depressive problems and clear rules for daughters (β = .03) and between maternal depressive problems and harsh parenting for sons (β = .09).

CONCLUSIONS

These results suggest that adolescent sleep difficulties may be one contributing factor to why mothers who are dealing with depressive symptoms have difficulty using clear rules/positive parenting and use more harsh parenting behaviors. In addition, several of these mediations differed for sons and daughters, indicating important gender differences which may help to better inform and design intervention programs for mothers experiencing depression.

0611 Intraindividual Variability in Subjective Sleep and Average Fatigue in Parents of Children on the Autism Spectrum

Introduction

Fatigue is related to various adverse health outcomes. Mean levels of some common sleep variables, such as total sleep time (TST), sleep onset latency (SOL), and wake after sleep onset (WASO), have been associated with fatigue. However, intraindividual variability (IIV) of sleep parameters might play an independent role in sleep’s relationship with fatigue. Understanding fatigue is particularly important for parents of children with autism spectrum disorder (ASD) given fatigue's negative associations with positive parenting and implementation of child interventions. This preliminary study examined linear associations between subjective sleep IIV and mean fatigue levels in parents of children on the autism spectrum.

Methods

The sample included 66 parents who expressed interest in a behavioral treatment sleep study for their school-aged children diagnosed with ASD (6-12 years old; NCT04545606). All parents (Mage=37.03, SD=6.53; 91% female) completed daily electronic diaries over a two-week baseline period. Daily fatigue rating was collected using a visual analog scale (0-100) and averaged within individuals. Within-individual standard deviations of subjective TST, SOL, and WASO were calculated to estimate IIV. Data were analyzed in R (v4.1.2) using multiple linear regression models controlling for participant age, gender, and individual sleep parameter means.

Results

Bivariate correlations between sleep variable IIV and average fatigue indicated a positive association between TST variability and average fatigue, r(64)=0.33, p<0.01. Multiple regression analyses showed that greater IIV of TST was associated with higher average fatigue (β=0.14, 95%CI [0.01, 0.27], sr2=0.06, p=0.041). No significant associations were found between average fatigue level and IIV of WASO or SOL.

Conclusion

Results suggest that greater TST variability may be one factor independently contributing to higher fatigue levels in parents of children on the autism spectrum, which warrants further examination of sleep variability in this population. Future research could explore IIV of additional sleep parameters, fatigue IIV as an outcome, alternative methods of sleep measurement, and study designs that address causation. Increased insight into these connections might inform the importance of considering sleep interventions for both children and parents, and potential subsequent treatment benefits.

Support (If Any)

MU Research Board Grant (McCrae, PI); Department of Defense Autism Research Program (McCrae, PI; W81XWH2010399).

Thousands of induced germline mutations affecting immune cells identified by automated meiotic mapping coupled with machine learning

Forward genetic studies use meiotic mapping to adduce evidence that a particular mutation, normally induced by a germline mutagen, is causative of a particular phenotype. Particularly in small pedigrees, cosegregation of multiple mutations, occasional unawareness of mutations, and paucity of homozygotes may lead to erroneous declarations of cause and effect. We sought to improve the identification of mutations causing immune phenotypes in mice by creating Candidate Explorer (CE), a machine-learning software program that integrates 67 features of genetic mapping data into a single numeric score, mathematically convertible to the probability of verification of any putative mutation-phenotype association. At this time, CE has evaluated putative mutation-phenotype associations arising from screening damaging mutations in ∼55% of mouse genes for effects on flow cytometry measurements of immune cells in the blood. CE has therefore identified more than half of genes within which mutations can be causative of flow cytometric phenovariation in Mus musculus The majority of these genes were not previously known to support immune function or homeostasis. Mouse geneticists will find CE data informative in identifying causative mutations within quantitative trait loci, while clinical geneticists may use CE to help connect causative variants with rare heritable diseases of immunity, even in the absence of linkage information. CE displays integrated mutation, phenotype, and linkage data, and is freely available for query online.

580 Psychosocial Functioning Mediates Parental Depression and Sleep Behaviors in Children with Autism Spectrum Disorder

Introduction

Parents who have been diagnosed with depression often report that their children have poor sleep behaviors. This relationship may occur because the children of parents with depression are more likely experience poor psychosocial functioning, which can negatively impact their sleep. Children with Autism Spectrum Disorder (ASD) are particularly at risk for sleep difficulties, and it is important to better understand these relationships as scant to no research has been done which investigates parental depression, child psychosocial functioning, and child sleep among children with ASD. The current study examined whether parental perception of their child’s psychosocial functioning mediated the relationship between parental depression and their child’s sleep behaviors.

Methods

The sample (N=36) consisted of parents (81% female) reporting on their children aged 6–12 (M=8.56, SD = 1.86; 75% male). All children were diagnosed with ASD and had sleep complaints as reported by their parents. Children and their parents were recruited because they expressed interest in a behavioral treatment sleep study and these data come from the baseline data collection associated with that study. Measures included Sleep Behaviors factor from the Child Sleep Health Questionnaire (CSHQ), the Pediatric Symptom Checklist (PSC), and a question asking if the parent had been diagnosed with depression.

Results

Analyses were conducting using AMOS 27.0. Child psychosocial functioning significantly mediated (β = .12) the relation between parental depression and child sleep behavior. Parents who had been diagnosed with depression were more likely to report greater child psychosocial difficulties (β =.39, p = .01) and child psychosocial difficulties were associated with a greater likelihood of the child having worse sleep behavior (β =.32, p = .04). The direct effect between parental depression and child sleep behavior was not significant.

Conclusion

These results indicate that child psychosocial functioning may help to explain the connection between diagnosed parental depression and poor child sleep behavior among children with ASD. This suggests that psychosocial functioning may be an important aspect to target in sleep interventions, particularly for children with ASD.

Support (if any)

University of Missouri Research Board Grant (McCrae, PI); United States Department of Defense USAMRAA Autism Research Program (McCrae, PI; CTA AR190047).

579 Child Sleep Onset Latency Mediates Parental Depression and Non-Compliance in Children with Autism Spectrum Disorder

Introduction

Parents who have been diagnosed with depression often report that their children are not compliant and have difficulty falling asleep. Parents with depression are less likely to be consistent or enforce bedtimes resulting in the child having less bedtime rules and getting less sleep. Overtime this may mean the child develops poor sleep habits and difficulty falling asleep. Although these relationships have yet to be studied in children with Autism Spectrum Disorder (ASD), it is an important area given the high prevalence of children with ASD who have sleep difficulties. The current study examined whether parent-reported child sleep onset latency mediated the relationship between parental depression and child non-compliance.

Methods

The sample (N=50) consisted of parents (81% female) reporting on their children aged 6–12 (M=8.63, SD = 2.00; 76% male). All children were diagnosed with ASD and had parent reported sleep complaints. Children and their parents were recruited because they expressed interest in a behavioral treatment sleep study and these data come from the baseline data collection associated with that study. Measures included sleep onset latency on the Child Sleep Health Questionnaire (CSHQ), an item on the Pediatric Symptom Checklist (PSC) which asked if a child follows rules, and a question asking if the parent had been diagnosed with depression.

Results

Analyses were conducting using AMOS 27.0. Slightly less than half (45%) of parents reported having been diagnosed with depression. Parent-reported child sleep onset latency significantly mediated (β =.13) the relation between parental depression and non-compliance. Parents who had been diagnosed with depression were associated with greater child sleep onset latency (β =.32, p = .04) and greater child sleep onset latency was associated with greater non-compliance (β =.40, p = .01). The direct effect between parental depression and non-compliance was not significant.

Conclusion

These results suggest that difficulty falling asleep may help to explain why children of parents who have depression are not compliant. Future research should utilize longitudinal and experimental methodology to determine the causality of these relationships.

Support (if any)

University of Missouri Research Board Grant (McCrae, PI); United States Department of Defense USAMRAA Autism Research Program (McCrae, PI; CTA AR190047).

383 Cortical thickness moderates association between sleep architecture and pain in adults with fibromyalgia

Introduction

Fibromyalgia is associated with chronic widespread pain and insomnia. While sleep and pain are mutually influential, how the cortical thickness (CT) of pain-related brain regions influences that relationship (i.e., sleep architecture and evening/morning pain) is unknown. This study examined how the CT of two regions involved in pain processing - the anterior cingulate cortex (ACC) and insula - influenced the link between sleep architecture and evening vs next morning pain in women with fibromyalgia.

Methods

Thirty adults with fibromyalgia and insomnia (Mage=57.2, SD=13.1) completed overnight polysomnography and daily diaries (14 days) tracking sleep and pain [0–100 (most intense). Pain discrepancy (PD) is the average difference between nighttime and next morning pain (evening - morning). Participants underwent MRI, and FreeSurfer (v5.1.0) estimated CT. Multiple regressions examined CT’s influence on the sleep stage [%stage1, %stage2, %stage3, %rapid eye movement (REM)] and PD relationship (controlling for age and education). For significant CT moderation, significance of simple slopes at different CT levels were examined: high (1 SD above), average, and low (1 SD below).

Results

Right rostral ACC (rRACC) CT moderated the relationship between %stage2 (B=-1.41, SE=0.6, p=.03, R^2=0.14), %stage3 (B=2.10, SE=0.97, p=.04, R^2 =0.13), %REM (B=2.35, SE=1.12, p=.04, R^2=0.13) and PD. Greater %stage2 was associated with higher morning vs evening pain at high rRACC thickness (B=-0.67, SE=0.22, p=0.005). Greater %stage3 (B=0.97, SE=0.38, p=0.02) and %REM (B=0.92, SE=0.42, p=0.04) were associated with lower morning pain vs evening pain at high, but not average or low rRACC thickness. Left insula CT moderated the association between increased %stage3 and lower morning vs evening pain (B=2.91, SE=1.18, p=.02, R^2=0.34) at the average and high, but not low thickness levels (B=0.36, SE=0.17, p=0.05; B=1.41, SE=0.48, p=0.008 respectively).

Conclusion

High cortical thickness in the rRACC and average to high L-insula cortical thickness moderated the association between restorative sleep (%stage3, REM) and lower morning vs evening pain. Future studies examining the role of CT in pain-related brain regions on the association of restorative sleep with overnight pain processing are warranted.

Support (if any)

National Institute of Nursing Research (NR017168; PI: McCrae). Clinical trial NCT02001077 Sleep and Pain Interventions (SPIN2), University of Missouri (PI: McCrae).

A viable hypomorphic Arnt2 mutation causes hyperphagic obesity, diabetes and hepatic steatosis

Aryl hydrocarbon receptor nuclear translocator 2 (ARNT2) is a member of the basic helix-loop-helix/PER-ARNT-SIM (bHLH/PAS) transcription factor family. ARNT2 heterodimerizes with several members of the family, including single-minded homolog-1 (SIM1) and neuronal PAS domain protein 4 (NPAS4), primarily in neurons of the central nervous system. We screened 64,424 third-generation germline mutant mice derived from N-ethyl-N-nitrosourea (ENU)-mutagenized great-grandsires for weight abnormalities. Among 17 elevated body weight phenotypes identified and mapped, one strongly correlated with an induced missense mutation in Arnt2 using a semidominant model of inheritance. Causation was confirmed by CRISPR/Cas9 gene targeting to recapitulate the original ENU allele, specifying Arg74Cys (R74C). The CRISPR/Cas9-targeted (Arnt2^R74C/R74C) mice demonstrated hyperphagia and increased adiposity as well as hepatic steatosis and abnormalities in glucose homeostasis. The mutant ARNT2 protein showed decreased transcriptional activity when coexpressed with SIM1. These findings establish a requirement for ARNT2-dependent genes in the maintenance of the homeostatic feeding response, necessary for prevention of obesity and obesity-related diseases.

Summary: A forward genetic approach identified genes involved in maintaining normal body weight. A mutation in Arnt2 caused obesity by regulating food intake.