Diagnosis of sleep disorders in child healthcare settings.

OBJECTIVES: Sleep disorders impact at least 10 % of children, pose risks to overall wellbeing, and are key targets of preventive interventions. The objectives of this study were to describe the prevalence of pediatric sleep disorder diagnoses across sociodemographic characteristics and co-occurring conditions, and to explore potential sociodemographic disparities. METHODS: Cross-sectional analysis of 12,394,902 children (0-17 years; 50.9 % Medicaid-insured) in the 2017 MarketScan database. Prevalence was assessed utilizing ICD-10 codes, with multivariate logistic regressions examining disparities (insurance coverage; race and ethnicity in Medicaid-insured) for diagnoses in ≥0.10 % of children. RESULTS: The prevalence of sleep disorder diagnoses was 2.36 %. The most common diagnoses were obstructive sleep disordered breathing (oSDB, 1.17 %), unspecified sleep disorders (0.64 %), insomnia (0.52 %), and other SDB (0.10 %), with <0.10 % for all other diagnoses. Insomnia and parasomnias diagnoses were much lower than diagnostic estimates. Sleep diagnoses were more prevalent in Medicaid versus commercially insured youth, 2-5-year-olds, and in children with co-occurring medical, neurodevelopmental, or behavioral health conditions. Girls and boys were generally equally likely to be diagnosed with any sleep disorder. In Medicaid-insured children, white children were more likely to have any sleep diagnosis compared to all other racial and ethnic groups. Black/African American children were more likely than white children to have oSDB. CONCLUSIONS: Compared to diagnostic estimates, claims data suggest sleep disorders are under-diagnosed, with notable sociodemographic disparities. Findings suggest a need for clinical resources to identify and address sleep disorders and to understand biases potentially driving disparities, given that sleep is a modifiable determinant of child wellbeing.

Contraception Initiation in the Emergency Department: Adolescent Perspectives.

PURPOSE: The purpose of this study was to identify factors affecting contraceptive intention and behavior among adolescent females in the pediatric Emergency Department. METHODS: We conducted a qualitative interview study nested within a larger prospective cohort study examining adolescent contraceptive counseling for females ages 15-18 years at-risk of unintended pregnancy presenting to the pediatric Emergency Department. Interviews were conducted in a subset of participants. The ecologically expanded Theory of Planned Behavior, expert opinion, and literature review informed the interview guide. Interviews were recorded, transcribed, coded and monitored for thematic saturation. RESULTS: Twenty-eight interviews were analyzed. Mean age was 17.1 years. Themes were mapped to ecologically expanded Theory of Planned Behavior constructs. Within health system influences, prior contraceptive experiences and patient-clinician interactions were described. Within community influences, contraceptive education, knowledge and misinformation, teen pregnancy norms, and social media impacts were described. Within attitudes influences, side-effect and safety concerns, contraceptive motivations and teen pregnancy beliefs were described. Within subjective norm influences, peer and family impacts were described. Within perceived behavioral control, Emergency Department (ED) counseling intervention impacts were described. DISCUSSION: We identified factors affecting contraceptive initiation/behavior among an ED adolescent population that otherwise may not have received contraceptive education in similar detail as provided by study clinicians. Adolescents' prior contraceptive and clinician interactions, limited access to contraceptive education, knowledge and misinformation, and side-effect and safety concerns affected initiation. Peer/family sharing and social media were leading contraceptive information sources. Future studies should incorporate insights into adolescent ED intervention design to make optimal use of resources while maximizing potential benefit.

Heart rate and breathing effects on attention and memory (HeartBEAM): study protocol for a randomized controlled trial in older adults.

BACKGROUND: In healthy people, the "fight-or-flight" sympathetic system is counterbalanced by the "rest-and-digest" parasympathetic system. As we grow older, the parasympathetic system declines as the sympathetic system becomes hyperactive. In our prior heart rate variability biofeedback and emotion regulation (HRV-ER) clinical trial, we found that increasing parasympathetic activity through daily practice of slow-paced breathing significantly decreased plasma amyloid-ß (Aß) in healthy younger and older adults. In healthy adults, higher plasma Aß is associated with greater risk of Alzheimer's disease (AD). Our primary goal of this trial is to reproduce and extend our initial findings regarding effects of slow-paced breathing on Aß. Our secondary objectives are to examine the effects of daily slow-paced breathing on brain structure and the rate of learning. METHODS: Adults aged 50-70 have been randomized to practice one of two breathing protocols twice daily for 9 weeks: (1) "slow-paced breathing condition" involving daily cognitive training followed by slow-paced breathing designed to maximize heart rate oscillations or (2) "random-paced breathing condition" involving daily cognitive training followed by random-paced breathing to avoid increasing heart rate oscillations. The primary outcomes are plasma Aß40 and Aß42 levels and plasma Aß42/40 ratio. The secondary outcomes are brain perivascular space volume, hippocampal volume, and learning rates measured by cognitive training performance. Other pre-registered outcomes include plasma pTau-181/tTau ratio and urine Aß42. Recruitment began in January 2023. Interventions are ongoing and will be completed by the end of 2023. DISCUSSION: Our HRV-ER trial was groundbreaking in demonstrating that a behavioral intervention can reduce plasma Aß levels relative to a randomized control group. We aim to reproduce these findings while testing effects on brain clearance pathways and cognition. TRIAL REGISTRATION: ClinicalTrials.gov NCT05602220. Registered on January 12, 2023.

Incidence of pediatric narcolepsy diagnosis and management: evidence from claims data.

STUDY OBJECTIVES: To characterize the incidence of pediatric narcolepsy diagnosis, subsequent care, and potential sociodemographic disparities in a large US claims database. METHODS: Merative MarketScan insurance claims (n=12,394,902) were used to identify youth (6-17 years) newly diagnosed with narcolepsy (ICD-10 codes). Narcolepsy diagnosis and care 1-year post-diagnosis included polysomnography (PSG) with Multiple Sleep Latency Test (MSLT), pharmacological care, and clinical visits. Potential disparities were examined by insurance coverage and child race and ethnicity (Medicaid-insured only). RESULTS: The incidence of narcolepsy diagnosis was 10:100,000, primarily type 2 (69.9%). Most diagnoses occurred in adolescents with no sex differences, but higher rates in Black versus White youth with Medicaid. Two-thirds had a prior sleep disorder diagnosis and 21-36% had other co-occurring diagnoses. Only half (46.6%) had a PSG with MSLT (± 1-year post-diagnosis). Specialty care (18.9% pulmonary, 26.9% neurology) and behavioral health visits were rare (34.4%), although half were prescribed stimulant medications (51.0%). Medicaid-insured were 86% less likely than commercially insured youth to have any clinical care and 33% less likely to have a PSG with MSLT. CONCLUSIONS: Narcolepsy diagnoses occurred in 0.01% of youth, primarily during adolescence, and at higher rates for Black versus White children with Medicaid. Only half had evidence of a diagnostically required PSG with MSLT, underscoring potential misdiagnosis. Many patients had co-occurring conditions, but specialty and behavioral health care were limited. Results suggest misdiagnosis, underdiagnosis, and limited narcolepsy treatment, as well as possible insurance-related disparities. Results highlight the need to identify determinants of evidence-based pediatric narcolepsy diagnosis and management.

Geospatial Disparities in Youth Sexually Transmitted Infections During COVID-19.

INTRODUCTION: Early in the COVID-19 pandemic, routine sexually transmitted infection (STI) screenings decreased, and test positivity rates increased due to limited screening appointments, national-level STI testing supply shortages, and social distancing mandates. It is unclear if adolescent preventive STI screening has returned to pre-pandemic levels and if pre-existing disparities worsened in late-pandemic. METHODS: This cross-sectional study examined 22,974 primary care visits by 13-19-year-olds in the Philadelphia metropolitan area undergoing screening for gonorrhea and chlamydia in a 31-clinic pediatric primary care network during 2018-2022. Using interrupted-time-series analysis and logistic regression, pandemic-related changes in the asymptomatic STI screening rate and test positivity were tracked across patient demographics. Neighborhood moderation was investigated by census-tract-level Child Opportunity Index in 2023. RESULTS: The asymptomatic STI screening rate dropped by 27.8 percentage points (pp) and 13.5pp when the pandemic and national STI test supply shortage began, respectively, but returned to pre-pandemic levels after supply availability was restored in early 2021. Non-Hispanic-Black adolescents had a significant pandemic drop in STI screening rate, and it did not return to prep-andemic levels (-3.6 pp in the late-pandemic period, p<0.01). This decrease was more pronounced in socioeconomically and educationally disadvantaged neighborhoods (7.5 pp and 9.9 pp lower, respectively) than in advantaged neighborhoods (both p<0.001), controlling for sex, age, insurance type and clinic characteristics. CONCLUSIONS: Neighborhood socioeconomic and educational disadvantage amplified racial-ethnic disparities in STI screening during the pandemic. Future interventions should focus on improving primary care utilization of non-Hispanic-Black adolescents to increase routine STI screening and preventive care utilization.

Resting heart rate variability is associated with neural adaptation when repeatedly exposed to emotional stimuli.

Higher heart rate variability (HRV) at rest is associated with better emotion regulation ability. While the neurovisceral integration model explains this by postulating that HRV can index how the brain adaptively modulates responses to emotional stimuli, neuroimaging studies directly supporting this idea are scarce. We examined the neural correlates of regulating negative and positive emotion in relation to resting HRV based on the neuroimaging and heart rate data of one hundred young adults. The results showed that those with higher HRV better recruit the medial prefrontal cortex while intensifying positive compared to negative emotion. We also examined how individual differences in resting HRV are associated with adjusting brain activity to repeated emotional stimuli. During repeated viewing of emotional images, subjects with higher resting HRV better reduced activity in the medial prefrontal cortex, posterior cingulate gyrus, and angular gyrus, most of which overlapped with the default mode network. This HRV-DMN association was observed during passively viewing emotional images rather than during actively regulating emotion. While the regulating trials can better detect task-induced changes, the viewing trials might approximate resting state, better revealing individual differences. These findings suggest two possibilities: people with higher resting HRV might have a tendency to spontaneously engage with emotion regulation or possess a trait helping emotional arousal fade away.

Pediatric obesity during COVID-19: the role of neighborhood social vulnerability and collective efficacy.

INTRODUCTION: Childhood obesity increased in the first year of COVID-19 with significant disparities across race, ethnicity, and socioeconomic status. Social distancing led to fewer physical activity opportunities but increased screen time and high-calorie food consumption, all co-determined by neighborhood environments. This study aimed to test the moderation effects of neighborhood socioeconomic and built environments on obesity change during COVID-19. METHODS: Using electronic health records from a large pediatric primary care network in 2018-2022, we cross-sectionally examined 163,042 well visits of 2-17-year-olds living in Philadelphia County in order to examine (1) the pandemic's effect on obesity prevalence and (2) moderation by census-tract-level neighborhood socioeconomic disadvantage, crime, food and physical activity-related environments using interrupted-time-series analysis, Poisson regression, and logistic regression. RESULTS: Weekly obesity prevalence increased by 4.9 percent points (pp) during the pandemic (January 2021-August 2022) compared to pre-pandemic (March 2018-March 2020) levels. This increase was pronounced across all age groups, racially/ethnically minoritized groups, and insurance types (ranging from 2.0 to 6.4 pp) except the Non-Hispanic-white group. The increase in obesity among children racially/ethnically minoritized groups was significantly larger in the neighborhoods with high social vulnerability (3.3 pp difference between high and low groups), and low collective efficacy (2.0 pp difference between high and low groups) after adjusting for age, sex, and insurance type. CONCLUSIONS: Racially/ethnically minoritized children experienced larger obesity increases during the pandemic, especially those in socioeconomically disadvantaged neighborhoods. However, the buffering effect of community collective efficacy on the disparities underscores the importance of environments in pediatric health.

Disparities in pediatric obesity during COVID-19: The role of neighborhood social vulnerability and collective efficacy.

Introduction: Childhood obesity increased in the first year of Covid-19 with significant disparities across race, ethnicity, and socioeconomic status. Social distancing led to fewer physical activity opportunities but increased screen time and high-calorie food consumption, all co-determined by neighborhood environments. This study aimed to test the moderation effects of neighborhood socioeconomic and built environments on racial/ethnic disparities in obesity change during Covid-19. Methods: Using electronic health records from a large pediatric primary care network in 2018-2022, we cross-sectionally examined 163,042 well visits of 2-17 year-olds living in Philadelphia county in order to examine (1) the pandemic's effect on obesity prevalence and (2) moderation by census-tract-level neighborhood socioeconomic disadvantage, crime, food and physical activity-related environments using interrupted-time-series analysis, Poisson regression, and logistic regression. Results: Weekly obesity prevalence increased by 4.9 percent points (pp) during the pandemic (Jan 2021-Aug 2022) compared to pre-pandemic (Mar 2018-Mar 2020) levels. This increase was pronounced across all age groups, racially/ethnically-minoritized groups, and insurance types (ranging from 2.0 to 6.4 pp) except the Non-Hispanic-white group. The increase in obesity among children racially/ethnically-minoritized groups was significantly larger in the neighborhoods with high social vulnerability (3.3 pp difference between high and low groups), and low collective efficacy (2.0 pp difference between high and low groups) after adjusting for age, sex, and insurance type. Conclusions: Racially/ethnically-minoritized children experienced larger obesity increases during the pandemic, especially those in socioeconomically disadvantaged neighborhoods. However, the buffering effect of community collective efficacy on the disparities underscores the importance of environments in pediatric health.

Indexed oxygen delivery during pediatric cardiopulmonary bypass is a modifiable risk factor for postoperative acute kidney injury.

BACKGROUND: Acute kidney injury after pediatric cardiac surgery is a common complication with few established modifiable risk factors. We sought to characterize whether indexed oxygen delivery during cardiopulmonary bypass was associated with postoperative acute kidney injury in a large pediatric cohort. METHODS: This was a retrospective analysis of patients under 1 year old undergoing cardiac surgery with cardiopulmonary bypass between January 1, 2013, and January 1, 2020. Receiver operating characteristic curves across values ranging from 260 to 400 mL/min/m2 were used to identify the indexed oxygen delivery most significantly associated with acute kidney injury risk. RESULTS: We included 980 patients with acute kidney injury occurring in 212 (21.2%). After adjusting for covariates associated with acute kidney injury, an indexed oxygen delivery threshold of 340 mL/min/m2 predicted acute kidney injury in STAT 4 and 5 neonates (area under the curve = 0.66, 95% CI = 0.60 - 0.72, sensitivity = 56.1%, specificity = 69.4%). An indexed oxygen delivery threshold of 400 mL/min/m2 predicted acute kidney injury in STAT 1-3 infants (area under the curve = 0.65, 95% CI = 0.58 - 0.72, sensitivity = 52.6%, specificity = 74.6%). CONCLUSION: Indexed oxygen delivery during cardiopulmonary bypass is a modifiable variable independently associated with postoperative acute kidney injury in specific pediatric populations. Strategies aimed at maintaining oxygen delivery greater than 340 mL/min/m2 in complex neonates and greater than 400 mL/min/m2 in infants may reduce the occurrence of postoperative acute kidney injury in the pediatric population.

Daily biofeedback to modulate heart rate oscillations affects structural volume in hippocampal subregions targeted by the locus coeruleus in older adults but not younger adults.

Using data from a clinical trial, we tested the hypothesis that daily sessions modulating heart rate oscillations affect older adults' volume of a region-of-interest (ROI) comprised of adjacent hippocampal subregions with relatively strong locus coeruleus (LC) noradrenergic input. Younger and older adults were randomly assigned to one of two daily biofeedback practices for 5 weeks: 1) engage in slow-paced breathing to increase the amplitude of oscillations in heart rate at their breathing frequency (Osc+); 2) engage in self-selected strategies to decrease heart rate oscillations (Osc-). The interventions did not significantly affect younger adults' hippocampal volume. Among older adults, the two conditions affected volume in the LC-targeted hippocampal ROI differentially as reflected in a significant condition x time-point interaction on ROI volume. These condition differences were driven by opposing changes in the two conditions (increased volume in Osc+ and decreased volume in Osc-) and were mediated by the degree of heart rate oscillation during training sessions.

Daily biofeedback to modulate heart rate oscillations affects structural volume in hippocampal subregions targeted by the locus coeruleus in older adults but not younger adults.

Using data from a clinical trial, we tested the hypothesis that daily sessions modulating heart rate oscillations affect older adults' volume of a region-of-interest (ROI) comprised of adjacent hippocampal subregions with relatively strong locus coeruleus (LC) noradrenergic input. Younger and older adults were randomly assigned to one of two daily biofeedback practices for 5 weeks: (1) engage in slow-paced breathing to increase the amplitude of oscillations in heart rate at their breathing frequency (Osc+); (2) engage in self-selected strategies to decrease heart rate oscillations (Osc-). The interventions did not significantly affect younger adults' hippocampal volume. Among older adults, the two conditions affected volume in the LC-targeted hippocampal ROI differentially as reflected in a significant condition × time-point interaction on ROI volume. These condition differences were driven by opposing changes in the two conditions (increased volume in Osc+ and decreased volume in Osc-) and were mediated by the degree of heart rate oscillation during training sessions.

Daily heart rate variability biofeedback training decreases locus coeruleus MRI contrast in younger adults in a randomized clinical trial.

As an arousal hub region in the brain, the locus coeruleus (LC) has bidirectional connections with the autonomic nervous system. Magnetic resonance imaging (MRI)-based measures of LC structural integrity have been linked to cognition and arousal, but less is known about factors that influence LC structure and function across time. Here, we tested the effects of heart rate variability (HRV) biofeedback, an intervention targeting the autonomic nervous system, on LC MRI contrast and sympathetic activity. Younger and older participants completed daily HRV biofeedback training for five weeks. Those assigned to an experimental condition performed biofeedback involving slow, paced breathing designed to increase heart rate oscillations, whereas those assigned to a control condition performed biofeedback to decrease heart rate oscillations. At the pre- and post-training timepoints, LC contrast was assessed using turbo spin echo MRI scans, and RNA sequencing was used to assess cAMP-responsive element binding protein (CREB)-regulated gene expression in circulating blood cells, an index of sympathetic nervous system signaling. We found that left LC contrast decreased in younger participants in the experimental group, and across younger participants, decreases in left LC contrast were related to the extent to which participants increased their heart rate oscillations during training. Furthermore, decreases in left LC contrast were associated with decreased expression of CREB-associated gene transcripts. On the contrary, there were no effects of biofeedback on LC contrast among older participants in the experimental group. These findings provide novel evidence that in younger adults, HRV biofeedback involving slow, paced breathing can decrease both LC contrast and sympathetic nervous system signaling.

Short-term blood pressure variability is inversely related to regional amplitude of low frequency fluctuations in older and younger adults.

Blood pressure variability (BPV), independent of mean blood pressure levels, is associated with cerebrovascular disease burden on MRI and postmortem evaluation. However, less is known about relationships with markers of cerebrovascular dysfunction, such as diminished spontaneous brain activity as measured by the amplitude of low frequency fluctuations (ALFF), especially in brain regions with vascular and neuronal vulnerability in aging. We investigated the relationship between short-term BPV and concurrent regional ALFF from resting state fMRI in a sample of community-dwelling older adults (n = 44) and healthy younger adults (n = 49). In older adults, elevated systolic BPV was associated with lower ALFF in widespread medial temporal regions and the anterior cingulate cortex. Higher systolic BPV in younger adults was also related to lower ALFF in the medial temporal lobe, albeit in fewer subregions, and the amygdala. There were no significant associations between systolic BPV and ALFF across the right/left whole brain or in the insular cortex in either group. Findings suggest a possible regional vulnerability to cerebrovascular dysfunction and short-term fluctuations in blood pressure. BPV may be an understudied risk factor for cerebrovascular changes in aging.

Multimodal neuroimaging data from a 5-week heart rate variability biofeedback randomized clinical trial.

We present data from the Heart Rate Variability and Emotion Regulation (HRV-ER) randomized clinical trial testing effects of HRV biofeedback. Younger (N = 121) and older (N = 72) participants completed baseline magnetic resonance imaging (MRI) including T1-weighted, resting and emotion regulation task functional MRI (fMRI), pulsed continuous arterial spin labeling (PCASL), and proton magnetic resonance spectroscopy (1H MRS). During fMRI scans, physiological measures (blood pressure, pulse, respiration, and end-tidal CO2) were continuously acquired. Participants were randomized to either increase heart rate oscillations or decrease heart rate oscillations during daily sessions. After 5 weeks of HRV biofeedback, they repeated the baseline measurements in addition to new measures (ultimatum game fMRI, training mimicking during blood oxygen level dependent (BOLD) and PCASL fMRI). Participants also wore a wristband sensor to estimate sleep time. Psychological assessment comprised three cognitive tests and ten questionnaires related to emotional well-being. A subset (N = 104) provided plasma samples pre- and post-intervention that were assayed for amyloid and tau. Data is publicly available via the OpenNeuro data sharing platform.

Sociodemographic disparities and healthcare utilization in pediatric obstructive sleep apnea management.

OBJECTIVES: We examined (1) disparities in obstructive sleep apnea (OSA) care by insurance coverage, and by child race and ethnicity among Medicaid-insured children (MIC), and (2) healthcare utilization changes after OSA care. METHODS: IBM MarketScan insurance claims were used to index OSA care 1-year before and after initial OSA diagnosis in 2017 among 2-17-year-old children (n = 31,787, MIC: 59%). OSA care and healthcare utilization analyses adjusted for child age, sex, obesity, and complex chronic conditions. RESULTS: We identified 8 OSA care pathways, including no care, which occurred in 34.4% of the overall sample. MIC had 13% higher odds of no OSA care compared to commercially-insured children (CIC). MIC had 32-48% lower odds of any treatment pathway involving specialty care, but a 13-46% higher likelihood of receiving surgical care without polysomnogram (PSG) and PSG only. In MIC, non-Latinx Black/African American (Black) and Hispanic/Latinx children were 1.3-2.2 times more likely than White children to receive treatment involving specialty care and/or PSG, while Black children were 31% less likely than White youth to undergo surgery. In the full sample, surgical care was associated with less outpatient and emergency healthcare utilization compared to those untreated or not surgically treated. CONCLUSIONS: Varied OSA management by insurance coverage suggests disparities in access to and engagement in care and potentially greater disease burden among MIC. Surgical care is associated with reduced healthcare utilization. The lower odds of surgery in Black MIC should be further evaluated in the context of OSA severity, healthcare biases, and family preferences.

Expanding Contraceptive Access for Teens-Leveraging the Pediatric Emergency Department.

PURPOSE: Adolescents have limited access to sexual healthcare services, and the emergency department (ED) may be the only place some will seek care. We implemented an ED-based contraception counseling intervention to assess intervention feasibility, and adolescent intention to initiate contraception, contraception initiation, and follow-up visit completion. METHODS: This prospective cohort study trained advanced practice providers in the EDs of two pediatric urban academic medical centers to deliver brief contraception counseling. A convenience sample of patients enrolled from 2019 to 2021 included females aged 15-18 not pregnant/desiring pregnancy and/or using hormonal contraception/an intrauterine device. Participants completed surveys to assess demographics and intention to initiate contraception (yes/no). Sessions were audiotaped and reviewed for fidelity. We ascertained contraception initiation and follow-up visit completion via medical record review and participant survey at 8 weeks. RESULTS: Twenty-seven advanced practice providers were trained, and 96 adolescents were counseled/responded to surveys (mean age 16.7 years; 19% non-Hispanic White, 56% non-Hispanic Black; 18% Hispanic). Mean counseling duration was 12 minutes and >90% of reviewed sessions maintained fidelity to content/style. Most participants (61%) reported intention to initiate contraception, and these participants were older and more likely to report prior contraceptive use, compared to those without intention. One-third (33%) initiated contraception in the ED or after the follow-up visit. DISCUSSION: Contraceptive counseling was feasible to integrate in the ED visit. Intention to initiate contraception was common and many adolescents initiated contraception. Future work should increase the pool of trained providers and supports for same-day contraception initiation for those desiring in this novel setting.

Sex Differences in Neural Correlates of Emotion Regulation in Relation to Resting Heart Rate Variability.

Prior studies suggest that sex differences in emotion regulation (ER) ability contribute to sex disparities in affective disorders. In behavioral studies, females rely more on maladaptive strategies to cope with emotional distress than males. Neuroimaging studies suggest that males more efficiently regulate emotion than females by showing less prefrontal cortex activity (suggesting less effort) for similar amygdala activity (similar regulation outcome). However, physiological studies involving heart rate variability (HRV) indicated that, compared with males, females have higher resting HRV, indicative of parasympathetic dominance and better control of emotion. To help resolve these apparently inconsistent findings, we examined sex differences in how resting HRV relates to brain activity while using cognitive reappraisal, one of the adaptive strategies. Based on 51 males and 49 females, we found that females showed different levels of self-rated emotional intensity and amygdala activity for negative versus positive emotions, while males did not. Females also showed greater overall prefrontal cortex activity but similar levels of amygdala activity compared to males. Sex differences in how resting HRV related to brain activity during ER were evident only during viewing or regulating positive emotion. The results suggest that sex differences in the neural correlates of ER and resting HRV might lie in valence more than arousal modulation.