Characterizing daily physical activity patterns with unsupervised learning via functional mixture models.

Physical inactivity is a significant public health concern. Consideration of inter-individual variations in physical activity (PA) trends can provide additional information about the groups under study to aid intervention design. This study aims to identify latent profiles ("phenotypes") based on daily PA trends among adults living in. This was a secondary analysis of 724 person-level days of accelerometry data from 133 urban-dwelling adults (89% Latinx, age = 19-77 years). We used Actigraph accelerometers and the Actilife software to collect and process 24-hour PA data. We implemented a probabilistic clustering technique based on functional mixture models. Multiple days of data per person were averaged for entry into the models. We evaluated step counts, moderate-intensity PA (MOD), total activity and sedentary minutes as potential model variables. Bayesian Information Criterion (BIC) index was used to select the model that provided the best fit for the data. A 4-cluster resolution provided the best fit for the data (i.e., BIC=-3257, improvements of Δ = 13 and Δ = 7 from 3- and 5-cluster models, respectively). MOD provided the greatest between-cluster discrimination. Phenotype 1 (N = 61) was characterized by a morning peak in PA that declined until bedtime. Later bedtimes and the highest daily PA volume were distinct for phenotype 2 (N = 18), along with a similar peak pattern. Phenotype 3 (N = 29) membership was associated with the lowest PA levels throughout the day. Phenotype 4 was characterized by a more evenly distributed PA during the day, and later waking/bedtimes. Our findings point to distinct, interpretable PA phenotypes based on temporal patterns. Functional clustering of PA data could provide additional actionable points for tailoring behavioral interventions.

Testing the cross-stressor hypothesis under real-world conditions: exercise as a moderator of the association between momentary anxiety and cardiovascular responses.

The cross-stressor adaptation hypothesis of exercise training has not been investigated under real-life conditions. Using ecological momentary assessment, we tested whether usual exercise level moderates the relationship of self-reported anxiety to concurrent ambulatory heart rate (HR) and systolic/diastolic blood pressure (SBP/DBP). Participants (N = 832) completed 24-h ambulatory monitoring of HR/BP, using a brachial BP cuff that took readings at 28-min intervals. Anxiety levels were concurrently reported on a visual analog scale (VAS) using a Palm Pilot. Usual exercise behavior was assessed by a self-report questionnaire. Random coefficients linear regression models predicting momentary HR/BP readings from time-matched anxiety scores were estimated, yielding the average within-person effect (slope) of anxiety. The interaction of exercise level (i.e., no weekly exercise, 1-149, and ≥ 150 min/week; a between-person factor) with anxiety was added to the model in order to estimate the average anxiety slope for participants in each exercise category. The relationship of HR/BP to anxiety did not differ significantly among exercise categories, hence not providing evidence for the cross-stressor hypothesis. In an exploratory analysis of the difference in HR/BP between occasions when anxiety was in the top versus bottom person-specific quintiles of responses, the difference in HR (but not SBP or DBP) varied significantly by exercise level (F(2,625) = 4.92, p = 0.008). Though our pre-specified analysis did not support the hypothesis, we provide some post hoc evidence supporting the cross-stressor hypothesis of exercise training for the HR response to anxiety.

Anxiety Sensitivity and Physical Inactivity in a National Sample of Adults with a History of Myocardial Infarction.

BACKGROUND: The psychological factors underlying physical inactivity in vulnerable cardiac adult populations remain understudied. Anxiety sensitivity, a cognitive vulnerability defined as fear of the physical, cognitive, and social consequences of anxiety, may be an important modifiable determinant of physical inactivity. We examined the association of anxiety sensitivity, and each anxiety sensitivity subscale (physical, cognitive, and social concerns), with physical inactivity in adults with a history of myocardial infarction (MI). METHODS: Using cross-sectional data from a nationally representative survey of adults (N = 1417) in the USA who reported a health professional diagnosis of MI, we used weighted logistic regression models to evaluate the association between anxiety sensitivity (overall, and each subscale) and physical inactivity (self-reported exercise 0-1 day/week), with adjustment for age, gender, race, education, number of MIs, and depression. RESULTS: Overall, 34.3% reported physical inactivity. Anxiety sensitivity was associated with greater odds of physical inactivity (OR = 1.01; 95% CI = 1.00, 1.02; p = .026). Of the subscales, only physical concerns were associated with physical inactivity (OR = 1.02; 95% CI = 1.01, 1.04; p = .008) in the final model. High vs. low fear of shortness of breath was most consistently associated with physical inactivity (OR = 1.49; 95% CI = 1.08, 2.06; p < .021). CONCLUSION: Anxiety sensitivity, generally, and fear of the physical sensations of anxiety (i.e., "fear of shortness of breath"), specifically, are important correlates of physical inactivity in adults with a history of MI. Future research should replicate these findings and experimentally test whether cardiac rehabilitation interventions that include an adjunctive component targeting reduction of anxiety sensitivity overall, or specific somatic symptoms, improve physical activity in this population.

The Influence of Daily Stress on Sedentary Behavior: Group and Person (N of 1) Level Results of a 1-Year Observational Study.

OBJECTIVE: The purpose of this study, which used mobile technologies to continuously collect data for 1 year, was to examine the association of psychological stress with objectively measured sedentary behavior in adults at both the group (e.g., nomothetic approach) and individual (e.g., idiographic approach) level. METHODS: Data were collected in an observational study of healthy adults (n = 79) residing in the New York City metro area who were studied for 365 days from 2014 to 2015. Sedentary behavior was objectively measured via accelerometry. A smartphone-based electronic diary was used to assess level of stress ("Overall, how stressful was your day?" 0-10 scale) and sources of stress. RESULTS: The end-of-day stress rating was not associated with total sedentary time (B = -1.34, p = .767) at the group level. When specific sources of stress were evaluated at the group level, argument-related stress was associated with increased sedentariness, whereas running late- and work-related stress were associated with decreased sedentariness. There was a substantial degree of interindividual variability in the relationship of stress with sedentary behavior. Both the level and sources of stress were associated with increased sedentariness for some, decreased sedentariness for others, and had no effect for many (within-person variance p < .001). CONCLUSIONS: These findings suggest that the influence of stress on sedentary behavior varies by source of stress and from person to person. A precision medicine approach may be warranted to target reductions in sedentary time, although further studies are needed to confirm the observed findings in light of study limitations including a small sample size and enrollment of participants from a single, urban metropolitan area.

Quantile Coarsening Analysis of High-Volume Wearable Activity Data in a Longitudinal Observational Study.

Owing to advances in sensor technologies on wearable devices, it is feasible to measure physical activity of an individual continuously over a long period. These devices afford opportunities to understand individual behaviors, which may then provide a basis for tailored behavior interventions. The large volume of data however poses challenges in data management and analysis. We propose a novel quantile coarsening analysis (QCA) of daily physical activity data, with a goal to reduce the volume of data while preserving key information. We applied QCA to a longitudinal study of 79 healthy participants whose step counts were monitored for up to 1 year by a Fitbit device, performed cluster analysis of daily activity, and identified individual activity signature or pattern in terms of the clusters identified. Using 21,393 time series of daily physical activity, we identified eight clusters. Employment and partner status were each associated with 5 of the 8 clusters. Using less than 2% of the original data, QCA provides accurate approximation of the mean physical activity, forms meaningful activity patterns associated with individual characteristics, and is a versatile tool for dimension reduction of densely sampled data.

Physiological response to firefighting activities of various work cycles using extended duration and prototype SCBA.

Firefighters' self-contained breathing apparatus (SCBA) protects the respiratory system during firefighting but increases the physiological burden. Extended duration SCBA (>30 min) have increased air supply, potentially increasing the duration of firefighting work cycles. To examine the effects of SCBA configuration and work cycle (length and rest), 30 firefighters completed seven trials using different SCBA and one or two bouts of simulated firefighting following work cycles common in the United States. Heart rate, core temperature, oxygen consumption, work output and self-reported perceptions were recorded during all activities. Varying SCBA resulted in few differences in these parameters. However, during a second bout, work output significantly declined while heart rates and core temperatures were elevated relative to a single bout. Thirty seven per cent of the subjects were unable to complete the second bout in at least one of the two-bout conditions. These firefighters had lower fitness and higher body mass than those who completed all assigned tasks. Practitioner Summary: The effects of extended duration SCBA and work/rest cycles on physiological parameters and work output have not been examined. Cylinder size had minimal effects, but extended work cycles with no rest resulted in increased physiological strain and decreased work output. This effect was more pronounced in firefighters with lower fitness.

Self-efficacy and Walking Performance in Persons With Multiple Sclerosis.

BACKGROUND AND PURPOSE: Impairment of walking function is a prevalent and burdensome feature of multiple sclerosis (MS), and represents a primary focus of rehabilitation research and clinical care. Research examining self-efficacy as a correlate of walking performance in MS is lacking; self-efficacy represents a theory-based, modifiable target of rehabilitation approaches for improving walking outcomes. This cross-sectional study examined the association between self-efficacy and walking performance in persons living with MS. METHODS: The sample included 69 persons with MS who completed the Multiple Sclerosis Self-Efficacy (MSSE) Scale and Exercise Self-Efficacy (EXSE) Scale and undertook the Timed 25-Foot Walk (T25FW) and the 6-Minute Walk (6MW) tests. The data were analyzed using the Pearson product moment correlation coefficients and linear regression. RESULTS: Correlation analysis indicated that function subscale scores on the MSSE correlated more strongly with T25FW (r = 0.55) than did the control subscale (r = 0.40) and EXSE (r = 0.38) scores, and both function (r = 0.67) and control (r = 0.53) subscale scores on the MSSE correlated more strongly with 6MW than did EXSE scores (r = 0.40). Linear regression analyses indicated that (1) function MSSE subscale, but not control subscale, explained significant variance in T25FW speed and 6MW distance and (2) function MSSE subscale, but not EXSE, explained significant variance in T25FW speed and 6MW distance. DISCUSSION AND CONCLUSIONS: We provide the first evidence of an association between self-efficacy, particularly for functioning with MS, and objective walking performance in MS. Future research to replicate and extend these results can inform rehabilitation efforts that target improvement of walking performance in persons with MS.Digital Abstract available for more insights from the authors (see Slides, Supplemental Digital Content 1, http://links.lww.com/JNPT/A171).

Cognitive Motor Interference in Multiple Sclerosis: Insights From a Systematic Quantitative Review.

OBJECTIVE: To synthesize the evidence for differences in cognitive motor interference (CMI) between persons with multiple sclerosis (MS) and those without MS by using systematic review and meta-analysis. DATA SOURCES: EMBASE, PubMed, ScienceDirect, Scopus, SPORTDiscus, and Web of Science. Our focused literature search was informed by past systematic reviews of CMI during walking in MS. STUDY SELECTION: The key terms searched included Multiple sclerosis and synonyms of motor function (eg, Gait disorders, Gait, Walking, Balance, or Fall) and motor and cognitive functions (eg, Cognitive motor interference or Thinking). DATA EXTRACTION: From the 116 abstract-identified articles, 13 experimental studies were selected for the final analysis and were rated using the Quality Assessment of Diagnostic Accuracy Studies tool. A meta-analysis was performed for all considered outcomes. DATA SYNTHESIS: The results yielded a small overall effect size (ES) of .08 (SE=.17; 95% confidence interval, -.25 to .40; z=.49; P>.05), which indicated a nonsignificant minimal difference in CMI between persons with MS and those without MS. The moderator analysis for motor task (mobility task: ES, .22; postural task: ES, -.11) was not significantly different between persons with MS and those without MS. The moderator analysis for cognitive task (verbal fluency task: ES, .66; mental tracking task: ES, .04; discrimination and decision-making task: ES, -.30) resulted in a significant difference in CMI between persons with MS and those without MS (P<.05). CONCLUSIONS: We provide evidence that overall there is a minimal difference in CMI between persons with MS and those without MS.

Firefighter exercise protocols conducted in an environmental chamber: developing a laboratory-based simulated firefighting protocol.

A standard exercise protocol that allows comparisons across various ergonomic studies would be of great value for researchers investigating the physical and physiological strains of firefighting and possible interventions for reducing the demands. We compared the pattern of cardiorespiratory changes from 21 firefighters during simulated firefighting activities using a newly developed firefighting activity station (FAS) and treadmill walking both performed within an identical laboratory setting. Data on cardiorespiratory parameters and core temperature were collected continuously using a portable metabolic unit and a wireless ingestible temperature probe. Repeated measures ANOVA indicated distinct patterns of change in cardiorespiratory parameters and heart rate between conditions. The pattern consisted of alternating periods of peaks and nadirs in the FAS that were qualitatively and quantitatively similar to live fire activities, whereas the same parameters increased logarithmically in the treadmill condition. Core temperature increased in a similarly for both conditions, although more rapidly in the FAS. Practitioner Summary: The firefighting activity station (FAS) yields a pattern of cardiorespiratory responses qualitatively and quantitatively similar to live fire activities, significantly different than treadmill walking. The FAS can be performed in a laboratory/clinic, providing a potentially standardised protocol for testing interventions to improve health and safety and conducting return to duty decisions.

Structural and construct validity of the Leeds Multiple Sclerosis Quality of Life scale.

PURPOSE: The Leeds Multiple Sclerosis Quality of Life (LMSQOL) scale was designed as an 8-item, unidimensional disease-targeted measure of quality of life (QOL). This study (1) tested the unidimensionality of the LMSQOL using confirmatory factor analysis (CFA) and (2) examined the construct validity of scores based on a nomological network. METHODS: The sample (N = 292) included persons with multiple sclerosis (MS) who were recruited from the Midwest region of the USA. Participants completed questionnaires that were delivered and returned using US Postal Service. We tested the fit of a single-factor model for the LMSQOL using CFA with the diagonally weighted least squares estimator in R. We examined the construct validity of the LMSQOL scores using Spearman rank-order correlations (r s) in SPSS. RESULTS: The single-factor model had a reasonable fit for the 8-item LMSQOL [χ (2) (20) = 83.19, p < .001, CFI = .97, SRMR = .07], but provided an excellent fit for a 7-item version of the LMSQOL [χ (2) (14) = 23.63, p > .05, CFI = .99, SRMR = .05]. LMSQOL scores demonstrated strong correlations with measures of psychological well-being (|r s| = .53-.74) and weak-to-moderate correlations with measures of physical functioning and disability (|r s| = .23-.57). CONCLUSION: The unidimensional model provides a good fit for the LMSQOL, and its scores provide a valid measure of QOL in MS.

Effect of Exercise Training on Fitness in Multiple Sclerosis: A Meta-Analysis.

OBJECTIVE: To provide a quantitative synthesis of randomized controlled trials (RCTs) examining the effect of exercise training on muscular and cardiorespiratory fitness in persons with multiple sclerosis (MS). DATA SOURCES: Three electronic databases, PubMed, Google Scholar, and Web of Science, were searched for all relevant articles published up until October 2014. STUDY SELECTION: Keywords included exercise or aerobic or strength or resistance training or cardiorespiratory and multiple sclerosis. Trials examining the effect of exercise training on muscular and/or cardiorespiratory fitness parameters were included. DATA EXTRACTION: The initial search yielded 1501 articles; of these, 62 were reviewed in detail, and 20 RCTs met the inclusion criteria and provided enough data to compute effect sizes (ESs) (Cohen d). The meta-analyses was conducted using a random effects model to compute the overall or mean ES per fitness parameter. DATA SYNTHESIS: The mean ES was .27 (SE=.05; 95% confidence interval [CI], .17-.38; z=5.05; P<.001) for muscular fitness outcomes and .47 (SE=.09; 95% CI, .30-.65; z=5.4; P<.001) for cardiorespiratory fitness outcomes. The weighted mean ES was not heterogeneous for muscular (Q13=11.09, P=.60, I(2)=.00) or cardiorespiratory (Q9=7.83, P=.55, I(2)=.00) fitness outcomes. CONCLUSIONS: The cumulative evidence supports that exercise training is associated with changes in muscular (small in magnitude) and cardiorespiratory (moderate in magnitude) fitness outcomes in persons with MS. Such an indication of magnitude is important for clinical research and practice by providing an evidence-based estimate of the actual benefit that exercise training confers on physiological fitness.

META-ANALYSIS OF ACUTE EXERCISE EFFECTS ON STATE ANXIETY: AN UPDATE OF RANDOMIZED CONTROLLED TRIALS OVER THE PAST 25 YEARS.

BACKGROUND: One prominent and well-cited meta-analysis published nearly 25 years ago reported that an acute or single bout of exercise reduced state anxiety by approximately » standard deviation. We conducted a meta-analysis of randomized controlled trials (RCTs) published after that meta-analysis for updating our understanding of the acute effects of exercise on state anxiety. METHODS: We searched PubMed, EBSCOHost, Medline, PsycINFO, ERIC, and ScienceDirect for RCTs of acute exercise and state anxiety as an outcome. There were 36 RCTs that met inclusion criteria and yielded data for effect size (ES) generation (Cohen's d). An overall ES was calculated using a random effects model and expressed as Hedge's g. RESULTS: The weighted mean ES was small (Hedge's g = 0.16, standard error (SE) = 0.06), but statistically significant (P < 0.05), and indicated that a single bout of exercise resulted in an improvement in state anxiety compared with control. The overall ES was heterogeneous and post hoc, exploratory analyses using both random- and fixed-effects models identified several variables as moderators including sample age, sex and health status, baseline activity levels, exercise intensity, modality and control condition, randomization, overall study quality, and the anxiety measure (P < 0.05). CONCLUSION: The cumulative evidence from high quality studies indicates that acute bouts of exercise can yield a small reduction in state anxiety. The research is still plagued by floor effects associated with recruiting persons with normal or lower levels of state anxiety, and this should be overcome in subsequent trials.

Effect of exercise on depressive symptoms in adults with neurologic disorders: a systematic review and meta-analysis.

OBJECTIVES: To review and quantify the effect of exercise on depression in adults with neurologic disorders. DATA SOURCES: CINAHL, Cochrane Register of Controlled Clinical Trials, EMBASE, ERIC, MEDLINE, PsycINFO, PubMed, and SPORTDiscus were searched, with the last search performed in May 2014. STUDY SELECTION: Included were randomized controlled trials conducted in adults with a diagnosed neurologic disorder that compared an exercise intervention group with a control group and used depression as an outcome measure. DATA EXTRACTION: Depression data were extracted independently by 2 authors. Methodological quality was assessed independently by 2 authors. DATA SYNTHESIS: Forty-three full-length articles were reviewed, and 26 trials met our inclusion criteria. These trials represented 1324 participants with 7 different neurologic disorders: Alzheimer disease (n=4 trials), migraine (n=1), multiple sclerosis (n=13), Parkinson disease (n=2), spinal cord injury (n=1), stroke (n=2), and traumatic brain injury (n=3). Data measuring depression were extracted and effect sizes were computed for 23 trials. Results from a meta-analysis yielded an overall effect size of .28 (SE=.07; 95% confidence interval, .15-.41; P=.00) favoring a reduction in depression outcomes after an exercise intervention compared with the control condition. Of note, interventions that met physical activity guidelines yielded an overall effect of .38 compared with .19 for studies that did not meet physical activity guidelines. CONCLUSIONS: This review provides evidence that exercise, particularly when meeting physical activity guidelines, can improve depressive symptoms in adults with neurologic disorders.

A modified SCBA facepiece for accurate metabolic data collection from firefighters.

To better assess the energy expenditure and exertion of firefighters during simulated firefighting activities, a commercial firefighter self-contained breathing apparatus (SCBA) facepiece was modified to interface with a portable metabolic monitoring device (Cosmed K4b(2)) while still functioning as a positive pressure SCBA air supply. To validate the device, standard National Fire Protection Association 1981 SCBA function tests were conducted and 14 subjects performed variable-workload assessments using all combinations of two test devices (Cosmed K4b(2) and metabolic cart) and two masks (modified SCBA facepiece and stock manufacturer-supplied breath collection). Metabolic data collected with the Cosmed K4b(2) via the modified facepiece were found to be accurate when compared to a ParvoMedics Truemax 2400 metabolic cart (average per cent difference: 4.6%). This modified facepiece design is suitable for use in metabolic studies requiring the utilisation of an SCBA system. Furthermore, the well-established overestimation of oxygen consumption from the Cosmed K4b(2) system was replicated.

Physiological responses to simulated firefighter exercise protocols in varying environments.

For decades, research to quantify the effects of firefighting activities and personal protective equipment on physiology and biomechanics has been conducted in a variety of testing environments. It is unknown if these different environments provide similar information and comparable responses. A novel Firefighting Activities Station, which simulates four common fireground tasks, is presented for use with an environmental chamber in a controlled laboratory setting. Nineteen firefighters completed three different exercise protocols following common research practices. Simulated firefighting activities conducted in an environmental chamber or live-fire structures elicited similar physiological responses (max heart rate: 190.1 vs 188.0 bpm, core temperature response: 0.047°C/min vs 0.043°C/min) and accelerometry counts. However, the response to a treadmill protocol commonly used in laboratory settings resulted in significantly lower heart rate (178.4 vs 188.0 bpm), core temperature response (0.037°C/min vs 0.043°C/min) and physical activity counts compared with firefighting activities in the burn building. Practitioner Summary: We introduce a new approach for simulating realistic firefighting activities in a controlled laboratory environment for ergonomics assessment of fire service equipment and personnel. Physiological responses to this proposed protocol more closely replicate those from live-fire activities than a traditional treadmill protocol and are simple to replicate and standardise.

Patterns and predictors of naturally occurring change in depressive symptoms over a 30-month period in multiple sclerosis.

BACKGROUND: Depressive symptoms are common in multiple sclerosis (MS), yet there is little information about the pattern and predictors of changes in depressive symptoms over time. OBJECTIVE: We examined changes in depressive symptoms over a 30-month period and the demographic, clinical and behavioral predictors of such changes in relapsing-remitting MS (RRMS). METHODS: 269 persons with RRMS completed the Hospital Anxiety and Depression Scale (HADS) and a demographic/clinical scale, Godin Leisure-Time Exercise Questionnaire (GLTEQ) and Patient Determined Disease Steps (PDDS) scale every 6 months over a 30-month period. Data were analyzed using latent class growth modeling (LCGM). RESULTS: LCGM identified a two-class model for changes in HADS depression scores over time. Class 1 involved lower initial status (i.e. fewer depressive symptoms) and linear decreases in depressive symptoms over time (i.e. improving HADS scores), whereas Class 2 involved higher initial status (i.e. more depressive symptoms) and linear increases in depressive symptoms over time (i.e. worsening HADS scores). LCGM further indicated that being older (OR = 2.46; p < .05), married (OR = 2.62; p < .05), employed (OR = 4.29; p < .005) and physically active (OR = 2.71; p < .05) predicted a greater likelihood of belonging to C1 than C2. CONCLUSIONS: Depressive symptoms change over time in persons with RRMS, and the pattern of change can be predicted by modifiable and non-modifiable factors.

Cognitive motor interference during walking in multiple sclerosis using an alternate-letter alphabet task.

OBJECTIVE: To examine cognitive motor interference (CMI) during walking using a simple, standardized, and well-refined alphabet dual-task (DT) paradigm in individuals with multiple sclerosis (MS) in whom cognitive and walking impairment often co-occur. DESIGN: A single time point, cross-sectional study. SETTING: A university clinical laboratory. PARTICIPANTS: Individuals with MS (N=61; mean age ± SD, 50.8±9.3 y) performed 4 walking trials over a 4.6-m walkway to determine gait parameters. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Gait parameters were assessed over 4 walking trials. The first 2 walks involved the single task (ST) of walking only; the second 2 walks involved participants performing the DT of reciting alternate letters of the alphabet while walking. The gait parameters recorded during the ST and DT walks were used to compute a dual-task cost (DTC) of walking (% change in gait parameter between ST and DT walks) as a metric of CMI. RESULTS: Our multivariate analysis with univariate follow-ups indicated CMI during walking based on slower velocity (ηp(2)=.59; F=84.6; P<.001) and cadence (ηp(2)=.46; F=51.6; P<.001), shorter step length (ηp(2)=.38; F=36; P<.001), and increased step time (ηp(2)=.34; F=31; P<.001) and double-support time (ηp(2)=.31; F=27.3; P<.001) in DT versus ST conditions. The DTC of walking for the gait parameters was not correlated with clinical (disability, disease duration) and demographic (eg, education, age) factors (all |r|≤.240). CONCLUSIONS: The alphabet DT paradigm is easily administered and well refined. We highlight its ability and acceptability to determine CMI during walking in people with MS, independent of disease status.

Day-to-day associations of intersectional minority stressors with sleep health in sexual and gender minority people of color.

OBJECTIVE: To determine the day-to-day associations between minority stressors (i.e., anticipated and experienced discrimination) and sleep health outcomes (i.e., total sleep time (TST), sleep disturbances, and sleep-related impairment) among sexual and gender minority (SGM) people of color. METHOD: An online sample of SGM people of color living in the United States participated in a 30-day daily diary study. Daily anticipated and experienced discrimination as well as subjective sleep outcomes were assessed via electronic diaries using validated measures. Wrist-worn actigraphy was used to objectively assess TST. Multilevel linear models (MLMs) were used to estimate the independent associations of daily intersectional minority stressors with subsequent sleep outcomes, adjusted for demographic factors and lifetime discrimination. RESULTS: The sample included 43 SGM people of color with a mean age of 27.0 years (± 7.7) of which 84% were Latinx, 47% were multiracial, and 37% were bisexual. Results of MLMs indicated that greater report of daily experienced discrimination was positively associated with same-night sleep disturbances, B (SE) = 0.45 (0.10), p < .001. Daily anticipated discrimination was positively associated with sleep-related impairment on the following day, B (SE) = 0.77 (0.17), p < .001. However, daily anticipated and experienced discrimination were not associated with same-night TST. CONCLUSIONS: Findings highlight the importance of considering the differential effects of daily intersectional minority stressors on the sleep health of SGM people of color. Further research is needed to identify factors driving the link between daily minority stressors and sleep outcomes to inform sleep health interventions tailored to this population. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Translational Research of the Acute Effects of Negative Emotions on Vascular Endothelial Health: Findings From a Randomized Controlled Study.

BACKGROUND: Provoked anger is associated with an increased risk of cardiovascular disease events. The underlying mechanism linking provoked anger as well as other core negative emotions including anxiety and sadness to cardiovascular disease remain unknown. The study objective was to examine the acute effects of provoked anger, and secondarily, anxiety and sadness on endothelial cell health. METHODS AND RESULTS: Apparently healthy adult participants (n=280) were randomized to an 8-minute anger recall task, a depressed mood recall task, an anxiety recall task, or an emotionally neutral condition. Pre-/post-assessments of endothelial health including endothelium-dependent vasodilation (reactive hyperemia index), circulating endothelial cell-derived microparticles (CD62E+, CD31+/CD42-, and CD31+/Annexin V+) and circulating bone marrow-derived endothelial progenitor cells (CD34+/CD133+/kinase insert domain receptor+ endothelial progenitor cells and CD34+/kinase insert domain receptor+ endothelial progenitor cells) were measured. There was a group×time interaction for the anger versus neutral condition on the change in reactive hyperemia index score from baseline to 40 minutes (P=0.007) with a mean±SD change in reactive hyperemia index score of 0.20±0.67 and 0.50±0.60 in the anger and neutral conditions, respectively. For the change in reactive hyperemia index score, the anxiety versus neutral condition group by time interaction approached but did not reach statistical significance (P=0.054), and the sadness versus neutral condition group by time interaction was not statistically significant (P=0.160). There were no consistent statistically significant group×time interactions for the anger, anxiety, and sadness versus neutral condition on endothelial cell-derived microparticles and endothelial progenitor cells from baseline to 40 minutes. CONCLUSIONS: In this randomized controlled experimental study, a brief provocation of anger adversely affected endothelial cell health by impairing endothelium-dependent vasodilation.

Screen time use in children under 3 years old: a systematic review of correlates.

BACKGROUND: A large percentage (68%) of children under age 3 use screen media, such as television, DVDs and video games, on a daily basis. Research suggests that increased screen time in young children is linked to negative health outcomes, including increased BMI, decreased cognitive and language development and reduced academic success. Reviews on correlates of screen time for young children have included preschool age children and children up to age 7; however, none have focused specifically on correlates among infants and toddlers. As research suggests that screen media use increases with age, examining correlates of early media exposure is essential to reducing exposure later in life. Thus, this paper systemically reviews literature published between January 1999 and January 2013 on correlates of screen time among children between 0 and 36 months of age. METHODS: Two methods were used to conduct this review: (1) Computerized searches of databases (PubMed, PsycINFO, ERIC, Medline); and (2) Reference sections of existing reviews and primary studies. Inclusion criteria were: (1) The article included separate data for children 36 months and younger, (2) English language, (3) peer reviewed article, (4) analysis reported for screen viewing as a dependent variable, (5) original research article and, (6) examined correlates or associations between screen time and other demographic, contextual or behavioral variables. Articles were compiled between 2011 and 2013 and evaluation occurred in 2012 and 2013. RESULTS: The literature search identified 29 studies that met inclusion criteria. These studies investigated a total of 33 potential correlates, which were examined in this review. Findings suggest demographic variables most commonly correlated with high screen time among infants and toddlers are child's age (older) and race/ethnicity (minority). Child BMI, maternal distress/depression, television viewing time of the mother and cognitive stimulation in the home environment were also associated with screen media use. Studies reported that child sex, first born status, paternal education, non-English speaking family, two-parent household, number of children in the home and non-parental childcare were not associated with screen time among children aged 0-36 months. Associations were unclear (fewer than 60% of studies report an association) for maternal age, maternal education and household income. The remaining correlates were investigated in fewer than three studies and thus not coded for an association. CONCLUSIONS: The correlates identified in this study point to avenues for intervention to reduce screen time use in young children. However, further research is necessary to explore a number of environmental, socio-cultural and behavioral correlates that are under-examined in this population and may further inform prevention and intervention strategies.