Impact of firefighters' work schedule on cardiovascular disease risk, wellbeing and safety in firefighters: protocol for the SWIFT study, a multidisciplinary prospective and cross-sectional study.

Introduction: Firefighters face frequent physical and psychosocial stressors, increasing their risk for hypertension. Rising call volumes with a stable workforce have heightened occupational burdens. To meet their occupational demands while increasing time off-duty, fire departments across the country have switched from a 24 hours on 48 hours off (termed '24/48') work schedule to one that increases the number of consecutive days off (eg, 1 day on, 3 days off, 2 days on, 3 days off (termed '1/3/2/3') or 48 hours on 96 hours off (termed '48/96')).

The endogenous circadian system impairs nighttime blood pressure responses to active standing in older adults.

Falls affect approximately 30% of older adults and are a major cause of morbidity and mortality, especially when they occur at night. Impaired blood pressure (BP) recovery upon standing is a known predictor of falls and mortality. Whereas younger adults show circadian-system-driven reductions in BP response to passive postural tilt at night, circadian influences on BP responses to active standing in both young and older adults are unknown.

Sex differences in the relationship between self-selected sleep-wake timing and morning cardiovascular risk in midlife adults.

Adverse cardiovascular (CV) events occur most frequently in the morning. People who wake up later in the morning appear to have an increased risk of these events, but the mechanisms causing this effect are unknown. Vascular endothelial function (VEF) is a prognostic marker for these adverse events.

Sleep, psychological symptoms, and cannabis use before, during, and after COVID-19 "stay-at-home" orders: a structural equation modeling approach.

Background: Given the frequent use of cannabis for sleep and mental health symptoms, we aimed to prospectively examine the reciprocal relationship between sleep, mental health, and cannabis use from before, during, and 1 year after the implementation of COVID-19 stay-at-home orders.

Methods: Five hundred thirty-four young adults (21-34 years old) from Oregon and Washington States who previously completed a survey on their sleep and cannabis use prior to stay-at-home orders (T0), were followed up after initial stay-at-home orders were in place for approximately two months (T1), and one year later (T2), to reassess sleep and cannabis use. Sleep measures included the presence of sleep trouble [yes/no], and weekday and weekend sleep duration.

Effectiveness and Durability of a Workplace Sedentary Behavior Intervention Based on the Approach.

We used the approach to develop a multi-component workplace sedentary behavior intervention and tested intervention effectiveness in a cluster randomized trial. Participants ( = 198; 75% female) were recruited from three call-centers (two intervention and one usual practice control). All worksites received pedal stand active workstations.

Circadian Alignment, Cardiometabolic Disease, and Sex-Specific Differences in Adults With Overweight/Obesity.

Context: Circadian disruption promotes weight gain and poor health. The extent to which sex plays a role in the relationship between the circadian timing of behaviors and health outcomes in individuals with overweight/obesity is unclear.

Objective: We investigated the sex-specific associations between circadian alignment and cardiometabolic health markers in females and males with overweight/obesity.

Belonging, endurance, and resistance: Black placemaking theory in primary care.

Black-Americans continue to experience pervasive health disparities. Factors contributing to increased disease risk include a general mistrust of biomedical institutions among Black Americans. The purpose of this focus group study was to identify, among Black patients who regularly seek care from a primary provider, salient themes regarding barriers to 1) receiving quality primary care; and 2) adhering to medical recommendations.

Obesity alters the circadian profiles of energy metabolism and glucose regulation in humans.

Objective: Given the complex interaction among the circadian system, energy metabolism, and obesity, the authors tested whether having obesity impacts the circadian variation in energy and glucose metabolism in humans.

Methods: Participants with BMI either in the healthy weight or obesity ranges were studied in a 5-day, in-laboratory protocol that equally distributed behaviors (i.e.

Chronological distribution of readings in ambulatory blood pressure monitoring exams affects the nighttime average and the magnitude of blood pressure dipping.

Study Objectives: Averaged nighttime blood pressure (BP) is superior to daytime BP for cardiovascular risk stratification, and the relative change between daytime/nighttime BP (dipping%) significantly predicts cardiovascular risk. Newer reports suggest that 4 measurements at night may be enough for cardiovascular risk stratification. Since BP oscillates across the night, the temporal distribution of measurements across the night may impact nighttime BP and dipping%.

Multidimensionality of the PROMIS sleep disturbance 8b short form in working adult populations.

Objectives: The Patient-Reported Outcomes Measurement Information System sleep disturbance measures were developed using item response theory assumptions of unidimensionality and local independence. Given that sleep health is multidimensional, we evaluate the factor structure of the Patient-Reported Outcomes Measurement Information System sleep disturbance 8b short form to examine whether it reflects a unidimensional or multidimensional construct.

Methods: Six full-time working adult samples were collected from civilian and military populations.

The Tech4Rest Randomized Controlled Trial: Applying the Hierarchy of Controls to Advance the Sleep, Health, and Well-being of Team Truck Drivers.

Objective: The aim of the study was to evaluate the effectiveness of interventions to improve sleep, reduce fatigue, and advance the well-being of team truck drivers.

Methods: In a randomized controlled trial ( k = 24 teams; N = 49 drivers; 61.3% of planned sample), intervention teams were exposed to baseline (3-4 weeks), cab enhancements (active suspension seat, therapeutic mattress; 3-4 weeks), and cab enhancements plus a behavioral sleep-health program (1-2 months).

Keeping an eye on circadian time in clinical research and medicine.

Background: Daily rhythms are observed in humans and almost all other organisms. Most of these observed rhythms reflect both underlying endogenous circadian rhythms and evoked responses from behaviours such as sleep/wake, eating/fasting, rest/activity, posture changes and exercise. For many research and clinical purposes, it is important to understand the contribution of the endogenous circadian component to these observed rhythms.

The circadian system modulates the cortisol awakening response in humans.

Background: In humans, circulating cortisol usually peaks 30-60 min after awakening from nocturnal sleep, this is commonly referred to as the cortisol awakening response (CAR). We examined the extent to which the CAR is influenced by the circadian system, independent of behaviors including sleep.

Materials And Methods: We examined the CAR in 34 adults (20 female) using two complementary multiday in-laboratory circadian protocols performed in dim light, throughout which behavioral factors were uniformly distributed across the 24-hour circadian cycle.

Daily cannabis use is associated with sleep duration differentially across ages.

Objective: To assess the relationship between frequency of cannabis use and sleep duration across age in a large US population (235,667 people).

Methods: Multinomial logistic regression was used to evaluate the association between the frequency of cannabis use and sleep duration using cross sectional data from the 2016-2018 Behavioral Risk Factor Surveillance System.

Results: When adjusted for sociodemographic factors, health related variables, and stratified by age we found that young adults (18-44 years) who reported daily-use (≥16 uses a month) had an increased risk ratio (RR [95% CI]) for either short or long sleep (1.

Chronobiology of Exercise: Evaluating the Best Time to Exercise for Greater Cardiovascular and Metabolic Benefits.

Physiological function fluctuates across 24 h due to ongoing daily patterns of behaviors and environmental changes, including the sleep/wake, rest/activity, light/dark, and daily temperature cycles. The internal circadian system prepares the body for these anticipated behavioral and environmental changes, helping to orchestrate optimal cardiovascular and metabolic responses to these daily changes. In addition, circadian disruption, caused principally by exposure to artificial light at night (e.

Sleep and Executive Functioning in Pediatric Traumatic Brain Injury Survivors after Critical Care.

Over 50,000 children are hospitalized annually for traumatic brain injury (TBI) and face long-term cognitive morbidity. Over 50% develop sleep/wake disturbances (SWDs) that can affect brain development and healing. We hypothesized SWDs would portend worse executive function outcomes in children aged 3−18 years with TBI 1−3 months after hospital discharge.

Slow wave synchronization and sleep state transitions.

Spontaneous synchronization over large networks is ubiquitous in nature, ranging from inanimate to biological systems. In the human brain, neuronal synchronization and de-synchronization occur during sleep, with the greatest degree of neuronal synchronization during slow wave sleep (SWS). The current sleep classification schema is based on electroencephalography and provides common criteria for clinicians and researchers to describe stages of non-rapid eye movement (NREM) sleep as well as rapid eye movement (REM) sleep.

Understanding Circadian Mechanisms of Sudden Cardiac Death: A Report From the National Heart, Lung, and Blood Institute Workshop, Part 2: Population and Clinical Considerations.

Sudden cardiac death (SCD) is the sudden, unexpected death due to abrupt loss of heart function secondary to cardiovascular disease. In certain populations living with cardiovascular disease, SCD follows a distinct 24-hour pattern in occurrence, suggesting day/night rhythms in behavior, the environment, and endogenous circadian rhythms result in daily spans of increased vulnerability. The National Heart, Lung, and Blood Institute convened a workshop, Understanding Circadian Mechanisms of Sudden Cardiac Death to identify fundamental questions regarding the role of the circadian rhythms in SCD.

Understanding Circadian Mechanisms of Sudden Cardiac Death: A Report From the National Heart, Lung, and Blood Institute Workshop, Part 1: Basic and Translational Aspects.

Sudden cardiac death (SCD), the unexpected death due to acquired or genetic cardiovascular disease, follows distinct 24-hour patterns in occurrence. These 24-hour patterns likely reflect daily changes in arrhythmogenic triggers and the myocardial substrate caused by day/night rhythms in behavior, the environment, and endogenous circadian mechanisms. To better address fundamental questions regarding the circadian mechanisms, the National Heart, Lung, and Blood Institute convened a workshop, Understanding Circadian Mechanisms of Sudden Cardiac Death.