Adiposity in preadolescent children: Associations with cardiorespiratory fitness

Lifestyle factors contribute to childhood obesity risk, however it is unclear which lifestyle factors are most strongly associated with childhood obesity. The purpose of this cross-sectional study was to simultaneously investigate the associations among dietary patterns, activity behaviors, and physical fitness with adiposity (body fat %, fat mass, body mass index [BMI], and waist to hip ratio) in preadolescent children. Preadolescent children (N = 392, 50% female, age: 9.5 ± 1.1year, BMI: 17.9 ± 3.3 kg/m2) were recruited. Body fat (%) and fat mass (kg) were measured with bioelectrical impedance analysis. Cardiorespiratory fitness (VO2 max), muscular strength (hand-grip strength), activity, sleep, and dietary pattern was assessed. Multivariable analysis revealed that cardiorespiratory fitness associated most strongly with all four indicators of adiposity (body fat (%) (β = -0.2; p < .001), fat mass (β = -0.2; p < .001), BMI (β = -0.1; p < .001) and waist to hip ratio (β = -0.2; p < .001). Additionally, fruit and vegetable consumption patterns were associated with body fat percentage, but the association was negligible (β = 0.1; p = 0.015). Therefore, future interventions should aim to promote the use of cardiorespiratory fitness as a means of reducing the obesity epidemic in children

Scheduled napping on the night shift : consequences for the performance and neurophysiological alertness of air traffic controllers : a thesis submitted for the degree of Doctor of Philosophy of the University of Otago, Dunedin New Zealand

Rapid technological change and increasing traffic volumes worldwide are adding to the safety challenges for air traffic control. The night shift has traditionally been a period of low workload and work practices have evolved to reflect this. Thus, despite the exemplary safety record, there is a need to consider further systemic defences for maintaining performance and safety on the night shift. One possible strategy is the provision of a scheduled nap at work. In order to investigate the consequences of a scheduled nap on the night shift, 28 operational air traffic controllers were monitored across four roster cycles. Each roster cycle included one of two night shifts. Air traffic controllers were given a nap opportunity on one night shift of each type, and did not nap on the other. Information on the timing, quantity, and quality of sleep during the work week and days off was collected using actigraphy, and supported with logbook data. Sleep during the nap was measured using polysomnography, and the EEG and EOG were further utilised to determine neurophysiological alertness over the latter part of the night shift. Reaction time performance was measured three times across the night shift (beginning, middle, and end) with the psychomotor vigilance test.Actigraphy data indicated that the backward, rapidly-rotating work schedule of air traffic controllers resulted in a progressive loss of sleep across the work week. The reduction in sleep lead to an increasing cumulative sleep debt that was at a maximum prior to the night shift. This sleep debt was not related to reaction time performance at the end of the night shift, but was found to influence neurophysiological alertness.It was determined that the large majority of air traffic controllers were able to sleep during the scheduled 40 minute nap opportunity. However, the latency to sleep onset was long, the sleep short, and of relatively poor quality. Circadian and homeostatic factors increased the likelihood of entry into, and waking from, slow wave sleep (SWS). They were also found to influence reaction time performance and neurophysiological alertness. More variable performance and lowered alertness were seen at the end of the later starting (and finishing) night shift, possibly due to the combined influence of circadian and time-on-task factors. Homeostatic variables had less influence on performance at the end of the night shift, but greater acute sleep loss and higher cumulative sleep debts were related to increased neurophysiological sleepiness.performance and greater neurophysiological alertness in a dose-dependent manner, with even small amounts of stage 1 sleep effecting a performance improvement. Performance improvement was consistent across a range of reaction time measures and consistent improvements were also evident in the neurophysiological data, with the occurrence of SEMs declining, and lower spectral power evident in all frequency bands and single frequencies.These findings clearly demonstrate that a minimal quantity of sleep benefits the performance and alertness of air traffic controllers despite the "noise" of a field setting, thus providing a link between laboratory studies of napping and the actual work environment. The findings also fully support management endorsing a 40 minute napping opportunity for air traffic controllers working the night shift.The short nap sleep had no measurable effect on sleep subsequent to the night shift. However, the amount of sleep obtained in the nap was related to improved reaction time

Shiftwork in air traffic services : coping strategies and well-being : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University

It is becoming widely recognised that shiftwork has significant implications for the health, safety and quality of life of shiftworkers. To date, little research has been carried out on how individuals cope with the problems caused by shiftwork and how effective coping strategies maintain their health and well-being. It has been proposed, by Monk (1994), that there are a number of aspects of a shiftworker's life which are important in determining the ability of an individual to cope with shiftwork. These factors are an individual's circadian rhythms, sleep patterns, and social and domestic situation. Further literature also suggests that workplace factors and coping style are an important part of tolerating shiftwork. The primary aim of the present study was to determine which factors are important in predicting the physical and mental well-being of Air Traffic Services staff working on shifts. It was hypothesised that individuals who are evening types, have few social, domestic, sleep, and work place difficulties will be physically and mentally healthy. In addition, it was hypothesised that the use of engagement strategies in dealing with shiftwork related problems will relate to better physical and mental health. To test the hypotheses, 183 Air Traffic Services staff from Melbourne centre, Australia were surveyed by questionnaire. The results of the regressions showed that physical health was predicted by variables from each of the five areas considered; circadian typology, the social and domestic situation, work place factors, sleep patterns and coping style. Mental well-being was best predicted by a single domestic variable, which is the extent to which shiftwork caused domestic problems and the two coping variables of engagement and disengagement. The results support the suggestion that in order for an individual to be able to tolerate shiftwork they must have strategies in place to help them deal with the effect of shiftwork variables on a range of factors in their lives. An additional aim of the present study was to determine the reliability of a questionnaire for use with Air Traffic Services staff. This was due to a lack of suitable questionnaires for use in this occupational context. Overall the items in the questionnaire were found to have acceptable reliability, although the collection of sleep data by subjective reporting is not recommended

Shared responsibility for managing fatigue: Hearing the pilots

<div><p>In commercial aviation, fatigue is defined as a physiological state of reduced mental or physical performance capability resulting from sleep loss, extended wakefulness, circadian phase, and/or workload. The International Civil Aviation Organisation mandates that responsibility for fatigue risk management is shared between airline management, pilots, and support staff. However, to date, the majority of research relating to fatigue mitigations in long range operations has focused on the mitigations required or recommended by regulators and operators. Little research attention has been paid to the views or operational experience of the pilots who use these (or other) mitigations. This study focused on pilots’ views and experiences of in-flight sleep as the primary fatigue mitigation on long range flights. It also sought information about other fatigue mitigation strategies they use. Thematic analysis was used to explore written comments from diary and survey data collected during long range and ultra-long range trips (N = 291 pilots on three different aircraft types, 17 different out-and-back trips, and four airlines based on three continents). The findings indicate that the recommended fatigue mitigation strategies on long-haul flights (particularly in-flight sleep) are effective and well-utilised, consistent with quantitative findings from the same trips. Importantly however, the analyses also highlight areas that require further investigation, including flight preparation strategies in relation to the uncertainty of in-flight break allocation. There were two strategies for sleep prior to a flight: maximising sleep if pilots were expecting later breaks in the flight; or minimising sleep if they were expecting breaks earlier or at unfavourable times in the circadian cycle. They also provide a broader view of the factors that affect the amount and quality of pilots’ in-flight sleep, about which evidence has previously been largely anecdotal. The study underscores the value of including the views and experience of pilots in fatigue risk management.</p></div

Categorisation and frequency of occurrence pilots’ comments relating to in-flight sleep.

<p>Categorisation and frequency of occurrence pilots’ comments relating to in-flight sleep.</p

Categorisation and frequency of occurrence of fatigue management strategies identified by pilots.

<p>Categorisation and frequency of occurrence of fatigue management strategies identified by pilots.</p

Self-reported sleep in late pregnancy in relation to birth size and fetal distress:the E Moe, Māmā prospective cohort study

OBJECTIVES: To explore associations between features of sleep during pregnancy and adverse outcomes for the infant. SETTING: E Moe, Māmā is a cohort study in Aotearoa/New Zealand that investigates self-reported sleep and maternal health in late pregnancy and the postpartum period. PARTICIPANTS: Women (N=633; 194 Māori) reported detailed information on their sleep duration, quality, disturbances, disorders (snoring, breathing pauses, twitching legs, restless legs) and daytime sleepiness between 35 and 37 weeks gestation. OUTCOME MEASURES: Birthweight and fetal distress during labour were extracted from medical records. Associations between each sleep variable and small or large for gestational age (SGA/LGA) using customised birthweight centile or fetal distress were estimated using multinomial/logistic regression, controlling for potential confounders. Secondary analyses considered differences in associations between Māori and non-Māori women. RESULTS: There was some indication that breathing pauses (a measure of sleep apnoea) were associated with both SGA (OR 2.8, 95% CI 0.9 to 9.0, p=0.08) and LGA (OR 2.0, 95% CI 0.7 to 5.7, p=0.20), with the association for LGA being stronger when only pregnancy-onset breathing pauses were considered (OR 3.5, 95% CI 1.3 to 9.6, p=0.01). There was also some evidence that pregnancy-onset leg twitching (OR 3.3, 95% CI 1.1 to 10.0, p=0.03) and frequent sleep disturbance due to feeling too hot or too cold (OR 1.7, 95% CI 0.9 to 3.6, p=0.13) were associated with higher risk of fetal distress. Other sleep measures, including snoring, were not associated with SGA, LGA or fetal distress. Many of the associations we observed were considerably stronger in Māori compared with non-Māori women. CONCLUSIONS: We did not find evidence of previously reported associations between snoring and SGA. Our findings tentatively suggest that self-reported breathing pauses and leg twitching in late pregnancy are associated with infant outcomes, and highlight ethnic inequalities

A Cross-Sectional Investigation of Preadolescent Cardiometabolic Health: Associations with Fitness, Physical Activity, Sedentary Behavior, Nutrition, and Sleep

Background: Cardiometabolic disease (CMD) risk often begins early in life. Healthy lifestyle behaviors can mitigate risk, but the optimal combination of behaviors has not been determined. This cross-sectional study simultaneously examined the associations between lifestyle factors (fitness, activity behaviors, and dietary patterns) and CMD risk in preadolescent children. Methods: 1480 New Zealand children aged 8–10 years were recruited. Participants included 316 preadolescents (50% female, age: 9.5 ± 1.1 years, BMI: 17.9 ± 3.3 kg/m2). Fitness (cardiorespiratory fitness [CRF], muscular fitness), activity behaviors (physical activity, sedentary, sleep), and dietary patterns were measured. Factor analysis was used to derive a CMD risk score from 13 variables (adiposity, peripheral and central hemodynamics, glycemic control, and blood lipids). Results: Only CRF (β = −0.45, p p = 0.019) were associated with the CMD risk score in the adjusted multivariable analysis. CRF was found to be nonlinear (VO2 max ≤ ≈42 mL/kg/min associated with higher CMD risk score), and thus a CRF polynomial term was added, which was also associated (β = 0.19, p < 0.001) with the CMD risk score. Significant associations were not found with sleep or dietary variables. Conclusion: The findings indicate that increasing CRF and decreasing sedentary behavior may be important public health targets in preadolescent children