Undiagnosed Obstructive Sleep Apnea and Physical Activity in Older Manual Workers

First paragraph: Sleep is essential for life and integral to health and well-being (Roehrs, 2000). However, during the aging process, sleep patterns become disrupted, which leads to sleep deprivation (Stanley, 2005). Inadequate sleep has adverse effects on the body, including the production of higher cortisol (stress hormone) levels, which causes wear and tear physiologically, and further contributes to wakefulness (Stanley, 2005)

Σύγκριση των επιδράσεων της έκθεσης σε Όζον στο αναπνευστικό σύστημα των παιδιών με χρήση διαφορετικών δεικτών έκθεσης στο πλαίσιο της μελέτης RESPOZE

Εισαγωγή: Αποτελέσματα πρόσφατων μελετών τεκμηριώνουν τις επιδράσεις της ατμοσφαιρικής ρύπανσης (κυρίως της σωματιδιακής) στην υγεία. Ωστόσο, υπάρχει η ανάγκη διερεύνησης των επιδράσεων των αέριων ρύπων, κυρίως του όζοντος (Ο3), σε ευαίσθητες ομάδες, με εκτίμηση της προσωπικής έκθεσης. Σκοπός: Ο σκοπός της παρούσας διπλωματικής εργασίας ήταν η αξιολόγηση του μοντέλου χρήσης γης και η σύγκρισή του με 2 άλλες μεθόδους προσδιορισμού της έκθεσης καθώς και η χρησιμότητά του στη διερεύνηση της βραχυχρόνιας και μακροχρόνιας εξατομικευμένης έκθεσης σε O3 στο αναπνευστικό σύστημα των παιδιών σχολικής ηλικίας, στο πλαίσιο της μελέτης RESPOZE. Υλικό και Μέθοδος: Στην επιδημιολογική μελέτη RESPOZE (RESpiratory effects of OZone Exposure in children) παρακολουθήθηκαν εντατικά 97 μαθητές Ε' Δημοτικού δημοσίων σχολείων μόνιμοι κάτοικοι της ευρύτερης περιοχής της Αθήνας για 35 ημέρες σε συνολική διάρκεια 5 εβδομάδων, και συλλέχθηκαν ημερήσια δεδομένα μέγιστης εκπνευστικής ροής (PEF) με φορητά ροόμετρα, οι εβδομαδιαίες μετρήσεις σπιρομετρήσεων, της ταχέως εκπνεόμενης ζωτικής χωρητικότητας (FVC) και τoυ ταχέως εκπνεόμενου όγκου αέρα στο πρώτο δευτερόλεπτο (FEV1), καθώς και η ημερήσια εμφάνιση αναπνευστικών συμπτωμάτων. Δείκτης εκτίμησης της εξατομικευμένης έκθεσης των παιδιών σε Ο3 στη διεύθυνση κατοικίας τους, αποτέλεσαν οι μετρήσεις Ο3 από τον κοντινότερο σταθμό μέτρησης του ΥΠΕΚΑ, οι εκτιμήσεις των συγκεντρώσεων όζοντος από χωρο-χρονικό μοντέλο χρήσης γης που αναπτύχθηκε για την ευρύτερη περιοχή της Αθήνας και οι εκτιμήσεις από μοντέλο διάχυσης χημικού μετασχηματισμού. Ως δείκτες της αναπνευστικής λειτουργίας των παιδιών χρησιμοποιήθηκαν οι μετρήσεις PEF, FVC και FEV1. Επίσης, μελετήθηκαν τα αυτο-αναφερόμενα συμπτώματα και συγκεκριμένα ο βήχας, το συνάχι/βουλωμένη μύτη, το οποιοδήποτε σύμπτωμα (παρουσία ή απουσία συμπτώματος) και τα δεδομένα για τις απουσίες από το σχολείο (απουσία ή όχι απουσία από το σχολείο τουλάχιστον μία φορά κατά τη διάρκεια της μελέτης). Για την προσαρμογή πιθανών συγχυτικών επιδράσεων χρησιμοποιήθηκαν ατομικά δεδομένα που συλλέχθηκαν από εκτενή ερωτηματολόγια. Η διερεύνηση των βραχυχρόνιων και μακροχρόνιων επιδράσεων του Ο3 έγινε με εφαρμογή μοντέλων μικτών επιδράσεων και πολλαπλής γραμμικής παλινδρόμησης, αντίστοιχα. Αποτελέσματα: Βρέθηκε επιβαρυντική και στατιστικά σημαντική σχέση μεταξύ της βραχυχρόνιας έκθεσης στο O3 , εκτιμώμενο από μετρήσεις από τον κοντινότερο σταθμό του ΥΠΕΚΑ, και των οποιοδήποτε σύμπτωμα, ρινική συμφόρηση και βήχα (σχετικός λόγος (ΣΛ) 1.09, 95% ΔΕ: 1.01, 1.18, 1.14, 95% ΔΕ: 1.03, 1.22 και 1.11, 95% ΔΕ: 1.01, 1.22 αντίστοιχα, για 10μg/m3 αύξηση στο O3). Δεν παρατηρήθηκε σχέση με τις μετρήσεις PEF και τους δείκτες FVC και FEV1 σε σχέση με τη βραχυχρόνια αλλά και μακροχρόνια έκθεση σε O3. Η σχέση της απουσίας από το σχολείο και της μακροχρόνιας έκθεσης στο O3 βρέθηκε επιβαρυντική και στατιστικά σημαντική, όσον αφορά τις εκτιμήσεις Ο3 από το χωρο-χρονικό μοντέλο χρήσης γης. Ενδεικτικά, για κάθε 10μg/m3 άνοδο στα επίπεδα O3 είναι 32% πιο πιθανό κάποιος μαθητής να απουσιάζει από το σχολείο. Συμπεράσματα: Η ημερήσια έκθεση σε Ο3 συσχετίζεται με αυξημένη πιθανότητα εμφάνισης οποιουδήποτε συμπτώματος, ρινικής συμφόρησης και βήχα. Επίσης, η μακροχρόνια έκθεση σε Ο3 συσχετίζεται με αυξημένη πιθανότητα απουσίας από το σχολείο. Από τα αποτελέσματα της παρούσας μελέτης προκύπτουν ενδείξεις για επιβαρυντική επίδραση της έκθεσης σε O3 στην αναπνευστική λειτουργία των παιδιών, οι οποίες χρήζουν περαιτέρω διερεύνησης.Introduction: Results from several epidemiological studies have provided evidence on the adverse health effects from exposure to air pollution. However, there is a need to investigate the effects from exposure to air pollution, mainly Ozone (Ο3), on sensitive groups, assesing personal exposure. Objective: The purpose of this present Dissertation was to evaluate the land use regression models and to compare it with 2 other evaluating methods of O3 exposure and also to investigate the effects, of short-term and long-term exposure to O3 on the respiratory health of children within the framework of the RESPOZE panel study. Materials and Methods: A panel of 97 children, aged 10-11 years, were followed intensively for 35 days (spanning over 5 weeks) and PEF was recorded with the use of mini-Wright portable spirometers and also FVC (forced vital capacity) and FEV1 (forced expiratory volume in 1 s). Moreover, every child was recording daily symptoms, such as cough, stuffy nose or any symptom and also data on absence of school. Our exposure metrics were predicted either from Land use regression models (LUR) or Dispersion models, or they were derived from fixed monitoring site nearest to the child’s school location. Confounding data were gathered from extensive questionnaires. On the one hand, mixed effects models for repeated measurements were applied for investigating the effects of short-term exposure to O3. On the other hand, multi-linear regression models were applied for investigating the effects of long-term exposure to O3. Multiple linear or logistic regression was used according to the outcome variable, adjusting for several confounders. Results: There was an aggravating and statistically significant relationship between the short-term exposure to O3 , derived from fixed monitoring sites, and any symptom, stuffy nose and cough (odds ratio (OR) 1.09, 95% CI: 1.01, 1.18, 1.14, 95% CI: 1.03, 1.22 and 1.11, 95% CI: 1.01, 1.22 respectively, for each 10μg/m3 increase in O3). No association was observed with PEF measurements and also FVC and FEV1 markers in relation to both short and long-term exposure to O3. The relationship between absence from school and long-term exposure to O3 has been aggravating and statistically significant with or without PM10 variable in the model, with regard to O3 predictions from LUR models. For instance, for every 10μg/m3 units increase in O3 levels in the atmosphere is 32% more likely that a student is absent from school. Conclusion: Our findings indicate association between short-term exposure to O3 with respiratory symptoms such as cough, stuffy nose or any symptom among the general population subgroup of children. We also found that there is association between long-term exposure to O3 with absence from school. The results of this study provide evidence on the adverse effects of exposure to O3 on the respiratory health of children, which need further investigation

Resilience, work engagement and stress reactivity in a middle-aged manual worker population

Work stress is a growing problem in Europe. Together, the negative physiological effect of stress on health, and increasing age increases the risk of developing cardiovascular disease in those aged over 50 years. Therefore, identifying older workers who may be at risk of work-related stress, and its physiological effects, is key to promoting their health and wellbeing in the workforce. The present study examined the relationship between perceived psychological resilience and work-related factors (work engagement and presenteeism) and the physiological response to acute psychological stress in older manual workers in the UK. Thirty-one participants, mean (SD) age 54.9 (3.78) years reported perceived levels of resilience, work engagement, and presenteeism using standardized questionnaires. Cardiovascular measurements (heart rate (HR) and blood pressure (BP) and salivary cortisol were used to assess their physiological response to an acute psychological stress task. Resilience was not associated with work-related factors or reactivity. However, workers with higher work engagement showed lower SBP (p = 0.02) and HR (p = 0.001) reactivity than those with lower work engagement. Further, those with higher sickness presenteeism also had higher HR reactivity (p = 0.03). This suggests a potential pathway by which higher work stress might contribute to the risk of future cardiovascular disease

Abnormal retinal vascular reactivity in individuals with impaired glucose tolerance:a preliminary study

To investigate the relationship between vascular function parameters measured at the retinal and systemic level and known markers for cardiovascular risk in patients with impaired glucose tolerance (IGT). Sixty age- and gender- matched White-European adults (30 IGT and 30 normal glucose tolerance -NGT) were recruited for the study. Fasting plasma glucose, lipids and 24-hour blood pressure (BP) was measured in all subjects. Systemic vascular and endothelial function was assessed using carotid-artery intimal media thickness (cIMT) and flow mediated dilation (FMD). Retinal vascular reactivity was assessed by the Dynamic Retinal Vessel Analyser (DVA). Additionally, blood glutathione (GSH, GSSG and tGSH) and plasma von-Willebrand (vWF) factor levels were also measured. Individuals with IGT demonstrated higher BP values (p<0.001), fasting TG and TG:HDL ratios (p<0.001) than NGT subjects. Furthermore, Total:HDL-C ratios and Framingham scores were raised (p=0.010 and p<0.001 respectively). Blood glutathione levels (GSH, GSSG and tGSH) were lower (p<0.001, p=0.039 and p<0.001 respectively) while plasma vWF was increased (p=0.014) in IGT subjects compared to controls. IGT individuals also demonstrated higher IMT in right and left carotid arteries (p=0.017 and p=0.005, respectively) alongside larger brachial artery diameter (p=0.015), lower FMD% (p=0.026) and GTN induced dilation (GID) (p=0.012) than healthy controls. At the retinal arterial level, the IGT subjects showed higher baseline fluctuations (BDF) (p=0.026), longer reaction time (RT) (p=0.032) and reduced baseline-corrected flicker response (bFR) (p=0.045). In IGT subjects retinal BDF correlated with and Total:HDL (p= 0.003) and HDL-C (p= 0.004). Arterial RT also correlated with FMD (p=0.017) in IGT but not NGT subjects. In IGT individuals there is a relationship between macro- and microvascular function, as well as a direct correlation between the observed retinal microcirculatory changes and established plasma markers for CVD. Multifactorial preventive interventions to decrease vascular risk in these individuals should be considered

The Use of Imagery to Manipulate Challenge and Threat Appraisal States in Athletes

The present study investigated whether imagery could manipulate athletes’ appraisal of stress-evoking situations (i.e., challenge or threat) and whether psychological and cardiovascular responses and interpretations varied according to cognitive appraisal of three imagery scripts: challenge, neutral, and threat. Twenty athletes (Mage = 20.85; SD = 1.76; 10 female, 10 male) imaged each script while heart rate, stroke volume, and cardiac output were obtained using Doppler echocardiography. State anxiety and self-confidence were assessed following each script using the Immediate Anxiety Measures Scale. During the imagery, a significant increase in heart rate, stroke volume, and cardiac output occurred for the challenge and threat scripts (p &lt; .05). Although there were no differences in physiological response intensities for both stress-evoking scripts, these responses, along with anxiety symptoms, were interpreted as facilitative during the challenge script and debilitative during the threat script. Results support using imagery to facilitate adaptive stress appraisal.</jats:p

The effects of time of day and chronotype on cognitive and physical performance in healthy volunteers

Abstract Background Whether you are a morning lark or a night owl has proven to be a key contributor in the timing of peak athletic performance. Recent evidence suggests that accounting for these differences, known as one’s chronotype, results in significantly different diurnal performance profiles. However, there is limited research investigating multiple measures of performance simultaneously over the course of a socially constrained day. Objectives This study aimed to investigate the impact of chronotype on indices of cognitive and physical performance at different times of day in healthy volunteers. Methods We recruited 56 healthy individuals categorised as early (ECT, n = 25) or late (LCT, n = 31) chronotypes using the Munich ChronoType Questionnaire, circadian phase markers and objective actigraphy. Measures of cognitive and physical performance, along with self-reported daytime sleepiness, were taken at multiple times of day (14:00 h, 20:00 h and 08:00 h the following morning). Results Here, we find significantly different diurnal variation profiles between ECTs and LCTs, for daytime sleepiness, psychomotor vigilance, executive function and isometric grip strength. LCTs were significantly impaired in all measures in the morning compared to ECTs. Conclusion Our results provide evidence to support the notion that ‘night owls’ are compromised earlier in the day. We offer new insight into how differences in habitual sleep patterns and circadian rhythms impact cognitive and physical measures of performance. These findings may have implications for the sports world, e.g. athletes, coaches and teams, who are constantly looking for ways to minimise performance deficits and maximise performance gains

The increase in pulmonary arterial pressure caused by hypoxia depends on iron status

Hypoxia is a major cause of pulmonary hypertension. Gene expression activated by the transcription factor hypoxia-inducible factor (HIF) is central to this process. The oxygen-sensing iron-dependent dioxygenase enzymes that regulate HIF are highly sensitive to varying iron availability. It is unknown whether iron similarly influences the pulmonary vasculature. This human physiology study aimed to determine whether varying iron availability affects pulmonary arterial pressure and the pulmonary vascular response to hypoxia, as predicted biochemically by the role of HIF. In a controlled crossover study, 16 healthy iron-replete volunteers undertook two separate protocols. The ‘Iron Protocol’ studied the effects of an intravenous infusion of iron on the pulmonary vascular response to 8 h of sustained hypoxia. The ‘Desferrioxamine Protocol’ examined the effects of an 8 h intravenous infusion of the iron chelator desferrioxamine on the pulmonary circulation. Primary outcome measures were pulmonary artery systolic pressure (PASP) and the PASP response to acute hypoxia (ΔPASP), assessed by Doppler echocardiography. In the Iron Protocol, infusion of iron abolished or greatly reduced both the elevation in baseline PASP (P < 0.001) and the enhanced sensitivity of the pulmonary vasculature to acute hypoxia (P = 0.002) that are induced by exposure to sustained hypoxia. In the Desferrioxamine Protocol, desferrioxamine significantly elevated both PASP (P < 0.001) and ΔPASP (P = 0.01). We conclude that iron availability modifies pulmonary arterial pressure and pulmonary vascular responses to hypoxia. Further research should investigate the potential for therapeutic manipulation of iron status in the management of hypoxic pulmonary hypertensive disease

Diurnal Variations in Vascular Endothelial Vasodilation Are Influenced by Chronotype in Healthy Humans

Introduction: The time of day when cardiovascular events are most likely to occur is thought to be aligned with the circadian rhythm of physiological variables. Chronotype has been shown to influence the time of day when cardiovascular events happen, with early chronotypes reported to be more susceptible in the morning and late chronotypes in the evening. However, no studies have investigated the influence of chronotype on physiological variables responsible for cardiovascular regulation in healthy individuals. Methods: 312 individuals completed the Munich ChronoType Questionnaire to assess chronotype. Twenty participants were randomly selected to continue into the main study. In a repeated-measures experiment, participants were tested between 08:00 and 10:00 h and again between 18:00 and 20:00 h. Measurements of mean arterial pressure, heart rate and vascular endothelial vasodilation via flow-mediated dilatation (FMD) were obtained at each session. Results: Individual diurnal differences in mean arterial pressure and heart rate show no significant relationship with chronotype. Diurnal differences in FMD showed a significant correlation (p = 0.010), driven by a clear significant relationship in the evening and not the morning (p &lt; 0.001). Conclusion: These preliminary data indicate that chronotype influences the diurnal variation of endothelial vasodilation measured using flow-mediated dilatation. Furthermore, we show that the influence of chronotype is much stronger in the evening, highlighting an increased susceptibility for later types. These findings are consistent with the diurnal rhythm in cardiovascular events and uncover potential mechanisms of local mediators that may underpin the influence of chronotype in the onset of these events