168 research outputs found

    Effects of Moderate Sleep Restriction During 8-week Calorie Restriction on Lipoprotein Particles and Glucose Metabolism

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    Study Objectives This study examined how glucose, glucose regulatory hormones, insulin sensitivity, and lipoprotein subclass particle concentrations and sizes change with sleep restriction during weight loss elicited by calorie restriction. Methods Overweight or obese adults were randomized into an 8-week calorie restriction intervention alone (CR, n = 12; 75% female; body mass index = 31.4 ± 2.9 kg/m2) or combined with sleep restriction (CR+SR, n = 16; 75% female; body mass index = 34.5 ± 3.1 kg/m2). Participants in both groups were given the same instructions to reduce calorie intake. Those in the CR+SR group were instructed to reduce their habitual time-in-bed by 30–90 minutes 5 days each week with 2 ad libitum sleep days. Fasting venous blood samples were collected at pre- and post-intervention. Results Differential changes were found between the two groups (p = 0.028 for group × time interaction) in glucagon concentration, which decreased in the CR group (p = 0.016) but did not change in CR+SR group. Although changes in mean HDL particle (HDL-P) size and visfatin concentration were not statistically different between groups (p = 0.066 and 0.066 for group×time interaction, respectively), mean HDL-P size decreased only in the CR+SR group (Cohen’s d = 0.50, p = 0.022); visfatin concentrations did not change significantly in either group but appeared to decrease in the CR group (Cohen’s d = 0.67, p = 0.170) but not in the CR+SR group (Cohen’s d = 0.43, p = 0.225). Conclusion These results suggest that moderate sleep restriction, despite the presence of periodic ad libitum sleep, influences lipoprotein subclass particles and glucose regulation in individuals undergoing calorie restriction. Clinical trial registration: ClinicalTrials.gov (NCT02413866, Weight Outlooks by Restriction of Diet and Sleep

    Circadian Disruption, \u3cem\u3ePer3\u3c/em\u3e, and Human Cytokine Secretion

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    Circadian disruption has been linked with inflammation, an established cancer risk factor. Per3 clock gene polymorphisms have also been associated with circadian disruption and with increased cancer risk. Patients completed a questionnaire and provided a blood sample prior to undergoing a colonoscopy (n=70). Adjusted mean serum cytokine concentrations (IL-6, TNF-alpha, gamma-INF, IL-I ra, IL-I-beta, VEGF) were compared among patients with high and low scores for fatigue (Multidimensional Fatigue Inventory), depressive symptoms (Beck Depression Inventory II), or sleep disruption (Pittsburgh Sleep Quality Index), or among patients with different Per3 clock gene variants. Poor sleep was associated with elevated VEGF, and fatigue-related reduced activity was associated with elevated TNF-alpha concentrations. Participants with the 4/5 or 5/5 Per3 variable tandem repeat sequence had elevated IL-6 concentrations compared to those with the 4/4 genotype. Biological processes linking circadian disruption with cancer remain to be elucidated. Increased inflammatory cytokine secretion may play a role

    Physical Fitness and Depressive Symptoms during Army Basic Combat Training

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    Mental health-related problems are a significant cause of attrition during Basic Combat Training (BCT). Evidence in civilian populations suggests that physical fitness is associated with psychological benefits in civilians, but little is known about the association between physical fitness and psychological adjustment during BCT

    Differences in pre-sleep activity and sleep location are associated with variability in daytime/nighttime sleep electrophysiology in the domestic dog

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    The domestic dog (Canis familiaris) is a promising animal model. Yet, the canine neuroscience literature is predominantly comprised of studies wherein (semi-)invasive methods and intensive training are used to study awake dog behavior. Given prior findings with humans and/or dogs, our goal was to assess, in 16 family dogs (1.5–7 years old; 10 males; 10 different breeds) the effects of pre-sleep activity and timing and location of sleep on sleep electrophysiology. All three factors had a main and/or interactive effect on sleep macrostructure. Following an active day, dogs slept more, were more likely to have an earlier drowsiness and NREM, and spent less time in drowsiness and more time in NREM and REM. Activity also had location- and time of day-specific effects. Time of day had main effects; at nighttime, dogs slept more and spent less time in drowsiness and awake after first drowsiness, and more time in NREM and in REM. Location had a main effect; when not at home, REM sleep following a first NREM was less likely. Findings are consistent with and extend prior human and dog data and have implications for the dog as an animal model and for informing future comparative research on sleep

    Stimulant Reduction Intervention using Dosed Exercise (STRIDE) - CTN 0037: Study protocol for a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>There is a need for novel approaches to the treatment of stimulant abuse and dependence. Clinical data examining the use of exercise as a treatment for the abuse of nicotine, alcohol, and other substances suggest that exercise may be a beneficial treatment for stimulant abuse, with direct effects on decreased use and craving. In addition, exercise has the potential to improve other health domains that may be adversely affected by stimulant use or its treatment, such as sleep disturbance, cognitive function, mood, weight gain, quality of life, and anhedonia, since it has been shown to improve many of these domains in a number of other clinical disorders. Furthermore, neurobiological evidence provides plausible mechanisms by which exercise could positively affect treatment outcomes. The current manuscript presents the rationale, design considerations, and study design of the National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN) CTN-0037 Stimulant Reduction Intervention using Dosed Exercise (STRIDE) study.</p> <p>Methods/Design</p> <p>STRIDE is a multisite randomized clinical trial that compares exercise to health education as potential treatments for stimulant abuse or dependence. This study will evaluate individuals diagnosed with stimulant abuse or dependence who are receiving treatment in a residential setting. Three hundred and thirty eligible and interested participants who provide informed consent will be randomized to one of two treatment arms: Vigorous Intensity High Dose Exercise Augmentation (DEI) or Health Education Intervention Augmentation (HEI). Both groups will receive TAU (i.e., usual care). The treatment arms are structured such that the quantity of visits is similar to allow for equivalent contact between groups. In both arms, participants will begin with supervised sessions 3 times per week during the 12-week acute phase of the study. Supervised sessions will be conducted as one-on-one (i.e., individual) sessions, although other participants may be exercising at the same time. Following the 12-week acute phase, participants will begin a 6-month continuation phase during which time they will attend one weekly supervised DEI or HEI session.</p> <p>Clinical Trials Registry</p> <p>ClinicalTrials.gov, <a href="http://www.clinicaltrials.gov/ct2/show/NCT01141608">NCT01141608</a></p> <p><url>http://clinicaltrials.gov/ct2/show/NCT01141608?term=Stimulant+Reduction+Intervention+using+Dosed+Exercise&rank=1</url></p

    Timely questions emerging in Chronobiology : the Circadian Clock keeps on ticking

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    Chronobiology investigations have revealed much about cellular and physiological clockworks but we are far from having a complete mechanistic understanding of the physiological and ecological implications. Here we present some unresolved questions in circadian biology research as posed by the editorial staff and guest contributors to the Journal of Circadian Rhythms. This collection of ideas is not meant to be comprehensive but does reveal the breadth of our observations on emerging trends in chronobiology and circadian biology. It is amazing what could be achieved with various expected innovations in technologies, techniques, and mathematical tools that are being developed. We fully expect strengthening mechanistic work will be linked to health care and environmental understandings of circadian function. Now that most clock genes are known, linking these to physiological, metabolic, and developmental traits requires investigations from the single molecule to the terrestrial ecological scales. Real answers are expected for these questions over the next decade. Where are the circadian clocks at a cellular level? How are clocks coupled cellularly to generate organism level outcomes? How do communities of circadian organisms rhythmically interact with each other? In what way does the natural genetic variation in populations sculpt community behaviors? How will methods development for circadian research be used in disparate academic and commercial endeavors? These and other questions make it a very exciting time to be working as a chronobiologist

    Effects of sleep deprivation on neural functioning: an integrative review

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    Sleep deprivation has a broad variety of effects on human performance and neural functioning that manifest themselves at different levels of description. On a macroscopic level, sleep deprivation mainly affects executive functions, especially in novel tasks. Macroscopic and mesoscopic effects of sleep deprivation on brain activity include reduced cortical responsiveness to incoming stimuli, reflecting reduced attention. On a microscopic level, sleep deprivation is associated with increased levels of adenosine, a neuromodulator that has a general inhibitory effect on neural activity. The inhibition of cholinergic nuclei appears particularly relevant, as the associated decrease in cortical acetylcholine seems to cause effects of sleep deprivation on macroscopic brain activity. In general, however, the relationships between the neural effects of sleep deprivation across observation scales are poorly understood and uncovering these relationships should be a primary target in future research

    Drivers of Change or Cut-Throat Competitors? Challenging Cultures of Innovation of Chinese and Nigerian Migrant Entrepreneurs in West Africa

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    L'afflux remarquable des entrepreneurs migrants chinois dans différents pays d'Afrique occidentale au cours des dernières années a été heurtée à une résistance de plus en plus farouche par des entrepreneurs locaux établis. Que le premiers ont un avantage concurrentiel sur ce dernier en raison de traits socio-culturels distinctifs, ou si l'efficacité supposée chinoise est juste une caractéristique de toutes les diasporas mercantiles, est ouvert à la question. Cette étude exploratoire des migrants entrepreneuriales chinois et nigérians au Ghana et au Bénin tente de répondre à cette question. Apparemment, les forces culturels des agents du changement migrants ne sont pas limités à des systèmes de valeurs héritées ou religions, comme une éthique protestante ou le confucianisme, mais ils sont adaptés en permanence et ont inventé de nouveau par des réseaux transnationaux de la migration dans un monde globalisé. Il n'y a aucune preuve d'une prétendue supériorité de la culture d’innovation chinois par rapport aux cultures d’innovation africains des migrants entrepreneuriales. Plutôt, il existe une capacité accrue d'innovation d'une diaspora mercantile en général vis à vis des entrepreneurs locaux, indépendamment de l'origine de la culture nationale dans lequel il est intégré. En outre, la rivalité des entrepreneurs migrants chinois et nigérians dans les marchés africains ne conduit pas nécessairement à la concurrence coupe-gorge souvent suspectée sous l'impact de la mondialisation. Souvent, les deux groupes agissent plutôt complémentaires. Cela contribue, sous certaines conditions, même à la réduction de la pauvreté dans le pays d'accueil

    Association between visual impairment and sleep duration: analysis of the 2009 National Health Interview Survey (NHIS)

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    BACKGROUND: Visual impairment (VI) is associated with increased mortality and health factors such as depression and cardiovascular disease. Epidemiologic studies consistently show associations between sleep duration with adverse health outcomes, but these have not systematically considered the influence of VI. The aim of this study was to ascertain the independent association between VI and sleep duration using the National Health Interview Survey (NHIS) data. We also examined whether race/ethnicity influenced these associations independently of sociodemographic and medical characteristics. METHODS: Our analysis was based on the 2009 NHIS, providing valid sleep and vision data for 29,815 participants. The NHIS is a cross-sectional household interview survey utilizing a multistage area probability design. Trained personnel from the US census bureau gathered data during face-to-face interview and obtained socio-demographic, self-reported habitual sleep duration and physician-diagnosed chronic conditions. RESULTS: The mean age of the sample was 48 years and 56% were female. Short sleep and long sleep durations were reported by 49% and 23% of the participants, respectively. Visual impairment was observed in 10%. Multivariate-adjusted logistic regression models showed significant associations between VI and short sleep (OR = 1.6, 95% CI = 1.5-1.9 and long sleep durations (OR = 1.6, 95% CI = 1.3-1.9). These associations persisted in multivariate models stratified by race-ethnic groups. CONCLUSION: Visual impairment was associated with both short and long sleep durations. Analysis of epidemiologic sleep data should consider visual impairment as an important factor likely to influence the amount of sleep experienced habitually
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