Chronobiology international
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New information has become available since the ISC, AAMCC, and SECAC released their first extensive guidedelines to improve the diagnosis and treatment of adult arterial hypertension. A critical assessment of evidence and a comparison of what international guidelines now propose are the basis for the following statements, which update the recommendations first issued in 2013. Office blood pressure (BP) measurements should no longer be considered to be the "gold standard" for the diagnosis of hypertension and assessment of cardiovascular risk. ⋯ In high-risk patients, including those diagnosed with diabetes or chronic kidney disease, and/or those having experienced past cardiovascular events, the thresholds are even lower by 15/10 mmHg, i.e., 105/60 mmHg. Bedtime treatment with the full daily dose of ≥1 hypertension medications is recommended as a cost-effective means to improve the management of hypertension and reduce hypertension-associated risk. Bedtime treatment entailing the full daily dose of ≥1 conventional hypertension medications must be the therapeutic regimen of choice for the elderly and those with diabetes, resistant and secondary hypertension, chronic kidney disease, obstructive sleep apnea, and medical history of past cardiovascular events, among others, given their documented high prevalence of sleep-time hypertension.
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Diagnosed cardiovascular disease has well-reported temporal patterns, with demand distribution peaks in the late morning and greater case numbers on Mondays and in winter. We aimed to report temporal patterns of presumptive cardiovascular disease cases as determined after emergency medical services (EMS) assessment and to characterize the demand distribution by day of the week. We conducted a secondary analysis of all Ambulance Victoria cases in metropolitan Melbourne (Victoria, Australia) between January 2008 and December 2011. ⋯ We have shown that examination of presumptive cardiovascular disease using not only case counts but also demand distribution patterns allows for a greater understanding of ambulance demand. Monday might be the most frequent day for cardiovascular cases but different patterns of demand occur on weekends. Increased knowledge of when different types of cases are most likely to occur will help inform EMS planning, including paramedic capacity and resources.
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In a study published in Cancer Causes & Control in 2010, Kloog with co-authors tested, apparently for the first time, the association between population-level ambient exposure to artificial light at night (ALAN) and incidence of several cancers in women from 164 countries worldwide. The study was based on 1996-2002 data and concluded that breast cancer (BC) incidence was significantly and positively associated with ALAN, while no such association was revealed for other cancer types. An open question, however, remains whether the trends revealed by Kloog and co-authors were time specific or also hold true for more recent data. ⋯ However, when the entire sample of countries was disaggregated into geographic clusters of similarly developed countries, a positive BC-ALAN association re-emerged as statistically significant (t > 2.2; p < 0.01), helping to explain, along with other factors covered by the analysis, about 65-85% of BC ASR variability worldwide, depending on the model type. Although the present analysis reconfirms a positive BC-ALAN association, this association appeared to diverge regionally in recent years, with countries in Western Europe showing the highest levels of such association, while countries in Southeast Asia and Gulf States exhibiting relatively low BC rates against the backdrop of relatively high ALAN levels. This regional stratification may be due to additional protective mechanisms, diminishing BC risks and potentially attributed to the local diet and lifestyles.
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It has frequently been reported that exposure to artificial light at night (ALAN) may cause negative health effects, such as breast cancer, circadian phase disruption and sleep disorders. Here, we reviewed the literature assessing the effects of human exposure to ALAN in order to list the health effects of various aspects of ALAN. Several electronic databases were searched for articles, published through August 2014, related to assessing the effects of exposure to ALAN on human health; these also included the details of experiments on such exposure. ⋯ ALAN also causes circadian phase disruption, which increases with longer duration of exposure and with exposure later in the evening. It has also been reported that shorter wavelengths of light preferentially disturb melatonin secretion and cause circadian phase shifts, even if the light is not bright. This literature review may be helpful to understand the health effects of ALAN exposure and suggests that it is necessary to consider various characteristics of artificial light, beyond mere intensity.
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The purpose of this pilot study was to explore the utility of the mammalian swine model under simulated intensive care unit (sICU) conditions and mechanical ventilation (MV) for assessment of the trajectory of circadian rhythms of sedation requirement, core body temperature (CBT), pulmonary mechanics (PM) and gas exchange (GE). Data were collected prospectively with an observational time-series design to describe and compare circadian rhythms of selected study variables in four swine mechanically ventilated for up to seven consecutive days. We derived the circadian (total variance explained by rhythms of τ between 20 and 28 h)/ultradian (total variance explained by rhythms of τ between 1 and <20 h) bandpower ratio to assess the robustness of circadian rhythms, and compare findings between the early (first 3 days) and late (subsequent days) sICU stay. ⋯ Individual subject observations were more informative than group data, and provided preliminary evidence that (a) circadian rhythms of multiple variables are lost or desynchronized in mechanically ventilated subjects, (b) robustness of circadian rhythm varies with subject morbidity and (c) healthier pigs develop more robust circadian rhythm profiles over time in the sICU. Comparison of biological rhythm profiles among sICU subjects with similar severity of illness is needed to determine if the results of this pilot study are reproducible. Identification of consistent patterns may provide insight into subject morbidity and timing of such therapeutic interventions as weaning from MV.