Allostatic load in women with and without PTSD symptoms.
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Allostatic load (AL) is the term used to describe cumulative physiological wear and tear that results from repeated efforts to adapt to stressors over time. Operationalized as a composite index of biological risk factors (e.g., blood pressure, cholesterol, glycosylated hemoglobin, and cortisol, norepinephrine, and epinephrine), AL has been shown to increase with age, predict long-term morbidity and mortality among the elderly, and be associated with low parent education in a large adolescent sample. However, AL has not yet been studied in samples with putative "high stress" or posttraumatic stress disorder (PTSD). Accordingly, AL was measured in women with high acute and chronic stress: mothers of pediatric cancer survivors with and without PTSD and control mothers of healthy children. AL emerged in a "dose-dependent" ranking from high to low: cancer mothers meeting all criteria for PTSD, cancer mothers with no or low symptoms, and control mothers, respectively (p < .001). Effects were not altered by self-reported sleep quality or substance use (tobacco, caffeine, alcohol, or drugs) and remained significant when analyzing AL without cortisol or catecholamines. Results indicate elevated AL can be detected in relatively young women with high stress histories and particularly those with PTSD. Future prospective studies must evaluate whether this pattern represents an accelerated aging process and increased risk of disease. (+info)
Repeated sleep restriction in rats leads to homeostatic and allostatic responses during recovery sleep.
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Recent studies indicate that chronic sleep restriction can have negative consequences for brain function and peripheral physiology and can contribute to the allostatic load throughout the body. Interestingly, few studies have examined how the sleep-wake system itself responds to repeated sleep restriction. In this study, rats were subjected to a sleep-restriction protocol consisting of 20 h of sleep deprivation (SD) followed by a 4-h sleep opportunity each day for 5 consecutive days. In response to the first 20-h SD block on day 1, animals responded during the 4-h sleep opportunity with enhanced sleep intensity [i.e., nonrapid eye movement (NREM) delta power] and increased rapid eye movement sleep time compared with baseline. This sleep pattern is indicative of a homeostatic response to acute sleep loss. Remarkably, after the 20-h SD blocks on days 2-5, animals failed to exhibit a compensatory NREM delta power response during the 4-h sleep opportunities and failed to increase NREM and rapid eye movement sleep times, despite accumulating a sleep debt each consecutive day. After losing approximately 35 h of sleep over 5 days of sleep restriction, animals regained virtually none of their lost sleep, even during a full 3-day recovery period. These data demonstrate that the compensatory/homeostatic sleep response to acute SD does not generalize to conditions of chronic partial sleep loss. We propose that the change in sleep-wake regulation in the context of repeated sleep restriction reflects an allostatic process, and that the allostatic load produced by SD has direct effects on the sleep-wake regulatory system. (+info)
The role of stress proteins in the study of allostatic overload in birds: use and applicability to current studies in avian ecology.
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Stress proteins offer a measure of stress in birds at the cellular level that are an alternative to the glucocorticoids. Stress proteins are not biased by handling stress, the increase in stress proteins lasts longer than with other measures (e.g., corticosterone), and, therefore, they may be a more appropriate measure of long-term or chronic stress. However, caution should be practiced when using stress proteins because the level of stress needed to elicit a response may be higher than with corticosterone. Stress proteins have only recently been used to measure the response to competition, food limitation, growth, and parasitism in birds. In other taxa, the stress proteins have been used to measure genetic stress, temperature, toxins, UV radiation, and physical activity. Stress proteins increase the options available to avian ecologists for understanding how avian species respond to changes in the environment. (+info)
Neuroendocrine biomarkers, social relations, and the cumulative costs of stress in Taiwan.
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Allostatic load (AL) is thought to represent the physiological toll that builds up over the life course as a consequence of the body's response to stress. An important aim of this paper is to test this widely held-but little investigated-understanding of what AL represents. More specifically, using the Social Environment and Biomarkers of Aging Study (SEBAS), a nationally representative survey of Taiwan conducted in year 2000, this paper scrutinizes the connection between stressful life histories and neuroendocrine allostatic load (NAL). Stressful life histories are operationalized through the use of two sets of indicators: one set makes use of respondents' subjective interpretations of various life domains and the other makes use of non-subjective data about conditions that are expected to be stressful (e.g., widowhood, living alone, and low education). NAL is an index of four neuroendocrine biomarkers (cortisol, dehydroepiandrosterone sulfate (DHEAS), epinephrine, and norepinephrine) collected in blood and urine samples under resting, basal states. The major findings of this paper are twofold. First, there is little evidence to support the hypothesis that baseline levels of the neuroendocrine markers stem from stressful life histories. Second, report of current stress (among women only) is positively correlated with higher NAL levels. Taken together, these findings question whether the neuroendocrine markers of the AL construct reflect long-term processes over the life course. Indeed, evidence here suggests that the neuroendocrine markers may reflect the exact opposite-a transient state at the time of the study. (+info)
Not Geropharmacotherapy 101.
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Critical to survival is the geriatric concept, allostasis, defined as the ability to achieve stability through change. It is appropriate that allostasis is an introduction to this commentary, which may partially apply to the medical and pharmacy profession as currently constituted. (+info)
Central effects of stress hormones in health and disease: Understanding the protective and damaging effects of stress and stress mediators.
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Relationships between self-rating of recovery from work and morning salivary cortisol.
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To date, the understanding of how recovery from work relates to cortisol output is poor. Considering this, the present study set out to investigate the associations between self-ratings of 15 items of rest and recovery and salivary cortisol sampled every second hour across two working days. Data came from 12 female and 13 male white-collar workers and were analyzed by linear regression analyses and repeated measures ANOVA. Poor rest and recovery was associated with high levels of morning cortisol, with the strongest relationships emerging for "rested in the morning", "rested after a weekend", "feel energetic during the working day", "tired during the working day", "sufficient sleep" and "worry about something". Moreover, significant interaction effects emerged between sex and "rested after a weekend" and "worry about something". To conclude, the findings show that self-ratings of rest and recovery are related to cortisol, particularly to morning cortisol, and that self-ratings provide important information on physiological recovery in terms of cortisol output. (+info)
Psychobiology of childhood maltreatment: effects of allostatic load?
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OBJECTIVE: Facing an adverse physical or psychosocial situation, an individual is forced to adapt in order to survive. Allostasis is the term used to refer to adapting processes used to maintain the stability of an organism through active processes. When allostatic response is excessive or inefficient, the organism develops an allostatic load. The cascade of molecular and neurobiological effects associated with childhood abuse and neglect could be an example of allostatic response that could precipitate allostatic load in organism still vulnerable during its development. This article reviews the psychobiological consequences related to childhood abuse and neglect. METHOD: A selective review with a systematic procedure was performed to investigate studies showing explicit association between childhood maltreatment and psychobiological/neurobiological consequences. We searched electronic database MedLine-PubMed to identify English-language articles from 1990 to 2007. RESULTS: From 115 articles we selected 55 studies from MedLine and 30 from their reference lists, in a total of 85 articles (JCR IF range: 1-31.4; median: 5.88). Only 29 studies showed direct and explicit association between them. CONCLUSION: Structural consequences of childhood maltreatment include disruptive development of corpus callosum, left neocortex, hippocampus, and amygdale; functional consequences include increased electrical irritability in limbic areas, frontal lobe dysfunctions and reduced functional activity of the cerebellar vermis; and neurohumoral consequences include the reprogramming activity of hypothalamo-pituitary-adrenal (HPA) axis and subsequently the stress response. (+info)