Business-centric data solutions for safeguarding animal agriculture in the United States of America

Business-centric solutions to data-related problems often yield the greatest positive impacts and improvements for private enterprises but are challenging to design and implement at scale within government agencies. The core mission of the Veterinary Services of the United States Department of Agriculture (USDA) Animal Plant Health Inspection Service is to safeguard animal agriculture in the United States of America, and effective data management underpins these efforts. As this agency works to assist data-driven decision-making in animal health management, it continues to use a blend of best practices from Federal Data Strategy initiatives and the International Data Management Association framework. This paper describes three case studies that focus on strategies to improve animal health data collection, integration, reporting and governance for animal health authorities. These strategies have enhanced the way USDA's Veterinary Services execute their mission and core operational activities for prevention, detection and early response to support disease containment and control.

A meta-analysis of the associations between insufficient sleep duration and antibody response to vaccination

Vaccination is a major strategy to control a viral pandemic. Simple behavioral interventions that might boost vaccine responses have yet to be identified. We conducted meta-analyses to summarize the evidence linking the amount of sleep obtained in the days surrounding vaccination to antibody response in healthy adults. Authors of the included studies provided the information needed to accurately estimate the pooled effect size (ES) and 95% confidence intervals (95% CI) and to examine sex differences.^{1,2,3,4,5,6,7} The association between self-reported short sleep (<6 h/night) and reduced vaccine response did not reach our pre-defined statistical significant criteria (total n = 504, ages 18-85; overall ES [95% CI] = 0.29 [-0.04, 0.63]). Objectively assessed short sleep was associated with a robust decrease in antibody response (total n = 304, ages 18-60; overall ES [95% CI] = 0.79 [0.40, 1.18]). In men, the pooled ES was large (overall ES [95% CI] = 0.93 [0.54, 1.33]), whereas it did not reach significance in women (overall ES [95% CI] = 0.42 [-0.49, 1.32]). These results provide evidence that insufficient sleep duration substantially decreases the response to anti-viral vaccination and suggests that achieving adequate amount of sleep during the days surrounding vaccination may enhance and prolong the humoral response. Large-scale well-controlled studies are urgently needed to define (1) the window of time around inoculation when optimizing sleep duration is most beneficial, (2) the causes of the sex disparity in the impact of sleep on the response, and (3) the amount of sleep needed to protect the response.

Transportation noise impairs cardiovascular function without altering sleep: The importance of autonomic arousals

AIMS

Chronic exposure to nocturnal transportation noise has been linked to cardiovascular disorders with sleep impairment as the main mediator. Here we examined whether nocturnal transportation noise affects the main stress pathways, and whether it relates to changes in the macro and micro structure of sleep.

METHODS AND RESULTS

Twenty-six young healthy participants (12 women, 24.6 ± 0.7 years, mean ± SE) spent five consecutive 24-h days and one last morning in the laboratory. The first (baseline) and last (recovery) nights comprised a quiet ambient scenario. In-between, four different noise scenarios (low/medium/high intermittent road or rail scenarios with an identical equivalent continuous sound level of 45 dB) were randomly presented during the 8-h nights. Participants felt more annoyed from the transportation noise scenarios compared to the quiet ambient scenario played back during the baseline and recovery nights (F_5,117 = 10.2, p < 0.001). Nocturnal transportation noise did not significantly impact polysomnographically assessed sleep macrostructure, blood pressure, nocturnal catecholamine levels and morning cytokine levels. Evening cortisol levels increased after sleeping with highly intermittent road noise compared to baseline (p = 0.002, noise effect: F_4,83 = 4.0, p = 0.005), a result related to increased cumulative duration of autonomic arousals during the noise nights (F_5,106 = 3.4, p < 0.001; correlation: r_pearson = 0.64, p = 0.006).

CONCLUSION

Under controlled laboratory conditions, highly intermittent nocturnal road noise exposure at 45 dB increased the cumulative duration of autonomic arousals during sleep and next-day evening cortisol levels. Our results indicate that, without impairing sleep macrostructure, nocturnal transportation noise of 45 dB is a physiological stressor that affects the hypothalamic-pituitary-adrenal axis during the following day in healthy young good sleepers.

Adverse impact of nocturnal transportation noise on glucose regulation in healthy young adults: Effect of different noise scenarios

BACKGROUND

Epidemiological evidence indicates an association between transportation noise exposure and a higher risk of developing type 2 diabetes. Sleep disturbances are thought to be one of the mechanisms as it is well established that a few nights of short or poor sleep impair glucose tolerance and insulin sensitivity in healthy good sleepers.

OBJECTIVES

The present study aimed to determine the extent to which exposure to nocturnal transportation noise affects glucose metabolism, and whether it is related to noise-induced sleep alterations.

METHODS

Twenty-one young healthy volunteers (nine women) participated in a six-day laboratory study starting with a noise-free baseline night, then four nights sleeping with randomly-presented transportation noise scenarios (three road and one railway noise scenario) with identical average sound level of 45dB but differing in eventfulness and ending with a noise-free recovery night. Sleep was measured by polysomnography. Glucose tolerance and insulin sensitivity were measured after the baseline, the last noise night and the recovery nights with an oral glucose tolerance test using Matsuda and Stumvoll insulin sensitivity indexes. Eleven participants were assigned a less eventful noise scenario during the last noise night (LE-group), while the other ten had a more eventful noise scenario (ME-group). Baseline metabolic and sleep variables between the two intervention groups were compared using a non-parametric Mann-Whitney U test while mixed models were used for repeated measure analysis.

RESULTS

All participants had increased glucose_AUC (mean±SE, 14±2%, p<0.0001) and insulin_AUC (55±10%, p<0.0001) after the last noise night compared to the baseline night. 2h-glucose level tended to increase only in the ME-group between baseline (5.1±0.22mmol·L^-1) and the last noise night (6.1±0.39mmol·L^-1, condition: p=0.001, interaction: p=0.08). Insulin sensitivity assessed with Matsuda and Stumvoll indexes respectively decreased by 7±8% (p=0.001) and 9±2% (p<0.0001) after four nights with transportation noise. Only participants in the LE-group showed beneficial effects of the noise-free recovery night on glucose regulation (relative change to baseline: glucose_AUC: 1±2%, p=1.0 for LE-group and 18±4%, p<0.0001 for ME-group; Stumvoll index: 3.2±2.6%, p=1.0 for LE-group and 11±2.5%, p=0.002 for ME-group). Sleep was mildly impaired with increased sleep latency of 8±2min (<0.0001) and more cortical arousals per hour of sleep (1.8±0.6arousals/h, p=0.01) during the last noise night compared to baseline. No significant associations between sleep measures and glucose tolerance and insulin sensitivity were found.

CONCLUSION

In line with epidemiological findings, sleeping four nights with transportation noise impaired glucose tolerance and insulin sensitivity. Based on the presented sound exposure, the eventfulness of the noise scenarios seems to play an important role for noise-induced alterations in glucose regulation. However, we could not confirm our hypothesis that transportation noise impairs glucose regulation via deterioration in sleep quality and quantity. Therefore, other factors, such as stress-related pathways, may need to be considered as potential triggers for noise-evoked glucose intolerance in future research.

Effects of Insufficient Sleep on Pituitary-Adrenocortical Response to CRH Stimulation in Healthy Men

Study Objectives

Severe sleep restriction results in elevated evening cortisol levels. We examined whether this relative hypercortisolism is associated with alterations in the pituitary-adrenocortical response to evening corticotropin-releasing hormone (CRH) stimulation.

Methods

Eleven subjects participated in 2 sessions (2 nights of 10 hours vs. 4 hours in bed) in randomized order. Sleep was polygraphically recorded. After the second night of each session, blood was sampled at 20-minute intervals from 09:00 to 24:00 for adrenocorticotropic hormone (ACTH) and cortisol measurements, and perceived stress was assessed hourly. Ovine CRH was injected at 18:00 (1 µg/kg body weight).

Results

Prior to CRH injection, baseline ACTH, but not cortisol, levels were elevated after sleep restriction. Relative to the well-rested condition, sleep restriction resulted in a 27% decrease in overall ACTH response to CRH (estimated by the incremental area under the curve from 18:00 to 24:00; p = .002) while the cortisol response was decreased by 21% (p = .083). Further, the magnitude of these decreases was correlated with the individual amount of sleep loss (ACTH: rSp = -0.65, p = .032; cortisol: rSp = -0.71, p = .015). The acute post-CRH increment of cortisol was reduced (p = .002) without changes in ACTH reactivity, suggesting decreased adrenal sensitivity. The rate of decline from peak post-injection levels was reduced for cortisol (p = .032), but not for ACTH. Scores of perceived stress were unaffected by CRH injection and were low and similar under both sleep conditions.

Conclusions

Sleep restriction is associated with a reduction of the overall ACTH and cortisol responses to evening CRH stimulation, and a reduced reactivity and slower recovery of the cortisol response.

Adverse effects of two nights of sleep restriction on the hypothalamic-pituitary-adrenal axis in healthy men

CONTEXT

Insufficient sleep is associated with increased cardiometabolic risk. Alterations in hypothalamic-pituitary-adrenal axis may underlie this link.

OBJECTIVE

Our objective was to examine the impact of restricted sleep on daytime profiles of ACTH and cortisol concentrations.

METHODS

Thirteen subjects participated in 2 laboratory sessions (2 nights of 10 hours in bed versus 2 nights of 4 hours in bed) in a randomized crossover design. Sleep was polygraphically recorded. After the second night of each session, blood was sampled at 20-minute intervals from 9:00 am to midnight to measure ACTH and total cortisol. Saliva was collected every 20 minutes from 2:00 pm to midnight to measure free cortisol. Perceived stress, hunger, and appetite were assessed at hourly intervals by validated scales.

RESULTS

Sleep restriction was associated with a 19% increase in overall ACTH levels (P < .03) that was correlated with the individual amount of sleep loss (rSp = 0.63, P < .02). Overall total cortisol levels were also elevated (+21%; P = .10). Pulse frequency was unchanged for both ACTH and cortisol. Morning levels of ACTH were higher after sleep restriction (P < .04) without concomitant elevation of cortisol. In contrast, evening ACTH levels were unchanged while total and free cortisol increased by, respectively, 30% (P < .03) and 200% (P < .04). Thus, the amplitude of the circadian cortisol decline was dampened by sleep restriction (-21%; P < .05). Sleep restriction was not associated with higher perceived stress but resulted in an increase in appetite that was correlated with the increase in total cortisol.

CONCLUSION

The impact of sleep loss on hypothalamic-pituitary-adrenal activity is dependent on time of day. Insufficient sleep dampens the circadian rhythm of cortisol, a major internal synchronizer of central and peripheral clocks.

The important role of sleep in metabolism

Both reduction in total sleep duration with slow-wave sleep (SWS) largely preserved and alterations of sleep quality (especially marked reduction of SWS) with preservation of total sleep duration are associated with insulin resistance without compensatory increase in insulin secretion, resulting in impaired glucose tolerance and increased risk of type 2 diabetes. When performed under rigorously controlled conditions of energy intake and physical activity, sleep restriction is also associated with a decrease in circulating levels of leptin (an anorexigenic hormone) and an increase in circulating levels of ghrelin (an orexigenic hormone), hunger and appetite. Furthermore, sleep restriction is also associated with a stimulation of brain regions sensitive to food stimuli, indicating that sleep loss may lead to obesity through the selection of high-calorie food. There is also evidence that sleep restriction could provide a permissive environment for the activation of genes that promote obesity. Indeed, the heritability of body mass index is increased in short sleepers. Thus, chronic sleep curtailment, which is on the rise in modern society, including in children, is likely to contribute to the current epidemics of type 2 diabetes and obesity.

Impact of GH replacement therapy on sleep in adult patients with GH deficiency of pituitary origin

OBJECTIVES

We previously reported that adult patients with GH deficiency (GHD) due to a confirmed or likely pituitary defect, compared with healthy controls individually matched for age, gender, and BMI, have more slow-wave sleep (SWS) and higher delta activity (a marker of SWS intensity). Here, we examined the impact of recombinant human GH (rhGH) therapy, compared with placebo, on objective sleep quality in a subset of patients from the same cohort.

DESIGN

Single-blind, randomized, crossover design study.

METHODS

Fourteen patients with untreated GHD of confirmed or likely pituitary origin, aged 22-74 years, participated in the study. Patients with associated hormonal deficiencies were on appropriate replacement therapy. Polygraphic sleep recordings, with bedtimes individually tailored to habitual sleep times, were performed after 4 months on rhGH or placebo.

RESULTS

Valid data were obtained in 13 patients. At the end of the rhGH treatment period, patients had a shorter sleep period time than at the end of the placebo period (479±11 vs 431±19 min respectively; P=0.005), primarily due to an earlier wake-up time, and a decrease in the intensity of SWS (delta activity) (559±125 vs 794±219 μV(2) respectively; P=0.048).

CONCLUSIONS

Four months of rhGH replacement therapy partly reversed sleep disturbances previously observed in untreated patients. The decrease in delta activity associated with rhGH treatment adds further evidence to the hypothesis that the excess of high-intensity SWS observed in untreated pituitary GHD patients is likely to result from overactivity of the hypothalamic GHRH system due to the lack of negative feedback inhibition by GH.

Impact of obesity in children with narcolepsy

AIMS

To evaluate the impact of obesity on clinical and sleep characteristics in a population of narcoleptic children.

METHODS

Data from the children diagnosed with idiopathic narcolepsy in the National Reference Centers for Narcolepsy were collected between 2008 and 2011. Clinical and electrophysiological characteristics were compared between obese (body mass index [BMI] greater than P97) and nonobese children.

RESULTS

The 117 children (65 boys, 59 de novo patients) had a mean age of 11.6 ± 3.1 years on diagnosis. Cataplexy was present in 81%, DQB1*0602 in 91%. Mean BMI was 23.2 ± 5.2 kg/m(2) and BMI z-score was 2.9 ± 2.6. Obesity was found in 60% with a similar prevalence in treated versus de novo patients and in patients with and without cataplexy. Sleepiness and cataplexy started earlier in obese children. Obese narcoleptic children had lower sleep efficiency, higher apnea hypopnea index and respiratory arousals index (RAI) than nonobese children. BMI z-score was positively correlated with RAI. Obese children were more tired and missed more often school than nonobese children.

CONCLUSION

Obesity affects more than 50% of narcoleptic children, mostly younger at disease onset, and has a deleterious impact on sleep quality as well as on school attendance.

A phenomenological model for circadian and sleep allostatic modulation of plasma cortisol concentration

Both circadian rhythmicity and sleep play significant roles in the regulation of plasma cortisol concentration by the hypothalamo-pituitary-adrenal (HPA) axis. Numerous studies have found links between sleep and changes in cortisol concentration, but the implications of these results have remained largely qualitative. In this article, we present a quantitative phenomenological model to describe the effects of different sleep durations on cortisol concentration. We constructed the proposed model by incorporating the circadian and sleep allostatic effects on cortisol concentration, the pulsatile nature of cortisol secretion, and cortisol's negative autoregulation of its own production and validated its performance on three study groups that experienced four distinct sleep durations. The model captured many disparate effects of sleep on cortisol dynamics, such as the inhibition of cortisol secretion after the wake-to-sleep transition and the rapid rise of cortisol concentration before morning awakening. Notably, the model reconciled the seemingly contradictory findings between studies that report an increase in cortisol concentration following total sleep deprivation and studies that report no change in concentration. This work provides a biomathematical approach to combine the results on the effects of sleep on cortisol concentration into a unified framework and predict the impact of varying sleep durations on the cortisol profile.

[Current developments in measuring quality of life with instruments of the European organisation for research and treatment of cancer (EORTC)]

Since many years, the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group develops and validates measures for the assessment of quality of life in cancer patients, using high standards of methodology. These questionnaires are meant to be used primarily in clinical trials.As treatment strategies are changing and because of some -methodological criticism, the head and neck module EORTC QLQ-H&N35 is currently being revised and updated.In this paper, we will present the current state of work and other recent developments regarding the EORTC Quality of Life questionnaire development.

Twenty-four-hour profiles of acylated and total ghrelin: relationship with glucose levels and impact of time of day and sleep

CONTEXT

The acylation of ghrelin is essential for its stimulatory effects on GH release and appetite. Most of the physiology of ghrelin has been defined based on the assay of total ghrelin (TG), which mainly reflects levels of unacylated ghrelin. Whether levels of acylated ghrelin (AG) are influenced by circadian time and sleep and impact glucose regulation under physiologic conditions is not known.

METHODS

Blood was sampled at 10- to 30-min intervals for 24 h in 14 healthy young lean men under controlled conditions of activity, light-dark cycle, and sleep-wake schedule. The subjects ingested three identical carbohydrate-rich meals at 5-h intervals. Sleep was polygraphically monitored. Levels of TG and AG were measured by RIA. The 24-h profiles of glucose and insulin levels were assessed simultaneously.

RESULTS

Postprandial glucose concentrations were positively correlated with mean levels of AG but not TG, independently of insulin. Postprandial suppression and rebound of AG and TG occurred in parallel and were not impacted by time of day. The nocturnal elevation of AG and TG reflects the postdinner rebound curbed by an inhibitory effect of sleep. The ratio of AG to TG was lower during sleep than during wake, consistent with a reduction of orexigenic signal.

CONCLUSIONS

Individual differences in AG levels may be an important predictor of overall glucose control under physiological conditions. Sleep, but not time of day, impacts postprandial TG and AG responses. The inhibitory effect of sleep on ghrelin release and acylation is consistent with the association between sleeping and fasting.

Role of sleep duration in the regulation of glucose metabolism and appetite

Sleep curtailment has become a common behavior in modern society. This review summarizes the current laboratory evidence indicating that sleep loss may contribute to the pathophysiology of diabetes mellitus and obesity. Experimentally induced sleep loss in healthy volunteers decreases insulin sensitivity without adequate compensation in beta-cell function, resulting in impaired glucose tolerance and increased diabetes risk. Lack of sleep also down-regulates the satiety hormone leptin, up-regulates the appetite-stimulating hormone ghrelin, and increases hunger and food intake. Taken together with the epidemiologic evidence for an association between short sleep and the prevalence or incidence of diabetes mellitus and/or obesity, these results support a role for reduced sleep duration in the current epidemic of these metabolic disorders. Screening for habitual sleep patterns in patients with "diabesity" is therefore of great importance. Studies are warranted to investigate the putative therapeutic impact of extending sleep in habitual short sleepers with metabolic disorders.

Sleep disturbances, daytime sleepiness, and quality of life in adults with growth hormone deficiency

CONTEXT

Low energy and fatigue are frequent complaints in subjects with GH deficiency (GHD). Because interrelations between sleep and GH regulation are well documented, these complaints could partly reflect alterations of sleep quality.

OBJECTIVE

The objective of the study was to determine objective and subjective sleep quality and daytime sleepiness in adult GHD patients.

SUBJECTS

Thirty patients, aged 19-74 yr, with untreated GHD (primary pituitary defects confirmed or likely in 26 patients, hypothalamic origin in four patients), and 30 healthy controls individually matched for gender, age, and body mass index participated in the study. Patients with associated pituitary deficiencies (n = 28) were on hormonal replacement therapy.

METHODS

Polygraphic sleep recordings, assessment of Pittsburgh Sleep Quality Index, and Quality of Life Assessment for GHD in Adults were measured.

RESULTS

Irrespective of etiology, GHD patients had a Pittsburgh Sleep Quality Index score above the clinical cutoff for poor sleep and lower Quality of Life Assessment for GHD in Adults scores than controls, with tiredness being the most affected domain. Patients with pituitary GHD spent more time in slow-wave sleep (SWS) and had a higher intensity of SWS than their controls. Among these patients, older individuals obtained less total sleep than controls, and their late sleep was more fragmented. Contrasting with pituitary GHD, the four patients with hypothalamic GHD had lower intensity of SWS than their controls.

CONCLUSIONS

GHD is associated with sleep disorders that may be caused by specific hormonal alterations as well as with poor subjective sleep quality and daytime sleepiness. Disturbed sleep is likely to be partly responsible for increased tiredness, a major component of quality of life in GHD.

Effects of poor and short sleep on glucose metabolism and obesity risk

The importance of sleep to hormones and glucose metabolism was first documented more than four decades ago. Since then, sleep curtailment has become an endemic behavior in modern society. In addition, the prevalence of sleep disorders, particularly obstructive sleep apnea (OSA), has increased. OSA is very common in endocrine and metabolic disorders, but often remains undiagnosed. This Review summarizes the laboratory and epidemiologic evidence that suggests how sleep loss, either behavioral or disease-related, and poor quality of sleep might promote the development of obesity and diabetes mellitus, and exacerbate existing endocrine conditions. Treatment of sleep disorders has the potential to improve glucose metabolism and energy balance. Screening for habitual sleep patterns and OSA might be critically important for patients with endocrine and metabolic disorders.

The metabolic consequences of sleep deprivation

The prevalence of diabetes and obesity is increasing at an alarming rate worldwide, and the causes of this pandemic are not fully understood. Chronic sleep curtailment is a behavior that has developed over the past 2-3 decades. Laboratory and epidemiological studies suggest that sleep loss may play a role in the increased prevalence of diabetes and/or obesity. Current data suggest the relationship between sleep restriction, weight gain and diabetes risk may involve at least three pathways: (1) alterations in glucose metabolism; (2) upregulation of appetite; and (3) decreased energy expenditure. The present article reviews the current evidence in support of these three mechanisms that might link short sleep and increased obesity and diabetes risk.

The brain H3-receptor as a novel therapeutic target for vigilance and sleep–wake disorders

Brain histaminergic neurons play a prominent role in arousal and maintenance of wakefulness (W). H(3)-receptors control the activity of histaminergic neurons through presynaptic autoinhibition. The role of H(3)-receptor antagonists/inverse agonists (H(3)R-antagonists) in the potential therapy of vigilance deficiency and sleep-wake disorders were studied by assessing their effects on the mouse cortical EEG and sleep-wake cycle in comparison to modafinil and classical psychostimulants. The H(3)R-antagonists, thioperamide and ciproxifan increased W and cortical EEG fast rhythms and, like modafinil, but unlike amphetamine and caffeine, their waking effects were not accompanied by sleep rebound. Conversely, imetit (H(3)R-agonist) enhanced slow wave sleep and dose-dependently attenuated ciproxifan-induced W, indicating that the effects of both ligands involve H(3)-receptor mechanisms. Additional studies using knockout (KO) mice confirmed the essential role of H(3)-receptors and histamine-mediated transmission in the wake properties of H(3)R-antagonists. Thus ciproxifan produced no increase in W in either histidine-decarboxylase (HDC, histamine-synthesizing enzyme) or H(1)- or H(3)-receptor KO-mice whereas its waking effects persisted in H(2)-receptor KO-mice. These data validate the hypothesis that H(3)R-antagonists, through disinhibition of H(3)-autoreceptors, enhancing synaptic histamine that in turn activates postsynaptic H(1)-receptors promoting W. Interestingly amphetamine and modafinil, despite their potent arousal effects, appear unlikely to depend on histaminergic mechanism as their effects still occurred in HDC KO-mice. The present study thus distinguishes two classes of wake-improving agents: the first acting through non-histaminergic mechanisms and the second acting via histamine and supports brain H(3)-receptors as potentially novel therapeutic targets for vigilance and sleep-wake disorders.

Impact of sleep and sleep loss on neuroendocrine and metabolic function

BACKGROUND

Sleep exerts important modulatory effects on neuroendocrine function and glucose regulation. During the past few decades, sleep curtailment has become a very common behavior in industrialized countries. This trend toward shorter sleep times has occurred over the same time period as the dramatic increases in the prevalence of obesity and diabetes.

AIMS

This article will review rapidly accumulating laboratory and epidemiologic evidence indicating that chronic partial sleep loss could play a role in the current epidemics of obesity and diabetes.

CONCLUSIONS

Laboratory studies in healthy young volunteers have shown that experimental sleep restriction is associated with a dysregulation of the neuroendocrine control of appetite consistent with increased hunger and with alterations in parameters of glucose tolerance suggestive of an increased risk of diabetes. Epidemiologic findings in both children and adults are consistent with the laboratory data.

Sleep loss: a novel risk factor for insulin resistance and Type 2 diabetes

Chronic sleep loss as a consequence of voluntary bedtime restriction is an endemic condition in modern society. Although sleep exerts marked modulatory effects on glucose metabolism, and molecular mechanisms for the interaction between sleeping and feeding have been documented, the potential impact of recurrent sleep curtailment on the risk for diabetes and obesity has only recently been investigated. In laboratory studies of healthy young adults submitted to recurrent partial sleep restriction, marked alterations in glucose metabolism including decreased glucose tolerance and insulin sensitivity have been demonstrated. The neuroendocrine regulation of appetite was also affected as the levels of the anorexigenic hormone leptin were decreased, whereas the levels of the orexigenic factor ghrelin were increased. Importantly, these neuroendocrine abnormalities were correlated with increased hunger and appetite, which may lead to overeating and weight gain. Consistent with these laboratory findings, a growing body of epidemiological evidence supports an association between short sleep duration and the risk for obesity and diabetes. Chronic sleep loss may also be the consequence of pathological conditions such as sleep-disordered breathing. In this increasingly prevalent syndrome, a feedforward cascade of negative events generated by sleep loss, sleep fragmentation, and hypoxia are likely to exacerbate the severity of metabolic disturbances. In conclusion, chronic sleep loss, behavioral or sleep disorder related, may represent a novel risk factor for weight gain, insulin resistance, and Type 2 diabetes.

Impact of carbohydrate-rich meals on plasma epinephrine levels: dysregulation with aging

CONTEXT

Plasma norepinephrine (NE) and epinephrine (E) levels are indicators of peripheral sympathetic and adrenomedullary activities, respectively. The sympathoadrenomedullary system is involved in the metabolic response to carbohydrate intake and is affected by aging; however, the relationship between glucose metabolism and adrenomedullary activity in older adults remains poorly defined.

OBJECTIVE

The objective of this study was to examine the changes in the impact of carbohydrate-rich meals on circulating catecholamines with aging.

DESIGN

After iv glucose tolerance testing and 1 d of habituation, blood samples were collected every 10-30 min for 24 h. Daytime hours were spent at bed rest. Sleep was scheduled between 2300 and 0700 h with polygraphic monitoring.

SETTING

The study was performed at a general clinical research center.

PARTICIPANTS

Nine young (age, 20-28 yr) and eight older (age, 50-69 yr) healthy men participated in this study.

INTERVENTION

Identical mixed meals (62% carbohydrate) were given at 0900, 1400, and 1900 h.

MAIN OUTCOME MEASURES

The main outcome measures were 24-h plasma E and NE measurements.

RESULTS

The profiles of E and NE were characterized by clear day-night differences, which were preserved in the older group. Young subjects showed a clear dissociation between postprandial adrenomedullary and sympathetic activities characterized by a rapid decline in plasma E and increased NE levels. There was an overall increase in NE levels and markedly dampened postprandial variation in plasma E in the older men.

CONCLUSIONS

In young adults, postprandial E levels follow a biphasic pattern that is inversely related to that of glucose and insulin. Aging is associated with a dysregulation of this response.

Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite

BACKGROUND

Total sleep deprivation in rodents and in humans has been associated with hyperphagia. Over the past 40 years, self-reported sleep duration in the United States has decreased by almost 2 hours.

OBJECTIVE

To determine whether partial sleep curtailment, an increasingly prevalent behavior, alters appetite regulation.

DESIGN

Randomized, 2-period, 2-condition crossover clinical study.

SETTING

Clinical Research Center, University of Chicago, Chicago, Illinois.

PATIENTS

12 healthy men (mean age [+/-SD], 22 +/- 2 years; mean body mass index [+/-SD], 23.6 +/- 2.0 kg/m2).

MEASUREMENTS

Daytime profiles of plasma leptin and ghrelin levels and subjective ratings of hunger and appetite.

INTERVENTION

2 days of sleep restriction and 2 days of sleep extension under controlled conditions of caloric intake and physical activity.

RESULTS

Sleep restriction was associated with average reductions in the anorexigenic hormone leptin (decrease, 18%; P = 0.04), elevations in the orexigenic factor ghrelin (increase, 28%; P < 0.04), and increased hunger (increase, 24%; P < 0.01) and appetite (increase, 23%; P = 0.01), especially for calorie-dense foods with high carbohydrate content (increase, 33% to 45%; P = 0.02).

LIMITATIONS

The study included only 12 young men and did not measure energy expenditure.

CONCLUSIONS

Short sleep duration in young, healthy men is associated with decreased leptin levels, increased ghrelin levels, and increased hunger and appetite.

Leptin levels are dependent on sleep duration: relationships with sympathovagal balance, carbohydrate regulation, cortisol, and thyrotropin

Sleep plays an important role in energy homeostasis. The present study tests the hypothesis that circulating levels of leptin, a hormone that signals energy balance to the brain, are influenced by sleep duration. We also analyzed associations between leptin and sympathovagal balance, cortisol, TSH, glucose, and insulin under different bedtime conditions. Twenty-four-hour hormonal and glucose profiles were sampled at frequent intervals, and sympathovagal balance was estimated from heart rate variability in 11 subjects studied after 6 d of 4-h bedtimes (mean +/- sem of sleep duration during last 2 d: 3 h and 49 +/- 2 min) and after 6 d of 12-h bedtimes (sleep: 9 h and 03 +/- 15 min). A study with 8-h bedtimes was performed 1 yr later (sleep: 6 h and 52 +/- 10 min). Caloric intake and activity levels were carefully controlled in all studies. Mean levels, maximal levels, and rhythm amplitude of leptin were decreased (-19%, -26%, and -20%, respectively) during sleep restriction compared with sleep extension. The decrease in leptin levels was concomitant with an elevation of sympathovagal balance. The effects of sleep duration on leptin were quantitatively associated with alterations of the cortisol and TSH profiles and were accompanied by an elevation of postbreakfast homeostasis model assessment values. Measures of perceived stress were not increased during sleep restriction. During the study with 8-h bedtimes, hormonal and metabolic parameters were intermediate between those observed with 4-h and 12-h bedtimes. In conclusion, sleep modulates a major component of the neuroendocrine control of appetite.

Leptin levels are dependent on sleep duration: relationships with sympathovagal balance, carbohydrate regulation, cortisol, and thyrotropin

Sleep plays an important role in energy homeostasis. The present study tests the hypothesis that circulating levels of leptin, a hormone that signals energy balance to the brain, are influenced by sleep duration. We also analyzed associations between leptin and sympathovagal balance, cortisol, TSH, glucose, and insulin under different bedtime conditions. Twenty-four-hour hormonal and glucose profiles were sampled at frequent intervals, and sympathovagal balance was estimated from heart rate variability in 11 subjects studied after 6 d of 4-h bedtimes (mean +/- sem of sleep duration during last 2 d: 3 h and 49 +/- 2 min) and after 6 d of 12-h bedtimes (sleep: 9 h and 03 +/- 15 min). A study with 8-h bedtimes was performed 1 yr later (sleep: 6 h and 52 +/- 10 min). Caloric intake and activity levels were carefully controlled in all studies. Mean levels, maximal levels, and rhythm amplitude of leptin were decreased (-19%, -26%, and -20%, respectively) during sleep restriction compared with sleep extension. The decrease in leptin levels was concomitant with an elevation of sympathovagal balance. The effects of sleep duration on leptin were quantitatively associated with alterations of the cortisol and TSH profiles and were accompanied by an elevation of postbreakfast homeostasis model assessment values. Measures of perceived stress were not increased during sleep restriction. During the study with 8-h bedtimes, hormonal and metabolic parameters were intermediate between those observed with 4-h and 12-h bedtimes. In conclusion, sleep modulates a major component of the neuroendocrine control of appetite.

Reciprocal interactions between the GH axis and sleep

For more than 30 years, growth hormone (GH) has been observed to be preferentially secreted during deep, slow-wave sleep (SWS). However, the mechanisms that underlie this robust relationship that links anabolic processes in the body with behavioral rest and decreased cerebral metabolism remain to be elucidated. Current evidence indicates that GH secretion during the beginning of sleep appears to be primarily regulated by GH-releasing hormone (GHRH) stimulation occurring during a period of relative somatostatin withdrawal, which also is associated with elevated levels of circulating ghrelin. Apparently, two populations of GHRH neurons need to be simultaneously active to stimulate, in a coordinated fashion, SWS and pituitary GH release. Pharmacological interventions that are capable of increasing the duration and/or the intensity of SWS such as oral administration of gamma-hydroxybutyrate (GHB), also increase the rate of GH release. Because the normal negative feedback exerted by GH on central GHRH is inoperative in patients with GH deficiency, it is possible that the decreased energy levels and fatigue often reported by GH-deficient adults partly reflect an alteration in sleep-wake regulation. Preliminary data from a sleep study of adults with GH deficiency using wrist actigraphy for 6 nights at home and polysomnography in the laboratory indeed show decreased total sleep time and increased sleep fragmentation in GH-deficient patients as compared with normal controls.

[Impact of sleep debt on physiological rhythms]

Sleep loss due to voluntary bedtime curtailment has become a hallmark of modern society. Even though sleep deprivation in rodents has been shown to result in death, it was until a few years ago thought that sleep loss results in increased sleepiness and decreased cognitive performance but has little or no adverse effects on human health. We measured sleep and 24-hour hormonal profiles in 11 healthy young males after 6 days of sleep restriction (4-hour bedtime) and after 6 days of sleep recovery (12-hour bedtime). At the end of sleep restriction, we observed reduced amounts of slow wave sleep (SWS) and rapid eye movement (REM) sleep and an alteration in the temporal distribution of these sleep stages, i.e. an increased pressure for REM sleep at the beginning of the sleep period and a decrease in the amount of slow wave activity (SWA) during the first sleep cycle. These later abnormalities are usually observed in depression. In addition, numerous alterations in the 24-hour hormonal profiles were observed in the state of sleep debt. The amount of melatonin secreted was reduced because of a delay in the onset of the nocturnal secretion and a reduction in the value of the acrophase. If the overall 24-hour cortisol profile was preserved, sleep restriction was associated with increased cortisol levels in late afternoon and evening hours and the duration of the quiescent period was reduced. The 24-hour mean TSH levels were reduced and the nocturnal TSH elevation was markedly dampened, most likely as a result of elevated levels of thyroid hormones. The acrophase of the 24-hour leptin profile occurred earlier, the amplitude of the rhythm and the overall mean levels were reduced. The nocturnal elevation of prolactin levels was abrupt but of short duration and the 24-hour mean levels were decreased. A pulse of growth hormone occurred prior to sleep onset, therefore affecting SWA distribution at the beginning of the sleep period. Since these alterations are qualitatively and quantitatively similar to those observed during aging and sometimes during depression, a state of sleep debt, as is experienced by a substantial fragment of the population in modern societies, is likely to increase the severity of depression and widespread age-related chronic conditions such as obesity, diabetes and hypertension.

Analysis of fatty acid ethyl esters in hair as possible markers of chronically elevated alcohol consumption by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS)

Fatty acid ethyl esters (FAEE) are products of the nonoxidative ethanol metabolism, which are known to be detectable in blood only about 24h after the last alcohol intake. After deposition in hair they should be suitable long-term markers of chronically elevated alcohol consumption. Therefore, a method for the analysis of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate from hair was developed based on the extraction of the hair sample by a dimethylsulphoxide (DMSO)/n-hexane mixture, separation and evaporation of the n-hexane phase and application of headspace solid-phase microextraction (HS-SPME) in combination with gas chromatography-mass spectrometry (GC-MS) to the extract. For use as internal standards, the corresponding D(5)-ethyl esters were prepared. The HS-SPME/GC-MS measurements were automatically performed using a multi-purpose sampler. The detection limits of the FAEE were between 0.01 and 0.04ng/mg and the reproducibility was between 3.5 and 16%. By application of the method to hair samples of 21 fatalities with known heavy alcohol abuse 0.045-2.4ng/mg ethyl myristate, 0.35-13.5ng/mg ethyl palmitate, 0.25-7.7ng/mg ethyl oleate and 0.05-3.85ng/mg ethyl stearate were measured. For social drinkers (30-60g ethanol per week), the concentrations were about one order of magnitude smaller. For 10 teetotalers negative results or traces of ethyl palmitate were found. It was shown by supplementary investigations in single cases that FAEE are also present in sebum, that there is no strong difference in their concentrations between pubic, chest and scalp hair, and that they are detectable in hair segments after a 2 months period of abstinence. From the results follows that the measurement of FAEE concentrations in hair is a useful way for a retrospective detection of alcohol abuse.

On the similarity of properties in solution or in the crystalline state: a molecular dynamics study of hen lysozyme

As protein crystals generally possess a high water content, it is assumed that the behaviour of a protein in solution and in crystal environment is very similar. This assumption can be investigated by molecular dynamics (MD) simulation of proteins in the different environments. Two 2ns simulations of hen egg white lysozyme (HEWL) in crystal and solution environment are compared to one another and to experimental data derived from both X-ray and NMR experiments, such as crystallographic B-factors, NOE atom-atom distance bounds, 3J(H N alpha)-coupling constants, and 1H-15N bond vector order parameters. Both MD simulations give very similar results. The crystal simulation reproduces X-ray and NMR data slightly better than the solution simulation.

Adaptation of the 24-h growth hormone profile to a state of sleep debt

In normal men, the majority of GH secretion occurs in a single large postsleep onset pulse that is suppressed during total sleep deprivation. We examined the impact of semichronic partial sleep loss, a highly prevalent condition, on the 24-h growth hormone profile. Eleven young men were studied after six nights of restricted bedtimes (0100-0500) and after 7 nights of extended bedtimes (2100-0900). Slow-wave sleep (SWS) was estimated as the duration of stages III and IV. Slow-wave activity (SWA) was calculated as electroencephalogram power density in the 0.5- to 3-Hz frequency range. During the state of sleep debt, the GH secretory pattern was biphasic, with both a presleep onset "circadian" pulse and a postsleep onset pulse. Postsleep onset GH secretion was negatively related to presleep onset secretion and tended to be positively correlated with the amount of concomitant SWA. When sleep was restricted, both SWS and SWA were increased during early sleep. Unexpectedly, the increase in SWA affected the second, rather than the first, SWA cycle, suggesting that presleep onset GH secretion may have limited SWA in the first cycle, possibly via an inhibition of central GH-releasing hormone activity. Thus neither the GH profile nor the distribution of SWA conformed with predictions from acute sleep deprivation studies, indicating that adaptation mechanisms are operative during chronic partial sleep loss.

The role of complement in Alzheimer's disease pathology

Complement proteins are integral components of amyloid plaques and cerebral vascular amyloid in Alzheimer brains. They can be found at the earliest stages of amyloid deposition and their activation coincides with the clinical expression of Alzheimer's dementia. This review will examine the origins of complement in the brain and the role of beta-amyloid peptide (Abeta) in complement activation in Alzheimer's disease, an event that might serve as a nidus of chronic inflammation. Pharmacology therapies that may serve to inhibit Abeta-mediated complement activation will also be discussed.

Pathophysiology of human circadian rhythms

The 24 h profiles of hormonal secretions represent a good model for the study of the human circadian system. Diurnal hormonal variations generally reflect the modulation of ultradian or pulsatile release at 1-2 h intervals by signals occurring at nearly 24 h periods and result from the interaction of an internal timekeeping system--or circadian clock--with the sleep-wake homeostasis and various environmental factors, including the light-dark cycle, periodic changes in activity levels and the meal schedule. This temporal organization is altered in many pathophysiological conditions, including ageing, sleep loss, night or shift work, jet lag, affective disorders and endocrine diseases. Both photic and non-photic stimuli may affect the regulation of the circadian pacemaker and, therefore, the diurnal pattern of hormonal secretions. Appropriately timed stimuli may induce either a phase-advance or a phase-delay of the circadian clock, according to the timing of administration. Phase-shifting effects have been shown in humans for light and for dark pulses, physical exercise, melatonin and melatonin agonists, and benzodiazepine hypnotics. These results open new perspectives for the treatment of a variety of disorders involving dysregulation of the circadian rhythmicity.

Traumatic brain injury elevates the Alzheimer's amyloid peptide A beta 42 in human CSF. A possible role for nerve cell injury

The increased risk for Alzheimer's Disease (AD) associated with traumatic brain injury (TBI) suggests that environmental insults may influence the development of this age-related dementia. Recently, we have shown that the levels of the beta-amyloid peptide (A beta 1-42) increase in the cerebrospinal fluid (CSF) of patients after severe brain injury and remain elevated for some time after the initial event. The relationships of elevated A beta with markers of blood-brain barrier (BBB) disruption, inflammation, and nerve cell or axonal injury were evaluated in CSF samples taken daily from TBI patients. This analysis reveals that the rise in A beta 1-42 is best correlated with possible markers of neuronal or axonal injury, the cytoskeletal protein tau, neuron-specific enolase (NSE), and apolipoprotein E (ApoE). Similar or better correlations were observed between A beta 1-40 and the three aforementioned markers. These results imply that the degree of brain injury may play a decisive role in determining the levels of A beta 1-42 and A beta 1-40 in the CSF of TBI patients. Inflammation and alterations in BBB may play lesser, but nonetheless significant, roles in determining the A beta level in CSF after brain injury.