Sleep Heart Rate Research Articles

Sleep Heart Rate Variability Analysis and k-Nearest Neighbours Classification of Primary Insomnia

The Heart Rate Variability (HRV) of many sleep disorders shows an alteration of the sympathovagal balance of the Autonomous Nervous System (ANS). Primary insomnia refers to the difficulty in initiating or maintaining sleep that is not caused by other illnesses or substances. The HRV of primary insomnia shows inconsistent findings although it is believed to impair the HRV variables. This study compares the HRV changes during different sleep stages and evaluates the k-nearest neighbours (kNN) classifier using the HRV features for primary insomnia classification. The time and frequency HRV variables were extracted from sleep ECG signals of 10 primary insomnia patients and 10 healthy controls during four sleep stages – N1, N2, N3 and REM. The Mann-Whitney U-test was conducted to evaluate the existence of statistical significant differences between the two groups at different sleep stages. The kNN classifier was adapted for the classification tool. Only the LF index of HRV was significantly higher in the primary insomnia patients compared to the healthy subjects. The classification accuracy of kNN was at 75% when both the HRV time and frequency variables were accounted as inputs to the classifier.

Obstructive sleep apnea as a predictor of reduced heart rate variability

PurposeThis study aimed to analyze the relationship between the occurrence of obstructive sleep apnea (OSA) and heart rate variability (HRV) in a group of patients with clinical suggestion of OSA. Methods104 patients with clinical suspicion of OSA were qualified to participate in the study (age: 53.15 ± 13.43 years). All participants took part in a survey and were subjected to laboratory tests, 24-hour ECG Holter monitoring, and polysomnography. The participants were divided into groups depending on the criterion of the presence of OSA. ResultsThe analysis of time HRV demonstrated lower parameters of SDNN for the entire recording and a 15-minute fragment of daily activity, as well as a lower pNN50 for the entire recording in those patients with diagnosed OSA. A statistically significant difference was observed for the spectral analysis of the LF/HF which was higher in the participants with OSA during the 15-minute fragment of N3 sleep. A negative correlation was observed between AHI and the following parameters: SDSD from the entire Holter recording (r = −0.21, p < 0.05) and from the 15-minute fragment of daily activity (r = −0.19, p < 0.05), mRR from the fragment of N3 sleep (r = −0.19, p < 0.05) and VLF from the entire Holter recording (r = −0.26, p < 0.05). A statistically significant positive correlation between AHI and LF/HF in 15-minute fragments of N3 sleep was found (r = 0.26, p < 0.05). ConclusionsThe study group of patients with OSA is characterized by reduced HRV. The higher AHI constitutes an independent predictor of reduced HRV, both in the sympathetic and parasympathetic components, and the sympathetic-parasympathetic balance.

Modeling Binary Time Series Using Gaussian Processes with Application to Predicting Sleep States

Motivated by the problem of predicting sleep states, we develop a mixed effects model for binary time series with a stochastic component represented by a Gaussian process. The fixed component captures the effects of covariates on the binary-valued response. The Gaussian process captures the residual variations in the binary response that are not explained by covariates and past realizations. We develop a frequentist modeling framework that provides efficient inference and more accurate predictions. Results demonstrate the advantages of improved prediction rates over existing approaches such as logistic regression, generalized additive mixed model, models for ordinal data, gradient boosting, decision tree and random forest. Using our proposed model, we show that previous sleep state and heart rates are significant predictors for future sleep states. Simulation studies also show that our proposed method is promising and robust. To handle computational complexity, we utilize Laplace approximation, golden section search and successive parabolic interpolation. With this paper, we also submit an R-package (HIBITS) that implements the proposed procedure.

Physical Activity and Sleep Analysis of Heart Failure Patients using Multi-sensor Patches.

Traditional heart failure markers fail to reliably predict heart-failure related hospitalisations and deaths. Multi- sensor patch data can provide an objective insight into activity and sleep patterns of patients and may therefore improve the performance of current risk-quantification algorithms. This work aimed to establish the feasibility of collecting multi-sensor patch data from heart failure patients and to perform an initial analysis of activity and sleep patterns of heart failure patients in relation to disease severity. 13 heart failure patients from the SUPPORT-HF study were provided with chest-worn multisensor patches and asked to wear the devices continuously for up to seven consecutive days. Using a combination of impedance, heart rate and accelerometer data participants' sleep and wakefulness information were extracted and analyzed in relation to self-reported symptom scores. Patch data for eleven patients were of high enough quality to be included in the analysis, accounting for 63 patient days worth of data. The heart failure patients slept for an average of 8.3 hours a night and experienced 2.8 sleep interruptions. Potential differences in sleep angle, heart rate and wake-time activity were found for patients with different heart failure severity. Larger studies are necessary to create a more coherent picture of the potential of activity and sleep as a markers for heart failure deterioration.

Sleep Quality and Heart Rate Variability in Adolescents with Type 1 or Type 2 Diabetes

Regardless of the type of diabetes, there is twice the risk of experiencing cardiovascular (CV) disease complications in comparison to not having the disease. Although these complications and associated symptoms are rarely noted in adolescents with diabetes, early identification of biobehavioral markers for CV risks are essential for targeted approaches for prevention of later disease sequelae. Decreased sleep quality and heart rate variability (HRV) have both independently been associated with diabetes or the presence of obesity and risk for developing diabetes, as well as with CV disease. Studies exploring both sleep quality and HRV in adolescents with diabetes are not available. Thus, we conducted a secondary analysis of data from an existing study to examine differences in sleep quality and HRV in adolescents with type 1 (T1D) vs. type 2 diabetes (T2D); and to determine if there were associations between HRV and sleep quality. Adolescents with T1D (n = 101; 56 males) or T2D (n= 37; 16 males) completed 24-hour HRV Holter monitoring and measurement using Burdick Vision Premier™ ECG Analysis and Editing software system (Waukesha, WI), hemoglobin A1c (HbA1c) using the Abbott IMx® assay method, and a self-report global measure of the impact of diabetes on their sleep quality using a 5-point Likert scale. Duration of diabetes was greater (P \ .001) and measures of HRV were higher in T1D (P \ .01); BMI and BMI z-scores (P \ .001) and systolic and diastolic BP (P ≤ .05) were higher in T2D. No differences in recent or average HbA1c, Tanner staging or sleep quality were found. Both spectral and time domain measures of HRV were associated with sleep quality in T2D (r = - .51 to -.38, P \ .02); only time domain measures were associated with sleep quality in T1D (r = -. 21 to -.19, P ≤ .05). Poorer sleep quality was evident in those with lower HRV; these linkages were stronger in those with T2D. Further study is warranted to elucidate risks and improve sleep quality and CV outcomes in youth with diabetes. Disclosure M.S. Faulkner: None. A. Helvig: None.

Absence Of Sympathetic Vasodilation During Mental Stress With Non‐Dipping Circadian Blood Pressure Pattern In Young White And Black Adults Could Be An Early Indicator Of Hypertension

People of Black African ethnicity (BA) have greater prevalence of hypertension compared with those of White European ethnicity (WE) and are at greater risk of developing hypertension‐associated cardiovascular disease (CVD). Older WE non‐dipper hypertensives show endothelial dysfunction. Endothelial dysfunction and higher prevalence of non‐dipping nocturnal blood pressure have been documented in Blacks relative to Whites. Novel environmental stress stimuli evoke sympathetic vasoconstriction in renal and splanchnic vasculature, but vasodilatation in limb muscle, which may habituate on repetition. In young adults altered response to novel stimuli is predictive of developing hypertension later on in life. However, It is not known whether non‐dippers also show endothelial dysfunction and altered responses to environmental stressors. Thus, we hypothesized that non dippers would show smaller muscle vasodilator or muscle vasoconstrictive responses on repetition of an environmental stressor and blunted reactive hyperaemia relative to dippers. Experiments were performed on 17 WEs (21±0.64 years) and 16 BAs (22±0.77 years) who were resident in the UK. Responses were recorded following release of arterial occlusion for 2 min (reactive hyperaemia) and by 5 sound stimuli (S1–5; 100 dB, 2 KHz). Continuous arterial blood pressure (ABP) was recorded by finger photoplethysmography. Forearm blood flow (FBF) was recorded by venous occlusion plethysmography; forearm vascular conductance (FVC) was calculated as FBF/ABP. 24 hour Ambulatory blood pressure monitoring was done. Relative to WES, BAs showed higher 24 hour systolic blood pressure (SBP)(110±1.33 vs 117±3.17 mmHg) and higher sleep‐time SBP (99±1.36 vs 108±3.05 mmHg) p&lt;0.05 as well as higher proportion of pre‐/hypertensives (7/16, 40%) compared with WE (1,5.8%). 40% BAs were non‐ dippers compared to 17.6 % WE. Six of the pre‐/hypertensive BAs were nocturnal dippers. Relative to normotensive BA dippers, BA non‐dippers showed higher sleep SBP (93±4.65 vs 108±3.01 mmHg) and heart rate (59±4.69 vs 72±3.11 bpm) p&lt;0.05. Relative to WE dippers, the WE non dippers showed higher day‐time and night time mean ABP (85.25±1.14 vs 91.57±2.39 mmHg) ; (71.55±0.88 vs 81.25±1.71 mmHg) p&lt;0.05. During reactive hyperaemia, there was no difference between dippers and non‐dippers in the two ethnic groups ( WE: +0.39± 0.03 vs +0.45± 0.08; BA : +0.41± 0.05 vs +0.34± 0.05 p&gt;0.05 ). During S1–5, WE and BA dippers showed a net increase in FVC indicating forearm vasodilatation (WE, +0.005±0.002 CU; BA, +0.007±0.002 CU) whilst WE and BA non‐dippers showed a net decrease in FVC indicating forearm vasoconstriction, (WE − 0.007±0.004 CU; BA −0.007±0.003 CU). These results indicate that in young normotensive non‐dippers, sympathetic vasoconstriction to mental stress precedes development of endothelial dysfunction and could serve as an early indicator of cardiovascular disorder. Thus, we propose that exaggerated sympathetic vasoconstrictor response to environmental stressors contributes to the development of hypertension and CVD in non‐dippersThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

P870Occurrence of atrial fibrillation in pacemaker patients and its association with sleep apnea and heart rate variability

P870Occurrence of atrial fibrillation in pacemaker patients and its association with sleep apnea and heart rate variability

Effect of the intervention based on Information-Motivation-Behavioral skills on the preoperative anxiety in patients with gynecological malignancies

Objective To investigate the effect of interventions based on Information-Motivation-Behavioral skills on the preoperative anxiety in patients with gynecological malignancies. Methods A total of 64 patients with malignant tumor were divided into two groups by random digits table method with 32 cases each. The patients in the two groups received routine nursing. In addition, interventions based on Information-Motivation-Behavioral skills were provided in the intervention group. All patients were investigated by the following indexes such as the Self-Rating Anxiety Scale (SAS), sleep quality scale, blood pressure and heart rate before and after the intervention. Results After the intervention, the SAS scores in the intervention group was (49.47 ± 3.81) points, sleep quality score was (3.66 ±0.97) points, and systolic blood pressure and heart rate were (128.56±5.93) mmHg (1 mmHg=0.133 kPa), (75.09 ± 3.78) beats/min, which were lower than those in the control group (57.38 ± 3.75) points, (5.50 ± 1.50) points, (134.97 ± 7.19) mmHg, (81.34 ± 4.88) beats/min, the differences were statistically significant (t=-8.350--3.887, P<0.05). Conclusions The intervention focused on Information-Motivation-Behavioral Skills can help patients to relieve anxiety, reduce stress response, improve quality of sleep. Key words: Gynecological malignancies; Anxiety; Information-motivation-behavioral skills

The relationship between severity of obstructive sleep apnea and heart rate variability

Background and Objective: Obstructive sleep apnea syndrome (OSAS) is a prevalent disease in adults. Limited evidence regarding the effect of severity of sleep apnea and depression on heart rate variability (HRV) indices exists. Hence, we decided to focus on the association between HRV and severity of OSAS based on depression score. Materials and Methods: A total of 193 patients with confirmed OSAS were selected from a sleep clinic setting. A checklist for demographic data and self-administered questionnaires including the Pittsburgh Sleep Quality Index; Epworth Sleepiness Scale; Beck Depression Inventory; Snoring, Tiredness, Observed apnea, Blood pressure, Body mass index, Age, Neck circumference (STOP-BANG), and Gender questionnaire were filled in. We used two domains of HRV (e.g., frequency and time) estimation. Results: The mean number of pairs of adjacent RR intervals (time between QRS complexes) differing by more than 50 ms in the entire analysis interval (NN50 count) was significantly different among various severity OSAS groups (μ = 2639.12 ± 478.98 for mild and moderate, and 2313.81 ± 670.54 in severe OSAS; P = 0.0200). In frequency do-main, the indices were higher in severe OSAS patients. Statistically significant association was between HRV parame-ters (standard deviation of all RR intervals, mean of the standard deviation of all RR intervals for all 5-minutes segments, NN50 count, the NN50 count divided by the total number of all RR intervals, average total power, low frequency power) and OSAS severity. Conclusion: There are some statistically significant differences between OSAS severity and parameters of HRV.

Wearable Activity Trackers and Older Adults: The Social Effect and Importance in Healthcare

Background: Many older adults develop chronic diseases, such as heart disease and diabetes, which are correlated with low levels of physical activity. Chronic diseases can result in a decreased quality of life, increased health care costs, and premature mortality. Adults, specifically older adults, who started using wearable activity trackers (WATs) have exhibited an increase in daily activity levels. Although WAT use has increased, only 7% of older adults use a WAT. The use of WATs has the potential to facilitate chronic condition self-management, with patients engaging in personalized care and health care providers receiving accurate data about patient physical activity. One benefit of WATs is the opportunity to develop social relationships. Social relationships have as much impact on physical health as physical activity. Older adults with larger networks show higher levels of health.

P6410QT intervals during sleep and circadian heart rate variability in healthy and long QT syndrome (LQTS) infants

P6410QT intervals during sleep and circadian heart rate variability in healthy and long QT syndrome (LQTS) infants

P4 medicine approach to obstructive sleep apnoea.

P4 medicine is an evolving approach to personalized medicine. The four Ps offer a means to: Predict who will develop disease and co-morbidities; Prevent rather than react to disease; Personalize diagnosis and treatment; have patients Participate in their own care. P4 medicine is very applicable to obstructive sleep apnoea (OSA) because each OSA patient has a different pathway to disease and its consequences. OSA has both structural and physiological mechanisms with different clinical subgroups, different molecular profiles and different consequences. This may explain why there are different responses to alternative therapies, such as intraoral devices and hypoglossal nerve stimulation therapy. Currently, technology facilitates patients to participate in their own care from screening for OSA (snoring and apnoea apps) to monitoring response to therapy (sleep monitoring, blood pressure, oxygen saturation and heart rate) as well as monitoring their own continuous positive airway pressure (CPAP) compliance. We present a conceptual framework that provides the basis for a new, P4 medicine approach to OSA and should be considered more in depth: predict and prevent those at high risk for OSA and consequences, personalize the diagnosis and treatment of OSA and build in patient participation to manage OSA.

1074 POSTTRAUMATIC STRESS DISORDER, CANINE COMPANIONSHIP, AND SLEEP: PRELIMINARY FINDINGS

Large numbers of Veterans with post-deployment psychological disorders have reported improvements in sleep in association with canine companionship. Studies have also provided support for an association between canine companionship and lower baseline heart rate. We tested both possibilities in a sample of combat Veterans undergoing inpatient treatment for posttraumatic stress disorder (PTSD) and participating in a Service Animal Training Intervention in which they shared custody of a service canine with another Veteran. Alternating custody enabled within-subjects modeling of associations between canine companionship and sleep. 18 military Veterans with deployment-related PTSD underwent mattress actigraphy for up to four weeks yielding 493 nights of sleep data. Mattress actigraphy relies upon accelerometers embedded in a mattress topper. The intended sleep period is delimited manually by blind raters after which sleep parameters are calculated automatically. Participants also rated morning restedness on a five-point scale following a total of 329 nights. Whether or not participants had custody of their service canines was carefully tracked. Linear mixed modeling was applied to the longitudinal data, controlling for AHI, snoring, and body movements. A random intercept was specified for each participant. Modeling morning restedness detected only main effects of minutes of actigraphic quiescence (F(1,324) = 4.44, p = 0.036) and canine presence (F(1,313) = 3.89, p = 0.049), both predictors having positive coefficients. Modeling of sleep heart rate also detected main effects of actigraphic quiescence (F(1,476) = 5.38, p = 0.021) and of canine presence (F(1,472) = 5.55, p = 0.018), as well as an effect of snoring (F(1,478) = 13.23, p = 0.0003). Quiescence and canine presence were negatively associated with sleep heart rate, while snoring was positively associated. After accounting for other predictors, canine presence was associated with lower sleep heart rate and greater morning restedness in Veterans with PTSD. Preliminarily, these results are consistent with Veterans’ reports of positive effects of a familiar canine presence on their sleep. This research was supported by Contract W81XWH-15-2-0005 to Steven H. Woodward, PhD, from the Defense Health Program, Military Operational Medical Research Program, and U.S. Army Medical Research and Materiel Command.

1059 POLYSOMNOGRAPHIC CHARACTERISTICS OF PATIENTS WITH REFRACTORY HYPERTENSION COMPARED TO CONTROLLED RESISTANT HYPERTENSION

Refractory hypertension (rHTN), a unique phenotype of antihypertensive treatment failure, is defined as the persistence of uncontrolled high blood pressure (>140/90 mmHg) despite treatment with 5 or more antihypertensive agents. Controlled resistant hypertension (crHTN) is defined as controlled blood pressure requiring 3 or more medications from different classes, including a diuretic. We have previously reported that patients with rHTN exhibit heightened sympathetic tone when compared with those with crHTN. Therefore, this study sought to investigate sleep as a potential mediating mechanism underlying rHTN. We hypothesized that patients with rHTN would have more severe obstructive sleep apnea (OSA) than patients with crHTN as a contributing factor to their heightened sympathetic tone. Consecutive patients (n=80) from the UAB Hypertension Clinic with either rHTN (n=29) or crHTN (n=51) were evaluated by overnight polysomnography. Multivariate analysis of variance was used to compare sleep characteristics between these two groups of patients. Compared with patients with crHTN, those with rHTN were younger (54.6 ± 9.9 versus 58.1 ± 11.6 years) and more likely to be black (75.9% versus 54.9%) and female (69.0% versus 37.3%). Patients with rHTN had more total sleep time (p=0.017) and more time spent in N2 sleep (p=0.002). There were no other significant differences in sleep architecture, number of awakenings, or time spent awake after sleep onset. Patients with rHTN had a higher sleeping heart rate (p=0.040). There were statistically non-significant trends for patients with rHTN to have a higher mean apnea hypopnea index (AHI), as well as for a larger percentage of these patients to have an AHI>5, although these trends were not statistically significant (p=0.367). These findings indicate that patients with rHTN do not exhibit worse OSA compared with patients with crHTN. Therefore, more severe OSA does not explain the heightened sympathetic tone observed in patients with rHTN. This study was supported by NIH grant R01 HL113004 and grant 15SFRN2390002 from the American Heart Association.

Nursing study in abdominal breathing training ameliorating sleep status in elderly patients with chronic heart failure

Objective To investigate the effects of abdominal breathing training on sleep disorders in elderly patients with chronic heart failure. Methods Total of 100 patients with chronic heart failure complain of sleeping disorders and Pittsburgh Sleep Quality Index (PSQI)>7 points were assigned into two groups by random digits table method, 50 cases in each group. The observation group and the control group were nursed in the same way except that abdominal breathing was adapted to the observation group. Sleep status, heart rate, blood pressure, SpO2 and brain natriuretic peptide (BNP) were evaluated before training, one week and eight weeks after training respectively. Statistics was used to analyze the differences between two groups. Results After training one week, the sleep status of the observation group was ameliorated, but without significant difference compared to the control group (P>0.05). And after training eight weeks, the PSQI, BNP and heart rate were (9.21 ± 6.38) points, (193.78 ± 152.16) μg/L, (63.5 ± 10.8) times/min in the observation group, and (12.92 ± 0.33) points, (417.55 ± 262.47) μg/L, (70.7 ± 8.5) times/min in the control group, and there was significant differences between 2 groups (t=3.627, 2.041, 2.767, all P 0.05). Conclusions Abdominal breathing training could ameliorate sleep status in elderly patients with chronic heart failure. Key words: Aged; Sleep disorders; Chronic heart failure; Abdominal breathing

Acute sleep disruption: does it limit performance but heighten immunity?

Introduction: Alterations to sleep patterns in athletes are commonly reported prior to competition and during travel to events (Juliff et al., 2015; Erlacher et al., 2011). When sleep is completely deprived decrements in performance and increased perceptions of effort are reported (Temesi et al., 2013; Oliver et al., 2009). Circulating levels of white blood cells are reported to alter during periods of sleep deprivation (Kerkhofs et al., 2007) or remain unchanged (Costa et al., 2010). Sleep disruption is perhaps more commonly experienced in athletic populations which could alter biological rhythms, immune responses and performance.  Purpose: To examine the effect of disrupted sleep on exercise-induced physiological and immunological parameters. Methodology: Ten healthy male cyclists performed 1h of cycling at a fixed power output on an indoor cycle ergometer following either a night of DS (woken every hour of the night over an 8h period) or a night of undisrupted sleep (US) (left undisrupted for an 8h period). Heart rate (HR), perceived rate of exertion and sleep parameters were all recorded. Blood was collected before, immediately after and 1h after exercise completion. White blood cells and their subtypes were enumerated.  Results: Statistically significant differences between US and DS trials were observed for the mean heart rate during the exercise bout (t (9) = 4.80, p < 0.01) and rate of perceived exertion (RPE) (t (9) = 3.86, p < 0.01). Repeated measures ANOVA revealed a significant trial (US/DS) * time (minutes) interaction with heart rate (F (12/108) = 5.94; p < 0.01) and RPE (F (12/108) = 3.8; p < 0.05), Bonferroni corrected post hoc analysis between trials is illustrated in figure 1 & 2 below. Repeated measures ANOVA yielded a significant trial (US/ DS) x interaction with time (pre, post, 1 h post) for total lymphocytes (F (2/18) = 5.84, p < 0.05, r = 0.5) suggesting lymphocytes were significantly altered with exercise depending on whether the participants had endured a night of DS or US. Bonferroni post hoc analysis revealed this was driven by the larger increase in lymphocytes at the post time point following the DS trial (t (9) = 2.88, p < 0.01, r = 0.69). CD8+ T-cells similarly demonstrated a trial x time interaction (F (2/18) = 4.12; p < 0.03, r = 0.43) with a larger increase in cell number apparent during the DS trial, post hoc analysis revealed this was driven by a larger increase in CD8+ T-cells immediately post exercise during the DS trial (t (9) = 2.69, p < 0.05, r = 0.67). There was no time x trial interaction observed for CD4+ T-cells, NK cells or I³I´ T-cells between US and DS conditions  Conclusions: Our findings indicate that short-term changes to sleep architecture lower heart rate during fixed intensity exercise while the perception of effort was increased, suggesting that acute sleep deprivation reduced cardio-respiratory function which could lead to performance decrements during endurance exercise. Sleep disruption augmented lymphocyte redeployment from the peripheral blood compartment which may ‘prime’ the system during exposure to short-term sleep disruption.

Energy expenditure in frontotemporal dementia: a behavioural and imaging study.

SEE FINGER DOI101093/AWW312 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Abnormal eating behaviour and metabolic parameters including insulin resistance, dyslipidaemia and body mass index are increasingly recognized as important components of neurodegenerative disease and may contribute to survival. It has previously been established that behavioural variant frontotemporal dementia is associated with abnormal eating behaviour characterized by increased sweet preference. In this study, it was hypothesized that behavioural variant frontotemporal dementia might also be associated with altered energy expenditure. A cohort of 19 patients with behavioural variant frontotemporal dementia, 13 with Alzheimer's disease and 16 (age- and sex-matched) healthy control subjects were studied using Actiheart devices (CamNtech) to assess resting and stressed heart rate. Actiheart devices were fitted for 7 days to measure sleeping heart rate, activity levels, and resting, active and total energy expenditure. Using high resolution structural magnetic resonance imaging the neural correlates of increased resting heart rate were investigated including cortical thickness and region of interest analyses. In behavioural variant frontotemporal dementia, resting (P = 0.001), stressed (P = 0.037) and sleeping heart rate (P = 0.038) were increased compared to control subjects, and resting heart rate (P = 0.020) compared to Alzheimer disease patients. Behavioural variant frontotemporal dementia was associated with decreased activity levels compared to controls (P = 0.002) and increased resting energy expenditure (P = 0.045) and total energy expenditure (P = 0.035). Increased resting heart rate correlated with behavioural (Cambridge Behavioural Inventory) and cognitive measures (Addenbrooke's Cognitive Examination). Increased resting heart rate in behavioural variant frontotemporal dementia correlated with atrophy involving the mesial temporal cortex, insula, and amygdala, regions previously suggested to be involved exclusively in social and emotion processing in frontotemporal dementia. These neural correlates overlap the network involved in eating behaviour in frontotemporal dementia, suggesting a complex interaction between eating behaviour, autonomic function and energy homeostasis. As such the present study suggests that increased heart rate and autonomic changes are prevalent in behavioural variant frontotemporal dementia, and are associated with changes in energy expenditure. An understanding of these changes and neural correlates may have potential relevance to disease progression and prognosis.

The effect of sleep apnea severity on cardiac autonomic activity during night time in obstructive sleep apnea patients

ABSTRACT CONTEXT AND OBJECTIVE: Impaired autonomic cardiac function is an important consequence of obstructive sleep apnea (OSA). This impairment is mainly due to intermittent hypoxia episodes following apneas. However, the impact of apnea severity on autonomic cardiac function remains unclear. The aim of this study was to evaluate the relationship between the severity of sleep apnea and heart rate turbulence (HRT) and heart rate variability (HRV) in OSA. DESIGN AND SETTING: Observational cross-sectional study conducted in the Departments of Cardiology and Pulmonary Diseases, Afyon Kocatepe University, Turkey. METHODS: 106 patients with OSA and 27 healthy volunteers were enrolled. Based on apnea hypopnea index (AHI) values, obstructive sleep apnea severity was classified as follows: mild OSA (AHI ≥ 5 and &lt; 15), moderate OSA (AHI ≥ 15 and ≤ 30) and severe OSA (AHI &gt; 30). HRV and HRT parameters were assessed via 24-hour digital Holter electrocardiogram recordings for all subjects. RESULTS: HRV and HRT results were significantly lower among OSA patients than among control subjects (P &lt; 0.05). However, there were no significant differences in HRT and HRV between the three patient subgroups. Correlations did emerge between AHI and the NN-interval parameter RMSSD and between oxygen desaturation and turbulence slope (respectively: r = -0.22, P = 0.037; and r = -0.28, P = 0.025). CONCLUSION: HRT and HRV results deteriorate in OSA. Correlations between apnea severity and these parameters seem to be present.

Effect of Preoperative Oral Amantadine on Acute and Chronic Postoperative Pain After Mandibular Fracture Surgery.

BackgroundPostoperative pain from open reduction and internal fixation of mandibular fracture is a serious issue. Amantadine is an N-methyl-D-aspartic acid or N-methyl-D-aspartate (NMDA) receptor antagonist that can be effective against postoperative pain.ObjectivesThe present study examined the efficacy of amantadine in alleviating the postoperative pain of mandibular fracture surgery.Patients and MethodsIn this double-blind study, 60 patients (ASA physical status I–II) were randomly divided into two groups. The mean ages of the participants were 31.2 ± 13.1 years and 32.3 ± 18.1 years, respectively. The male/female ratios were 24/6 and 26/4, respectively, in the case and control groups. Randomization was based on a single sequence of random assignments using computer-generated random numbers. Group I was given oral amantadine 100 mg 1 hour before surgery, and group II received a placebo at the identical time. Through PCA pumps, patients received a bolus dose of morphine at 0.02 mg/kg body weight, to a maximum of 1.5 mg. PCA pumps were set at 6 minutes lockout intervals and a maximum dose of 0.15 mg/kg/h, to a maximum of 10 mg/h. Pain was assessed using a visual analog scale (VAS) at 0, 2, 4, 6, 12, and 24 hours and 1, 2, 3, 4, 5, and 6 months after surgery. The amounts of analgesic consumed were recorded for the first 24 hours, and for 6 months after surgery.ResultsThere were no significant differences between the two groups with respect to age, gender, nausea and vomiting, sleep quality, blood pressure, and heart rate. No significant differences were observed between the two groups in pain scores (P = 0.39) and analgesic consumption (P = 0.78).ConclusionsThe results suggest that a single dose of preoperative oral amantadine did not reduce acute or chronic postoperative pain, nor analgesic consumption.

The association between prolonged sleep onset latency and heart rate dynamics among young sleep-onset insomniacs and good sleepers

A blunting of heart rate (HR) reduction during sleep has been reported to be associated with increased all-cause mortality. An increased incident of cardiovascular events has been observed in patients with insomnia but the relationship between nighttime HR and insomnia remains unclear. Here we investigated the HR patterns during the sleep onset period and its association with the length of sleep onset latency (SOL). Nineteen sleep-onset insomniacs (SOI) and 14 good sleepers had their sleep analyzed. Linear regression and nonlinear Hilbert-Huang transform (HHT) of the HR slope were performed in order to analyze HR dynamics during the sleep onset period. A significant depression in HR fluctuation was identified among the SOI group during the sleep onset period when linear regression and HHT analysis were applied. The magnitude of the HR reduction was associated with both polysomnography-defined and subjective SOL; moreover, we found that the linear regression and HHT slopes of the HR showed great sensitivity with respect to sleep quality. Our findings indicate that HR dynamics during the sleep onset period are sensitive to sleep initiation difficulty and respond to the SOL, which indicates that the presence of autonomic dysfunction would seem to affect the progress of falling asleep.