Nocturnal blood pressure dipping, blood pressure variability, and cognitive function in early and middle-aged adults.

Higher nighttime blood pressure (BP), less BP dipping, and higher BP variability have been linked with worse cognitive function in the elderly. The goal of this study is to explore whether this relationship already exists in early and middle adulthood. We further examined whether ethnic differences between African Americans and European Americans in BP parameters can explain ethnic differences in cognitive function. 24-h ambulatory BP monitoring and cognitive function were obtained from 390 participants (average age: 37.2 years with a range of 25-50; 54.9% African Americans; 63.6% females). We observed that higher nighttime BP, decreased dipping, and higher variability were significantly associated with lower scores on the Picture Sequence Memory Test. Significant negative associations between variability and overall composite scores were also observed. No significant associations between average 24-h or daytime BP and cognitive function were observed. Ethnic differences in nighttime diastolic pressures and dipping can explain 6.81% to 10.8% of the ethnicity difference in the score of the Picture Sequence Memory Test (ps < .05). This study suggests that the associations of nighttime BP, dipping, and variability with cognitive function already exist in young and middle-aged adults. Ethnic differences in nighttime BP and dipping can at least partially explain ethnic differences in cognitive function. The stronger association of these parameters with cognitive function than daytime or average BP in this age range raises the importance of using ambulatory BP monitoring for more precise detection of abnormal BP patterns in young adulthood.

Sleep Variability, Sleep Irregularity, and Nighttime Blood Pressure Dipping.

BACKGROUND: Circadian rhythm regulates many important biological functions in humans. The goal of this study is to explore the impact of day-to-day deviations in the sleep-wake cycle on nighttime blood pressure (BP) dipping and further examine whether the ethnic difference in day-to-day deviations in sleep patterns can explain the ethnic difference in nighttime BP dipping. METHODS: Twenty-four-hour ambulatory BP monitoring and 7-day accelerometer data were obtained from 365 adult participants (age range, 18.7-50.1 years; 52.6% Black participants and 47.3% European Americans; 64.1% females). Systolic BP dipping level was used to represent nighttime BP dipping. The SD of sleep duration was calculated as the index of sleep variability, and the SD of sleep midpoint was calculated as the index of sleep irregularity. RESULTS: A 1-hour increase in the SD of sleep midpoint was associated with a 1.16% decrease in nighttime BP dipping (P<0.001). A 1-hour increase in the SD of sleep duration was associated with a 1.39% decrease in nighttime BP dipping (P=0.017). The ethnic difference in the SD of sleep midpoint can explain 29.2% of the ethnicity difference in BP dipping (P=0.008). CONCLUSIONS: Sleep variability and sleep irregularity are associated with blunted BP dipping in the general population. In addition, data from the present investigation also demonstrate that the ethnic difference in sleep irregularity could partly explain the ethnic difference in BP dipping, an important finding that may help reduce the health disparity between Black participants and European Americans.

A Pilot Randomized Controlled Trial Evaluating Essential Oils for Chemotherapy-Induced Peripheral Neuropathy.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a painful, debilitating consequence of cancer treatment affecting up to 60% of patients. Pharmacological approaches to CIPN are often ineffective and cause adverse effects. Essential oils are an underutilized non-pharmacological approach to pain reduction. AIMS: To ascertain the efficacy of an essential oil intervention to reduce CIPN. DESIGN: A single-blind, pilot randomized controlled trial. METHODS: Participants (n = 27) were stratified by baseline pain scores and randomized to intervention (n = 13) and placebo groups (n = 14). Participants topically-applied the essential oil intervention or placebo every eight hours for six weeks. Pain was assessed using the Short-Form-McGill Pain Questionnaire-2 weekly and the Visual Analogue Scale daily. Quality-of-life was assessed using the Quality-of-Life: CIPN-20 and Quality-of-Life Adult Cancer Survivor questionnaires. Data were analyzed in SPSS using generalized estimating equations. RESULTS: No significant difference was observed between groups in pain or quality-of-life scores over seven weeks, but improvement was observed in both groups. Participants using the intervention with pain medications showed a significant reduction in pain compared to placebo (p = .001). Educational level (p = .041) and annual income (p = .005) were significant covariates mirroring these social determinates of pain. Older participants felt less negatively about their CIPN (p = .002). Positive placebo effect and spatiotemporal interactions were observed. CONCLUSIONS: This pilot study demonstrated that participants adhered to the intervention for six weeks. Essential oils have potential direct and adjuvant pain-reducing effects and should be studied further.

Micro-calibration of space and motion by photoreceptors synchronized in parallel with cortical oscillations: A unified theory of visual perception.

A fundamental function of the visual system is detecting motion, yet visual perception is poorly understood. Current research has determined that the retina and ganglion cells elicit responses for motion detection; however, the underlying mechanism for this is incompletely understood. Previously we proposed that retinogeniculo-cortical oscillations and photoreceptors work in parallel to process vision. Here we propose that motion could also be processed within the retina, and not in the brain as current theory suggests. In this paper, we discuss: 1) internal neural space formation; 2) primary, secondary, and tertiary roles of vision; 3) gamma as the secondary role; and 4) synchronization and coherence. Movement within the external field is instantly detected by primary processing within the space formed by the retina, providing a unified view of the world from an internal point of view. Our new theory begins to answer questions about: 1) perception of space, erect images, and motion, 2) purpose of lateral inhibition, 3) speed of visual perception, and 4) how peripheral color vision occurs without a large population of cones located peripherally in the retina. We explain that strong oscillatory activity influences on brain activity and is necessary for: 1) visual processing, and 2) formation of the internal visuospatial area necessary for visual consciousness, which could allow rods to receive precise visual and visuospatial information, while retinal waves could link the lateral geniculate body with the cortex to form a neural space formed by membrane potential-based oscillations and photoreceptors. We propose that vision is tripartite, with three components that allow a person to make sense of the world, terming them "primary, secondary, and tertiary roles" of vision. Finally, we propose that Gamma waves that are higher in strength and volume allow communication among the retina, thalamus, and various areas of the cortex, and synchronization brings cortical faculties to the retina, while the thalamus is the link that couples the retina to the rest of the brain through activity by gamma oscillations. This novel theory lays groundwork for further research by providing a theoretical understanding that expands upon the functions of the retina, photoreceptors, and retinal plexus to include parallel processing needed to form the internal visual space that we perceive as the external world.

Self-Regulation of Breathing as an Adjunctive Treatment of Insomnia.

Sleep is a quiescent behavioral state during which complex homeostatic functions essential to health and well-being occur. Insomnia is a very common psychiatric disorder leading to a myriad of detrimental effects including loss of concentration, memory, and performance as well as disease. Current pharmaceutical treatments can be expensive, impairing, unhealthy, and habit-forming. Relaxation techniques, such as meditation target the brain and body in contrast to pharmaceutical interventions which solely target neurotransmitter systems in the brain. In this article we present a viewpoint on the treatment of insomnia that techniques of slow, deep breathing (0.1 Hz) in adjunct to sleep hygiene and relaxation therapies may be highly effective in initiating sleep as well as facilitating falling back asleep. The autonomic nervous system is integral to sleep initiation, maintenance, and disruption. Understanding the relationship between the autonomic nervous system and sleep physiology along with the nature of sleep itself remains a challenge to modern science. We present this perspective in light of a prevailing "dysevolution" theory on the pathology of insomnia that proposes hyper-arousal characterized in part by chronic sympathetic hyperactivation and/or parasympathetic hypoactivation disrupts normal sleep onset latency, sleep quality, and sleep duration. We additionally discuss physiological mechanisms responsible for the effectiveness of the breathing treatment we describe. A better understanding of these mechanisms and autonomic pathologies of insomnia may provide support for the effectiveness of such techniques and provide relief to sufferers of this health epidemic.

How lateral inhibition and fast retinogeniculo-cortical oscillations create vision: A new hypothesis.

The role of the physiological processes involved in human vision escapes clarification in current literature. Many unanswered questions about vision include: 1) whether there is more to lateral inhibition than previously proposed, 2) the role of the discs in rods and cones, 3) how inverted images on the retina are converted to erect images for visual perception, 4) what portion of the image formed on the retina is actually processed in the brain, 5) the reason we have an after-image with antagonistic colors, and 6) how we remember space. This theoretical article attempts to clarify some of the physiological processes involved with human vision. The global integration of visual information is conceptual; therefore, we include illustrations to present our theory. Universally, the eyeball is 2.4cm and works together with membrane potential, correspondingly representing the retinal layers, photoreceptors, and cortex. Images formed within the photoreceptors must first be converted into chemical signals on the photoreceptors' individual discs and the signals at each disc are transduced from light photons into electrical signals. We contend that the discs code the electrical signals into accurate distances and are shown in our figures. The pre-existing oscillations among the various cortices including the striate and parietal cortex, and the retina work in unison to create an infrastructure of visual space that functionally "places" the objects within this "neural" space. The horizontal layers integrate all discs accurately to create a retina that is pre-coded for distance. Our theory suggests image inversion never takes place on the retina, but rather images fall onto the retina as compressed and coiled, then amplified through lateral inhibition through intensification and amplification on the OFF-center cones. The intensified and amplified images are decompressed and expanded in the brain, which become the images we perceive as external vision. SUMMARY: This is a theoretical article presenting a novel hypothesis about the physiological processes in vision, and expounds upon the visual aspect of two of our previously published articles, "A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience", and "Functional representation of vision within the mind: A visual consciousness model based in 3D default space." Currently, neuroscience teaches that visual images are initially inverted on the retina, processed in the brain, and then conscious perception of vision happens in the visual cortex. Here, we propose that inversion of visual images never takes place because images enter the retina as coiled and compressed graded potentials that are intensified and amplified in OFF-center photoreceptors. Once they reach the brain, they are decompressed and expanded to the original size of the image, which is perceived by the brain as the external image. We adduce that pre-existing oscillations (alpha, beta, and gamma) among the various cortices in the brain (including the striate and parietal cortex) and the retina, work together in unison to create an infrastructure of visual space thatfunctionally "places" the objects within a "neural" space. These fast oscillations "bring" the faculties of the cortical activity to the retina, creating the infrastructure of the space within the eye where visual information can be immediately recognized by the brain. By this we mean that the visual (striate) cortex synchronizes the information with the photoreceptors in the retina, and the brain instantaneously receives the already processed visual image, thereby relinquishing the eye from being required to send the information to the brain to be interpreted before it can rise to consciousness. The visual system is a heavily studied area of neuroscience yet very little is known about how vision occurs. We believe that our novel hypothesis provides new insights into how vision becomes part of consciousness, helps to reconcile various previously proposed models, and further elucidates current questions in vision based on our unified 3D default space model. Illustrations are provided to aid in explaining our theory.

Impact of Transcendental Meditation on Psychotropic Medication Use Among Active Duty Military Service Members With Anxiety and PTSD.

The purpose of the study was to determine whether the regular practice of Transcendental Meditation (TM) decreased the need for psychotropic medications required for anxiety and post-traumatic stress disorder (PTSD) management and increased psychological wellbeing. The sample included 74 military Service Members with documented PTSD or anxiety disorder not otherwise specified (ADNOS), 37 that practiced TM and 37 that did not. At 1 month, 83.7% of the TM group stabilized, decreased, or ceased medications and 10.8% increased medication dosage; compared with 59.4% of controls that showed stabilizations, decreases, or cessations; and 40.5% that increased medications (p < 0.03). A similar pattern was observed after 2 (p < 0.27), 3 (p < 0.002), and 6 months (p < 0.34). Notably, there was a 20.5% difference between groups in severity of psychological symptoms after 6 months, that is, the control group experienced an increase in symptom severity compared with the group practicing TM. These findings provide insight into the benefits of TM as a viable treatment modality in military treatment facilities for reducing PTSD and ADNOS psychological symptoms and associated medication use.

Impact of Mindfulness-Based Eating Awareness on Diet and Exercise Habits in Adolescents.

BACKGROUND: Childhood and adolescent overweight is one of the most important current public health concerns. There is an urgent need to initiate community-based prevention to support healthy eating and physical activity in children. Mindfulness-Based Eating Awareness Training (MB-EAT) is a 12-w eek manualized intervention developed by Kristeller et al. that uses focused meditation techniques to help obese individuals normalize eating behaviors, and improve exercise and dietary habits. OBJECTIVE: To adapt the MB-EAT program to adolescents (MB-EAT-A) and assess the impact of the MB-EAT-A program implemented in a high school setting on self-reported assessment of eating and exercise habits and dietary intake of fat. METHODS: 40 ninth grade adolescents (14 males; 35 African-Americans, 1 Caucasian, 4 Others; mean age 16.2±1.2 yrs; BMI=32.4±9.0, BMI range 19.1 to 58.4) from 6 high school health/physical education classes were randomly assigned to 12-weekly sessions of MB-EAT-A intervention (n=18) or health education control (CTL, n=22). Assessments of eating and exercise habits and dietary fat and caloric content were conducted at pre-test, post-test at 3 mo. immediately following intervention and follow-up, 3 months after intervention ended, with 85% retention at follow up. RESULTS: At 6 mo. follow-up, the MB-EAT-A group increased days/week of moderate exercise >30 min/day (0.8 vs -0.7 days/week), and intense aerobic exercise >20 min/day (1.4 vs. -0.5 days/week, both ps<.05) compared to decreases in CTLs. At 6 mo. follow-up the MB-EAT-A group increased number of servings per week of low calorie foods (7.7 vs. -.05, p<.02), foods with no saturated fats (5.1 vs. -0.4, p<.10) and low in saturated fats (4.6 vs. -2.7, p<.02). At 6 mo. follow-up the MBEAT-A group increased number of foods with no fat (3.9 vs -0.3, p<.08) and low in fat (5.8 vs. -1.4, p<.02) compared to decreases in CTLs. Weight gains at follow-up (4.2 vs 6.2 lbs, MB-EAT-A vs CTL) did not differ significantly between the two conditions (p=.87). In a sub-sample of 29 African American adolescents, 58% reported, a binge eating problem with most being mild to moderate in severity. Excessively eating on a regular basis and thinking about trying to control eating urges were the most common features present. Binge eating severity did not significantly correlate with anxiety, depression, or self-esteem. CONCLUSION: The MB-EAT-A program increased moderate and intense aerobic exercise and improved dietary habits in favor of low calorie and low fat foods in an overweight/obese adolescent sample. The MB-EAT-A program increased moderate and intense aerobic exercise and improved consumption of low calorie and low fat foods in overweight/obese adolescents. The study demonstrated feasibility of conducting the MB-EAT-A program in a high school setting, and good acceptability by the students. The successful implementation of MB-EAT-A points to the potential of school-based mindful eating programs as a means of addressing early onset of obesity in high-risk youth.

A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience.

The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D illustrations to explain how both visual and non-visual sensory information may be filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system.

Self-regulation of breathing as a primary treatment for anxiety.

Understanding the autonomic nervous system and homeostatic changes associated with emotions remains a major challenge for neuroscientists and a fundamental prerequisite to treat anxiety, stress, and emotional disorders. Based on recent publications, the inter-relationship between respiration and emotions and the influence of respiration on autonomic changes, and subsequent widespread membrane potential changes resulting from changes in homeostasis are discussed. We hypothesize that reversing homeostatic alterations with meditation and breathing techniques rather than targeting neurotransmitters with medication may be a superior method to address the whole body changes that occur in stress, anxiety, and depression. Detrimental effects of stress, negative emotions, and sympathetic dominance of the autonomic nervous system have been shown to be counteracted by different forms of meditation, relaxation, and breathing techniques. We propose that these breathing techniques could be used as first-line and supplemental treatments for stress, anxiety, depression, and some emotional disorders.

Education of Physicians and Implementation of a Formal Referral System Can Improve Cardiac Rehabilitation Referral and Participation Rates after Percutaneous Coronary Intervention.

BACKGROUND: Cardiac rehabilitation (CR) is an effective preventive measure that remains underutilised in the United States. The study aimed to determine the CR referral rate (RR) after percutaneous coronary intervention (PCI) at an academic tertiary care centre, identify barriers to referral, and evaluate awareness of CR benefits and indications (CRBI) among cardiologists. Subsequently, it aimed to evaluate if an intervention consisting of physicians' education about CRBI and implementation of a formal CR referral system could improve RR and consequently participation rate (PR). METHODS: Data were retrospectively collected for all consecutive patients who underwent PCI over 12 months. Referral rate was determined and variables were compared for differences between referred and non-referred patients. A questionnaire was distributed among the physicians in the Division of Cardiology to assess awareness of CRBI and referral practice patterns. After implementation of the intervention, data were collected retrospectively for consecutive patients who underwent PCI in the following six months. Referral rate and changes in PRs were determined. RESULTS: Prior to the intervention, RR was 17.6%. Different barriers were identified, but the questionnaire revealed lack of physicians' awareness of CRBI and inconsistent referral patterns. After the intervention, RR increased to 88.96% (Odds Ratio 37.73, 95% CI 21.34-66.70, p<0.0001) and PR increased by 32.8% to reach 26%. Personal endorsement of CRBI by cardiologists known to patients increased CR program graduation rate by 35%. CONCLUSIONS: Cardiologists' awareness of CRBI increases CR RR and their personal endorsement improves PR and compliance. Education of providers and implementation of a formal referral system can improve RR and PR.

Effects of a community-based multimodal exercise program on physical function and quality of life in cancer survivors: a pilot study.

The purpose of this single-arm pilot study was to examine the effects of a community-based multimodal exercise program on: physical function (Timed-Up-and-Go [TUG], 6-min walk test [6MWT], leg and chest press strength, and functional reach [FR]); and quality of life, QoL [FACT-G]), in cancer survivors. Fifty-nine cancer survivors (91.5% female; mean age 59 ± 12 years) completed supervised exercise training for 90 min twice weekly for 12 weeks. Exercise training consisted of 30 min of each of the following: (1) aerobic conditioning; (2) resistance training; and (3) balance and flexibility training. Pre-post-outcome measures were compared for statistically significant differences (p < 0.01) and were related to the International Classification of Functioning, Disability and Health Model. Effect sizes (ES), minimal clinically important differences, and minimal detectable change at 90% confidence intervals were calculated. Participants decreased TUG time by 21.1% and walked 15.5% farther during 6-MWT (p < 0.001). Leg and chest press strength increased by 34.5% and 32.7%, respectively (p < 0.001). FR increased by 15.1% (p < 0.001). Significant improvements for physical well-being (13.9%), emotional well-being (6.7%), functional well-being (13.0%), and total well-being (9.6%) were found (p < 0.01). Improvements in physical function and QoL showed "moderate to large" ESs indicating improvements in physical function and QoL are clinically meaningful.

Widespread depolarization during expiration: a source of respiratory drive?

Respiration influences various pacemakers and rhythms of the body during inspiration and expiration but the underlying mechanisms are relatively unknown. Understanding this phenomenon is important, as breathing disorders, breath holding, and hyperventilation can lead to significant medical conditions. We discuss the physiological modulation of heart rhythm, blood pressure, sympathetic nerve activity, EEG, and other changes observed during inspiration and expiration. We also correlate the intracellular mitochondrial respiratory metabolic processes with real-time breathing and correlate membrane potential changes with inspiration and expiration. We propose that widespread minor hyperpolarization occurs during inspiration and widespread minor depolarization occurs during expiration. This depolarization is likely a source of respiratory drive. Further knowledge of intracellular and extracellular ionic changes associated with respiration will enhance ourunderstanding of respiration and its role as a modulator of cellular membrane potential. This could expand treatment options for a wide range of health conditions, such as breathing disorders, stress-related disorders, and further our understanding of the Hering-Breuer reflex and respiratory sinus arrhythmia.

Prognostic value of normal stress echocardiography in obese patients.

BACKGROUND: Chest pain is a common problem in obese patients. Because of the body habitus, the results of noninvasive evaluation for CAD may be limited in this group. METHODS: We reviewed the records of 1446 consecutive patients who had undergone clinically indicated stress echocardiography (SE). We compared major adverse cardiac events (MACE; myocardial infarction, cardiac intervention, cardiac death, subsequent hospitalization for cardiac events, and emergency department visits) at 1 year in normal weight, overweight, and obese subjects with normal SE. RESULTS: Excluding patients with an abnormal and indeterminate SE and those who were lost to follow-up, a retrospective analysis of 704 patients was performed. There were 366 obese patients (BMI ≥ 30), 196 overweight patients (BMI 25-29.9), and 142 patients with normal BMI (18.5-24.9). There was no MACE in the groups at 1-year follow-up after a normal SE. CONCLUSIONS: In obese patients including those with multiple risk factors and symptoms concerning for cardiac ischemia, stress echocardiography is an effective and reliable noninvasive tool for identifying those with a low 1-year risk of cardiac events.

Role of cardiorespiratory synchronization and sleep physiology: effects on membrane potential in the restorative functions of sleep.

Although sleep physiology has been extensively studied, many of the cellular processes that occur during sleep and the functional significance of sleep remain unclear. The degree of cardiorespiratory synchronization during sleep increases during the progression of slow-wave sleep (SWS). Autonomic nervous system (ANS) activity also assumes a pattern that correlates with the progression of sleep. The ANS is an integral part of physiologic processes that occur during sleep with the respective contribution of parasympathetic and sympathetic activity varying between different sleep stages. In our paper, we attempt to unify the activities of various physiologic systems, namely the cardiac, respiratory, ANS and brain, during sleep into a consolidated picture with particular attention to the membrane potential of neurons. In our unified model, we explore the potential of sleep to promote restorative processes in the brain.

Effects of the transcendental meditation technique on trait anxiety: a meta-analysis of randomized controlled trials.

OBJECTIVE: This meta-analysis of randomized controlled trials (RCTs) on the Transcendental Meditation® (TM) technique updates previous meta-analyses and assesses the effects of initial anxiety level, age, duration of practice, regularity of practice, research quality, author affiliation, and type of control group on effect sizes. DESIGN: This systematic review of the literature used the Comprehensive Meta-Analysis (CMA) program for core analyses of effect sizes, bias analysis, meta-regression, and moderator variable analysis. Comprehensive literature searches included databases devoted to meditation research. RESULTS: More than 600 TM research papers were identified; 14 of these addressed trait anxiety and reported on 16 studies among 1295 participants with diverse demographic characteristics. No adverse effects were reported. The standardized difference in mean, d, for the TM technique compared with controls receiving an active alternative treatment (10 studies) was d=-0.50 (95% CI, -.70 to -0.30; p=0.0000005). Compared with controls receiving treatment as usual (wait list or attention controls, 16 studies), d=-0.62 (95% CI, -0.82 to -0.43; p=1.37E-10). Meta-regression found that initial anxiety level, but not other variables, predicted the magnitude of reduction in anxiety (p=0.00001). Populations with elevated initial anxiety levels in the 80th to 100th percentile range (e.g., patients with chronic anxiety, veterans with post-traumatic stress disorder, prison inmates) showed larger effects sizes (-0.74 to -1.2), with anxiety levels reduced to the 53rd to 62nd percentile range. Studies using repeated measures showed substantial reductions in the first 2 weeks and sustained effects at 3 years. CONCLUSION: Overall, TM practice is more effective than treatment as usual and most alternative treatments, with greatest effects observed in individuals with high anxiety. More research is needed in this area, especially with high-anxiety patients, conducted under medically supervised conditions.

Clinical case series: treatment of PTSD with transcendental meditation in active duty military personnel.

Active duty U.S. Army Service Members previously diagnosed with post-traumatic stress disorder (PTSD) were selected from review of patient records in the Traumatic Brain Injury Clinic at the Department of Defense Eisenhower Army Medical Center at Fort Gordon in Augusta, Georgia. Patients agreed to practice the Transcendental Meditation (TM) technique for 20 minutes twice a day for the duration of a 2-month follow-up period. Three cases are presented with results that show the feasibility of providing TM training to active duty soldiers with PTSD in a Department of Defense medical facility. Further investigation is suggested to determine if a TM program could be used as an adjunct for treatment of PTSD. Impact of this report is expected to expand the complementary and alternative evidence base for clinical care of PTSD.

A genome-wide methylation study on obesity: differential variability and differential methylation.

Besides differential methylation, DNA methylation variation has recently been proposed and demonstrated to be a potential contributing factor to cancer risk. Here we aim to examine whether differential variability in methylation is also an important feature of obesity, a typical non-malignant common complex disease. We analyzed genome-wide methylation profiles of over 470,000 CpGs in peripheral blood samples from 48 obese and 48 lean African-American youth aged 14-20 y old. A substantial number of differentially variable CpG sites (DVCs), using statistics based on variances, as well as a substantial number of differentially methylated CpG sites (DMCs), using statistics based on means, were identified. Similar to the findings in cancers, DVCs generally exhibited an outlier structure and were more variable in cases than in controls. By randomly splitting the current sample into a discovery and validation set, we observed that both the DVCs and DMCs identified from the first set could independently predict obesity status in the second set. Furthermore, both the genes harboring DMCs and the genes harboring DVCs showed significant enrichment of genes identified by genome-wide association studies on obesity and related diseases, such as hypertension, dyslipidemia, type 2 diabetes and certain types of cancers, supporting their roles in the etiology and pathogenesis of obesity. We generalized the recent finding on methylation variability in cancer research to obesity and demonstrated that differential variability is also an important feature of obesity-related methylation changes. Future studies on the epigenetics of obesity will benefit from both statistics based on means and statistics based on variances.

Prevention of Traumatic Brain Injury in Youth and Adolescents.

The goal of this project was to promote bicycle helmet use via an inpatient educational program. We hypothesized that this program would increase bicycle helmet use. One hundred twenty inpatients with history of regular (>1 time per week) bicycle riding (mean age 10.0 ± 3.6 years; 67 males, 53 females; 57 whites, 59 blacks, 4 other) were randomized to treatment (n = 58) or control (n = 62) groups. All participants received a bicycle helmet. At 1 month, 50 (92.6%) of the intervention group and 48 (82.8%) of the control group wore a helmet every bike ride (P < .07). At 3 months, 50 (96.2%) of the intervention group and 44 (80%) of the controls wore a helmet with every bike ride (P < .03). The study proved feasible, requiring trained personnel to deliver the intervention. Providing a helmet without the intervention was effective in 80% to 83% of cases with respect to parental report of helmet wearing compliance.