Body composition and body fat distribution are related to cardiac autonomic control in non-alcoholic fatty liver disease patients

BACKGROUND/OBJECTIVES: Heart rate recovery (HRR), a cardiac autonomic control marker, was shown to be related to body composition (BC), yet this was not tested in non-alcoholic fatty liver disease (NAFLD) patients. The aim of this study was to determine if, and to what extent, markers of BC and body fat (BF) distribution are related to cardiac autonomic control in NAFLD patients. SUBJECTS/METHODS: BC was assessed with dual-energy X-ray absorptiometry in 28 NAFLD patients (19 men, 51±13 years, and 9 women, 47±13 years). BF depots ratios were calculated to assess BF distribution. Subjects’ HRR was recorded 1 (HRR1) and 2 min (HRR2) immediately after a maximum graded exercise test. RESULTS: BC and BF distribution were related to HRR; particularly weight, trunk BF and trunk BF-to-appendicular BF ratio showed a negative relation with HRR1 (r 1⁄4 0.613, r 1⁄4 0.597 and r 1⁄4 0.547, respectively, Po0.01) and HRR2 (r 1⁄4 0.484, r 1⁄4 0.446, Po0.05, and r 1⁄4 0.590, Po0.01, respectively). Age seems to be related to both HRR1 and HRR2 except when controlled for BF distribution. The preferred model in multiple regression should include trunk BF-to-appendicular BF ratio and BF to predict HRR1 (r2 1⁄4 0.549; Po0.05), and trunk BF-to-appendicular BF ratio alone to predict HRR2 (r2 1⁄4 0.430; Po0.001). CONCLUSIONS: BC and BF distribution were related to HRR in NAFLD patients. Trunk BF-to-appendicular BF ratio was the best independent predictor of HRR and therefore may be best related to cardiovascular increased risk, and possibly act as a mediator in age-related cardiac autonomic control variation.info:eu-repo/semantics/publishedVersio

Initial intramuscular perfusion pressure predicts early skeletal muscle function following isolated tibial fractures

<p>Abstract</p> <p>Background</p> <p>The severity of associated soft tissue trauma in complex injuries of the extremities guides fracture treatment and decisively determines patient's prognosis. Trauma-induced microvascular dysfunction and increased tissue pressure is known to trigger secondary soft tissue damage and seems to adversely affect skeletal muscle function.</p> <p>Methods</p> <p>20 patients with isolated tibial fractures were included. Blood pressure and compartment pressure (anterior and deep posterior compartment) were measured continuously up to 24 hours. Corresponding perfusion pressure was calculated. After 4 and 12 weeks isokinetic muscle peak torque and mean power of the ankle joint in dorsal and plantar flexion were measured using a Biodex dynamometer.</p> <p>Results</p> <p>A significant inverse correlation between the anterior perfusion pressure at 24 hours and deficit in dorsiflexion at 4 weeks was found for both, the peak torque (R = -0.83; p < 0.01) and the mean power (R = -0.84; p < 0.01). The posterior perfusion pressure at 24 h and the plantar flexion after 4 weeks in both, peak torque (R = -0.73, p =< 0.05) and mean power (R = -0.7, p =< 0.05) displayed a significant correlation.</p> <p>Conclusion</p> <p>The functional relationship between the decrease in intramuscular perfusion pressures and muscle performance in the early rehabilitation period indicate a causative and prognostic role of early posttraumatic microcirculatory derangements and skeletal muscle function. Therapeutic concepts aimed at effective muscle recovery, early rehabilitation, and decreased secondary tissue damage, should consider the maintenance of an adequate intramuscular perfusion pressure.</p

Genome-wide association analysis of insomnia complaints identifies risk genes and genetic overlap with psychiatric and metabolic traits.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesPersistent insomnia is among the most frequent complaints in general practice. To identify genetic factors for insomnia complaints, we performed a genome-wide association study (GWAS) and a genome-wide gene-based association study (GWGAS) in 113,006 individuals. We identify three loci and seven genes associated with insomnia complaints, with the associations for one locus and five genes supported by joint analysis with an independent sample (n = 7,565). Our top association (MEIS1, P < 5 × 10-8) has previously been implicated in restless legs syndrome (RLS). Additional analyses favor the hypothesis that MEIS1 exhibits pleiotropy for insomnia and RLS and show that the observed association with insomnia complaints cannot be explained only by the presence of an RLS subgroup within the cases. Sex-specific analyses suggest that there are different genetic architectures between the sexes in addition to shared genetic factors. We show substantial positive genetic correlation of insomnia complaints with internalizing personality traits and metabolic traits and negative correlation with subjective well-being and educational attainment. These findings provide new insight into the genetic architecture of insomnia.Netherlands Organization for Scientific Research NWO Brain & Cognition 433-09-228 European Research Council ERC-ADG-2014-671084 INSOMNIA Netherlands Scientific Organization (NWO) VU University (Amsterdam, the Netherlands) Dutch Brain Foundation Helmholtz Zentrum Munchen - German Federal Ministry of Education and Research state of Bavaria German Migraine & Headache Society (DMKG) Almirall AstraZeneca Berlin Chemie Boehringer Boots Health Care GlaxoSmithKline Janssen Cilag McNeil Pharma MSD Sharp Dohme Pfizer Institute of Epidemiology and Social Medicine at the University of Munster German Ministry of Education and Research (BMBF) German Restless Legs Patient Organisation (RLS Deutsche Restless Legs Vereinigung) Swiss RLS Patient Association (Schweizerische Restless Legs Selbsthilfegruppe

Association between sleep disorders, obesity, and exercise: a review

Trent A Hargens,1 Anthony S Kaleth,2 Elizabeth S Edwards,1 Katrina L Butner31Department of Kinesiology, James Madison University, Harrisonburg, VA, USA; 2Department of Kinesiology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA; 3Laboratory for Health and Exercise Science, Department of Human Nutrition, Food and Exercise, Virginia Tech, Blacksburg, VA, USAAbstract: Decreased sleep duration and quality is associated with an increase in body weight and adiposity. Insomnia, obstructive sleep apnea, and restless legs syndrome are three of the most prevalent types of sleep disorder that lead to an increased risk for numerous chronic health conditions. Various studies have examined the impact of these sleep disorders on obesity, and are an important link in understanding the relationship between sleep disorders and chronic disease. Physical activity and exercise are important prognostic tools in obesity and chronic disease, and numerous studies have explored the relationship between obesity, sleep disorders, and exercise. As such, this review will examine the relationship between sleep disorders and obesity. In addition, how sleep disorders may impact the exercise response and how exercise may impact patient outcomes with regard to sleep disorders will also be reviewed.Keywords: obesity, sleep disorders, obstructive sleep apnea, insomni

THE EFFECT OF ONE NIGHT OF SLEEP FRAGMENTATION ON SUBSEQUENT AEROBIC PERFORMANCE

Trent A. Hargens, FACSM, Tara L. Thompson, Nicki Stallings, Nicholas D. Luden. James Madison University, Harrisonburg, VA. Sleep is a vital component of health and wellness. Poor sleep has been shown to significantly impact athletic performance. Most research, however, has focused on several days or more of sleep deprivation. Sleep fragmentation is defined as multiple arousals during the night, which may impact an athlete before an important event due to pre-competition anxiety. PURPOSE: To examine the effect of one night of sleep fragmentation (SF) on cycle time trial (TT) performance compared to a night of normal sleep (NS). METHODS: Eight active individuals [age = 20.4 ± 1.7 yr.; body mass index (BMI) = 22.0 ± 2.1; VO2max = 41.1 ± 9.8 mL.kg-1.min-1] completed 3 performance trials (1 familiarization and 2 experimental) consisting of a 3-kilometer time trial (TT) on a cycle ergometer. Trials were performed after NS (6-8 hours) or SF. The SF condition consisted of being awakened at least one time per hour of sleep for 8 hours. The trials were performed at the same time of day (8:00 - 10:00 am), with randomly counter-balances sleep conditions. Diet was replicated prior to each trial and physical activity was monitored for 48 hours prior to each trial with accelerometer. Sleep was monitored via accelerometry the night of the experimental trials to confirm sleep duration. Data are presented as means ± SD. RESULTS: There was no difference in peak power (294 ± 107 vs. 306 ± 123 Watts for SF and NS, respectively; P = 0.7), average heart rate (162 ± 16 vs. 168 beats.min-1 ± 12; P = 0.5), or TT finish time (5.6 ± 1.0 vs. 5.5 ± 1.0 minutes; P = 0.1) between the experimental trials. Average TT power trended towards significance (211 ± 83 vs. 228 ± 100 Watts for SF and NS, respectively; P = 0.08). Peak TT oxygen consumption was lower during the SF trial (43.6 ± 12.3 mL.kg-1.min-1) compared to the NS trial (47.9 ± 11.5 mL.kg-1.min-1; P = 0.017), while average oxygen consumption trended lower during the SF trial (37.0 ± 11.5 mL.kg-1.min-1) compared to NS (44.6 ± 14.2 mL.kg-1.min-1, P = 0.07). CONCLUSION: Results showed that SF may impact subsequent 3-km TT performance, reflected by a lower peak VO2 and a trend towards lower average power output and oxygen consumption, although there were no differences in TT finish time. Further research with a larger sample size is needed to make more definitive conclusions about the potential consequences of SF

THE EFFECT OF ONE NIGHT OF SLEEP RESTRICTION ON SUBSEQUENT AEROBIC PERFORMANCE

Trent A. Hargens, FACSM, Lindsay J. Lickers, Amanda J. Becker, Christopher J. Womack, FACSM, Nicholas D. Luden. James Madison University, Harrisonburg, VA. Adequate sleep is a vital component of health and wellness. Poor sleep has been shown to significantly impact athletic performance; however most research has focused on several days or more of sleep deprivation. The impact of a single night of sleep restriction on subsequent performance is less well understood. This paradigm would more closely mimic anxiety and nervousness prior to an important event. PURPOSE: To examine the effect of one night of sleep restriction (SR) on cycle time trial (TT) performance compared to a night of normal sleep (NS). METHODS: Eight recreational cyclists [age = 20.6 ± 1.4 yr; body mass index (BMI) = 23.0 ± 1.9; VO2max = 42.7 ± 6.6 mL/kg/min/] completed 3 performance trials (1 familiarization and 2 experimental) on a cycle ergometer. Performance trials consisted of a 3-kilometer TT. Experimental trials were performed after NS (6-8 hours) or SR (3 hours). Order of experimental trials was randomized. Experimental trials were performed at the same time of day (6:00 - 8:00 am). Diet was replicated prior to each trial and physical activity was monitored for 48 hours prior to each trial with accelerometer. Sleep was monitored via accelerometry the night of the experimental trials to confirm sleep duration. RESULTS: There was no difference in average power (151 ± 32 vs. 146 ± 41 Watts for SR and NS, respectively; P = 0.3), peak power (230 ± 66 vs. 239 ± 89 Watts; P = 0.6) or average heart rate (187 ± 11 vs. 189 ± 15; P = 0.5) between the experimental trials. Additionally, there was no significant difference in TT finish time (6.0 ± 0.5 vs. 6.2 ± 0.8 sec for SR and NS, respectively; P = 0.5) despite a 10.5 second faster time with SR. 5 of 8 subjects has a faster finishing time with the SR trial. CONCLUSION: Results showed no difference in TT finishing time between the SR and NS conditions, yet a majority of subjects performed better during the SR condition. Additional research with a greater sample is needed to further assess this question. A potential mechanism for the faster time with SR may be sleep inertia, which is the transitional state between sleep and wake, characterized by impaired performance. Sleep inertia can last for several hours. In the current study, subjects completed the TT in the NS condition within the time frame where sleep inertia could affect performance

Using hierarchical unsupervised learning to integrate and reduce multi-level and multi-paraspinal muscle MRI data in relation to low back pain.

PurposeThe paraspinal muscles (PSM) are a key feature potentially related to low back pain (LBP), and their structure and composition can be quantified using MRI. Most commonly, quantifying PSM measures across individual muscles and individual spinal levels renders numerous separate metrics that are analyzed in isolation. However, comprehensive multivariate approaches would be more appropriate for analyzing the PSM within an individual. To establish and test these methods, we hypothesized that multivariate summaries of PSM MRI measures would associate with the presence of LBP symptoms (i.e., pain intensity).MethodsWe applied hierarchical multiple factor analysis (hMFA), an unsupervised integrative method, to clinical PSM MRI data from unique cohort datasets including a longitudinal cohort of astronauts with pre- and post-spaceflight data and a cohort of chronic LBP subjects and asymptomatic controls. Three specific use cases were investigated: (1) predicting longitudinal changes in pain using combinations of baseline PSM measures; (2) integrating baseline and post-spaceflight MRI to assess longitudinal change in PSM and how it relates to pain; and (3) integrating PSM quality and adjacent spinal pathology between LBP patients and controls.ResultsOverall, we found distinct complex relationships with pain intensity between particular muscles and spinal levels. Subjects with high asymmetry between left and right lean muscle composition and differences between spinal segments PSM quality and structure are more likely to increase in pain reported outcome after prolonged time in microgravity. Moreover, changes in PSM quality and structure between pre and post-spaceflight relate to increase in pain after prolonged microgravity. Finally, we show how unsupervised hMFA recapitulates previous research on the association of CEP damage and LBP diagnostic.ConclusionOur analysis considers the spine as a multi-segmental unit as opposed to a series of discrete and isolated spine segments. Integrative and multivariate approaches can be used to distill large and complex imaging datasets thereby improving the clinical utility of MRI-based biomarkers, and providing metrics for further analytical goals, including phenotyping

Biomechanical changes in the lumbar spine following spaceflight and factors associated with postspaceflight disc herniation

Background contextFor chronic low back pain, the causal mechanisms between pathological features from imaging and patient symptoms are unclear. For instance, disc herniations can often be present without symptoms. There remains a need for improved knowledge of the pathophysiological mechanisms that explore spinal tissue damage and clinical manifestations of pain and disability. Spaceflight and astronaut health provides a rare opportunity to study potential low back pain mechanisms longitudinally. Spaceflight disrupts diurnal loading on the spine and several lines of evidence indicate that astronauts are at a heightened risk for low back pain and disc herniation following spaceflight.PurposeTo examine the relationship between prolonged exposure to microgravity and the elevated incidence of postflight disc herniation, we conducted a longitudinal study to track the spinal health of twelve NASA astronauts before and after approximately 6 months in space. We hypothesize that the incidence of postflight disc herniation and low back complaints associates with spaceflight-included muscle atrophy and pre-existing spinal pathology.Study designThis is a prospective longitudinal study.Patient sampleOur sample included a cohort of twelve astronaut crewmembers.Outcome measuresFrom 3T MRI, we quantified disc water content (ms), disc degeneration (Pfirrmann grade), vertebral endplate irregularities, facet arthropathy and/ fluid, high intensity zones, disc herniation, multifidus total cross-sectional area (cm2), multifidus lean muscle cross-sectional area (cm2), and muscle quality/composition (%). From quantitative fluoroscopy we quantified, maximum flexion-extension ROM (°), maximum lateral bending ROM (°), and maximum translation (%). Lastly, patient outcomes and clinical notes were used for identifying postflight symptoms associated with disc herniations from 3T MRI.MethodsAdvanced imaging data from 3T MRI were collected at three separate time points in relation to spending six months in space: (1) within a year before launch ("pre-flight"), (2) within a week after return to Earth ("post-flight"), and (3) between 1 and 2 months after return to Earth ("recovery"). Fluoroscopy of segmental kinematics was collected at preflight and postflight timepoints. We assessed the effect of spaceflight and postflight recovery on longitudinal changes in spinal structure and function, as well as differences between crew members who did and did not present a symptomatic disc herniation following spaceflight.ResultsHalf of our astronauts (n=6) experienced new symptoms associated with a new or previously asymptomatic lumbar disc protrusion or extrusion following spaceflight. We observed decreased multifidus muscle quality following spaceflight in the lower lumbar spine, with a reduced percentage of lean muscle at L4L5 (-6.2%, p=.009) and L5S1 (-7.0%, p=.006) associated with the incidence of new disc herniation. Additionally, we observed reduced lumbar segment flexion-extension ROM for L2L3 (-17.2%, p=.006) and L3L4 (-20.5%, p=.02) following spaceflight, and furthermore that reduced ROM among the upper three lumbar segments (-24.1%, p=.01) associated with the incidence of disc herniation. Existing endplate pathology was most prevalent in the upper lumbar spine and associated with reduced segmental ROM (-20.5%, p=.02).ConclusionsIn conclusion from a 10-year study investigating the effects of spaceflight on the lumbar spine and risk for disc herniation, we found the incidence of lumbar disc herniation following spaceflight associates with compromised multifidus muscle quality and spinal segment kinematics, as well as pre-existing spinal endplate irregularities. These findings suggest differential effects of spinal stiffness and muscle loss in the upper versus lower lumbar spine regions that may specifically provoke risk for symptomatic disc herniation in the lower lumbar spine following spaceflight. Results from this study provide a unique longitudinal assessment of mechanisms and possible risk factors for developing disc herniations and related low back pain. Furthermore, these findings will help inform physiologic countermeasures to maintain spinal health in astronauts during long-duration missions in space