Influence of a home-based exercise intervention on human health indices in individuals with chronic spinal cord injury (HOMEX-SCI):study protocol for a randomized controlled trial

BACKGROUND: Spinal cord injury (SCI) creates a complex pathology that can lead to an increase in sedentary behaviours and deleterious changes in body composition. Consequently, individuals with SCI are at increased risk of developing cardiovascular disease and type-2 diabetes mellitus. While the role of physical activity on the reduction of chronic disease risk is well documented in non-disabled individuals the evidence is less conclusive for persons with SCI. The aim of this methodological paper is to outline the design of a study that will assess the role of a home-based exercise intervention on biomarkers of metabolic and cardiovascular health in persons with SCI: the HOMEX-SCI study. METHODS/DESIGN: Eligible participants will be inactive (physical activity level ≤1.60) individuals, with a chronic (more than 1 year) spinal cord lesion between the second thoracic and the fifth lumbar vertebrae, and aged between 18 and 65 years. Following baseline laboratory testing and lifestyle monitoring, participants will be randomly allocated to a control (CON) group or a 6-week home-based exercise intervention (INT) group. The INT consists of 45 minutes of moderate-intensity (60–65 % peak oxygen uptake) arm-crank exercise four times per week. Participants assigned to the CON group will be asked to maintain their normal lifestyle. The main outcomes of this study (biomarkers of metabolic and cardiovascular health) are obtained from venous blood samples, collected in the fasted and postprandial state. Eight other measurement categories will be assessed: (1) body composition, (2) physical activity, (3) energy intake, (4) measures of health and wellbeing, (5) resting metabolic rate, heart rate and blood pressure, (6) aerobic capacity, (7) immune function, and (8) adipose tissue gene expression. DISCUSSION: This study will explore the feasibility of home-based moderate-intensity exercise and ascertain its impact on metabolic and cardiovascular health in comparison to a lifestyle maintenance CON group. Findings from this study may help to inform new evidence-based physical activity guidelines and also help to elucidate the physiological mechanisms whereby exercise might exert beneficial effects in persons with chronic SCI. The results will also act as a scientific platform for further intervention studies in other diverse and at-risk populations. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number: ISRCTN57096451. Registered on 11 July 2014

Adipose tissue responses to breaking sitting in men and women with central adiposity

Purpose Breaking prolonged sitting reduces postprandial glucose and insulin concentrations and influences skeletal muscle molecular signaling pathways, but it is unknown whether breaking sitting also affects adipose tissue. Methods Eleven central overweight participants (seven men and four postmenopausal women) 50 ± 5 yr old (mean ± SD) completed two mixed-meal feeding trials (prolonged sitting vs breaking sitting) in a randomized, counterbalanced design. The breaking sitting intervention comprised walking for 2 min every 20 min over 5.5 h. Blood samples were collected at regular intervals to examine metabolic biomarkers and adipokine concentrations. Adipose tissue samples were collected at baseline and at 5.5 h to examine changes in mRNA expression and secretion of selected adipokines ex vivo. Results Postprandial glycemia and insulinemia were attenuated by approximately 50% and 40% in breaking sitting compared with prolonged sitting (iAUC: 359 ± 117 vs 697 ± 218 mmol per 330 min·L -1, P = 0.001, and 202 ± 71 vs 346 ± 150 nmol per 330 min·L -1, P = 0.001, respectively). Despite these pronounced and sustained differences in postprandial glucose and insulin concentrations, adipose tissue mRNA expression for various genes (interleukin 6, leptin, adiponectin, pyruvate dehydrogenase kinase isozyme 4, insulin receptor substrates 1 and 2, phosphoinositide 3-kinase, and RAC-alpha serine/threonine-protein kinase) and ex vivo adipose tissue secretion of interleukin 6, leptin, and adiponectin were not different between trials. Conclusions This study demonstrates that breaking sitting with short bouts of physical activity has very pronounced effects on systemic postprandial glucose and insulin concentrations, but this does not translate into corresponding effects within adipose tissue. </p

Effect of diet or diet plus physical activity versus usual care on inflammatory markers in patients with newly diagnosed type 2 diabetes: The Early ACTivity in Diabetes (ACTID) randomized, controlled trial

This is the final version. Available on open access from Wiley via the DOI in this recordBACKGROUND: Inflammation plays a major role in diabetes-associated cardiovascular disease (CVD). There is uncertainty whether diet and physical activity interventions can be successfully integrated into healthcare settings and reduce markers of inflammation and risk of CVD in patients with type 2 diabetes (T2D). METHODS AND RESULTS: Systemic markers of inflammation were determined in a 12-month, real-world, multicenter, randomized, controlled trial that investigated the effect of diet, diet plus physical activity, and usual care in 593 individuals with newly diagnosed T2D. During the first 6 months, serum C-reactive protein (CRP) improved by -21 (-36 to -1.4)% and -22 (-38 to -3.1)% in diet and diet plus physical activity arms versus usual care. There were also improvements in adiponectin and soluble intercellular adhesion molecule-1 (sICAM-1). Though medication-adjusted CRP was improved between 6 and 12 months for usual care, both interventions were more successful in reducing the relative risk of a high-risk CRP level of >3 mg/L (risk ratios of 0.72 [0.55 to 0.95] for diet versus usual care and 0.67 [0.50 to 0.90] for diet plus activity versus usual care). Furthermore, sICAM-1 (a marker of vascular risk), remained substantially lower than usual care in both intervention arms at 12 months. CONCLUSIONS: Motivational, unsupervised diet and/or diet plus physical activity interventions given soon after diagnosis in real-world healthcare settings improve markers of inflammation and cardiovascular risk in patients with T2D, even after accounting for the effect of adjustments to medication to try and control blood pressure, glycated hemoglobin, and lipids. CLINICAL TRIAL REGISTRATION URL: http://www.controlled-trials.com/. Unique identifier: ISRCTN92162869.British Heart FoundationDiabetes UKUK Department of Healt

Home-based exercise enhances health-related quality of life in persons with spinal cord injury::a randomized controlled trial

Objective: To assess the influence of a home-based exercise intervention on indices of health-related quality of life (HRQOL) in persons with spinal cord injury (SCI). Design: This was a randomized controlled trial (HOMEX-SCI; ISRCTN57096451). After baseline laboratory testing and a week of free-living physical activity monitoring, eligible participants were randomly assigned (2:1 allocation ratio) to a home-based moderate-intensity upper-body exercise intervention group (INT, n=13), or a lifestyle maintenance control group (CON, n=8), for 6 weeks. Setting: Home-based with short laboratory visits immediately before and after the intervention/control period. Participants: Inactive participants (N=21) with chronic (&gt;1yr) SCI (injury level &lt;T4). Intervention: Participants assigned to the INT completed 4, 45-minute moderate-intensity (60%-65% peak oxygen uptake) arm-crank exercise sessions per week for 6 weeks. Participants assigned to the control group (CON) were asked to maintain their habitual physical activity behavior. Main Outcome Measures: Secondary outcome measures were assessed, including physical and mental component scores (PCS and MCS) of health-related quality of life (HRQOL), fatigue, global fatigue (FSS), and shoulder pain index (WUSPI). Cardiorespiratory fitness (CRF), objectively measured habitual moderate-to-vigorous physical activity (MVPA), and exercise self-efficacy (ESE) were also assessed at baseline and follow-up. Results: Changes in the PCS (P=.017) of the Short Form 36 Health Survey (SF-36), ESE (P=.011), and FSS (P=.036) were significantly different between the 2 groups, with moderate to large effect sizes (d=0.75-1.37). Various HRQOL outcomes demonstrated likely to very likely positive inferences in favor of the INT group following the 6-week exercise intervention. Changes in ESE were significantly (P&lt;.01) associated with changes in PCS (r=0.62), MCS (r=0.71), FSS (r=-0.71), and global fatigue (r=0.57). Conclusions: A 6-week upper-body exercise intervention improved indices of HRQOL in persons with SCI. Improvements were associated with increases in ESE. While this intervention demonstrated a positive effect on perceived physical functioning, future interventions should aim to support social and mental functioning and exercise maintenance.</p

The impact of long-term physical inactivity on adipose tissue immunometabolism

CONTEXT: Adipose tissue and physical inactivity both influence metabolic health and systemic inflammation, but how adipose tissue responds to chronic physical inactivity is unknown. OBJECTIVE: This work aimed to characterize the impact of chronic physical inactivity on adipose tissue in healthy, young males. METHODS: We collected subcutaneous adipose tissue from 20 healthy, young men before and after 60 days of complete bed rest with energy intake reduced to maintain energy balance and fat mass. We used RNA sequencing, flow cytometry, ex vivo tissue culture, and targeted protein analyses to examine adipose tissue phenotype. RESULTS: Our results indicate that the adipose tissue transcriptome, stromal cellular compartment, and insulin signaling protein abundance are largely unaffected by bed rest when fat mass is kept stable. However, there was an increase in the circulating concentration of several adipokines, including plasma leptin, which was associated with inactivity-induced increases in plasma insulin and absent from adipose tissue cultured ex vivo under standardized culture conditions. CONCLUSION: Physical inactivity–induced disturbances to adipokine concentrations such as leptin, without changes to fat mass, could have profound metabolic implications outside a clinical facility when energy intake is not tightly controlled

Influence of accelerometer type and placement on physical activity energy expenditure prediction in manual wheelchair users

To assess the validity of two accelerometer devices, at two different anatomical locations, for the prediction of physical activity energy expenditure (PAEE) in manual wheelchair users (MWUs).Seventeen MWUs (36 ± 10 yrs, 72 ± 11 kg) completed ten activities; resting, folding clothes, propulsion on a 1% gradient (3,4,5,6 and 7 km·hr-1) and propulsion at 4km·hr-1 (with an additional 8% body mass, 2% and 3% gradient) on a motorised wheelchair treadmill. GT3X+ and GENEActiv accelerometers were worn on the right wrist (W) and upper arm (UA). Linear regression analysis was conducted between outputs from each accelerometer and criterion PAEE, measured using indirect calorimetry. Subsequent error statistics were calculated for the derived regression equations for all four device/location combinations, using a leave-one-out cross-validation analysis.Accelerometer outputs at each anatomical location were significantly (p < .01) associated with PAEE (GT3X+-UA; r = 0.68 and GT3X+-W; r = 0.82. GENEActiv-UA; r = 0.87 and GENEActiv-W; r = 0.88). Mean ± SD PAEE estimation errors for all activities combined were 15 ± 45%, 14 ± 50%, 3 ± 25% and 4 ± 26% for GT3X+-UA, GT3X+-W, GENEActiv-UA and GENEActiv-W, respectively. Absolute PAEE estimation errors for devices varied, 19 to 66% for GT3X+-UA, 17 to 122% for GT3X+-W, 15 to 26% for GENEActiv-UA and from 17.0 to 32% for the GENEActiv-W.The results indicate that the GENEActiv device worn on either the upper arm or wrist provides the most valid prediction of PAEE in MWUs. Variation in error statistics between the two devices is a result of inherent differences in internal components, on-board filtering processes and outputs of each device