102 research outputs found
Adipose Tissue Differs and Correlates to Carbohydrate Metabolism and Proinflammatory Adipokines by Level of Spinal Cord Injury
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Retained differentiation capacity of human skeletal muscle satellite cells from spinal cordâinjured individuals
Despite the wellâknown role of satellite cells in skeletal muscle plasticity, the effect of spinal cord injury on their function in humans remains unknown. We determined whether spinal cord injury affects the intrinsic ability of satellite cells to differentiate and produce metabolically healthy myotubes. We obtained vastus lateralis biopsies from eight spinal cordâinjured and six ableâbodied individuals. Satellite cells were isolated, grown and differentiated in vitro. Gene expression was measured by quantitative PCR. Abundance of differentiation markers and regulatory proteins was determined by Western blotting. Protein synthesis and fatty acid oxidation were measured by radioactive tracerâbased assays. Activated satellite cells (myoblasts) and differentiated myotubes derived from skeletal muscle of ableâbodied and spinal cordâinjured individuals expressed similar (P > 0.05) mRNA levels of myogenic regulatory factors. Myogenic differentiation factor 1 expression was higher in myoblasts from spinal cordâinjured individuals. Desmin and myogenin protein content was increased upon differentiation in both groups, while myotubes from spinal cordâinjured individuals contained more type I and II myosin heavy chain. Phosphorylated and total protein levels of Aktâmechanistic target of rapamycin and forkhead box protein O signalling axes and protein synthesis rate in myotubes were similar (P > 0.05) between groups. Additionally, fatty acid oxidation of myotubes from spinal cordâinjured individuals was unchanged (P > 0.05) compared to ableâbodied controls. Our results indicate that the intrinsic differentiation capacity of satellite cells and metabolic characteristics of myotubes are preserved following spinal cord injury. This may inform potential interventions targeting satellite cell activation to alleviate skeletal muscle atrophy
Effects of two different paradigms of electrical stimulation exercise on cardio-metabolic risk factors after spinal cord injury. A randomized clinical trial
ObjectiveTo examine the combined effects of neuromuscular electrical stimulation-resistance training (NMES-RT) and functional electrical stimulation-lower extremity cycling (FES-LEC) compared to passive movement training (PMT) and FES-LEC in adults with SCI on (1) oxygen uptake (VO2), insulin sensitivity and glucose disposal in adults with SCI; (2) Metabolic and inflammatory biomarkers; (3) skeletal muscle, intramuscular fat (IMF) and visceral adipose tissue (VAT) cross-sectional areas (CSAs).Materials and methodsThirty-three participants with chronic SCI (AIS A-C) were randomized to 24âweeks of NMES-RTâ+âFES or PMTâ+âFES. The NMES-RTâ+âFES group underwent 12âweeks of evoked surface NMES-RT using ankle weights followed by an additional 12âweeks of progressive FES-LEC. The control group, PMTâ+âFES performed 12âweeks of passive leg extension movements followed by an additional 12âweeks of FES-LEC. Measurements were performed at baseline (BL; week 0), post-intervention 1 (P1; week 13) and post-intervention 2 (P2; week 25) and included FES-VO2 measurements, insulin sensitivity and glucose effectiveness using the intravenous glucose tolerance test; anthropometrics and whole and regional body composition assessment using dual energy x-ray absorptiometry (DXA) and magnetic resonance imaging to measure muscle, IMF and VAT CSAs.ResultsTwenty-seven participants completed both phases of the study. NMES-RTâ+âFES group showed a trend of a greater VO2 peak in P1 [pâ=â0.08; but not in P2 (pâ=â0.25)] compared to PMTâ+âFES. There was a time effect of both groups in leg VO2 peak. Neither intervention elicited significant changes in insulin, glucose, or inflammatory biomarkers. There were modest changes in leg lean mass following PMTâ+âFES group. Robust hypertrophy of whole thigh muscle CSA, absolute thigh muscle CSA and knee extensor CSA were noted in the NMES-RTâ+âFES group compared to PMTâ+âFES at P1. PMTâ+âFES resulted in muscle hypertrophy at P2. NMES-RTâ+âFES resulted in a decrease in total VAT CSA at P1.ConclusionNMES-RT yielded a greater peak leg VO2 and decrease in total VAT compared to PMT. The addition of 12âweeks of FES-LEC in both groups modestly impacted leg VO2 peak. The addition of FES-LEC to NMES-RT did not yield additional increases in muscle CSA, suggesting a ceiling effect on signaling pathways following NMES-RT.Clinical trial registrationidentifier NCT02660073
Age-associated differences in triceps surae muscle composition and strength â an MRI-based cross-sectional comparison of contractile, adipose and connective tissue
Electrical muscle stimulation in thomboprophylaxis: review and a derived hypothesis about thrombogenesisâthe 4th factor
Lipoprotein heterogeneity in persons with Spinal Cord Injury: a model of prolonged sitting and restricted physical activity
The future of SCI rehabilitation: Understanding the impact of exoskeletons on gait mechanics
Oral baclofen administration in persons with chronic spinal cord injury does not prevent the protective effects of spasticity on body composition and glucose homeostasis
Study design: Correlation study.
Objectives: To determine the effects of oral baclofen on body composition (fat mass (FM), fat-free mass (FFM)), extra-and intracellular fluid compartments and glucose homeostasis (plasma glucose and plasma insulin concentrations) in individuals with spinal cord injury (SCI) after controlling for spasticity.
Settings: Laboratory settings at the University of Michigan, MI, USA.
Methods: Fifteen individuals with chronic motor complete SCI (32 +/- 8 years old, 25 +/- 5 kg/m(2), C6-T11, American Spinal Injury Association A and B) underwent multifrequency bioelectrical impedance analysis to measure body composition and body fluid compartments. Spasticity of the hip, knee and ankle flexors and extensors was measured using a modified Ashworth Scale and the dose of daily oral baclofen was recorded. After overnight fasting, plasma glucose and insulin sensitivity were measured in response to an oral glucose tolerance test.
Results: Oral baclofen dose was positively related to body mass index, but not to extensor or flexor spasticity. The dose of baclofen seemed to be correlated to extensor spasticity after considering spasticity per FFM. The increased dose of oral baclofen was positively associated with increased FFM, extra-and intracellular fluid compartments and total body water, but not with FM. Oral baclofen dose was negatively associated with the homeostatic model assessment index.
Conclusion: Administration of oral baclofen did not attenuate the protective effects of spasticity on body composition and metabolic profile after SCI. The possibility that oral baclofen could exert an independent protective effect needs to be further investigated. Spinal Cord (2010) 48, 160-165; doi: 10.1038/sc.2009.105; published online 18 August 200
Prediction of thigh skeletal muscle mass using dual energy x-ray absorptiometry compared to magnetic resonance imaging after spinal cord injury
Therapistsâ experience of training and implementing an exoskeleton in a rehabilitation centre
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