Introduction: Implanted spinal cord epidural stimulation (SCES) is an emerging neuromodulation approach that increases the excitability of the central pattern generator [CPG] and enhances tonic and rhythmic motor patterns after spinal cord injury (SCI). We determine the effects of exoskeleton-assisted walking [EAW] + epidural stimulation [ES] + resistance training [RT] on volitional motor control as a primary outcome, as well as autonomic cardiovascular profile, body composition, and bladder function compared to EAW + delayed ES + noRT in persons with motor-complete SCI AIS A and B. Methods and Analysis: Twenty male and female participants [age 18–60 years] with traumatic motor-complete SCI [2 years or more post injury], and level of injury below C5 were randomized into either EAW + ES + RT or EAW + delayed-ES + no-RT groups for more than 12 months. Baseline, post-interventions 1 and 2 were conducted six months apart. Measurements included body composition assessment using anthropometry, dual x-ray absorptiometry, and magnetic resonance imaging prior to implantation to evaluate the extent of spinal cord damage, neurophysiologic assessments to record H-reflexes, overground ambulation and peak torque for both groups, and the Walking Index for Spinal Cord Injury Scale [WISCI 2]. Metabolic profile measurements included the resting metabolic rate, fasting biomarkers of HbA1c, lipid panels, total testosterone CRP, IL-6, TNF-α, plasma IGF-I, IGFBP-3, and then a glucose tolerance test. Finally, urodynamic testing was conducted to assess functional bladder improvement due to ES. Results: The restoration of locomotion with ES and EAW may result in a reduction in psychosocial, cardiovascular, and metabolic bladder parameters and socioeconomic burden. The addition of the resistance training paradigm may further augment the outcomes of ES on motor function in persons with SCI. Conclusions: Percutaneous SCES appears to be a feasible and safe rehabilitation approach for the restoration of motor function in persons with SCI. The procedure may be successfully implemented with other task-specific training similar to EAW and resistance training.
BACKGROUND:An existing association was noted between leisure time physical activity (LTPA) and quality of life (QOL) after spinal cord injury (SCI). Furthermore, electrical stimulation exercise program has been shown to improve domains of QOL. However, the relative causality between indices of LTPA and domains of QOL are not well studied before or after a regimen of electrical stimulation program in persons with SCI. OBJECTIVE:To examine the relationships between levels of weekly leisure-time physical activity (LTPA) and quality of life (QOL) domains before and after 24 weeks of an electrical stimulation exercise program in persons with spinal cord injury (SCI). DESIGN:Longitudinal exploratory trial as part of a randomized clinical trial. SETTING:Veterans Affairs medical center and SCI center. PARTICIPANTS:A convenience sample of 31 participants with chronic SCI were randomized into two groups of 15 and 16, respectively. INTERVENTIONS:The first group underwent twice weekly sessions of lower extremity neuromuscular electrical stimulation-resistance training (NMES-RT) for 12 weeks and a subsequent 12 weeks of twice-per-week functional electrical stimulation lower extremity cycling. The second group underwent an identical regimen with the exception that NMES-RT was substituted for passive movement training. MAIN OUTCOME MEASURES:Outcome measures included the QOL Short Form and the LTPA Questionnaire that were conducted at baseline (T1); post intervention one (T2) and post intervention two (T3). A series of cross-lagged panel models was run with Amos Version 29.0 to test relative directional effects of LTPA and QOL on each other over time. RESULTS:After combining both groups, psychological and social QOL tended to have a stronger directional effect on LTPA, but after the intervention the directional effect reversed. Although LTPA had no directional effect on physical health QOL, it became more dominant in the psychological health domain from T2 to T3. The cross-lagged effect from LTPA to psychological health QOL was either larger or demonstrated a more positive effect relative to the cross-lagged effect from psychological health QOL to LTPA. CONCLUSIONS:Twenty-four weeks of an electrical stimulation program did not directly enhance indices of LTPA after SCI. However, suggested improvements in psychological and social domains may be due in part to LTPA following an electrical stimulation exercise program.
Total energy expenditure (TEE) is estimated as the product of BMR and a spinal cord injury (SCI)-specific factor. The agreement between TEE and total energy intake (TEI) was just established. The findings suggested the existence of positive and negative energy balance distributions. Forty-two males with chronic SCI underwent BMR followed by a detailed metabolic profile after an overnight fast. TEI and macronutrients of 3-d dietary logs were analysed using the Nutrition Data System for Research software. Energy surplus was calculated as TEE minus TEI. Body composition assessment was conducted using dual-energy X-ray absorptiometry. 57 % of SCI participants were classified as negative energy surplus with an average TEI of 1284 ( sd 422) compared with 2197 ( sd 553) kcal/d in the positive energy group ( P = 0·0002). Negative energy group had a higher BMR (9 %; P = 0·02), greater body weight ( P = 0·03) and greater total body lean mass ( P = 0·03) and consumed a greater percentage of protein compared with the positive energy group. Percentage macronutrients of protein explained 27 % of the variance of energy surplus in a multivariate regression model ( r 2 0·27; P = 0·008). TEI adjusted to fat-free mass explained 87 % of the variance in energy surplus, and an intake of 34·7 kcal/kg per d was recommended to balance TEI with TEE. Persons with SCI are either classified into negative or positive energy surplus groups. Larger body weight and greater protein intakes are among the major characteristics of the negative energy group. Clinicians may need to consider the spectrum of energy balance before starting a dietary regimen after SCI.
Background: Long pulse width stimulation (LPWS; 120–150 ms) has the potential to stimulate denervated muscles in persons with spinal cord injury (SCI). We examined whether testosterone treatment (TT) + LPWS would increase skeletal muscle size, leg lean mass and improve overall metabolic health in SCI persons with denervation. We hypothesized that one year of combined TT + LPWS would downregulate gene expression of muscle atrophy and upregulate gene expression of muscle hypertrophy and increase mitochondrial health in SCI persons with lower motor neuron (LMN) injury. Methods: Ten SCI participants with chronic LMN injury were randomized into either 12 months, twice weekly, of TT + LPWS (n = 5) or a TT+ standard neuromuscular electrical stimulation (NMES; n = 5). Measurements were conducted at baseline (week 0), 6 months following training (post-intervention 1), and one week following 12 months of training (post-intervention 2). Measurements included body composition assessment using magnetic resonance imaging (MRI) and dual x-ray absorptiometry (DXA). Metabolic profile assessment encompassed measurements of resting metabolic rate, carbohydrate and lipid profiles. Finally, muscle biopsy was captured to measure RNA signaling pathways and mitochondrial oxidative phosphorylation. Results: Compliance and adherence were greater in the TT + NMES compared to the TT + LPWS group. There was a 25% increase in the RF muscle CSA following P1 measurement in the TT + LPWS group. There was a recognizable non-significant decrease in intramuscular fat in both groups. There was a trend (p = 0.07) of decrease in trunk fat mass following TT + LPWS, with an interaction (p = 0.037) in android lean mass between groups. There was a trend (p = 0.08) in mean differences in DXA-visceral adipose tissue (VAT) between groups at P1 measurements. For genes targeting muscle atrophy, TT + LPWS showed a trending decline in MURF1 and FOXO3 genes returning to similar levels as TT + NMES before 12 months. Conclusions: These pilot data demonstrated the safety of applying LPWS in persons with SCI. Six months of TT + LPWS demonstrated increases in rectus femoris muscle CSA. The effects on muscle size were modest between groups. Signaling pathway analysis suggested downregulation of genes involved in muscle atrophy pathways. Future clinical trials may consider a home-based approach with more frequent applications of LPWS.
Background: Neurogenic osteoporosis as a result of bone demineralization is a well-known complication after spinal cord injury (SCI). Bone demineralization is a result of the inevitable mechanical unloading of paralyzed limbs and decreased skeletal muscle activity. Objectives: To determine the impact of a home-based electrical stimulation (ES)-induced exercise (Excs) protocol plus 2000 IU oral daily vitamin D (vit D) supplementation compared to passive movement training (PMT) plus 2000 IU oral daily vit D supplementation on bone microarchitectural properties as measured by magnetic resonance imaging (MRI), bone mineral density (BMD) as measured by dual-energy x-ray absorptiometry (DXA), and biomarkers of bone formation and bone resorption in persons with chronic SCI. Methods: Six men with motor complete SCI ranging from C8 to T10 were randomized into either 9 months of vit D+ES-Excs or vit D+PMT groups. The vit D+ES-Excs group underwent daily supplementation of vit D with 4.5 months of neuromuscular electrical stimulation-resistance training (NMES-RT) followed by 4.5 months of functional electrical stimulation (FES) rowing, twice weekly, using a home-based training approach. MRI, DXA, and blood biomarkers were captured at the beginning of the study (baseline), 4.5 months (post-intervention 1), and 9 months after training (post-intervention 2). Results: The percentage changes indicated that 2 persons in the vit D+ES-Excs group showed decreases in trabecular spacing (28%) and increases in trabecular network (33%-49% at post-intervention 2). This was accompanied by attenuation of BMD loss at the pelvis (3.6%-7.7%), femoral necks (4.5%- 8.4%), and knees (10.5%-18.7%). The vit D+ES-Excs group showed increases in leg (5.3%) to total body lean mass and decreases in biomarkers of bone resorption (7.0%-23.5%). Similar changes were not demonstrated following 9 months of vit D+PMT. Conclusion: Home-based training with 9 months of vit D+ES exercise demonstrated the safety and practicability in mitigating deleterious changes in bone health in persons with chronic SCI. This is concomitant with increased leg lean mass and decreased circulating biomarkers of bone resorption in persons with SCI.
We examined 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 on mitochondrial electron transport chain (ETC) complexes and citrate synthase (CS) in adults with SCI. Thirty-two participants with chronic SCI were randomized to 24 weeks of NMES-RT + FES [n = 16 (14 males and 2 females) with an age range of 20–54 years old] or PMT + FES [n = 16 (12 males and 4 females) with an age range of 21–61 years old]. The NMES-RT + FES group underwent 12 weeks of surface NMES-RT using ankle weights followed by an additional 12 weeks of FES-LEC. The PMT + FES performed 12 weeks of passive leg extension movements followed by an additional 12 weeks of FES-LEC. Using repeated measures design, muscle biopsies of the vastus lateralis were performed at baseline (BL), post-intervention 1 (P1) and post-intervention 2 (P2). Spectrophotometer was used to measure ETC complexes (I-III) and CS using aliquots of the homogenized muscle tissue. Magnetic resonance imaging was used to measure skeletal muscle CSAs. A time effect was noted on CS (P = 0.001) with an interaction between both groups (P = 0.01). 46
We examined the association among basal metabolic rate (BMR) as well as dietary intakes of vitamin D (Vit D) and calcium on body composition and bone mineral density (BMD) after spinal cord injury (SCI). Cross-sectional design. Veterans Affairs Medical Center, Richmond, VA. About 33 individuals with chronic SCI who recorded their food consumption 3 days per week for 2 weeks. BMR was measured after 10 to 12 h of overnight fast. Average daily vit D and calcium intakes, and total caloric intake were recorded and analyzed using the Nutrition Data System for Research (NDSR) software. Fasting blood analysis for 25-hydroxyvitamin D (25[OH]D) status and Triiodothyronine (T3) status was performed (n = 10). Total and regional BMD, % fat mass (FM), and % lean mass (LM) were measured by dual X-ray absorptiometry scans. Participants consumed less than the Institute of Medicine (IOM) recommended daily allowances (RDA) for vit D (600-800 IU) and calcium (1000-1200 mg) for adults. BMR was positively related to total-lean mass ( r = .62, P = .0001; n = 32) and leg-lean mass ( r = .51, P = .003; n = 32). Adjusted BMR was negatively related to BMD of the left (r = −.38, P = .047; n = 28) and the right (r = −.41, P = .032; n = 28) proximal tibia. Vit D intake was negatively related to percentage total-FM ( r = −.33, P = .07; n = 29) and legs-%FM ( r = −.37, P = .047; n = 29). Multivariate regression models indicated that adjusted BMR explained the variance in leg fat mass (34%; P = .002) and percentage fat mass (44%; P < .0001). Persons with SCI are likely to consume less than the RDAs for vit D and calcium. BMR may explain the changes in body composition and bone metabolism. Dietary vit D should be considered as a prophylactic intervention in maintenance of bone health after SCI.
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 24 weeks of NMES-RT + FES or PMT + FES. The NMES-RT + FES group underwent 12 weeks of evoked surface NMES-RT using ankle weights followed by an additional 12 weeks of progressive FES-LEC. The control group, PMT + FES performed 12 weeks of passive leg extension movements followed by an additional 12 weeks 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-RT + FES group showed a trend of a greater VO2 peak in P1 [p = 0.08; but not in P2 (p = 0.25)] compared to PMT + FES. 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 PMT + FES group. Robust hypertrophy of whole thigh muscle CSA, absolute thigh muscle CSA and knee extensor CSA were noted in the NMES-RT + FES group compared to PMT + FES at P1. PMT + FES resulted in muscle hypertrophy at P2. NMES-RT + FES 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 12 weeks 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.
Study design Cross-sectional study. Objectives To compare muscle size, body composition, bone mineral density (BMD), and metabolic profiles in denervated versus innervated individuals with spinal cord injury (SCI). Setting Hunter Holmes McGuire Veterans Affairs (VA) Medical Center. Methods Body composition, bone mineral density (BMD), muscle size, and metabolic parameters were collected in 16 persons with chronic SCI ( n = 8 denervated, n = 8 innervated) using dual-energy x-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and fasting blood samples. BMR was measured by indirect calorimetry. Results Percent differences of the whole thigh muscle cross-sectional area (CSA; 38%), knee extensor CSA (49%), vasti CSA (49%), and rectus femoris CSA (61%) were smaller in the denervated group ( p < 0.05). Leg lean mass was also lower (28%) in the denervated group ( p < 0.05). Whole muscle intramuscular fat (IMF%; 15.5%), knee extensor IMF% (22%), and % fat mass (10.9%) were significantly greater in the denervated group ( p < 0.05). Knee distal femur and proximal tibia BMD were lower in the denervated group, 18–22% and 17–23%; p < 0.05. Certain indices of metabolic profile were more favorable in the denervated group though were not significant. Conclusions SCI results in skeletal muscle atrophy and dramatic changes in body composition. Lower motor neuron (LMN) injury results in denervation of the lower extremity muscles which exacerbates atrophy. Denervated participants exhibited lower leg lean mass and muscle CSA, greater muscle IMF, and reduced knee BMD compared to innervated participants. Future research is needed to explore therapeutic treatments for the denervated muscles after SCI.
Introduction Long pulse width stimulation (LPWS; 120–150 ms) has the potential to stimulate denervated muscles and to restore muscle size in denervated people with spinal cord injury (SCI). We will determine if testosterone treatment (TT)+LPWS would increase skeletal muscle size, leg lean mass and improve overall metabolic health in persons with SCI with denervation. We hypothesise that the 1-year TT+LPWS will upregulate protein synthesis pathways, downregulate protein degradation pathways and increase overall mitochondrial health. Methods and analysis Twenty-four male participants (aged 18–70 years with chronic SCI) with denervation of both knee extensor muscles and tolerance to the LPWS paradigm will be randomised into either TT+neuromuscular electrical stimulation via telehealth or TT+LPWS. The training sessions will be twice weekly for 1 year. Measurements will be conducted 1 week prior training (baseline; week 0), 6 months following training (postintervention 1) and 1 week after the end of 1 year of training (postintervention 2). Measurements will include body composition assessment using anthropometry, dual X-ray absorptiometry and MRI to measure size of different muscle groups. Metabolic profile will include measuring of basal metabolic rate, followed by blood drawn to measure fasting biomarkers similar to hemoglobin A1c, lipid panels, C reactive protein, interleukin-6 and free fatty acids and then intravenous glucose tolerance test to test for insulin sensitivity and glucose effectiveness. Finally, muscle biopsy will be captured to measure protein expression and intracellular signalling; and mitochondrial electron transport chain function. The participants will fill out 3 days dietary record to monitor their energy intake on a weekly basis. Ethics and dissemination The study was approved by Institutional Review Board of the McGuire Research Institute (ID # 02189). Dissemination plans will include the Veteran Health Administration and its practitioners, the national SCI/D services office, the general healthcare community and the veteran population, as well as the entire SCI community via submitting quarterly letters or peer-review articles. Trial registration number NCT03345576.
The purpose of the study was to identify potential predictors of muscle hypertrophy responsiveness following neuromuscular electrical stimulation resistance training (NMES-RT) in persons with chronic spinal cord injury (SCI). Data for twenty individuals with motor complete SCI who completed twice weekly NMES-RT lasting 12–16 weeks as part of their participation in one of two separate clinical trials were pooled and retrospectively analyzed. Magnetic resonance imaging (MRI) was used to measure muscle cross-sectional area (CSA) of the whole thigh and knee extensor muscle before and after NMES-RT. Muscle biopsies and fasting biomarkers were also measured. Following the completion of the respective NMES-RT trials, participants were classified into either high-responders (n = 8; muscle CSA > 20
Changes in body composition and dietary intake occur following spinal cord injury (SCI). The Geometric Framework for Nutrition (GFN) is a tool that allows the examination of the complex relationships between multiple nutrition factors and health parameters within a single model. This study aimed to utilize the GFN to examine the associations between self-reported macronutrient intakes and body composition in persons with chronic SCI. Forty-eight individuals with chronic SCI were recruited. Participants completed and returned 3- or 5-day self-reported dietary recall sheets. Dietary intake of macronutrients (fats, proteins, and carbohydrates) were analysed. Anthropometric measures (circumferences), dual-energy x-ray absorptiometry (DXA), and magnetic resonance imaging (MRI) were used to assess whlole-body composition. Associations between all circumference measures and carbohydrates were observed. Among MRI measures, only significant associations between subcutaneous adipose tissue and protein x carbohydrate as well as carbohydrates alone were identified. Carbohydrates were negatively associated with several measures of fat mass as measured by DXA. Overall, carbohydrates appear to play an important role in body composition among individuals with SCI. Higher carbohydrate intake was associated with lower fat mass. Additional research is needed to determine how carbohydrate intake influences body composition and cardiometabolic health after SCI.
(1) Background: Resource intensive imaging tools have been employed to examine muscle and bone qualities after spinal cord injury (SCI). We tested the hypothesis that surface neuromuscular electrical stimulation (NMES) amplitude can be used to examine knee extensor muscle quality, distal femur and proximal tibia bone mineral density (BMD) in persons with SCI. (2) Methods: Seventeen persons (2 women) with chronic SCI participated in three weeks of NMES-resistance training twice weekly of 4 sets of 10 repetitions. Participants were classified according to the current amplitude (>100 mA) and the number of repetitions (>70 reps) of leg extension into greater (n = 8; 1 woman; group A) and lower (n = 9; 1 woman; group B) musculoskeletal qualities. Magnetic resonance imaging, dual energy x-ray absorptiometry, isometric peak torque, Modified Ashworth and Penn spasm frequency scales were conducted. (3) Results: In between group comparisons, current amplitude was lower (38–46%) in group A. Whole (27–32%; p = 0.02), absolute (26–33%, p = 0.02) thigh muscle and absolute knee extensor muscle cross-sectional areas (22–33%, p = 0.04) were greater in group A. Right distal femur (24%; p = 0.08) and proximal tibia (29%; p = 0.03) BMDs were lower in group B, and peak isometric torque (p < 0.01), extensor spasticity scorers (p = 0.04) and muscle spasm scores (p = 0.002) were significantly higher in group A. Regression models revealed that amplitude of current, repetitions and body weight can accurately predict musculoskeletal qualities in persons with SCI. (4) Conclusions: Surface NMES amplitude and repetitions of leg extension differentiated between SCI survivors with greater versus lower musculoskeletal qualities. The study may shed the light on the interplay between muscle and bone in persons with SCI.
The objective of the current work was to examine the relationships between quality of life (QOL) domains in persons with spinal cord injury (SCI) and their levels of weekly leisure-time physical activity (LTPA), anthropometric variables, and body composition variables. This exploratory cross-sectional study consisted of baseline data collected as part of a randomized clinical trial at a VA Medical Center and SCI center. A convenience sample of 36 community-dwelling persons with SCI participated in the current study. Outcome measures included the World Health Organization Quality of Life Short Form (WHOQOL-BREF), Leisure-Time Physical Activity Questionnaire for People with Spinal Cord Injury (LTPAQ-SCI), anthropomorphic measures (waist, hip, and abdominal circumference), and dual-energy x-ray absorptiometry (DXA) to quantify regional and total body composition. Multiple regression models suggested that engagement in LTPA accounted for 35.7% of the variance in physical health QOL, 33.5% in psychological QOL, 14.2% in social relationships QOL, and 38.2% in environmental QOL. Anthropometric measures accounted for 11.3%, 3.1%, 12.0%, and 6.7% of the variance in these QOL indices, respectively, and DXA indices accounted for 18.7%, 17.5%, 27.4%, and 21.9%. Within these models, the number of minutes of heavy LTPA per day uniquely predicted physical health QOL, the number of mild LTPA days per week uniquely predicted psychological QOL, and the amount of mild LTPA per day uniquely predicted environmental QOL. Bivariate analyses also suggested that android and trunk fat, as well as supine waist and abdominal circumferences, were positively associated with social relationships QOL. Encouraging individuals with SCI to engage in LTPA may robustly enhance multiple aspects of QOL while reducing the risk for cardiovascular and metabolic morbidities associated with SCI. Moreover, this may lead to a further understanding of how QOL may impact longitudinal intervention trials. The study protocol and procedures were reviewed and approved by the McGuire VA Research Institutional Review Board (IRB# 02152, approval date August 9, 2015; IRB# 02375, approval date May 2, 2018).
PURPOSE: The purpose of the work is to determine whether neuromuscular electrical stimulation resistance training (NMES-RT) evoked muscle hypertrophy is accompanied with increased VO2 peak, ventilatory efficiency and mitochondrial respiration in individuals with chronic spinal cord injury (SCI). METHODS: Thirty-three men and women with chronic SCI were randomized into either NMES-RT (n = 20) or PMT (n = 13). Functional electrical stimulation-lower extremity cycling (FES-LEC) was used to test leg VO2 peak, VE/VCO2 ratio and substrate utilization prior to and post-intervention. Magnetic resonance imaging was used to measure muscle cross-sectional area (CSA). Finally, muscle biopsy was performed to measure mitochondrial complexes and respiration. RESULTS: The NMES-RT group showed a significant increase in post-intervention VO2 compared to baseline (∆ VO2 = 14%, P < 0.01) with no changes in the PMT group (∆ VO2 = 1.6%, P = 0.47). Similarly, thigh muscle CSAs increased following NMES-RT without changes after PMT [(∆ CSA Thigh = 19%, P < 0.01) and knee extensor (∆ CSA Knee = 30.4 %, P < 0.01)]. The changes in thigh and knee extensor muscle CSAs were positively correlated with the change in VO2 peak (∆ CSAThigh - ∆ VO2: r2 = 0.31, P < 0.01; ∆ CSA Knee - ∆ VO2: r2 = 0.15, P = 0.04). NMES-RT or PMT did not influence mitochondrial complex content; however, changes in peak VO2 was related to complex I. CONCLUSIONS: NMES-RT-induced skeletal muscle hypertrophy was accompanied with increased peak VO2 consumption which may partially be explained by enhanced activity of mitochondrial complex I.
The dose de-escalation (DD) effects of testosterone and evoked resistance training (RT) on body composition, cardiometabolic, and neuromuscular variables were investigated. Thirteen men with chronic complete spinal cord injury (SCI) were followed for additional 16 weeks after receiving either testosterone treatment only (TT) or TT+RT. During the 16-week DD period, the TT+RT group underwent a program of once weekly electrical stimulation with gradually decreasing ankle weights and testosterone patches of 2 mg day(-1) (TT+RT group). The TT only group did not receive any intervention throughout the detraining period (no-TT group). Body composition was tested using anthropometrics, dual energy X-ray absorptiometry, and magnetic resonance imaging. After an overnight fast, basal metabolic rate (BMR), lipid panel, serum testosterone, inflammatory biomarkers, glucose effectiveness, and insulin sensitivity were measured. Finally, peak isometric and isokinetic torques were measured only in the TT+RT group. All measurements were conducted at the beginning and at the end of DD. Absolute thigh muscle cross-sectional areas (CSAs) demonstrated interaction effects (p < 0.05) between the TT+RT (-8.15%, -6.5%) and no-TT (2.3%, 4.4%) groups. Similarly, absolute knee extensor muscle CSA demonstrated interaction effects (p < 0.05) between the TT+RT (-11%, -7.0%) and no-TT (2.6%, 3.8%) groups. There was a trend (p = 0.07) of increasing visceral adipose tissue (VAT) CSAs in the TT+RT (18%) and in the no-TT (16% cm(2)) groups. There was an interaction (p = 0.005) between TT+RT (decreased by 3.7%) and no-TI' groups (increased by 9.0%) in BM R. No interactions were evident between groups over time for biomarkers related to carbohydrate, lipid metabolism, or inflammation. Finally, there were no changes (p > 0.05) in peak isometric or isokinetic torques and rise time following 16 weeks of the DD period in the TF-FRT group. Tr+RT during 16 weeks of DD was minimally effective at preventing detraining relative to no-TT on muscle size, BMR, and VAT. However, neuromuscular gains were successfully maintained.
The purpose of the study was to determine whether neuromuscular electrical stimulation resistance training (NMES-RT)-evoked muscle hypertrophy is accompanied by increased V̇o2 peak, ventilatory efficiency, and mitochondrial respiration in individuals with chronic spinal cord injury (SCI). Thirty-three men and women with chronic, predominantly traumatic SCI were randomized to either NMES-RT (n = 20) or passive movement training (PMT; n = 13). Functional electrical stimulation-lower extremity cycling (FES-LEC) was used to test the leg V̇o2 peak, V̇E/V̇co2 ratio, and substrate utilization pre- and postintervention. Magnetic resonance imaging was used to measure muscle cross-sectional area (CSA). Finally, muscle biopsy was performed to measure mitochondrial complexes and respiration. The NMES-RT group showed a significant increase in postintervention V̇o2 peak compared with baseline (ΔV̇o2 = 14%, P < 0.01) with no changes in the PMT group (ΔV̇o2 = 1.6%, P = 0.47). Similarly, thigh (ΔCSAthigh = 19%) and knee extensor (ΔCSAknee = 30.4%, P < 0.01) CSAs increased following NMES-RT but not after PMT. The changes in thigh and knee extensor muscle CSAs were positively related with the change in V̇o2 peak. Neither NMES-RT nor PMT changed mitochondrial complex tissue levels; however, changes in peak V̇o2 were related to complex I. In conclusion, in persons with SCI, NMES-RT-induced skeletal muscle hypertrophy was accompanied by increased peak V̇o2 consumption which may partially be explained by enhanced activity of mitochondrial complex I.NEW & NOTEWORTHY Leg oxygen uptake (V̇o2) and ventilatory efficiency (V̇E/V̇co2 ratio) were measured during functional electrical stimulation cycling testing following 12-16 wk of either electrically evoked resistance training or passive movement training, and the respiration of mitochondrial complexes. Resistance training increased thigh muscle area and leg V̇o2 peak but decreased V̇E/V̇co2 ratio without changes in mitochondrial complex levels. Leg V̇o2 peak was associated with muscle hypertrophy and mitochondrial respiration of complex I following training.
The purpose of the study was to determine whether neuromuscular electrical stimulation resistance training (NMES-RT) evoked muscle hypertrophy is accompanied by increased VO2 peak, ventilatory efficiency and mitochondrial respiration in individuals with chronic spinal cord injury (SCI). Thirty-three men and women with chronic, predominantly traumatic, SCI were randomized to either NMES-RT (n=20) or passive movement training (PMT; n=13). Functional electrical stimulation-lower extremity cycling (FES-LEC) was used to test leg VO2 peak, VE/VCO2 ratio and substrate utilization prior to and post-intervention. Magnetic resonance imaging was used to measure muscle cross-sectional area (CSA). Finally, muscle biopsy was performed to measure mitochondrial complexes and respiration. The NMES-RT group showed a significant increase in post-intervention VO2 peak compared to baseline (∆ VO2 = 14%, P < 0.01) with no changes in the PMT group (∆ VO2 = 1.6%, P= 0.47). Similarly, thigh (∆ CSA Thigh = 19%) and knee extensor (∆ CSA Knee = 30.4 %, P < 0.01) CSAs increased following NMES-RT but not after PMT. The changes in thigh and knee extensor muscle CSAs were positively related with the change in VO2 peak. Neither NMES-RT nor PMT changed mitochondrial complex tissue levels; however, changes in peak VO2 were related to complex I. In conclusion, in persons with SCI, NMES-RT-induced skeletal muscle hypertrophy was accompanied with increased peak VO2 consumption which may partially be explained by enhanced activity of mitochondrial complex I.
BACKGROUND:Severe spasticity may negatively impact functionality and quality of life after spinal cord injury (SCI). Intrathecal baclofen treatment (IBT) is effectively used to manage severe spasticity and reduce comorbidities. However, long-term IBT may have a negative effect on bone mineral content (BMC), bone mineral density (BMD) and body composition (such as percentage fat mass and lean body mass). We demonstrated the negative effects of long-term IBT use in a single case compared with two non-IBT users. CASE SUMMARY:A 46-year old Caucasian male Veteran (case) with a 21 year history of complete tetraplegia (complete C6 SCI) was implanted with IBT for 20 years. The case was matched to two participants with different time since injuries [2 (match 1) and 13 (match 2) years] without IBT. Knee BMC and BMD at the epiphysis and metaphysis of the distal femur and proximal tibia were evaluated using dual knee and the dual femur modules of GE Lunar iDXA software. Total and leg body composition assessments were also conducted for the three participants. Potential effect of long-term IBT was demonstrated by changes in BMD, consistent with bone demineralization, at the distal femur and proximal tibia and changes in percentage fat mass and lean mass of legs. The case showed 113% lower BMD at the distal femur, and 78.1% lower at the proximal tibia compared to match 1, moreover the case showed 45% lower BMD at the distal femur, and no observed changes at the proximal tibia compared to match 2. The case had 27.1% and 16.5% greater leg %fat mass compared to match 1 and match 2, respectively. Furthermore, the case had 17.4% and 11.8% lower % leg lean mass compared to match 1 and match 2, respectively. CONCLUSION:Long-term IBT may impact bone health and body composition parameters in persons with complete SCI. It may be prudent to encourage regular screening of individuals on long-term IBT considering the prevalence of osteoporosis related fractures, cardiovascular diseases, and metabolic disorders in this population.
Introduction Spinal cord injury (SCI) may cause impairments of the motor, sensory, and autonomic nervous systems, which result in adverse changes in body composition and cardiovascular health. Functional electrical stimulation (FES) cycling may provide an effective alternative approach to perform exercise and improve cardiovascular health after SCI. Persons with an injury at or above T6 level are at high risk of developing a life-threatening complication of autonomic dysreflexia (AD). Case presentation Two participants with motor-complete C6 SCI completed either 12 weeks of passive range of motion or surface neuromuscular electrical stimulation (NMES) resistance training, followed by 12 weeks of functional electrical stimulation (FES) lower extremity cycling for both participants. Systolic and diastolic blood pressure (BP) were measured to determine the effects of NMES-resistance training and FES-lower extremity cycling during rest and exercise. Discussion The difference between mean value of BP during FES-lower extremity cycling exercise and resting BP averaged for 24 sessions was smaller for participant A (31.25 mmHg for systolic BP and 10.44 mmHg for diastolic BP), who received NMES-resistance training, as compared with participant B (58.62 mmHg for systolic BP and 35.07 mmHg for diastolic BP). The results of these case reports suggest that 12 weeks of NMES-resistance training preceding FES-lower extremity cycling may attenuate the development of AD after SCI. Risk of AD, triggered by noxious stimuli, may be dampened with FES-lower extremity cycling training in persons with SCI.