Arm-Cranking Exercise Training Reduces Plasminogen Activator Inhibitor 1 in People With Spinal Cord Injury

Untargeted blood serum proteomics identifies novel proteins related to neurological recovery after human spinal cord injury

BACKGROUND

The discovery of new prognostic biomarkers following spinal cord injury (SCI) is a rapidly growing field that could help uncover the underlying pathological mechanisms of SCI and aid in the development of new therapies. To date, this search has largely focused on the initial days after the lesion. However, during the subacute stage of SCI (weeks to months after the injury), there remains potential for sensorimotor recovery, and numerous secondary events develop in various organs. Additionally, the confounding effects of early interventions after the injury are less likely to interfere with the results.

METHODS

In this study, we conducted an untargeted proteomics analysis to identify biomarkers of recovery in blood serum samples during the subacute phase of SCI patients, comparing those with strong recovery to those with no recovery between 30 and 120 days. We analyzed the fraction of serum that is depleted of the most abundant proteins to unmask proteins that would otherwise go undetected. Linear models were used to identify peptides and proteins related to neurological recovery and we validated changes in some of these proteins using Enzyme-linked Immunosorbent Assay (ELISA).

RESULTS

Our findings reveal that differences in subacute recovery after SCI (from 30 to 120 days) are associated with an enrichment in proteins involved in inflammation, coagulation, and lipid metabolism. Technical validation using commercial ELISAs further confirms that high levels of SERPINE1 and ARHGAP35 are associated with strong neurological recovery, while high levels of CD300a and DEFA1 are associated with a lack of recovery.

CONCLUSIONS

Our study identifies new candidates for biomarkers of neurological recovery and for novel therapeutic targets after SCI.

Cultural validation and language translation of the scientific SCI exercise guidelines for use in Indonesia, Japan, Korea, and Thailand

CONTEXT

Indonesia, Japan, Korea, Thailand.

OBJECTIVE

To culturally validate and translate the Scientific Exercise Guidelines for Adults with Spinal Cord Injury (SEG-SCI) for use in four Asian countries.

DESIGN

Systematic Review.

PARTICIPANTS

N/A.

METHODS

A systematic review was conducted to identify all published English- and local-language studies conducted in Indonesia, Japan, Korea, and Thailand, testing the effects of exercise training interventions on fitness and cardiometabolic health in adults with acute or chronic SCI. Protocols and results from high-quality controlled studies were compared with the SEG-SCI. Forward and backward translation processes were used to translate the guidelines into Bahasa Indonesian, Japanese, Korean and Thai languages.

RESULTS

Fifteen studies met the review criteria. At least one study from each country implemented exercise prescriptions that met or exceeded the SEG-SCI. Two were controlled studies. In those two studies, relative to control conditions, participants in exercise conditions achieved significant improvements in fitness or cardiometabolic health outcomes only when the exercise intervention protocol met or exceeded the SEG-SCI. During the language translation processes, end-users confirmed that SEG-SCI language and terminology were clear.

CONCLUSION

Clinical researchers in Indonesia, Japan, Korea and Thailand have implemented exercise protocols that meet or exceed the SCI-SEG. Results of high-quality studies align with the SEG-SCI recommendations. Based on this evidence, we recommend that the SEG-SCI be adopted in these countries. The cultural validation and translation of the SEG-SCI is an important step towards establishing consistent SCI exercise prescriptions in research, clinical and community settings around the world.

The Diagnosis and Management of Cardiometabolic Risk and Cardiometabolic Syndrome after Spinal Cord Injury

Individuals with spinal cord injuries (SCI) commonly present with component risk factors for cardiometabolic risk and combined risk factors for cardiometabolic syndrome (CMS). These primary risk factors include obesity, dyslipidemia, dysglycemia/insulin resistance, and hypertension. Commonly referred to as “silent killers”, cardiometabolic risk and CMS increase the threat of cardiovascular disease, a leading cause of death after SCI. This narrative review will examine current data and the etiopathogenesis of cardiometabolic risk, CMS, and cardiovascular disease associated with SCI, focusing on pivotal research on cardiometabolic sequelae from the last five years. The review will also provide current diagnosis and surveillance criteria for cardiometabolic disorders after SCI, a novel obesity classification system based on percent total body fat, and lifestyle management strategies to improve cardiometabolic health.

Benefits and interval training in individuals with spinal cord injury: A thematic review

BACKGROUND

Arm crank ergometry (ACE), functional electrical stimulation leg cycling exercise (FES-LCE), and the combination of the two (FES hybrid exercise) have all been used as activities to help improve the fitness-related health of individuals with spinal cord injury (SCI). More recently, high-intensity interval training (HIIT) has become popular in the non-disabled community due to its ability to produce greater aerobic fitness benefits or equivalent benefits with reduced time commitment.

OBJECTIVE

This thematic review of the literature sought to determine the potential benefits and practicality of using ACE, FES-LCE, and FES hybrid exercise in an interval training format for individuals with SCI.

METHODS

Systematic literature searches were conducted in May 2020 and March 2021 focusing on interval training in individuals with SCI. Pre-defined nested search terms were used to narrow the available literature from 4273 citations to 1362 articles. The titles and abstracts were then reviewed to determine the appropriateness of the articles ending with fifteen articles.

RESULTS

The literature was limited to fifteen articles with low participant numbers (n = 1-20). However, in each article, HIIT protocols either demonstrated a greater improvement in cardiovascular, metabolic, or practicality scores compared to moderate intensity continuous training (MICT) protocols, or improvement during relatively brief time commitments.

CONCLUSION

The available literature lacked sufficient numbers of randomized control trials. However, the available evidence is encouraging concerning the potential benefits and practicality of using HIIT (ACE, FES-LCE, or FES hybrid exercise) to improve aerobic and anaerobic capacity and decrease cardiometabolic risk after SCI.

Effects of Arm-Crank Exercise on Fitness and Health in Adults With Chronic Spinal Cord Injury: A Systematic Review

Individuals with spinal cord injury (SCI) may benefit less from exercise training due to consequences of their injury, leading to lower cardiorespiratory fitness and higher risks of developing cardiovascular diseases. Arm-crank exercise (ACE) is the most common form of volitional aerobic exercise used by people with SCI outside a hospital. However, evidence regarding the specific effects of ACE alone on fitness and health in adults with SCI is currently lacking. Hence, this review aimed to determine the effects of ACE on cardiorespiratory fitness, body composition, cardiovascular disease (CVD) risk factors, motor function, health-related quality of life (QoL), and adverse events in adults with chronic SCI. Inclusion criteria were: inactive adults (≥18 years) with chronic SCI (>12 months post injury); used ACE alone as an intervention; measured at least one of the following outcomes; cardiorespiratory fitness, body composition, cardiovascular disease risk factors, motor function, health-related QoL, and adverse events. Evidence was synthesized and appraised using GRADE. Eighteen studies with a combined total of 235 participants having an injury between C4 to L3 were included. There was a moderate certainty of the body of evidence on ACE improving cardiorespiratory fitness. Exercise prescriptions from the included studies were 30-40 min of light to vigorous-intensity exercise, 3-5 times per week for 2-16 weeks. GRADE confidence ratings were very low for ACE improving body composition, CVD risks factors, motor function, or health-related QoL. No evidence suggests ACE increases the risk of developing shoulder pain or other injuries. Overall, this review recommends adults with chronic SCI should engage in regular ACE to improve cardiorespiratory fitness. More high-quality, larger-scale studies are needed to increase the level of evidence of ACE in improving cardiorespiratory fitness and to determine the effects of ACE on other outcomes. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_reco rd.php?ID=CRD42021221952], identifier [CRD42021221952].

Biomarkers from Secondary Complications in Spinal Cord Injury

PURPOSE OF REVIEW

In the USA, spinal cord injury (SCI) occurs in 40 people per million every year due to events such as car accidents, falls, violence, or sports injury. Secondary complications that arise from SCI are life-threatening and should be treated as early as possible. In some cases, it is not completely obvious what complication a patient may have until it is too late. Therefore, biomarkers are required to assess the levels of secondary complications after SCI. As there are several complications that pose different warning signs, different biomarkers may be beneficial in early detection, maintenance, and long-term care for patients with SCI.

RECENT FINDINGS

Numerous studies have been conducted on biomarkers in various SCI and its related complications, such as neuropathic pain and deep vein thrombosis. In recent years, research has expanded with biomarkers discovered by cellular and molecular, genome-wide transcriptomic analysis, bioinformatics, and clinical studies. Biomarkers have allowed early prediction of the severity of secondary complications due to SCI.

SUMMARY

In this review, we summarize recent studies on the common biomarkers for the secondary complications related to SCI. We highlight the reliable biomarkers that have been tested, e.g., sclerostin, NGF, D-dimer, oncostatin M (OSM), microbiota, and C-reactive protein, which are valuable and with clinical importance. This review also emphasizes continuing research in biomarkers as they can provide valuable cellular and molecular insight into secondary complications after SCI.

Effects of arm cranking exercise on muscle oxygenation between active and inactive muscles in people with spinal cord injury

Objective: We investigated the effects of the incremental arm-cranking exercise (ACE) on tissue oxygen saturation (StO₂) between active and inactive muscles, and the relationship between peak oxygen uptake (VO_2peak) and changes in the StO₂ in inactive muscles.Design: Observational study.Setting: Community-based supervised intervention.Participants: The participants were individuals with motor and sensory complete spinal cord injury (complete SCI; n = 8) and motor complete but sensory incomplete SCI (incomplete SCI; n = 8), and able-bodied (AB) individuals (n = 8) matched for age, height, and body mass index.Intervention: The ACE was performed at a rate increasing by 10 watts min^-1 until exhaustion.Outcome Measures: VO_2peak, heart rate (HR), and StO₂.Results: While VO_2peak was similar among the groups, peak HR was significantly higher in both SCI groups than in the AB (P < 0.05). In active muscles (biceps brachii), no differences in the StO₂ were observed among the groups (P > 0.05). In inactive muscles (vastus lateralis), the StO₂ in the AB and the incomplete SCI began to decrease at approximately 40% of the peak work rate; however, they remained unchanged in the complete SCI. The reductions in StO₂ in the AB were significantly greater than in the incomplete SCI.Conclusions: These results suggest that sympathetic vasoconstriction occurred in the incomplete SCI and AB, although it did not occur in the complete SCI, probably due to a reduction in sympathetic nerve activity. Sympathetic vasoconstriction in inactive muscles may not contribute to an individual's VO_2peak regardless of their group.

Acute exercise improves glucose effectiveness but not insulin sensitivity in paraplegia

PURPOSE

To determine the effect of a single session of arm crank ergometry (ACE) exercise on carbohydrate metabolism immediately and 24 h after the exercise bout in paraplegia and able-bodied controls (ABC).

METHODS

Paraplegia (n = 11; 91% male; age 34.8 ± 11.4 years) and ABC (n = 6; 67% male; age 28.7 ± 11.9 years) underwent 45 min of ACE exercise at 75% VO_2Peak. Glucose effectiveness (Sg) and insulin sensitivity (Si) were assessed. Data were analyzed with two-way mixed analysis of variance and Wilcoxon rank-sum or signed-rank post hoc test.

RESULTS

VO_2Peak was lower in paraplegia versus ABC (22.3 ± 3.99 vs. 30.8 ± 2.9 ml/kg/min, p = 0.003). Si was lower paraplegia vs. ABC immediately following exercise (3.28 ± 1.6 vs. 5.30 ± 1.2 min^-1/[µU/mL^-1]x10^-4, p = 0.023). In paraplegia, Sg was higher immediately after exercise than baseline (B: 0.021 ± 0.01 vs. I: 0.026 ± 0.01 min^-1, p = 0.037). Twenty-four hours after exercise, Sg was lower than immediately following exercise (I: 0.026 ± 0.01 vs. 24: 0.017 ± 0.01 min^-1, p = 0.001), but not different than baseline in paraplegia (B: 0.021 ± 0.01 vs. 24: 0.017 ± 0.01 min^-1, p = 0.216). In the ABC group, Sg was not different at all timepoints (p > 0.05). Si did not differ at all timepoints (p > 0.05).

CONCLUSION

A single bout of ACE at 75% VO_2Peak helped to acutely control glucose metabolism in those with paraplegia by increasing Sg by nearly 27%; however, this was not sustained past 24-hours. These data provide support for regular exercise engagement.Implications for RehabilitationDisorders of glucose metabolism have been reported at a greater prevalence in persons with spinal cord injury.A single bout of arm crank ergometry exercise at 75% VO_2Peak helped to acutely control glucose metabolism persons with paraplegia; however, this was not sustained past 24 h.These data provide support for regular exercise engagement in persons with paraplegia.

Effect of Exercise on Cardiovascular Function Following Spinal Cord Injury: A REVIEW

Spinal cord injury (SCI) is associated with a reduced level of physical activity, deterioration of patient body composition, metabolic profile, quality of life, and psychological functioning. As a result, risk of cardiovascular disease (CVD) increases and CVD-related death occurs at an earlier age than in individuals without SCI. Regular participation in exercise has been shown to exert beneficial effects also in patients with SCI. In this review, we analyze and discuss the effects of regular exercise training in SCI on cardiovascular function, autonomic function of the cardiovascular system, arterial stiffness, metabolism, inflammation, and gene expression.

Energy Expenditure, Cardiorespiratory Fitness, and Body Composition Following Arm Cycling or Functional Electrical Stimulation Exercises in Spinal Cord Injury: A 16-Week Randomized Controlled Trial

Background: Physical deconditioning and inactivity following spinal cord injury (SCI) are associated with multiple cardiometabolic risks. To mitigate cardiometabolic risk, exercise is recommended, but it is poorly established whether arm cycling exercise (ACE) or functional electrical stimulation (FES) leg cycling yields superior benefits. Objectives: To determine the adaptations of 16 weeks of FES cycling and ACE on exercise energy expenditure (EEE), cardiorespiratory fitness (CRF), and obesity after SCI. Methods: Thirteen physically untrained individuals were randomly assigned to FES (n = 6) or ACE (n = 7) exercise 5 days/week for 16 weeks. Pre- and post-intervention EEE, peak oxygen consumption (absolute and relative VO2Peak), and work were assessed using indirect calorimetry, while body composition was measured by dual-energy x-ray absorptiometry. Results: Main effects were found for peak power (p < .001), absolute (p = .046) and relative (p = .042) VO2Peak, and peak work (p = .013). Compared to baseline, the ACE group increased in EEE (+85%, p = .002), peak power (+307%, p < .001), VO2Peak (absolute +21%, relative +22%, p ≤ .024), peak work (19% increase, p = .003), and total body fat decreased (-6%, p = .05). The FES group showed a decrease in percentage body fat mass (-5%, p = .008). The ACE group had higher EEE (p = .008), peak power (p < .001), and relative VO2Peak (p = .025) compared to postintervention values in the FES group. Conclusion: In the current study, ACE induced greater increases in EEE and CRF, whereas ACE and FES showed similar results on body fat. Exercise promotional efforts targeting persons with SCI should use both FES and ACE to reduce sedentary behavior and to optimize different health parameters after SCI.

Effect of Different Forms of Activity-Based Recovery Training on Bladder, Bowel, and Sexual Function After Spinal Cord Injury

OBJECTIVES

To investigate whether the urogenital and bowel functional gains previously demonstrated post-locomotor step training after chronic spinal cord injury could have been derived due to weight-bearing alone or from exercise in general.

DESIGN

Prospective cohort study; pilot trial with small sample size.

SETTING

Urogenital and bowel scientific core facility at a rehabilitation institute and spinal cord injury research center in the United States.

PARTICIPANTS

Men and women (N=22) with spinal cord injury (American Spinal Injury Association Impairment Scale grades of A-D) participated in this study.

INTERVENTIONS

Approximately 80 daily 1-hour sessions of either stand training or nonweight-bearing arm crank ergometry. Comparisons were made with previously published locomotor training data (step; N=7).

MAIN OUTCOME MEASURES

Assessments at both pre- and post-training timepoints included cystometry for bladder function and International Data Set Questionnaires for bowel and sexual functions.

RESULTS

Cystometry measurements revealed a significant decrease in bladder pressure and limited improvement in compliance with nonweight-bearing exercise but not with standing. Although International Data Set questionnaires revealed profound bowel dysfunction and marked deficits in sexual function pretraining, no differences were identified poststand or after nonweight-bearing exercise.

CONCLUSIONS

These pilot trial results suggest that, although stand and weight-bearing alone do not benefit pelvic organ functions after spinal cord injury, exercise in general may contribute at least partially to the lowering of bladder pressure and the increase in compliance that was seen previously with locomotor training, potentially through metabolic, humoral, and/or cardiovascular mechanisms. Thus, to maximize activity-based recovery training benefits for functions related to storage and emptying, an appropriate level of sensory input to the spinal cord neural circuitries controlling bladder and bowel requires task-specific stepping.

Effects of High-Intensity Interval Training Versus Moderate-Intensity Training on Cardiometabolic Health Markers in Individuals With Spinal Cord Injury: A Pilot Study

Background: Recent studies in nondisabled individuals have demonstrated that low-volume high-intensity interval training (HIIT) can improve cardiometabolic health similar to moderate-intensity training (MIT) despite requiring 20% of the overall time commitment. To date, there have been no studies assessing the effects of HIIT for improving cardiometabolic health in individuals with SCI. Objectives: The primary purpose of this pilot study was to compare the effects of 6 weeks of low-volume HIIT vs MIT using arm crank ergometer exercise to improve body composition, cardiovascular fitness, glucose tolerance, blood lipids, and blood pressure in a cohort of individuals with longstanding SCI. Methods: Participants were randomized to 6 weeks of HIIT or MIT arm crank exercise training. Aerobic capacity, muscular strength, blood lipids, glucose tolerance, blood pressure, and body composition were assessed at baseline and 6 weeks post training. Results: Seven individuals (6 male, 1 female; n = 3 in MIT and n = 4 in HIIT; mean age 51.3 ± 10.5 years) with longstanding SCI completed the study. The preliminary findings from this pilot study demonstrated that individuals with SCI randomized to either 6 weeks of HIIT or MIT displayed improvements in (a) insulin sensitivity, (b) cardiovascular fitness, and (c) muscular strength (p < .05). However, MIT led to greater improvements in arm fat percent and chest press strength compared to HIIT (p < .05). Conclusion: No differences between MIT and HIIT were observed. Both conditions led to improvements in insulin sensitivity, aerobic capacity, muscle strength, and blood lipids in individuals with SCI. Future larger cohort studies are needed to determine if the shorter amount of time required from HIIT is preferable to current MIT exercise recommendations.