Cardiometabolic risk in community-dwelling persons with chronic spinal cord injury

Reducing endocrine metabolic disease risk in adults with chronic spinal cord injury: strategic activities conducted by the Ontario-Quebec RIISC team

PURPOSE

The Rehabilitation Interventions for Individuals with a Spinal Cord Injury in the Community (RIISC) team aimed to develop and evaluate innovative rehabilitation interventions to identify endocrine metabolic disease (EMD) risk, intending to reduce the frequency and severity of EMD related morbidity and mortality among adults living with chronic spinal cord injury or disease (SCI/D).

MATERIALS AND METHODS

An interprovincial team from Ontario and Quebec reviewed available EMD literature and evidence syntheses and completed an inventory of health services, policies and practices in SCI/D care. The review outcomes were combined with expert opinion to create an EMD risk model to inform health service transformation.

RESULTS

EMD risk and mortality are highly prevalent among adults with chronic SCI/D. In stark contrast, few rehabilitation interventions target EMD outcomes. The modelled solution proposes: 1) abandoning single-disease paradigms and examining a holistic perspective of the individual's EMD risk, and 2) developing and disseminating practice-based research approaches in outpatient community settings.

CONCLUSIONS

RIISC model adoption could accelerate EMD care optimization, and ultimately inform the design of large-scale longitudinal pragmatic trials likely to improve health outcomes. Linking the RIISC team activities to economic evaluations and policy deliverables will strengthen the relevance and impact among policymakers, health care providers and patients.

Cardiometabolic risk factor clustering in persons with spinal cord injury: A principal component analysis approach

CONTEXT/OBJECTIVE

To identify cardiometabolic (CM) measurements that cluster to confer increased cardiovascular disease (CVD) risk using principal component analysis (PCA) in a cohort of chronic spinal cord injury (SCI) and healthy non-SCI individuals.

APPROACH

A cross-sectional study was performed in ninety-eight non-ambulatory men with chronic SCI and fifty-one healthy non-SCI individuals (ambulatory comparison group). Fasting blood samples were obtained for the following CM biomarkers: lipid, lipoprotein particle, fasting glucose and insulin concentrations, leptin, adiponectin, and markers of inflammation. Total and central adiposity [total body fat (TBF) percent and visceral adipose tissue (VAT) percent, respectively] were obtained by dual x-ray absorptiometry (DXA). A PCA was used to identify the CM outcome measurements that cluster to confer CVD risk in SCI and non-SCI cohorts.

RESULTS

Using PCA, six factor-components (FC) were extracted, explaining 77% and 82% of the total variance in the SCI and non-SCI cohorts, respectively. In both groups, FC-1 was primarily composed of lipoprotein particle concentration variables. TBF and VAT were included in FC-2 in the SCI group, but not the non-SCI group. In the SCI cohort, logistic regression analysis results revealed that for every unit increase in the FC-1 standardized score generated from the statistical software during the PCA, there is a 216% increased risk of MetS (P = 0.001), a 209% increased risk of a 10-yr. FRS ≥ 10% (P = 0.001), and a 92% increase in the risk of HOMA2-IR ≥ 2.05 (P = 0.01).

CONCLUSION

Application of PCA identified 6-FC models for the SCI and non-SCI groups. The clustering of variables into the respective models varied considerably between the cohorts, indicating that CM outcomes may play a differential role on their conferring CVD-risk in individuals with chronic SCI.

Evaluation of the feasibility and acceptability of a home-based supervised exercise programme in individuals with spinal cord injuries: SCI-HOME-ACTIVE study protocol

Physical activity is essential to a healthy lifestyle for adults with spinal cord injuries (SCI). Although exercise is recognised as an important tool for improving the well-being and independence of people with SCI, most individuals do not engage in physical exercise. Traditional exercise programmes often require participation in rehabilitation centres or specialised facilities, making them less accessible for individuals with chronic SCI. Many people with SCI live in rural communities and other geographically isolated areas where access to fitness facilities and outdoor recreational areas involves long commutes or expensive transportation, which is one of the most common barriers to exercise reported by people with physical disabilities. Consequently, exercise remains an underused intervention for improving health and function in people with SCI despite its proven effects in reducing pain, fatigue, fall risk and other secondary health conditions. This pilot study evaluates the feasibility and acceptability of a home-based supervised exercise programme for individuals with chronic SCI. The study will be an interventional and prospective pilot study. People with SCI will participate in a 3-month home-based exercise programme. Primary outcomes will include adherence to the exercise programme, while secondary outcomes will encompass quality of life, functional capacity, musculoskeletal health and clinical parameters. The programme will be structured into 1-hour sessions, held twice weekly for 3 months, conducted online and in small groups. The results of this study could be relevant for future indications of the best setting and strategy to ensure adherence to physical activity.

Current Status and Barriers of Exercise in Individuals with Spinal Cord Injuries in Korea: A Survey

This study investigated exercise participation, health status, and barriers to exercise in 109 individuals with spinal cord injury (SCI) using a self-report questionnaire. The responses of the exercise and non-exercise groups were statistically analyzed using t-tests or Fisher's exact test. Significant differences were observed in the cause of injury and the American Spinal Injury Association Impairment Scale between the groups. The non-exercise group had a higher incidence of traumatic and complete injuries. Demographic factors such as gender, age, income level, and marital status did not significantly influence exercise participation. The exercise group reported lower pain scores, less inconvenience from complications, and higher activity and participation scores. However, less than half of the individuals with SCI met the recommended exercise intensity, and community facility usage was low. Barriers to exercise participation included severe disabilities, lack of time, insufficient exercise information, and lack of facility accessibility. To enhance exercise among individuals with SCI, it is essential to develop and extend exercise programs tailored to individual physical factors and a comprehensive understanding of barriers. Prioritizing community-based data management, alongside developing social systems and health policies, is crucial to overcome barriers to exercise participation for individuals with SCI.

Reasons for meal termination, eating frequency, and typical meal context differ between persons with and without a spinal cord injury

Overeating associated with neurogenic obesity after spinal cord injury (SCI) may be related to how persons with SCI experience satiation (processes leading to meal termination), their eating frequency, and the context in which they eat their meals. In an online, cross-sectional study, adults with (n = 688) and without (Controls; n = 420) SCI completed the Reasons Individuals Stop Eating Questionnaire-15 (RISE-Q-15), which measures individual differences in the experience of factors contributing to meal termination on five scales: Physical Satisfaction, Planned Amount, Decreased Food Appeal, Self-Consciousness, and Decreased Priority of Eating. Participants also reported weekly meal and snack frequency and who prepares, serves, and eats dinner with them at a typical dinner meal. Analysis revealed that while Physical Satisfaction, Planned Amount, and Decreased Food Appeal were reported as the most frequent drivers of meal termination in both groups, scores for the RISE-Q-15 scales differed across the groups. Compared to Controls, persons with SCI reported Physical Satisfaction and Planned Amount as drivers of meal termination less frequently, and Decreased Food Appeal and Decreased Priority of Eating more frequently (all p < 0.001). This suggests that persons with SCI rely less on physiological satiation cues for meal termination than Controls and instead rely more on hedonic cues. Compared to Controls, persons with SCI less frequently reported preparing and serving dinner meals and less frequently reported eating alone (all p < 0.001), indicating differences in meal contexts between groups. Individuals with SCI reported consuming fewer meals than Controls but reported a higher overall eating frequency due to increased snacking (p ≤ 0.015). A decrease in the experience of physical fullness, along with a dependence on a communal meal context and frequent snacking, likely contribute to overeating associated with neurogenic obesity after SCI.

Assessing the efficacy of duration and intensity prescription for physical activity in mitigating cardiometabolic risk after spinal cord injury

PURPOSE OF REVIEW

Spinal cord injury (SCI) heightens susceptibility to cardiometabolic risk (CMR), predisposing individuals to cardiovascular disease. This monograph aims to assess the optimal duration and intensity of physical activity (PA) for managing CMR factors, particularly obesity, after SCI and provide modality-specific PA durations for optimal energy expenditure.

RECENT FINDINGS

PA guidelines recommend at least 150 min/week of moderate-intensity activity. However, non-SCI literature supports the effectiveness of engaging in vigorous-intensity PA (≥6 METs) and dedicating 250-300 min/week (≈2000 kcal/week) to reduce CMR factors. Engaging in this volume of PA has shown a dose-response relationship, wherein increased activity results in decreased obesity and other CMR factors in persons without SCI.

SUMMARY

To optimize cardiometabolic health, individuals with SCI require a longer duration and higher intensity of PA to achieve energy expenditures comparable to individuals without SCI. Therefore, individuals with SCI who can engage in or approach vigorous-intensity PA should prioritize doing so for at least 150 min/wk. At the same time, those unable to reach such intensities should engage in at least 250-300 min/week of PA at a challenging yet comfortable intensity, aiming to achieve an optimal intensity level based on their abilities. Given the potential to decrease CMR after SCI, increasing PA duration and intensity merits careful consideration in future SCI PA directives.

Autonomic Cardiovascular Control, Psychological Well-Being, and Cognitive Performance in People With Spinal Cord Injury

PURPOSE

To examine associations between parameters of psychological well-being, injury characteristics, cardiovascular autonomic nervous system (ANS) control, and cognitive performance in persons with spinal cord injury (SCI) compared with age-matched uninjured controls. This is an observational, cross-sectional study including a total of 94 participants (52 with SCI and 42 uninjured controls: UIC). Cardiovascular ANS responses were continuously monitored at rest and during administration of the Paced Auditory Serial Addition Test (PASAT). Self-report scores on the SCI-Quality of Life questionnaires are reported for depression, anxiety, fatigue, resilience, and positive affect. Participants with SCI performed significantly more poorly on the PASAT compared with the uninjured controls. Although not statistically significant, participants with SCI tended to report more psychological distress and less well-being than the uninjured controls. In addition, when compared with uninjured controls, the cardiovascular ANS responses to testing were significantly altered in participants with SCI; however, these responses to testing did not predict PASAT performance. Self-reported levels of anxiety were significantly related to PASAT score in the SCI group, but there was no significant relationship between PASAT and the other indices of SCI-Quality of Life. Future investigations should more closely examine the relationship among cardiovascular ANS impairments, psychological disorders, and cognitive dysfunction to better elucidate the underpinnings of these deficits and to guide interventions aimed at improving physiological, psychological, and cognitive health after SCI. Tetraplegia, paraplegia, blood pressure variability, cognitive, mood.

Intervention Design of High-Intensity Interval Training in Individuals With Spinal Cord Injury: Narrative Review and Future Perspectives

Background

Individuals with spinal cord injury (SCI) have lower levels of physical activity compared to the nondisabled population. Exercise guidelines recommend moderate or vigorous exercise to improve cardiovascular health and reduce cardiometabolic risk factors in persons with SCI. High-intensity interval training (HIIT) is a popular exercise choice and encompasses brief periods of vigorous exercise paired with intermittent periods of recovery.

Objectives

This review describes the available literature on HIIT for individuals with SCI, including differences in protocol design and suggested areas of further investigation.

Methods

Our institution's library system performed the comprehensive search. The primary keywords and phrases used to search included spinal cord injury, high-intensity interval training, tetraplegia, paraplegia, and several other related terms.

Results

Initially 62 records were screened, and 36 were deemed outside the scope of this review. Twenty-six studies published between 2001 and 2021 fulfilled the eligibility criteria and were divided among two researchers for review and analysis. All records required persons with SCI and a standardized HIIT intervention. Study design varied widely with respect to mode of exercise, prescribed intensity, duration of performance intervals, and session duration. This variability necessitates further investigation into the specifics of a HIIT prescription and the associated outcomes for persons with SCI.

Conclusion

Standardization of HIIT protocols may lead to more robust conclusions regarding its effects on cardiorespiratory fitness as well as mitigation of cardiometabolic risk factors. Meta-analyses will eventually be needed on proper dosing and session parameters to improve cardiorespiratory fitness and cardiometabolic risk factors.

Intensity of overground robotic exoskeleton training in two persons with motor-complete tetraplegia: a case series

INTRODUCTION

Participation in moderate-to-vigorous intensity physical activity (MVPA) is recommended to reduce chronic disease risk in individuals with tetraplegia. Assessing exercise intensity using traditional methods, such as heart rate, may be inaccurate in patients with motor-complete tetraplegia due to autonomic and neuromuscular dysfunction. Direct gas analysis may be more accurate. Overground robotic exoskeleton (ORE) training can be physiologically demanding. Yet, its utility as an aerobic exercise modality to facilitate MVPA in patients with chronic and acute motor-complete tetraplegia has not been explored.

CASE PRESENTATION

We present the results of two male participants with motor-complete tetraplegia who completed one ORE exercise session while intensity was assessed using a portable metabolic system and expressed in metabolic equivalents (METs). METs were calculated using a rolling 30-s average with 1 MET defined as 2.7 mL/kg/min and MVPA defined as MET ≥ 3.0. Participant A (28-year-old) with a chronic (12 yrs) spinal cord injury (C5, AIS A) completed 37.4 min of ORE exercise (28.9 min walking) achieving 1047 steps. Peak METs were 3.4 (average 2.3) with 3% of walk time spent in MVPA. Participant B (21-year-old) with an acute (2 months) spinal cord injury (C4, AIS A) completed 42.3 min of ORE exercise (40.5 min walking) achieving 1023 steps. Peak METs were 3.2 (average 2.6) with 12% of walk time spent in MVPA. Both participants tolerated activity well without observed adverse responses to activity.

DISCUSSION

ORE exercise may be an effective aerobic exercise modality that may increase participation in physical activity in patients with motor-complete tetraplegia.

At-Home High-Intensity Interval Training for Individuals with Paraplegia Following Spinal Cord Injury: A Pilot Study

Objective

This pilot study aimed to assess the efficacy of a 16-week at-home high-intensity interval training (HIIT) program among individuals with spinal cord injury (SCI).

Methods

Eight individuals (age: 47±11 (SD) years, 3 females) with SCI below the sixth thoracic vertebrae participated in a 16-week at-home HIIT program using an arm ergometer. Participants completed baseline graded exercise tests to determine target heart rate zones. HIIT was prescribed thrice per week. Each training session consisted of six one-minute bouts with a target heart rate ~80% heart rate reserve (HRR), interspersed with two minutes of recovery at ~30% HRR. A portable heart rate monitor and phone application provided visual feedback during training and allowed for measurements of adherence and compliance. Graded exercise tests were completed after 8 and 16 weeks of HIIT. Surveys were administered to assess participation, self-efficacy, and satisfaction.

Results

Participants demonstrated a decrease in submaximal cardiac output (P=0.028) and an increase in exercise capacity (peak power output, P=0.027) following HIIT, indicative of improved exercise economy and maximal work capacity. An 87% adherence rate was achieved during the HIIT program. Participants reached a high intensity of 70% HRR or greater during ~80% of intervals. The recovery HRR target was reached during only ~35% of intervals. Self-reported metrics of satisfaction and self-efficacy with at-home HIIT scored moderate to high.

Conclusion

Participants demonstrated an improvement in exercise economy and maximal work capacity following at-home HIIT. Additionally, participant adherence, compliance, satisfaction, and self-efficacy metrics suggest that at-home HIIT was easily implemented and enjoyable.

Systemic inflammation after spinal cord injury: A review of biological evidence, related health risks, and potential therapies

Individuals with chronic traumatic spinal cord injury (SCI) develop progressive multi-system health problems that result in clinical illness and disability. Systemic inflammation is associated with many of the common medical complications and acquired diseases that accompany chronic SCI, suggesting that it contributes to a number of comorbid pathological conditions. However, many of the mechanisms that promote persistent systemic inflammation and its consequences remain ill-defined. This review describes the significant biological factors that contribute to systemic inflammation, major organ systems affected, health risks, and the potential treatment strategies. We aim to highlight the need for a better understanding of inflammatory processes, and to establish appropriate strategies to address inflammation in SCI.

Association between weekly exercise minutes and resting IL-6 in adults with chronic spinal cord injury: findings from the fracture risk after spinal cord injury exercise study

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To assess associations between weekly aerobic exercise minutes and resting interleukin-6 (IL-6), C-reactive protein (CRP), or leptin levels in adults with chronic spinal cord injury (SCI).

SETTING

Three hundred and forty-four community-dwelling men and women with SCI duration of > 1 year.

METHODS

CRP, IL-6, and leptin levels were quantified by ultra-sensitive enzyme-linked immunoassay. Smoking, medication use, comorbidities, and aerobic exercise minutes per week were assessed by self-reported questionnaire. Body composition was determined by whole-body dual-energy X-ray absorptiometry. Generalized linear models were used to assess associations.

RESULTS

In multivariable modeling, resting IL-6 levels were 0.001 pg/mL lower for every 1 min of weekly aerobic exercise. IL-6 levels increased with increasing android-to-gynoid fat ratio, in active/ever smokers compared to never smokers, and in individuals with skin pressure injuries compared to those without. IL-6 levels were lower in active ibuprofen users compared to nonusers. We found no association between weekly exercise minutes and CRP or leptin when designing similar models.

CONCLUSIONS

Increasing aerobic exercise minutes is associated with lower IL-6 levels in adults with chronic SCI when considering body composition, smoking, skin pressure injuries, and ibuprofen use. CRP and leptin did not demonstrate an association with exercise when considering the similar variables. The use of these biomarkers in assessing the therapeutic value of future exercise-related interventions will be paramount for meaningful health improvement among those with SCI. Although a large, prospective dataset, this cross-sectional study cannot assign causation. Future prospective studies are needed to confirm these findings.

Energy expenditure and nutrient intake after spinal cord injury: a comprehensive review and practical recommendations

Many persons with spinal cord injury (SCI) have one or more preventable chronic diseases related to excessive energetic intake and poor eating patterns. Appropriate nutrient consumption relative to need becomes a concern despite authoritative dietary recommendations from around the world. These recommendations were developed for the non-disabled population and do not account for the injury-induced changes in body composition, hypometabolic rate, hormonal dysregulation and nutrition status after SCI. Because evidence-based dietary reference intake values for SCI do not exist, ensuring appropriate consumption of macronutrient and micronutrients for their energy requirements becomes a challenge. In this compressive review, we briefly evaluate aspects of energy balance and appetite control relative to SCI. We report on the evidence regarding energy expenditure, nutrient intake and their relationship after SCI. We compare these data with several established nutritional guidelines from American Heart Association, Australian Dietary Guidelines, Dietary Guidelines for Americans, Institute of Medicine Dietary Reference Intake, Public Health England Government Dietary Recommendations, WHO Healthy Diet and the Paralyzed Veterans of America (PVA) Clinical Practice Guidelines. We also provide practical assessment and nutritional recommendations to facilitate a healthy dietary pattern after SCI. Because of a lack of strong SCI research, there are currently limited dietary recommendations outside of the PVA guidelines that capture the unique nutrient needs after SCI. Future multicentre clinical trials are needed to develop comprehensive, evidence-based dietary reference values specific for persons with SCI across the care continuum that rely on accurate, individual assessment of energy need.

Bioelectrical impedance vector analysis and body composition in cervical spinal cord injury: A pilot study

Introduction

Body composition assessment in cervical spinal cord injury (c-SCI) individuals is important to monitor the fat free-mass (FFM) loss, due to immobilization, or gain, due to exercise practice. Single frequency bioelectrical impedance analysis (SF-BIA) is low in cost, simple and easy.

Objectives

The aims of this study are: to evaluate the concordance between the FFM values obtained using dual X-ray absorptiometry (DXA) and the three SF-BIA previous predictive equations; and to test the applicability of the bioelectrical impedance vector analysis (BIVA).

Methods

Twenty-three c-SCI males were divided into two groups: Physically active (PA; n = 13; at least 150 min/week) and non-active individuals (NPA) and were assessed by DXA and SF-BIA simultaneously.

Results

FFM values were similar between groups PA and NPA. Considering all participants, FFM values obtained by Kocina and Heyward (>11%) and Sun (<15.4%) predictive equations were different when compared to DXA (p < 0.01). However, Buchholz's et al. predictive equation showed FFM values similar to DXA, but presented poor concordance (<7%, p = 0.99; concordance coefficient = 0.85). BIVA showed consistency in ellipse distribution using FFM obtained using Buchholz et al. predictive equation.

Conclusions

The use of non-specific BIA equations can lead to misinterpretation in FFM values in male c-SCI individuals. Predictive equations for this group need to be developed.

Unravelling innervation of pancreatic islets

The central and peripheral nervous systems play critical roles in regulating pancreatic islet function and glucose metabolism. Over the last century, in vitro and in vivo studies along with examination of human pancreas samples have revealed the structure of islet innervation, investigated the contribution of sympathetic, parasympathetic and sensory neural pathways to glucose control, and begun to determine how the structure and function of pancreatic nerves are disrupted in metabolic disease. Now, state-of-the art techniques such as 3D imaging of pancreatic innervation and targeted in vivo neuromodulation provide further insights into the anatomy and physiological roles of islet innervation. Here, we provide a summary of the published work on the anatomy of pancreatic islet innervation, its roles, and evidence for disordered islet innervation in metabolic disease. Finally, we discuss the possibilities offered by new technologies to increase our knowledge of islet innervation and its contributions to metabolic regulation.

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.

Disparities in Morbidity After Spinal Cord Injury Across Insurance Types in the United States

OBJECTIVE

To compare the prevalence and incidence of, and adjusted hazards for comorbidities among adults with traumatic spinal cord injuries (TSCIs) across insurance types (private vs governmental insurance) in the United States.

PATIENTS AND METHODS

Privately insured (N=9081) and Medicare (N=7645) beneficiaries with a diagnosis of TSCI were included. Prevalence and incidence estimates of common psychological, cardiometabolic, and musculoskeletal morbidities were compared at baseline and at 4-years after index diagnosis, respectively. Survival models were used to quantify hazard ratios (HRs) for outcomes, controlling for insurance type, sociodemographic characteristics, and other comorbidities. Sensitivity analyses were conducted to determine the effects of insurance and race/ethnicity.

RESULTS

Adults with TSCIs on Medicare had a higher prevalence of any psychological (54.7% vs 35.4%), cardiometabolic (74.7% vs 70.1%), and musculoskeletal (72.8% vs 66.3%) morbidity than privately insured adults with TSCIs. Similarly, the 4-year incidences of most psychological (eg, depression: 37.6% [Medicare] vs 24.2% [private]), cardiometabolic (eg, type 2 diabetes: 22.5% [Medicare] vs 12.9% [private], and musculoskeletal (eg, osteoarthritis: 42.1% [Medicare] vs 34.6% [private]) morbidities were considerably higher among adults with TSCIs on Medicare. Adjusted survival models found that adults with TSCIs on Medicare had a greater hazard for developing psychological (HR, 1.40; 95% CI, 1.31-1.50) and cardiometabolic (HR, 1.21; 95% CI, 1.10-1.33) morbidities compared with privately insured adults with TSCI. There was evidence of both insurance and racial disparities.

CONCLUSION

Adults with TSCIs on Medicare had significantly higher prevalence and risk for developing common physical and mental health comorbidities, compared with privately insured adults with TSCIs.

Management of blood pressure disorders in individuals with spinal cord injury

Blood pressure regulation is impacted by a spinal cord injury (SCI) due to impaired descending sympathetic vascular control. Common blood pressure problems in the SCI population include persistently low blood pressure with bouts of orthostatic hypotension and autonomic dysreflexia, which are more prevalent in individuals with lesions above the sixth thoracic vertebral level; however, they may occur regardless of the neurological level of injury. Although blood pressure disorders adversely impact daily function and quality of life, most individuals with SCI do not acknowledge this association. Few pharmacological options have been rigorously tested for safety and efficacy to manage blood pressure disorders in the SCI population. Furthermore, clinical management of any one blood pressure disorder may adversely impact others, as such treatment is complicated and not often prioritized.

A systematic review of cardiovascular risk factors in patients with traumatic spinal cord injury

Objective: The main risk factors for cardiac events, and particularly for the development of atherosclerosis, are diabetes mellitus, arterial hypertension, dyslipidemia and smoking. Patients with a traumatic spinal cord injury (SCI) may present with autonomic nervous system dysfunction depending on their level of spinal cord injury. Studies have found a rise in cardiovascular mortality. A systematic review was conducted that focused on this patient group's predisposition to vascular risk. Methods: We performed a PubMed and Cochrane database search. After applying specific search criteria, 42 articles were included in our analysis out of a total of 10,784 matches. The articles were selected with the aim of establishing cardiovascular risk factors in patients with traumatic spinal cord injury. Results: Patients with SCI are at an increased risk for peripheral artery disease even in the absence of cardiovascular risk factors. Major vascular changes to the arteries of patients with SCI include: a reduction in lumen size, increased vessel wall tension, higher vascular stiffness, an impaired reactive hyperemic response, and a lack of reduced vascular resistance. The findings for carotid atherosclerosis were inconclusive. This group of patients also has a higher disposition for diabetes mellitus, lipid metabolism disorders and coronary artery disease. Paraplegics are more likely to suffer from dyslipidemia, obesity and PAD, while tetraplegics are more likely to have diabetes mellitus. Conclusions: Patients with SCI are more likely to have cardiovascular risk factors and have cardiovascular disease compared to the normal population. Peripheral circulatory disorders are particularly common. Patients with SCI are now considered to be a new risk group for cardiovascular disease; however, large epidemiological studies are needed to verify in more detail the cardiovascular risk profile of this patient group.

Selective Myostatin Inhibition Spares Sublesional Muscle Mass and Myopenia-Related Dysfunction after Severe Spinal Cord Contusion in Mice

Clinically relevant myopenia accompanies spinal cord injury (SCI), and compromises function, metabolism, body composition, and health. Myostatin, a transforming growth factor (TGF)β family member, is a key negative regulator of skeletal muscle mass. We investigated inhibition of myostatin signaling using systemic delivery of a highly selective monoclonal antibody - muSRK-015P (40 mg/kg) - that blocks release of active growth factor from the latent form of myostatin. Adult female mice (C57BL/6) were subjected to a severe SCI (65 kdyn) at T9 and were then immediately and 1 week later administered test articles: muSRK-015P (40 mg/kg) or control (vehicle or IgG). A sham control group (laminectomy only) was included. At euthanasia, (2 weeks post-SCI) muSRK-015P preserved whole body lean mass and sublesional gastrocnemius and soleus mass. muSRK-015P-treated mice with SCI also had significantly attenuated myofiber atrophy, lipid infiltration, and loss of slow-oxidative phenotype in soleus muscle. These outcomes were accompanied by significantly improved sublesional motor function and muscle force production at 1 and 2 weeks post-SCI. At 2 weeks post-SCI, lean mass was significantly decreased in SCI-IgG mice, but was not different in SCI-muSRK-015P mice than in sham controls. Total energy expenditure (kCal/day) at 2 weeks post-SCI was lower in SCI-immunoglobulin (Ig)G mice, but not different in SCI-muSRK-015P mice than in sham controls. We conclude that in a randomized, blinded, and controlled study in mice, myostatin inhibition using muSRK-015P had broad effects on physical, metabolic, and functional outcomes when compared with IgG control treated SCI animals. These findings may identify a useful, targeted therapeutic strategy for treating post-SCI myopenia and related sequelae in humans.

Genomic and Epigenomic Evaluation of Electrically Induced Exercise in People With Spinal Cord Injury: Application to Precision Rehabilitation

OBJECTIVE

Physical therapists develop patient-centered exercise prescriptions to help overcome the physical, emotional, psychosocial, and environmental stressors that undermine a person's health. Optimally prescribing muscle activity for people with disability, such as a spinal cord injury, is challenging because of their loss of volitional movement control and the deterioration of their underlying skeletal systems. This report summarizes spinal cord injury-specific factors that should be considered in patient-centered, precision prescription of muscle activity for people with spinal cord injury. This report also presents a muscle genomic and epigenomic analysis to examine the regulation of the proliferator-activated receptor γ coactivator 1α (PGC-1α) (oxidative) and myostatin (hypertrophy) signaling pathways in skeletal muscle during low-frequency (lower-force) electrically induced exercise versus higher-frequency (higher-force) electrically induced exercise under constant muscle recruitment (intensity).

METHODS

Seventeen people with spinal cord injury participated in 1 or more unilateral electrically induced exercise sessions using a lower-force (1-, 3-, or 5-Hz) or higher-force (20-Hz) protocol. Three hours after the exercise session, percutaneous muscle biopsies were performed on exercised and nonexercised muscles for genomic and epigenomic analysis.

RESULTS

We found that low-frequency (low-force) electrically induced exercise significantly increased the expression of PGC-1α and decreased the expression of myostatin, consistent with the expression changes observed with high-frequency (higher-force) electrically induced exercise. Further, we found that low-frequency (lower-force) electrically induced exercise significantly demethylated, or epigenetically promoted, the PGC-1α signaling pathway. A global epigenetic analysis showed that >70 pathways were regulated with low-frequency (lower-force) electrically induced exercise.

CONCLUSION

These novel results support the notion that low-frequency (low-force) electrically induced exercise may offer a more precise rehabilitation strategy for people with chronic paralysis and severe osteoporosis. Future clinical trials are warranted to explore whether low-frequency (lower-force) electrically induced exercise training affects the overall health of people with chronic spinal cord injury.

Cardiovascular and metabolic morbidity following spinal cord injury

BACKGROUND CONTEXT

Individuals living with a spinal cord injury (SCI) are at heightened risk for a number of chronic health conditions such as secondary comorbidities that may develop or be influenced by the injury, the presence of impairment, and/or the process of aging.

PURPOSE

The objective of this study was to compare the incidence of and adjusted hazards for cardiovascular and metabolic (cardiometabolic) morbidities among adults following SCI compared to adults without SCIs.

STUDY DESIGN/SETTING

Longitudinal cohort from a nationwide insurance claims database.

PATIENT SAMPLE

Privately-insured beneficiaries were included if they had an ICD-9-CM diagnostic code for traumatic SCI (n=9,081). Adults without SCI were also included (n=1,474,232).

OUTCOME MEASURES AND METHODS

Incidence estimates of common cardiometabolic morbidities were compared at 4-years of enrollment. Survival models were used to quantify unadjusted and adjusted hazard ratios for incident cardiometabolic morbidities.

RESULTS

Adults living with traumatic SCIs had a higher 5-year incidence of any cardiometabolic morbidities (56.2% vs. 36.4%) as compared to adults without SCI, and differences were to a clinically meaningful extent. Survival models demonstrated that adults with SCI had a greater hazard for any cardiometabolic morbidity (Hazard Ratio [HR]: 1.67; 95%CI: 1.58, 1.76) and all cardiometabolic disorders; this ranged from HR: 1.45 (1.32, 1.59) for non-alcoholic fatty liver disease to HR: 3.55 (3.36, 3.76) for heart failure.

CONCLUSIONS

Adults with SCIs have a significantly higher incidence of and risk for common cardiometabolic morbidities, as compared to adults without SCIs. Efforts are needed to facilitate the development of improved clinical screening algorithms and early interventions to reduce risk of cardiometabolic disease onset/progression in this vulnerable population.

Body Composition According to Spinal Cord Injury Level: A Systematic Review and Meta-Analysis

The level of injury is linked with biochemical alterations and limitations in physical activity among individuals with spinal cord injury (SCI), which are crucial determinants of body composition. We searched five electronic databases from inception until 22 July 2021. The pooled effect estimates were computed using random-effects models, and heterogeneity was calculated using I² statistics and the chi-squared test. Study quality was assessed using the Newcastle–Ottawa Scale. We pooled 40 studies comprising 4872 individuals with SCI (3991 males, 825 females, and 56 sex-unknown) in addition to chronic SCI (median injury duration 12.3 y, IQR 8.03–14.8). Individuals with tetraplegia had a higher fat percentage (weighted mean difference (WMD) 1.9%, 95% CI 0.6, 3.1) and lower lean mass (WMD −3.0 kg, 95% CI −5.9, −0.2) compared to those with paraplegia. Those with tetraplegia also had higher indicators of central adiposity (WMD, visceral adipose tissue area 0.24 dm² 95% CI 0.05, 0.43 and volume 1.05 L 95% CI 0.14, 1.95), whereas body mass index was lower in individuals with tetraplegia than paraplegia (WMD −0.9 kg/mg², 95% CI −1.4, −0.5). Sex, age, and injury characteristics were observed to be sources of heterogeneity. Thus, individuals with tetraplegia have higher fat composition compared to paraplegia. Anthropometric measures, such as body mass index, may be inaccurate in describing adiposity in SCI individuals.

Virtual Strategies for the Broad Delivery of High Intensity Exercise in Persons With Spinal Cord Injury: Ongoing Studies and Considerations for Implementation

Spinal cord injury (SCI) results in a multitude of metabolic co-morbidities that can be managed by exercise. As in the non-injured population, manipulation of exercise intensity likely allows for fruitful optimization of exercise interventions targeting metabolic health in persons with SCI. In this population, interventions employing circuit resistance training (CRT) exhibit significant improvements in outcomes including cardiorespiratory fitness, muscular strength, and blood lipids, and recent exploration of high intensity interval training (HIIT) suggests the potential of this strategy to enhance health and fitness. However, the neurological consequences of SCI result in safety considerations and constrain exercise approaches, resulting in the need for specialized exercise practitioners. Furthermore, transportation challenges, inaccessibility of exercise facilities, and other barriers limit the translation of high intensity "real world" exercise strategies. Delivering exercise via online ("virtual") platforms overcomes certain access barriers while allowing for broad distribution of high intensity exercise despite the limited number of population-specific exercise specialists. In this review, we initially discuss the need for "real world" high intensity exercise strategies in persons with SCI. We then consider the advantages and logistics of using virtual platforms to broadly deliver high intensity exercise in this population. Safety and risk mitigation are considered first followed by identifying strategies and technologies for delivery and monitoring of virtual high intensity exercise. Throughout the review, we discuss approaches from previous and ongoing trials and conclude by giving considerations for future efforts in this area.

Traumatic Spinal Cord Injury and Risk of Early and Late Onset Alzheimer's Disease and Related Dementia: Large Longitudinal Study

OBJECTIVE

Traumatic spinal cord injury (TSCI) is a life altering event most often causing permanent physical disability. Little is known about the risk of developing Alzheimer disease and related dementia (ADRD) among middle-aged and older adults living with TSCI. Time to diagnosis of and adjusted hazard for ADRD was assessed.

DESIGN

Cohort study.

SETTING

Using 2007-2017 claims data from the Optum Clinformatics Data Mart, we identified adults (45+) with diagnosis of TSCI (n=7019). Adults without TSCI diagnosis were included as comparators (n=916,516). Using age, sex, race/ethnicity, cardiometabolic, psychological, and musculoskeletal chronic conditions, US Census division, and socioeconomic variables, we propensity score matched persons with and without TSCI (n=6083). Incidence estimates of ADRD were compared at 4 years of enrollment. Survival models were used to quantify unadjusted, fully adjusted, and propensity-matched unadjusted and adjusted hazard ratios (HRs) for incident ADRD.

PARTICIPANTS

Adults with and without TSCI (N=6083).

INTERVENTION

Not applicable.

MAIN OUTCOMES MEASURES

Diagnosis of ADRD.

RESULTS

Both middle-aged and older adults with TSCI had higher incident ADRD compared to those without TSCI (0.5% vs 0.2% and 11.7% vs 3.3% among 45-64 and 65+ y old unmatched cohorts, respectively) (0.5% vs 0.3% and 10.6% vs 6.2% among 45-64 and 65+ y old matched cohorts, respectively). Fully adjusted survival models indicated that adults with TSCI had a greater hazard for ADRD (among 45-64y old: unmatched HR: 3.19 [95% confidence interval, 95% CI, 2.30-4.44], matched HR: 1.93 [95% CI, 1.06-3.51]; among 65+ years old: unmatched HR: 1.90 [95% CI, 1.77-2.04], matched HR: 1.77 [1.55-2.02]).

CONCLUSIONS

Adults with TSCI are at a heightened risk for ADRD. Improved clinical screening and early interventions aiming to preserve cognitive function are of paramount importance for this patient cohort.

Meeting Proceedings for SCI 2020: Launching a Decade of Disruption in Spinal Cord Injury Research

The spinal cord injury (SCI) research community has experienced great advances in discovery research, technology development, and promising clinical interventions in the past decade. To build upon these advances and maximize the benefit to persons with SCI, the National Institutes of Health (NIH) hosted a conference February 12-13, 2019 titled "SCI 2020: Launching a Decade of Disruption in Spinal Cord Injury Research." The purpose of the conference was to bring together a broad range of stakeholders, including researchers, clinicians and healthcare professionals, persons with SCI, industry partners, regulators, and funding agency representatives to break down existing communication silos. Invited speakers were asked to summarize the state of the science, assess areas of technological and community readiness, and build collaborations that could change the trajectory of research and clinical options for people with SCI. In this report, we summarize the state of the science in each of five key domains and identify the gaps in the scientific literature that need to be addressed to move the field forward.

A systematic review of the effect of dietary interventions on cardiovascular disease risk in adults with spinal cord injury

CONTEXT

Cardiovascular disease is one of the leading causes of mortality in individuals with spinal cord injury (SCI), highlighting the need for targeted risk minimization interventions.

OBJECTIVE

To determine the effect of dietary interventions on CVD risk in adults with SCI.

METHODS

A systematic literature review of studies investigating the impact of dietary intervention on CVD risk in SCI individuals was conducted according to the PRISMA statement. CASP checklists were used for critical appraisal, Academy of Nutrition and Dietetics Quality criteria checklist (QCC) for determining risk of bias and the GRADE approach to ascertain the quality of evidence of the outcomes. The results were reported descriptively.

RESULTS

A total of eight studies were included from the identified 862 articles. Dietary intervention strategies varied across all studies, as did the outcome measures. Adult learning theories were not considered. The lack of controlled trials (two only) meant that while some interventions proved useful, risk of bias was high. Outcome measures were assessed as low to very low quality again identifying that this area is highly under-researched.

CONCLUSION

Despite documented evidence of the benefits of diet on CVD risk reduction, this review has identified a dearth of research in SCI. Nonetheless, the review emphasizes the potential of diet in conjunction with exercise in minimizing CVD risk in SCI. Further good quality research backed by robust data collection, simple, actionable strategies and knowledge translation techniques are essential to ascertain the effects of dietary intervention in lowering CVD risk in SCI.

Cardiometabolic risks and atherosclerotic disease in ApoE knockout mice: Effect of spinal cord injury and Salsalate anti-inflammatory pharmacotherapy

OBJECTIVE

To test in mice with a double mutation of the ApoE gene (ApoE-/-) whether spinal cord injury (SCI) hastens the native trajectory of, and established component risks for, atherosclerotic disease (AD), and whether Salsalate anti-inflammatory pharmacotherapy attenuates the impact of SCI.

METHODS

ApoE-/- mice were anesthetized and underwent a T9 laminectomy. Exposed spinal cords were given a contusion injury (70 k-dynes). Sham animals underwent all surgical procedures, excluding injury. Injured animals were randomized to 2 groups: SCI or SCI+Salsalate [120 mg/Kg/day i.p.]. Mice were serially sacrificed at 20-, 24-, and 28-weeks post-SCI, and body mass was recorded. At sacrifice, heart and aorta were harvested intact, fixed in 10% buffered formalin, cleaned and cut longitudinally for en face preparation. The aortic tree was stained with oil-red-O (ORO). AD lesion histomorphometry was calculated from the proportional area of ORO. Plasma total cholesterol, triglycerides and proatherogenic inflammatory cytokines (PAIC's) were analyzed.

RESULTS

AD lesion in the aortic arch progressively increased in ApoE-/-, significant at 24- and 28-weeks. AD in SCI is significantly greater at 24- and 28-weeks compared to time-controlled ApoE-/-. Salsalate treatment attenuates the SCI-induced increase at these time points. Body mass in all SCI groups are significantly reduced compared to time-controlled ApoE-/-. Cholesterol and triglycerides are significantly higher with SCI by 24- and 28-weeks, compared to ApoE-/-, and Salsalate reduces the SCI-induced effect on cholesterol. PAIC's interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1), and chemokine (C-C motif) ligand 5 (CCL-5) are significantly greater with SCI compared to ApoE-/- at varying timepoints. Salsalate confers a marginal reducing effect on PAIC's by 28-weeks compared to SCI. Regression models determine that each PAIC is a significant and positive predictor of lesion. (p's <0.05).

CONCLUSIONS

SCI accelerates aortic AD and associated risk factors, and anti-inflammatory treatment may attenuate the impact of SCI on AD outcomes. PAIC's IL-1β, IL-6, TNFα, MCP-1, and CCL-5 may be effective predictors of AD.

Cardiac, Autonomic, and Cardiometabolic Impact of Exercise Training in Spinal Cord Injury: A QUALITATIVE REVIEW

INTRODUCTION

Direct and indirect effects of spinal cord injury lead to important cardiovascular (CV) complications that are further increased by years of injury and the process of "accelerated aging." The present review examines the current evidence in the literature for the potential cardioprotective effect of exercise training in spinal cord injury.

REVIEW METHODS

PubMed and Web of Science databases were screened for original studies investigating the effect of exercise-based interventions on aerobic capacity, cardiac structure/function, autonomic function, CV function, and/or cardiometabolic markers. We compared the effects in individuals <40 yr with time since injury <10 yr with those in older individuals (≥40 yr) with longer time since injury (≥10 yr), reasoning that the two can be considered individuals with low versus high CV risk factors.

SUMMARY

Studies showed similar exercise effects in both groups (n = 31 in low CV risk factors vs n = 15 in high CV risk factors). The evidence does not support any effect of exercise training on autonomic function but does support an increased peripheral blood flow, improved left ventricular mass, higher peak cardiac output, greater lean body mass, better antioxidant capacity, and improved endothelial function. In addition, some evidence suggests that it can result in lower blood lipids, systemic inflammation (interleukin-6, tumor necrosis factor α, and C-reactive protein), and arterial stiffness. Training intensity, volume, and frequency were key factors determining CV gains. Future studies with larger sample sizes, well-matched groups of subjects, and randomized controlled designs will be needed to determine whether high-intensity hybrid forms of training result in greater CV gains.

The neurological level of spinal cord injury and cardiovascular risk factors: a systematic review and meta-analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To determine the difference in cardiovascular risk factors (blood pressure, lipid profile, and markers of glucose metabolism and inflammation) according to the neurological level of spinal cord injury (SCI).

METHODS

We searched 5 electronic databases from inception until July 4, 2020. Data were extracted by two independent reviewers using a pre-defined data collection form. The pooled effect estimate was computed using random-effects models, and heterogeneity was calculated using I² statistic and chi-squared test (CRD42020166162).

RESULTS

We screened 4863 abstracts, of which 47 studies with 3878 participants (3280 males, 526 females, 72 sex unknown) were included in the meta-analysis. Compared to paraplegia, individuals with tetraplegia had lower systolic and diastolic blood pressure (unadjusted weighted mean difference, -14.5 mmHg, 95% CI -19.2, -9.9; -7.0 mmHg 95% CI -9.2, -4.8, respectively), lower triglycerides (-10.9 mg/dL, 95% CI -19.7, -2.1), total cholesterol (-9.9 mg/dL, 95% CI -14.5, -5.4), high-density lipoprotein (-1.7 mg/dL, 95% CI -3.3, -0.2) and low-density lipoprotein (-5.8 mg/dL, 95% CI -9.0, -2.5). Comparing individuals with high- vs. low-thoracic SCI, persons with higher injury had lower systolic and diastolic blood pressure (-10.3 mmHg, 95% CI -13.4, -7.1; -5.3 mmHg 95% CI -7.5, -3.2, respectively), while no differences were found for low-density lipoprotein, serum glucose, insulin, and inflammation markers. High heterogeneity was partially explained by age, prevalent cardiovascular diseases and medication use, body mass index, sample size, and quality of studies.

CONCLUSION

In SCI individuals, the level of injury may be an additional non-modifiable cardiovascular risk factor. Future well-designed longitudinal studies with sufficient follow-up and providing sex-stratified analyses should confirm our findings and explore the role of SCI level in cardiovascular health and overall prognosis and survival.

Barriers and Facilitators to Lifestyle Intervention Engagement and Weight Loss in People Living With Spinal Cord Injury

Background: Individuals living with spinal cord injury (SCI) have a high prevalence of obesity and unique barriers to healthy lifestyle. Objective: To examine barriers and facilitators to engagement and weight loss among SCI participants enrolled in the Group Lifestyle Balance Adapted for individuals with Impaired Mobility (GLB-AIM), a 12-month intensive lifestyle intervention. Methods: SCI participants (N = 31) enrolled in a wait-list, randomized controlled trial where all participants received intervention between August 2015 and February 2017. Analyses of pooled data occurred in 2020 to examine cross-sectional and prospective associations of hypothesized barriers and facilitators with (1) intervention engagement, comprised of attendance and self-monitoring, and (2) percent weight change from baseline to 12 months. We performed multivariable linear regression on variables associated with outcomes at p < .05 in bivariate analyses and controlled for intervention group. Results: Participants were middle-aged (mean age, 48.26 ± 11.01 years), equally male (50%) and female, White (80.7%), and unemployed (65.6%). In participants who completed baseline surveys (n = 30), dietary self-efficacy explained 26% of variance in engagement (p < .01); among the 12-month study completers (n = 22, 71.0%), relationship issues explained 23% of variance in engagement (p < .01). Money problems, health issues unrelated to SCI, lack of motivation, and experimental group explained 57% of variance in weight loss (p for model < .01), with lack of motivation uniquely explaining 24% of variance (p < .01). Conclusion: Improving engagement and weight loss for persons with SCI in the GLBAIM program may be achieved by addressing lack of motivation, relationship issues, and nutrition self-efficacy.

Comparison of the 6-Min Propulsion and Arm Crank Ergometer Tests to Assess Aerobic Fitness in Manual Wheelchair Users With a Spinal Cord Injury

OBJECTIVE

The 6-Min Manual Wheelchair Propulsion Test is proposed to easily and rapidly assess aerobic fitness among long-term (≥3 mos) manual wheelchair users with spinal cord injury. However, aerobic responses to this test have not been established. This study aimed (1) to characterize aerobic responses during the 6-Min Manual Wheelchair Propulsion Test, (2) to establish parallel reliability between the 6-Min Manual Wheelchair Propulsion Test and the Maximal Arm Crank Ergometer Test, and (3) to quantify the strength of association between the total distance traveled during the 6-Min Manual Wheelchair Propulsion Test and peak oxygen consumption.

DESIGN

Twenty manual wheelchair users with a spinal cord injury completed both tests. Aerobic parameters were measured before, during, and after the tests. Main outcome measures were peak oxygen consumption and total distance traveled.

RESULTS

Progressive cardiorespiratory responses, consistent with guidelines for exercise testing, were observed during both tests. Similar peak oxygen consumption values were obtained during both tests (6-Min Manual Wheelchair Propulsion Test: 20.2 ± 4.9 ml/kg·min; Maximal Arm Crank Ergometer Test: 20.4 ± 5.0 ml/kg·min), were highly correlated (r = 0.92, P < 0.001), and had a good agreement (mean absolute difference = 0.21, 95% confidence interval = -0.70 to 1.11, P = 0.639). The peak oxygen consumption and total distance traveled (mean = 636.6 ± 56.9 m) during the 6-Min Manual Wheelchair Propulsion Test were highly correlated (r = 0.74, P < 0.001).

CONCLUSIONS

The 6-Min Manual Wheelchair Propulsion Test induces progressive aerobic responses consistent with guidelines for exercise testing and can be used to efficiently estimate aerobic fitness in manual wheelchair users with a spinal cord injury.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Explain how to administer the Six-Minute Manual Wheelchair Propulsion Test in long-term manual wheelchair users with a spinal cord injury; (2) Contrast how the workload is developed between the Six-Minute Manual Wheelchair Propulsion Test and the Maximal Arm Crank Ergometry Test and recognize how these differences may affect physiological responses; and (3) Explain why caution is advised regarding the use of the Six-Minute Manual Wheelchair Propulsion Test if aiming to estimate aerobic fitness.

LEVEL

Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

A Western diet impairs CNS energy homeostasis and recovery after spinal cord injury: Link to astrocyte metabolism

A diet high in fat and sucrose (HFHS), the so-called Western diet promotes metabolic syndrome, a significant co-morbidity for individuals with spinal cord injury (SCI). Here we demonstrate that the spinal cord of mice consuming HFHS expresses reduced insulin-like growth factor 1 (IGF-1) and its receptor and shows impaired tricarboxylic acid cycle function, reductions in PLP and increases in astrogliosis, all prior to SCI. After SCI, Western diet impaired sensorimotor and bladder recovery, increased microgliosis, exacerbated oligodendrocyte loss and reduced axon sprouting. Direct and indirect neural injury mechanisms are suggested since HFHS culture conditions drove parallel injury responses directly and indirectly after culture with conditioned media from HFHS-treated astrocytes. In each case, injury mechanisms included reductions in IGF-1R, SIRT1 and PGC-1α and were prevented by metformin. Results highlight the potential for a Western diet to evoke signs of neural insulin resistance and injury and metformin as a strategy to improve mechanisms of neural neuroprotection and repair.

A Provider's Guide to Vascular Disease, Dyslipidemia, and Glycemic Dysregulation in Chronic Spinal Cord Injury

Individuals with chronic spinal cord injury (SCI) are predisposed to accelerated atherogenesis, dyslipidemia, and glycemic dysregulation, although not enough is known about the etiologies or clinical consequences of these secondary effects of paralysis. While guidelines for the detection and treatment of cardiometabolic disease in SCI have recently been published, there has been a historical paucity of data-driven approaches to these conditions. This article will describe what is and not known about the cardiovascular disease and glycemic dysregulation that frequently attend SCI. It will conclude with a review of both guideline-driven and informal recommendations addressing the clinical care of people living with SCI.

Impact of short- and long-term electrically induced muscle exercise on gene signaling pathways, gene expression, and PGC1a methylation in men with spinal cord injury

Exercise attenuates the development of chronic noncommunicable diseases (NCDs). Gene signaling pathway analysis offers an opportunity to discover if electrically induced muscle exercise regulates key pathways among people living with spinal cord injury (SCI). We examined short-term and long-term durations of electrically induced skeletal muscle exercise on complex gene signaling pathways, specific gene regulation, and epigenetic tagging of PGC1a, a major transcription factor in skeletal muscle of men with SCI. After short- or long-term electrically induced exercise training, participants underwent biopsies of the trained and untrained muscles. RNA was hybridized to an exon microarray and analyzed by a gene set enrichment analysis. We discovered that long-term exercise training regulated the Reactome gene sets for metabolism (38 gene sets), cell cycle (36 gene sets), disease (27 gene sets), gene expression and transcription (22 gene sets), organelle biogenesis (4 gene sets), cellular response to stimuli (8 gene sets), immune system (8 gene sets), vesicle-mediated transport (4 gene sets), and transport of small molecules (3 gene sets). Specific gene expression included: oxidative catabolism of glucose including PDHB (P < 0.001), PDHX (P < 0.001), MPC1 (P < 0.009), and MPC2 (P < 0.007); Oxidative phosphorylation genes including SDHA (P < 0.006), SDHB (P < 0.001), NDUFB1 (P < 0.002), NDUFA2 (P < 0.001); transcription genes including PGC1α (P < 0.030) and PRKAB2 (P < 0.011); hypertrophy gene MSTN (P < 0.001); and the myokine generating FNDC5 gene (P < 0.008). Long-term electrically induced exercise demethylated the major transcription factor PGC1a. Taken together, these findings support that long-term electrically induced muscle activity regulates key pathways associated with muscle health and systemic metabolism.

Emergence of Epidural Electrical Stimulation to Facilitate Sensorimotor Network Functionality After Spinal Cord Injury

BACKGROUND

Traumatic spinal cord injury (SCI) disrupts signaling pathways between the brain and spinal networks below the level of injury. In cases of severe SCI, permanent loss of sensorimotor and autonomic function can occur. The standard of care for severe SCI uses compensation strategies to maximize independence during activities of daily living while living with chronic SCI-related dysfunctions. Over the past several years, the research field of spinal neuromodulation has generated promising results that hold potential to enable recovery of functions via epidural electrical stimulation (EES).

METHODS

This review provides a historical account of the translational research efforts that led to the emergence of EES of the spinal cord to enable intentional control of motor functions that were lost after SCI. We also highlight the major limitations associated with EES after SCI and propose future directions of spinal neuromodulation research.

RESULTS

Multiple, independent studies have demonstrated return of motor function via EES in individuals with chronic SCI. These enabled motor functions include intentional, controlled movement of previously paralyzed extremities, independent standing and stepping, and increased grip strength. In addition, improvements in cardiovascular health, respiratory function, body composition, and urologic function have been reported.

CONCLUSIONS

EES holds promise to enable functions thought to be permanently lost due to SCI. However, EES is currently restricted to scientific investigation in humans with SCI and requires further validation of factors such as safety and efficacy before clinical translation.

Cardiovascular Risk Factors Among Older Adults With Long-Term Spinal Cord Injury

BACKGROUND

Individuals with spinal cord injury (SCI) now live longer, which increases the risk of cardiovascular disease. Knowledge of cardiovascular risk factors amenable to intervention are therefore needed to support their healthy aging.

OBJECTIVE

To describe the occurrence of cardiovascular risk factors among older adults with long-term SCI and investigate the association with sociodemographics and injury characteristics.

DESIGN

Cross-sectional descriptive cohort study.

SETTING

Home settings.

PARTICIPANTS

In total, 123 individuals (71% men, injury levels C1-L5, American Spinal Injury Association Impairment Scale A-D), mean age 63 years, mean time since injury 24 years.

METHODS

Data from the Swedish Aging with Spinal Cord Injury Study (SASCIS), collected through interviews and assessments during home visits and from medical records.

MAIN OUTCOME MEASURES

Anthropometric measurements, blood pressure, fasting plasma glucose and blood lipids, and data on cardiovascular comorbidity and tobacco use.

RESULTS

One third had a previous diagnosis of hypertension, and 55% presented with a blood pressure ≥ 140/90 mm Hg at the time of assessment. Sixteen percent had a history of diabetes and in 15% fasting glucose levels were ≥ 7 mmol/L. Dyslipidemia was present in 76%, whereas 16% had prediagnosed dyslipidemia. Mean body mass index (BMI) was 27 kg/m² and mean waist circumference was 101 cm. When SCI-adjusted BMI cut-off values were used, 93% were considered overweight (BMI ≥22 kg/m² ), and 60% had a waist circumference associated with cardiometabolic risk. A total of 16% smoked regularly. The median number of cardiovascular risk factors was 3. No significant associations were found between the total number of risk factors and sociodemographics and injury characteristics.

CONCLUSIONS

The high occurrence of cardiovascular risk factors among older adults with long-term SCI can pose additional consequences to their health. Regular assessments and interventions targeting cardiovascular risk in this population are therefore warranted. Further research is needed to identify modifiable factors associated with their risk profile.

LEVEL OF EVIDENCE

III.

Effects of exercise interventions on cardiovascular health in individuals with chronic, motor complete spinal cord injury: protocol for a randomised controlled trial [Cardiovascular Health/Outcomes: Improvements Created by Exercise and education in SCI (CHOICES) Study]

INTRODUCTION

Recent studies demonstrate that cardiovascular diseases and associated complications are the leading cause of morbidity and mortality in individuals with spinal cord injury (SCI). Abnormal arterial stiffness, defined by a carotid-to-femoral pulse wave velocity (cfPWV) ≥10 m/s, is a recognised risk factor for heart disease in individuals with SCI. There is a paucity of studies assessing the efficacy of conventional training modalities on arterial stiffness and other cardiovascular outcomes in this population. Therefore, this study aims to compare the efficacy of arm cycle ergometry training (ACET) and body weight-supported treadmill training (BWSTT) on reducing arterial stiffness in individuals with chronic motor complete, high-level (above the sixth thoracic segment) SCI.

METHODS AND ANALYSIS

This is a multicentre, randomised, controlled, clinical trial. Eligible participants will be randomly assigned (1:1) into either ACET or BWSTT groups. Sixty participants with chronic (>1 year) SCI will be recruited from three sites in Canada (Vancouver, Toronto and Hamilton). Participants in each group will exercise three times per week up to 30 min and 60 min for ACET and BWSTT, respectively, over the period of 6 months. The primary outcome measure will be change in arterial stiffness (cfPWV) from baseline. Secondary outcome measures will include comprehensive assessments of: (1) cardiovascular parameters, (2) autonomic function, (3) body composition, (4) blood haematological and metabolic profiles, (5) cardiorespiratory fitness and (6) quality of life (QOL) and physical activity outcomes. Outcome measures will be assessed at baseline, 3 months, 6 months and 12 months (only QOL and physical activity outcomes). Statistical analyses will apply linear-mixed modelling to determine the training (time), group (ACET vs BWSTT) and interaction (time × group) effects on all outcomes.

ETHICS AND DISSEMINATION

Ethical approval was obtained from all three participating sites. Primary and secondary outcome data will be submitted for publication in peer-reviewed journals and widely disseminated.

TRIAL REGISTRATION NUMBER

NCT01718977; Pre-results.

TRIAL STATUS

Recruitment for this study began on January 2013 and the first participant was randomized on April 2013. Recruitment stopped on October 2018.

Guideline Approaches for Cardioendocrine Disease Surveillance and Treatment Following Spinal Cord Injury

PURPOSE OF REVIEW

Persons with spinal cord injuries (SCI) commonly experience individual risks and coalesced health hazards of the cardiometabolic syndrome (CMS). This review will examinethe role of exercise and nutritional intervention as countermeasures to these disease risks.

RECENT FINDINGS

The CMS hazards of overweight/obesity, insulin resistance, hypertension, and dyslipidemia are strongly associated with physical deconditioning and are common after SCI. Both the CMS diagnosis and physical deconditioning worsen the prognosis for all-cause cardiovascular disease occurring early after SCI. Evidence supports a therapeutic role for physical activity after SCI as an effective countermeasure to these risks and often represents the first-line approach to CMS abatement. This evidence is supported by authoritative systematic reviews and associated guidelines that recommend specific activities, frequencies, and activities of work. In many cases, the most effective exercise programming uses more intense periods of work with limited rest. As SCI is also associated with poor dietary habits, including excessive energy intake and saturated fat consumption, more comprehensive lifestyle management incorporating both exercise and nutrition represents a preferred approach for overall health management.

SUMMARY

Irrespective of the interventional strategy, improved surveillance of the population for CMS risks and encouraged incorporation of exercise and nutritional management according to recent population-specific guidelines will most likely play an important role in the preservation of activity, optimal health, and independence throughout the lifespan.

Differences in Glucose Metabolism Among Women With Spinal Cord Injury May Not Be Fully Explained by Variations in Body Composition

OBJECTIVE

To investigate the differences in glucose metabolism among women with paraplegic, and tetraplegic spinal cord injury (SCI) in comparison to their able-bodied (AB) counterparts after adjusting for differences in body composition.

DESIGN

Cross-sectional study. After an overnight fast, each participant consumed a 75-g glucose solution for oral glucose tolerance test (OGTT). Blood glucose, insulin, and C-peptide concentrations were analyzed before and 30, 60, 90, and 120 minutes after ingesting glucose solution. Insulin sensitivity index (ISI) was estimated using the Matsuda index. Percentage fat mass (%FM) and total body lean mass (TBLM) were estimated using data from dual-energy x-ray absorptiometry. Visceral fat (VF) was quantified using computed tomography. Outcome measures were compared among groups using analysis of covariance with %FM (or VF) and TBLM as covariates.

SETTING

Research university.

PARTICIPANTS

Women (N=42) with SCI (tetraplegia: n=8; paraplegia: n=14) and their race-, body mass index-, and age-matched AB counterparts (n=20).

INTERVENTIONS

Not applicable.

RESULTS

At fasting, there was no difference in glucose homeostasis (glucose, insulin, C-peptide concentrations) among 3 groups of women. In contrast, glucose, insulin, and C-peptide concentrations at minute 120 during OGTT were higher in women with tetraplegia versus women with paraplegia and AB women (P<.05, adjusted for TBLM and %FM). In addition, women with tetraplegia had lower ISI (P<.05, adjusted for TBLM and %FM) versus AB women. These differences remained after adjusting for VF and TBLM.

CONCLUSION

Our study confirms that impaired glucose metabolism among women with tetraplegia may not be fully explained by changes in their body composition. Future studies exploring additional factors involved in glucose metabolism are warranted.

Effects of ursolic acid on sub-lesional muscle pathology in a contusion model of spinal cord injury

Spinal Cord Injury (SCI) results in severe sub-lesional muscle atrophy and fiber type transformation from slow oxidative to fast glycolytic, both contributing to functional deficits and maladaptive metabolic profiles. Therapeutic countermeasures have had limited success and muscle-related pathology remains a clinical priority. mTOR signaling is known to play a critical role in skeletal muscle growth and metabolism, and signal integration of anabolic and catabolic pathways. Recent studies show that the natural compound ursolic acid (UA) enhances mTOR signaling intermediates, independently inhibiting atrophy and inducing hypertrophy. Here, we examine the effects of UA treatment on sub-lesional muscle mTOR signaling, catabolic genes, and functional deficits following severe SCI in mice. We observe that UA treatment significantly attenuates SCI induced decreases in activated forms of mTOR, and signaling intermediates PI3K, AKT, and S6K, and the upregulation of catabolic genes including FOXO1, MAFbx, MURF-1, and PSMD11. In addition, UA treatment improves SCI induced deficits in body and sub-lesional muscle mass, as well as functional outcomes related to muscle function, motor coordination, and strength. These findings provide evidence that UA treatment may be a potential therapeutic strategy to improve muscle-specific pathological consequences of SCI.

Exercise and Health-Related Risks of Physical Deconditioning After Spinal Cord Injury

A sedentary lifestyle occurring soon after spinal cord injury (SCI) may be in contrast to a preinjury history of active physical engagement and is thereafter associated with profound physical deconditioning sustained throughout the lifespan. This physical deconditioning contributes in varying degrees to lifelong medical complications, including accelerated cardiovascular disease, insulin resistance, osteopenia, and visceral obesity. Unlike persons without disability for whom exercise is readily available and easily accomplished, exercise options for persons with SCI are more limited. Depending on the level of injury, the metabolic responses to acute exercise may also be less robust than those accompanying exercise in persons without disability, the training benefits more difficult to achieve, and the risks of ill-considered exercise both greater and potentially irreversible. For exercise to ultimately promote benefit and not impose additional impairment, an understanding of exercise opportunities and risks if exercise is undertaken by those with SCI is important. The following monograph will thus address common medical challenges experienced by persons with SCI and typical modes and benefits of voluntary exercise conditioning.

Associations between lean mass and leptin in men with chronic spinal cord injury: Results from the FRASCI-muscle study

Leptin is an adipo-myokine that regulates appetite and energy expenditure by a neuroendocrine feedback loop. Leptin levels are positively correlated with BMI in the spinal cord injury population and leptin levels are greater in individuals with spinal cord injury compared to uninjured controls. Leptin is produced in multiple tissues, including fat, bone, and skeletal muscle and is a putative biomarker of sedentary behavior in older adults. We assessed body composition leptin, adiponectin, and IL-6 levels in 205 men with chronic spinal cord injury. We found no association between age, injury duration, injury level, injury completeness, or walking status and leptin. There was a significant positive association between lean mass and leptin in men with SCI that was independent of fat. Adjusting for body composition, leptin levels were positively associated with IL-6 and negatively associated with adiponectin levels. When considering men with SCI and sarcopenic obesity, only fat mass remained positively associated with leptin. We found no association between IL-6, adiponectin, or lean mass and leptin in the sarcopenic obesity group. Our findings suggest that lean mass is an under recognized, but substantial, source of circulating leptin. Furthermore, SCI-related sarcopenic obesity may result in dysregulated adipo-myokine metabolism with local and systemic physiologic effects.

Relationship Between Gonadal Function and Cardiometabolic Risk in Young Men With Chronic Spinal Cord Injury

BACKGROUND

We reported previously that young men with chronic spinal cord injury (SCI) have a greater prevalence of testosterone deficiency compared with an age-matched, healthy control population. Young men with SCI also are at increased risk for developing cardiometabolic dysfunction after injury. It is unclear whether testosterone deficiency is associated with heightened cardiometabolic risk in men with SCI.

OBJECTIVE

To investigate associations among levels of testosterone in young men with chronic SCI and surrogate markers of cardiometabolic risk.

DESIGN

Secondary cross-sectional analysis.

SETTING

Rehabilitation research centers in Washington, DC, and Miami, Florida.

PARTICIPANTS

Men (n = 58) aged 18-45 years with chronic (≥1 year), motor complete SCI without comorbidities or use of testosterone therapy.

METHODS

Plasma concentrations of testosterone, lipids, inflammatory markers (C-reactive protein and interleukin-6), percent hemoglobin A1c, glucose, and insulin were measured in a fasting state using standard assays. A 2-hour oral glucose tolerance test and Framingham Risk Score were assessed for each subject. Body composition was assessed by dual X-ray absorptiometry scan.

MAIN OUTCOME MEASUREMENTS

Surrogate markers of cardiometabolic risk among men based on the level of total testosterone (TT; ≤300, 301-500, or >500 ng/dL) and free testosterone (fT; ≤9 or >9 ng/dL). Comparisons were made between men with normal and low TT or fT.

RESULTS

Framingham Risk Score was significantly greater in men with low fT (P < .05). Percent body fat (P < .05) and waist-to-hip ratio (P < .05) but not body mass index (P > .08), were greater in men with low TT or low fT. Men with low TT or low fT had lower high-density lipoprotein cholesterol levels (P < .05) without differences in fasting triglycerides (P > .1) or low-density lipoprotein cholesterol (P > .07). Men with low TT had greater levels of inflammatory markers C-reactive protein (P < .05) and interleukin-6 (P < .05). Men with low TT or low fT had greater fasting glucose (P < .05) and greater insulin resistance (P < .04), without differences in percent hemoglobin A1c (P > .8).

CONCLUSIONS

In young men with chronic SCI who undergo an accelerated aging process postinjury, hypogonadism is associated with an unfavorable cardiometabolic risk profile. Further research is needed to determine whether a causal relationship exists between hypogonadism and heightened cardiometabolic risk in men with SCI and whether routine screening for testosterone deficiency is warranted in this population.

LEVEL OF EVIDENCE

IV.

Community-based physical activity and wheelchair mobility programs for individuals with spinal cord injury in Canada: Current reflections and future directions

RATIONALE

A clear need has been identified to find strategies and opportunities, beyond services provided during rehabilitation, to enhance community-based mobility and leisure-time physical activity (LTPA) participation among members of the spinal cord injury (SCI) population.

METHOD

This review of existing mobility and LTPA programs that are available for individuals with SCI in Canada reflects the authors' current knowledge of existing evidence-based and community-based programs. The authors aim to highlight the gaps between existing programs and future needs.

RESULTS

The major gaps identified in this brief clinical report include the need for: community-based mobility training programs, patient reported outcomes, assessment of long-term impact of programs, identifying the best approaches for program delivery, and developing researcher-stakeholder partnerships.

CONCLUSION

Evidence-based mobility programs and community-based LTPA do exist, and the available research shows their promise. Despite the growing research for LTPA and mobility programs among adults with SCI, many gaps remain. Additional partnerships, community engagement practices, service program funding and health policy changes are needed to address the highlighted gaps to optimize community-based programs and enhance the lives of adults with SCI.

Evidence-based scientific exercise guidelines for adults with spinal cord injury: an update and a new guideline

OBJECTIVES

To describe the process and outcomes of using a new evidence base to develop scientific guidelines that specify the type and minimum dose of exercise necessary to improve fitness and cardiometabolic health in adults with spinal cord injury (SCI).

SETTING

International.

METHODS

Using Appraisal of Guidelines, Research and Evaluation (AGREE) II reporting criteria, steps included (a) determining the guidelines' scope; (b) conducting a systematic review of relevant literature; (c) holding three consensus panel meetings (European, Canadian and International) to formulate the guidelines; (d) obtaining stakeholder feedback; and (e) process evaluation by an AGREE II consultant. Stakeholders were actively involved in steps (c) and (d).

RESULTS

For cardiorespiratory fitness and muscle strength benefits, adults with a SCI should engage in at least 20 min of moderate to vigorous intensity aerobic exercise 2 times per week AND 3 sets of strength exercises for each major functioning muscle group, at a moderate to vigorous intensity, 2 times per week (strong recommendation). For cardiometabolic health benefits, adults with a SCI are suggested to engage in at least 30 min of moderate to vigorous intensity aerobic exercise 3 times per week (conditional recommendation).

CONCLUSIONS

Through a systematic, rigorous, and participatory process involving international scientists and stakeholders, a new exercise guideline was formulated for cardiometabolic health benefits. A previously published SCI guideline was endorsed for achieving fitness benefits. These guidelines represent an important step toward international harmonization of exercise guidelines for adults with SCI, and a foundation for developing exercise policies and programs for people with SCI around the world.