Identification and Management of Cardiometabolic Risk after Spinal Cord Injury

Development of a Risk Score to Aid With the Diagnosis of Infections After Spinal Cord Injury: Protocol for a Retrospective Cohort Study

BACKGROUND

Patients with spinal cord injury (SCI) who develop urinary tract infection (UTI) present differently than the non-SCI population. UTIs can cause loss of quality of life and even lead to life-threatening complications including urosepsis. Challenges in SCI management include distinguishing symptomatic UTI from asymptomatic bacteriuria (ASB), which occurs often in patients with SCI, and the lack of standardization in UTI diagnosis in SCI.

OBJECTIVE

This study aims to set the foundation for the development of a risk score to improve diagnostic accuracy of UTI after SCI.

METHODS

This study will use data from the Veterans Health Administration Corporate Data Warehouse from national outpatient clinics. It will use 2 approaches: (1) a case-control study comparing frequency-matched healthy SCI cases (n=2000) with healthy non-SCI controls (n=2000) to establish a physiologic baseline for vital sign and lab measurements after SCI and (2) a retrospective cohort study of patients with SCI (n=400) to determine the positive predictive value of the baseline vital signs and lab measurements found in step 1, from which a threshold for clinically meaningful UTI after SCI will be established.

RESULTS

The study was funded in May 2023, and initial data extraction started in early 2024 and is expected to be completed in 2026. Data extraction, analysis, and results for aim 1 were completed as of manuscript submission. For aim 1, we hypothesize that SCI will be associated with lower temperature, heart rate, and systolic blood pressure when compared with non-SCI controls. SCI will also be associated with higher baseline levels of pyuria and peripheral white blood cells when compared with non-SCI controls. Data extraction for aim 2 will begin in year 1, and analysis and results will be completed in year 2. For aim 2, we hypothesize that pyuria, heart rate, and temperature measurements will have a high positive predictive value for clinically meaningful UTI.

CONCLUSIONS

Once complete, this study will be the basis for our future work developing a risk score to aid with the diagnosis of UTI after SCI and prevent antibiotic overuse in patients with SCI.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/52610.

Treatment of obesity in spinal cord injury with tirzepatide: a case report

INTRODUCTION

Individuals with spinal cord injury (SCI) experience alterations in metabolism that result in increased central obesity, insulin resistance, and dyslipidemia placing them at elevated risk for developing cardiometabolic disease (CMD). Increased exercise and dietary modifications are the primary interventions for preventing CMD. However, people with SCI face unique challenges that prevent them from increasing their physical activity and easily modifying their nutritional intake. Tirzepatide is a medication that has been approved by the Food and Drug Administration to be used in conjunction with lifestyle changes to treat obesity in adults with type 2 diabetes mellitus.

CASE PRESENTATION

A male in his 40's with C6 American Spinal Injury Association Impairment Scale B SCI 15 years prior with a body mass index of 32 presented to his primary care provider for treatment of obesity. He previously worked with multiple dietitians and increased his physical activity to lose weight. Despite these interventions, he was unable to reduce his weight. He was started on tirzepatide. After 3 months of treatment, he lost 31 pounds and saw improvements in his lipid profile. The only adverse effect reported was heartburn.

DISCUSSION

The metabolic dysfunction associated with SCI and barriers to adequate exercise for weight loss place individuals with SCI at increased risk for obesity and developing CMD. Tirzepatide may be an effective adjunct therapy to lifestyle interventions to help prevent CMD in those with SCI. Further research is indicated to examine the long-term efficacy, benefits, and adverse effects that may be associated with tirzepatide.

"I think it was helpful but not as helpful as it could have been" - a qualitative study of the experiences and perspectives of using fitness apps among manual wheelchair users with spinal cord injury

PURPOSE

To gain knowledge of the experiences and perceptions of using fitness apps by full-time wheelchair users with spinal cord injury (SCI) and to explore experiences and perceptions of using these apps in relation to barriers to and facilitators of physical activity (PA).

MATERIALS AND METHODS

A qualitative design was employed. Semi-structured interviews were conducted with ten manual wheelchair users with SCI. Data were analysed using reflexive thematic analysis.

RESULTS

Four themes were developed: 1) App functionality and experience, 2) Enhancing motivation, 3) Precursors to engagement and 4) Knowledge gaps. Experience and perception were strongly influenced by app design, particularly the presence or absence of features tailored for wheelchair users. Many apps incorporated the use wearable or mountable sensors. Fitness apps were perceived to increase motivation, although, this had its limitations. Conversely, apps were reported to have limited influence on commonly reported barriers to PA. Furthermore, the data highlighted gaps in knowledge which created barriers to effective app use.

CONCLUSIONS

Fitness apps were perceived to increase motivation to engage in PA in manual wheelchair users with SCI. However, more needs to be done to further develop app features for wheelchair users with SCI and to address remaining barriers to engagement.

Peak V̇O2 during handcycling in spinal cord injured athletes: incremental versus verification testing

The present study aimed to compare peak oxygen uptake (V̇O2peak), peak heart rate (HRpeak), and peak O2pulse during an incremental and a verification test performed on the same day in hand-cyclists with spinal cord injury (SCI). Eight competitive SCI hand-cyclists (age: 23 ± 2.7 years; V̇O2peak: 36.3 ± 14.0 mL.kg-1.min-1) performed a maximal incremental handcycling test and a verification test to exhaustion at 100% of the peak speed on an oversized treadmill. The V̇O2peak, HRpeak, and peak O2pulse (i.e., VO2/HR) were compared between incremental and verification tests. Absolute and relative V̇O2peak obtained in the verification test (2.51 ± 0.96 L.min-1; 36.3 ± 14.0 mL.kg.min-1) were significantly higher than values obtained in the incremental test (2.24 ± 0.79 L.min-1; 33.5 ± 12.9 mL.kg.min-1; P < 0.05). The mean differences (95% CL) of absolute and relative V̇O2peak between tests were 8.2% (3.3%-13.2%) and 10.9% (4.3%-18.1%), respectively. There was no difference in HR peak (incremental: 169 ± 24 bpm; verification 167 ± 25 bpm; P = 0.130). Peak O2pulse from the verification test (14.6 ± 4.7 mL.beat-1) was higher than incremental test (13.0 ± 3.8 mL.beat-1; P = 0.007). In conclusion, the verification test elicited greater V̇O2peak and O2pulse than a two-phase incremental test despite the similar HRpeak. This indicates that for this progressive protocol lasting ≥25 min, the verification phase adds value to determining V̇O2peak in SCI athletes.

The role of astrocytes response triggered by hyperglycaemia during spinal cord injury

OBJECTIVE

This manuscript aimed to provide a comprehensive overview of the physiological, molecular, and cellular mechanisms triggered by reactive astrocytes (RA) in the context of spinal cord injury (SCI), with a particular focus on cases involving hyperglycaemia.

METHODS

The compilation of articles related to astrocyte responses in neuropathological conditions, with a specific emphasis on those related to SCI and hyperglycaemia, was conducted by searching through databases including Science Direct, Web of Science, and PubMed.

RESULTS AND CONCLUSIONS

This article explores the dual role of astrocytes in both neurophysiological and neurodegenerative conditions within the central nervous system (CNS). In the aftermath of SCI and hyperglycaemia, astrocytes undergo a transformation into RA, adopting a distinct phenotype. While there are currently no approved therapies for SCI, various therapeutic strategies have been proposed to alleviate the detrimental effects of RAs following SCI and hyperglycemia. These strategies show promising potential in the treatment of SCI and its likely comorbidities.

Health consequences associated with poor diet and nutrition in persons with spinal cord injuries and disorders

PURPOSE

To describe health consequences associated with poor diet in persons with spinal cord injuries and disorders (SCI/D).

MATERIALS/METHODS

Descriptive qualitative design using in-depth interviews with SCI/D health providers. Audio-recorded and transcribed verbatim transcripts were coded and analyzed using thematic analysis.

RESULTS

Participants (n = 12) were from 11 nationwide VA hospitals. Participants were male (75%), white (67%), 26-49 years of age, and most were dietitians (75%) and physiatrists (17%). Seven key themes identified consequences associated with poor diet in persons with SCI/D, including (1) Weight gain and body composition changes, (2) cardiometabolic conditions, (3) bowel dysfunction, (4) pressure injuries/wounds, (5) other SCI/D secondary conditions/complications (renal/kidney; immune function/susceptibility to infections; autonomic dysreflexia; bone health/osteoporosis; pain), (6) physical fatigue, and (7) poor mental health.

CONCLUSIONS

Excess weight, cardiometabolic conditions, SCI/D secondary conditions/complications (e.g., bowel dysfunction, pressure injuries), and poor mental health were identified as health consequences of inadequate nutrition. Health providers should make individuals with SCI/D aware of the risks and health consequences to incentivize healthier dietary behaviors. Efforts to identify nutrition shortcomings and to develop interventions and tailored care plans are needed to improve a myriad of health consequences due to poor diet and nutrition in persons with SCI/D.

Potential barriers to the use of anti-obesity medications in persons with spinal cord injuries and disorders

Background

Anti-obesity medications (AOMs) may provide a viable option for obesity management. However, little is known about the use of AOMs in persons with SCI/D.

Objective

Describe health care providers' (HCPs) views about barriers to AOM use in persons living with SCI/D.

Methods

Descriptive qualitative design using in-depth interviews Descriptive statistics were used to calculate demographic and employment characteristics. Interviews were audio-recorded and transcribed verbatim. Transcripts were coded and analyzed using Braun and Clarke's (2006) six thematic analysis phases.

Results

HCPs (n = 12) were from 11 different nationwide facilities. Most HCPs were male (75%), a large majority were white (67%), and most were 26-49 years of age. Participants were dietitians (75%), physicians (17%), and psychologists (8%). HCPs ranged from 1.5 to 15 years of providing SCI/D care. HCPs described four main thematic barriers to AOM use in persons with SCI/D: (1) AOM side effects that are especially concerning in persons with SCI/D; (2) AOMs contribute to poor eating habits; (3) availability, accessibility, and administration; and (4) lack of evidence, clinical agreement, and knowledge about AOM use in the SCI/D population.

Conclusions

There are several potential barriers to AOM use in the SCI/D population. Barriers include AOM side effects which may cause or exacerbate conditions that are already concerns in persons with SCI/D, such as bowel and skin problems, and muscle loss. SCI/D HCPs reported a lack of evidence about AOM use in persons with SCI/D, but interest in obtaining more knowledge.

Correlates of metabolic syndrome in people with chronic spinal cord injury

PURPOSE

We aimed at identifying clinical risk factors or early markers of metabolic syndrome (MetS) in people with spinal cord injury (SCI) that would facilitate a timely diagnosis and implementation of preventive/therapeutic strategies.

METHODS

One hundred sixty-eight individuals with chronic (> 1 year) SCI underwent clinical and biochemical evaluations. MetS was diagnosed according to modified criteria of the International Diabetes Federation validated in people with SCI. Wilcoxon rank-sum test and χ2 test were used to compare variables between groups with and without MetS. Multiple logistic regression analysis was performed to reveal independent associations with MetS among variables selected by univariate linear regression analyses.

RESULTS

MetS was diagnosed in 56 of 132 men (42.4%) and 17 of 36 women (47.2%). At univariate regression analyses, putative predictors of MetS were an older age, a higher number of comorbidities, a lower insulin-sensitivity, the presence and intensity of pain, a shorter injury duration, a poorer leisure time physical activity (LTPA) and an incomplete motor injury. At the multiple logistic regression analysis, a significant independent association with MetS only persisted for a poorer LTPA in hours/week (OR: 0.880, 95% CI 0.770, 0.990) and more severe pain symptoms as assessed by the numeral rating scale (OR: 1.353, 95% CI 1.085, 1.793).

CONCLUSION

In people with chronic SCI, intense pain symptoms and poor LTPA may indicate a high likelihood of MetS, regardless of age, SCI duration, motor disability degree, insulin-sensitivity and comorbidities.

Measuring Overweight and Obesity in Persons with Spinal Cord Injury: What Do Health Providers Use and What are the Challenges?

INTRODUCTION

Obesity is a significant health concern for veterans and individuals with spinal cord injury, yet screening for overweight/obesity can be challenging. This study examines how healthcare providers screen for overweight/obesity and the challenges encountered in identifying overweight/obesity in veterans and persons with spinal cord injury.

MATERIALS AND METHODS

Healthcare providers who provide care for persons with spinal cord injury completed a semi-structured interview. The interview explored their perspectives on measuring overweight/obesity in persons with spinal cord injury and the challenges they faced. Thematic analysis was used to identify themes that emerged from the interviews.

RESULTS

Twenty-five providers (88% female with an average experience of 9.6 ± 7.3 years in providing care for spinal cord injury patients) participated in the interviews. The themes described the health indicators and equipment used to assess overweight/obesity, provider concerns regarding measurement, and criteria for classifying overweight/obesity. Body weight and body mass index were the most commonly used indicators. However, concerns were raised regarding accuracy of these measures for spinal cord injury patients, as well as issues related to the accessibility, calibration, and usability of the equipment. Many providers reported using standard body mass index ranges and categories instead of those specific to spinal cord injury.

CONCLUSION

This study identified the most commonly used indicators of weight or body composition in veterans and persons with spinal cord injury and highlighted providers' concerns with these measures. Future research is needed to identify the most feasible, accurate, and appropriate health indicators that could be used in a clinical setting to identify overweight and obesity in this population.

Innervation of adipocytes is limited in mouse perivascular adipose tissue

Perivascular adipose tissue (PVAT) regulates vascular tone by releasing anticontractile factors. These anticontractile factors are driven by processes downstream of adipocyte stimulation by norepinephrine; however, whether norepinephrine originates from neural innervation or other sources is unknown. The goal of this study was to test the hypothesis that neurons innervating PVAT provide the adrenergic drive to stimulate adipocytes in aortic and mesenteric perivascular adipose tissue (aPVAT and mPVAT), and white adipose tissue (WAT). Healthy male and female mice (8-13 wk) were used in all experiments. Expression of genes associated with synaptic transmission were quantified by qPCR and adipocyte activity in response to neurotransmitters and neuron depolarization was assessed in AdipoqCre+;GCaMP5g-tdTf/WT mice. Immunostaining, tissue clearing, and transgenic reporter lines were used to assess anatomical relationships between nerves and adipocytes. Although synaptic transmission component genes are expressed in adipose tissues (aPVAT, mPVAT, and WAT), strong nerve stimulation with electrical field stimulation does not significantly trigger calcium responses in adipocytes. However, norepinephrine consistently elicits strong calcium responses in adipocytes from all adipose tissues studied. Bethanechol induces minimal adipocyte responses. Imaging neural innervation using various techniques reveals that nerve fibers primarily run alongside blood vessels and rarely branch into the adipose tissue. Although nerve fibers are associated with blood vessels in adipose tissue, they demonstrate limited anatomical and functional interactions with adjacent adipocytes, challenging the concept of classical innervation. These findings dispute the significant involvement of neural input in regulating PVAT adipocyte function and emphasize alternative mechanisms governing adrenergic-driven anticontractile functions of PVAT.NEW & NOTEWORTHY This study challenges prevailing views on neural innervation in perivascular adipose tissue (PVAT) and its role in adrenergic-driven anticontractile effects on vasculature. Contrary to existing paradigms, limited anatomical and functional connections were found between PVAT nerve fibers and adipocytes, underscoring the importance of exploring alternative mechanistic pathways. Understanding the mechanisms involved in PVAT's anticontractile effects is critical for developing potential therapeutic interventions against dysregulated vascular tone, hypertension, and cardiovascular disease.

Validation of basal metabolic rate equations in persons with innervated and denervated chronic spinal cord injury

Basal metabolic rate (BMR) measurement is time consuming and requires specialized equipment. Prediction equations allow clinicians and researchers to estimate BMR; however, their accuracy may vary across individuals with chronic spinal cord injury (SCI). The objective of this study was to investigate the validity of SCI-specific equations as well as able-bodied (AB) prediction equations in individuals with upper motor neuron (UMN), lower motor neuron (LMN), and females with SCI. Twenty-six men and women with chronic SCI (n = 12 innervated males, n = 6 innervated females, n = 8 denervated males) participated in this cross-sectional study. BMR values were measured by indirect calorimetry. Body composition (dual-energy X-ray absorptiometry and anthropometrics) assessment was conducted. AB-prediction equations [Cunningham, Nelson, Owen, Harris and Benedict, Mifflin, Schofield, Henry] and SCI-specific equations [Chun and Nightingale & Gorgey] were used to estimate and validate BMR. The accuracy of AB-specific FFM equations in predicting BMR was evaluated using Bland-Altman plots, paired t-tests, and error metrics. Measured BMR for innervated males, females, and denervated males was 1436 ± 213 kcal/day, 1290 ± 114, and 1597 ± 333 kcal/day, respectively. SCI-specific equations by Chun et al., Nightingale & Gorgey, and AB-specific FFM equations accurately predicted BMR for innervated males. For the denervated males, Model 4 equation by Nightingale & Gorgey was not different (p = 0.18), and Bland-Altman analyses showed negative mean bias but similar limits of agreement between measured and predicted BMR for the SCI-specific equations and AB-specific FFM equations. We demonstrated that SCI-specific equations accurately predicted BMR for innervated males but underpredicted it for denervated males. The Model 4 equation by Nightingale & Gorgey accurately estimated BMR in females with SCI. Findings from the current study will help to determine caloric needs in different sub-groups of SCI.

The Clinical Management of Electrical Stimulation Therapies in the Rehabilitation of Individuals with Spinal Cord Injuries

Background: People with spinal cord injuries (SCIs) often have trouble remaining active because of paralysis. In the past, exercise recommendations focused on the non-paralyzed muscles in the arms, which provides limited benefits. However, recent studies show that electrical stimulation can help engage the paralyzed extremities, expanding the available muscle mass for exercise. Methods: The authors provide an evidence-based approach using expertise from diverse fields, supplemented by evidence from key studies toward the management of electrical stimulation therapies in individuals with SCIs. Literature searches were performed separately using the PubMed, Medline, and Google Scholar search engines. The keywords used for the searches included functional electrical stimulation cycling, hybrid cycling, neuromuscular electrical stimulation exercise, spinal cord injury, cardiovascular health, metabolic health, muscle strength, muscle mass, bone mass, upper limb treatment, diagnostic and prognostic use of functional electrical stimulation, tetraplegic hands, and hand deformities after SCI. The authors recently presented this information in a workshop at a major rehabilitation conference. Additional information beyond what was presented at the workshop was added for the writing of this paper. Results: Functional electrical stimulation (FES) cycling can improve aerobic fitness and reduce the risk of cardiovascular and metabolic diseases. The evidence indicates that while both FES leg cycling and neuromuscular electrical stimulation (NMES) resistance training can increase muscle strength and mass, NMES resistance training has been shown to be more effective for producing muscle hypertrophy in individual muscle groups. The response to the electrical stimulation of muscles can also help in the diagnosis and prognosis of hand dysfunction after tetraplegia. Conclusions: Electrical stimulation activities are safe and effective methods for exercise and testing for motor neuron lesions in individuals with SCIs and other paralytic or paretic conditions. They should be considered part of a comprehensive rehabilitation program in diagnosing, prognosing, and treating individuals with SCIs to improve function, physical activity, and overall health.

Patient Perceptions and Clinical Assessments of Cardiometabolic Disease After Subacute Spinal Cord Injury

OBJECTIVES

To investigate the effectiveness of health care team communication regarding cardiometabolic disease (CMD) risk factors with patients with subacute spinal cord injury (SCI).

DESIGN

Multi-site prospective cross-sectional study.

SETTING

Five National Institute on Disability, Independent Living, and Rehabilitation Research Model SCI Rehabilitation Centers.

PARTICIPANTS

Ninety-six patients with subacute SCI, aged 18-70 years, with SCI (neurologic levels of injury C2-L2, American Spinal Injury Association Impairment Scale grades A-D), and enrolled within 2 months of initial rehabilitation discharge (N=96).

INTERVENTIONS

None.

MAIN OUTCOME MEASURE(S)

Objective risk factors of CMD (body mass index, fasting glucose, insulin, high-density lipoprotein cholesterol, triglyceride levels, and resting blood pressure). Patient reported recall of these present risk factors being shared with them by their health care team. Medications prescribed to patients to address these present risk factors were checked against guideline- assessed risk factors.

RESULTS

Objective evidence of 197 CMD risk factors was identified, with patients recalling less than 12% of these (P<.0001) being shared with them by their health care team. Thirty-one individuals (32%) met criteria for a diagnosis of CMD, with only 1 of these patients (3.2%) recalling that this was shared by their health care team (P<.0001). Pharmacologic management was prescribed to address these risk factors only 7.2% of the time.

CONCLUSIONS

Despite high prevalence of CMD risk factors after acute SCI, patients routinely do not recall being told of their present risk factors. Multifaceted education and professionals' engagement efforts are needed to optimize treatment for these individuals.

Physical and emotional consequences of excess weight as experienced by individuals with spinal cord injuries

CONTEXT/OBJECTIVE

Excess weight has the potential to carry a substantial physical and emotional burden. A better understanding of perceived consequences of excess weight may facilitate the development of patient-centered programs and interventions to promote weight management efforts in persons with spinal cord injury (SCI). The study objective was to describe consequences of excess weight from the personal perspectives of individuals with SCI.

DESIGN

Descriptive qualitative design using in-depth semi-structured interviews and thematic analysis.

SETTING

Veterans Health Administration (VHA) SCI System of Care.

PARTICIPANTS

Individuals with SCI (n-33).

OUTCOME MEASURES

Key themes from thematic analysis.

RESULTS

Participants were male (61%), ranged from 29 to 84 years of age, and about half had tetraplegia (55%). Five themes were identified that demonstrate negative consequences of excess weight experienced by individuals with SCI, including: (1) physical health conditions (including chronic conditions and SCI secondary conditions), (2) physical symptoms (such as pain, discomfort, and fatigue), (3) movement challenges, (4) appearance-related concerns, and (5) emotional impacts.

CONCLUSIONS

Carrying excess weight is concerning to individuals with SCI and in terms of consequences such onset or exacerbation of chronic conditions, SCI secondary conditions, physical symptoms, e.g. pain, movement impairment (including hampered mobility, difficult transfers and self-care), image/appearance concerns (e.g. body image, clothing misfit), and negative emotions (e.g. unhappy, sad, depressed). Our findings may inform SCI healthcare providers about the consequences of excess weight as experienced by individuals with SCI, highlighting what matters most to persons with SCI and guiding a patient-centered approach to weight management in this population.

Relationship of cardiometabolic disease risk factors with age and spinal cord injury duration

CONTEXT/OBJECTIVES

Cardiometabolic disease (CMD) is increased after spinal cord injury (SCI), with an increased number of CMD risk factors that relate to higher mortality. The study objective was to characterize the relationship of age and injury duration with CMD.

DESIGN

Retrospective cohort assessment of CMD risks using unbiased recursive partitioning to divide for group comparison: (1) Lowest Risk, (2) Moderate Risk, and (3) Highest Risk based on classification and regression trees predicting CMD diagnosis by age and injury duration.

SETTING

Academic rehabilitation center laboratory.

PARTICIPANTS

Adults (N = 103; aged 18-75) with traumatic SCI (C4-L2) of 3 months to 42 years duration.

INTERVENTIONS

NA.

OUTCOME MEASURES

CMD risk factors (obesity, insulin resistance, dyslipidemia, and hypertension) using Paralyzed Veterans of America SCI-specific guidelines.

RESULTS

Obesity was prevalent (82%) and co-occurred with most other risk factors present. Age increased odds for CMD diagnosis by 1.05 per year (P = 0.02) and was directly related to elevated body mass index (BMI, β = 0.42, P < 0.05), fasting glucose (β =  0.58, P < 0.01), and higher systolic blood pressure (β = 0.31, P < 0.10). In contrast, time since injury contributed to lower risk factor count (β = -0.29, P < 0.10) and higher HDL-C (β = 0.50, P < 0.01), and was not related to odds of CMD diagnosis.

CONCLUSION

While SCI is linked to an increased risk of CMD, age is associated with higher CMD risk. Increased SCI duration related to improvement in individual CMD risk factors but did not decrease overall risk for CMD diagnosis. SCI may not uniformly increase CMD risks and highlight a necessary focus on weight management for risk prevention.

Profiling Immunological Phenotypes in Individuals During the First Year After Traumatic Spinal Cord Injury: A Longitudinal Analysis

Abstract Individuals with SCI are severely affected by immune system changes, resulting in increased risk of infections and persistent systemic inflammation. While recent data support that immunological changes after SCI differ in the acute and chronic phases of living with SCI, only limited immunological phenotyping in humans is available. To characterize dynamic molecular and cellular immune phenotypes over the first year, we assess RNA (bulk-RNA sequencing), protein, and flow cytometry (FACS) profiles of blood samples from 12 individuals with SCI at 0-3 days and at 3, 6, and 12 months post injury (MPI) compared to 23 uninjured individuals (controls). We identified 967 differentially expressed (DE) genes in individuals with SCI (FDR <0.001) compared to controls. Within the first 6 MPI we detected a reduced expression of NK cell genes, consistent with reduced frequencies of CD56bright, CD56dim NK cells present at 12 MPI. Over 6MPI, we observed increased and prolonged expression of genes associated with inflammation (e.g. HMGB1, Toll-like receptor signaling) and expanded frequencies of monocytes acutely. Canonical T-cell related DE genes (e.g. FOXP3, TCF7, CD4) were upregulated during the first 6 MPI and increased frequencies of activated T cells at 3-12 MPI. Neurological injury severity was reflected in distinct whole blood gene expression profiles at any time after SCI, verifying a persistent 'neurogenic' imprint. Overall, 2876 DE genes emerge when comparing motor complete to motor incomplete SCI (ANOVA, FDR <0.05), including those related to neutrophils, inflammation, and infection. In summary, we identify a dynamic immunological phenotype in humans, including molecular and cellular changes which may provide potential targets to reduce inflammation, improve immunity, or serve as candidate biomarkers of injury severity.

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.

Therapeutic Lifestyle Intervention Targeting Enhanced Cardiometabolic Health and Function for Persons with Chronic Spinal Cord Injury in Caregiver/Care-Receiver Co-Treatment: A Study Protocol of a Multisite Randomized Controlled Trial

BACKGROUND

Chronic spinal cord injury (SCI) significantly accelerates morbidity and mortality, partly due to the increased risk of cardiometabolic diseases (CMD), including neurogenic obesity, dyslipidemia, and impaired glucose metabolism. While exercise and dietary interventions have shown some transient benefits in reducing CMD risk, they often fail to improve clinically relevant disease markers and cardiovascular events. Moreover, SCI also places caregiving demands on their caregivers, who themselves experience health and functional decline. This underscores the need for more substantial interventions that incorporate appropriate physical activity, heart-healthy nutrition, and behavioral support tailored to the SCI population.

OBJECTIVES

This randomized clinical trial (RCT) protocol will (1) assess the health and functional effects, user acceptance, and satisfaction of a 6-month comprehensive therapeutic lifestyle intervention (TLI) adapted from the National Diabetes Prevention Program (DPP) for individuals with chronic SCI and (2) examine the impact of a complementary caregiver program on the health and function of SCI caregivers and evaluate user acceptance and satisfaction. Caregivers (linked with their partners) will be randomized to 'behavioral support' or 'control condition'.

METHODS

Dyadic couples comprise individuals with SCI (18-65 years, >1-year post-injury, ASIA Impairment Scale A-C, injury levels C5-L1) and non-disabled SCI caregivers (18-65 years). Both groups undergo lock-step circuit resistance training, a calorie-restricted Mediterranean-style diet, and 16 educational sessions focused on diet/exercise goals, self-monitoring, psychological and social challenges, cognitive behavioral therapy, and motivational interviewing. The outcome measures encompass the cardiometabolic risks, cardiorespiratory fitness, inflammatory stress, multidimensional function, pain, life quality, independence, self-efficacy, program acceptance, and life satisfaction for SCI participants. The caregiver outcomes include multidimensional function, pain, quality of life, independence, and perceived caregiver burden.

DISCUSSION/CONCLUSIONS

This study evaluates the effects and durability of a structured, multi-modal intervention on health and function. The results and intervention material will be disseminated to professionals and consumers for broader implementation.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02853149 Registered 2 August 2016.

Development of a Systems Medicine Approach to Spinal Cord Injury

Traumatic spinal cord injury (SCI) causes a sudden onset multi-system disease, permanently altering homeostasis with multiple complications. Consequences include aberrant neuronal circuits, multiple organ system dysfunctions, and chronic phenotypes such as neuropathic pain and metabolic syndrome. Reductionist approaches are used to classify SCI patients based on residual neurological function. Still, recovery varies due to interacting variables, including individual biology, comorbidities, complications, therapeutic side effects, and socioeconomic influences for which data integration methods are lacking. Infections, pressure sores, and heterotopic ossification are known recovery modifiers. However, the molecular pathobiology of the disease-modifying factors altering the neurological recovery-chronic syndrome trajectory is mainly unknown, with significant data gaps between intensive early treatment and chronic phases. Changes in organ function such as gut dysbiosis, adrenal dysregulation, fatty liver, muscle loss, and autonomic dysregulation disrupt homeostasis, generating progression-driving allostatic load. Interactions between interdependent systems produce emergent effects, such as resilience, that preclude single mechanism interpretations. Due to many interacting variables in individuals, substantiating the effects of treatments to improve neurological outcomes is difficult. Acute injury outcome predictors, including blood and cerebrospinal fluid biomarkers, neuroimaging signal changes, and autonomic system abnormalities, often do not predict chronic SCI syndrome phenotypes. In systems medicine, network analysis of bioinformatics data is used to derive molecular control modules. To better understand the evolution from acute SCI to chronic SCI multi-system states, we propose a topological phenotype framework integrating bioinformatics, physiological data, and allostatic load tested against accepted established recovery metrics. This form of correlational phenotyping may reveal critical nodal points for intervention to improve recovery trajectories. This study examines the limitations of current classifications of SCI and how these can evolve through systems medicine.

Diagnosis and Management of Cardiovascular Risk in Individuals With Spinal Cord Injury: A Narrative Review

More than 16 000 Americans experience spinal cord injury (SCI), resulting in chronic disability and other secondary sequelae, each year. Improvements in acute medical management have increased life expectancy. Cardiovascular disease is a leading cause of death in this population, and seems to occur earlier in individuals with SCI compared with the general population. People with SCI experience a high burden of traditional cardiovascular disease risk factors, including dyslipidemia and diabetes, and demonstrate anatomic, metabolic, and physiologic changes alongside stark reductions in physical activity after injury. They also experience multiple, complex barriers to care relating to disability and, in many cases, compounding effects of intersecting racial and socioeconomic health inequities. Given this combination of risk factors, some investigators have proposed that people with SCI are at increased risk for cardiovascular disease, beyond that associated with traditional risk factors, and SCI could be considered a risk-enhancing factor, analogous to other risk-enhancing factors defined by the 2019 American Heart Association/American College of Cardiology Primary Prevention Guidelines. However, more research is needed in this population to clarify the role of traditional risk factors, novel risk factors, health care access, social determinants of health, and intersectionality of disability, race, and socioeconomic status. There is an urgent need for primary care physicians and cardiologists to have awareness of the importance of timely diagnosis and management of cardiac risk factors for people with SCI.

Interaction between increasing body mass index and spinal cord injury to the probability of developing a diagnosis of nonalcoholic fatty liver disease

Background

The prevalence of obesity and comorbidities is high in the population with spinal cord injury (SCI). We sought to determine the effect of SCI on the functional form of the relationship between body mass index (BMI) and risk of developing nonalcoholic fatty liver disease (NAFLD), and assess whether SCI-specific mapping of BMI to risk of developing NAFLD is needed.

Methods

Longitudinal cohort study comparing Veterans Health Administration patients with a diagnosis of SCI to a 1:2 matched control group without SCI. The relationship between BMI and development of NAFLD at any time was assessed with propensity score matched Cox regression models; NAFLD development at 10-year with a propensity score matched logistic model. The positive predictive value of developing NAFLD at 10 years was calculated for BMI 19-45 kg/m2.

Results

14,890 individuals with SCI met study inclusion criteria, and 29,780 Non-SCI individuals in matched control group. Overall, 9.2% in SCI group and 7.3% in Non-SCI group developed NAFLD during the study period. A logistic model assessing the relationship between BMI and the probability of developing a diagnosis of NAFLD demonstrated that the probability of developing disease increased as BMI increased in both cohorts. The probability was significantly higher in the SCI cohort at each BMI threshold (p < 0.01), and increased at a higher rate compared with the Non-SCI cohort as BMI increased 19-45 kg/m2. Positive predictive value for developing a diagnosis of NAFLD was higher in the SCI group for any given BMI threshold from 19 kg/m2 to BMI 45 kg/m2.

Conclusions

The probability of developing NAFLD is greater in individuals with SCI than without SCI, at every BMI level 19 kg/m2 to 45 kg/m2. Individuals with SCI may warrant a higher level of suspicion and closer screening for NAFLD. The association of SCI and BMI is not linear.

Prevalence of Sarcopenic Obesity and Factors Influencing Body Composition in Persons with Spinal Cord Injury in Japan

This study aims to investigate the prevalence of sarcopenic obesity and factors influencing body composition in persons with spinal cord injury (SCI) in Japan. Adults with SCI aged ≥ 20 years who underwent whole-body dual-energy X-ray absorptiometry between 2016 and 2022 were retrospectively analyzed. Data from 97 patients were examined. The primary outcome was appendicular skeletal muscle mass (ASM). Multiple linear regression analysis was conducted to assess factors influencing the lean and adipose indices in persons with SCI. Sarcopenia, obesity, and sarcopenic obesity were prevalent in 76%, 85%, and 64% of patients, respectively. Multivariate linear regression analysis revealed that sex (β = 0.34, p < 0.001), lesion level (β = 0.25, p = 0.007), severity (β = 0.20, p = 0.043), and ability to walk (β = 0.29, p = 0.006) were independently associated with ASM. Sex (β = −0.63, p < 0.001) was independently associated with percent body fat. In conclusion, sarcopenia, obesity, and sarcopenic obesity were prevalent among patients with SCI in Japan. Female sex, tetraplegia, motor-complete injury, and inability to walk were risk factors for sarcopenia, whereas female sex was a risk factor for obesity in persons with SCI. A routine monitoring of body composition is necessary, especially among those with multiple risk factors, to identify individuals in need of preventive and therapeutic interventions.

Nutrition Education to Reduce Metabolic Dysfunction for Spinal Cord Injury: A Module-Based Nutrition Education Guide for Healthcare Providers and Consumers

Spinal cord injury (SCI) results in a high prevalence of neurogenic obesity and metabolic dysfunction. The increased risk for neurogenic obesity and metabolic dysfunction is mainly due to the loss of energy balance because of significantly reduced energy expenditure following SCI. Consequently, excessive energy intake (positive energy balance) leads to adipose tissue accumulation at a rapid rate, resulting in neurogenic obesity, systemic inflammation, and metabolic dysfunction. The purpose of this article is to review the existing literature on nutrition, dietary intake, and nutrition education in persons with SCI as it relates to metabolic dysfunction. The review will highlight the poor dietary intakes of persons with SCI according to authoritative guidelines and the need for nutrition education for health care professionals and consumers. Nutrition education topics are presented in a module-based format with supporting literature. The authors emphasize the role of a diet consisting of low-energy, nutrient-dense, anti-inflammatory foods consistent with the Dietary Guidelines for Americans' MyPlate to effectively achieve energy balance and reduce the risk for neurogenic obesity and metabolic dysfunction in individuals with SCI.

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.

Similar fat and carbohydrate oxidation in response to arm cycling exercise in persons with spinal cord injury versus able-bodied

CONTEXT

Persons with spinal cord injury (SCI) present with low fat oxidation that is associated with poor cardiometabolic health. This study compared changes in fat and carbohydrate (CHO) oxidation during moderate intensity continuous exercise in persons with SCI and able-bodied adults (AB).

DESIGN

Repeated measures, within-subjects study.

SETTING

University laboratory in San Diego, CA.

PARTICIPANTS

Nine men and women with SCI (age and time since injury = 32 ± 11 yr and 7 ± 6 yr) and 10 AB adults (age = 25 ± 8 yr).

INTERVENTIONS

To assess peak oxygen uptake (VO2peak) and peak power output (PPO), participants performed progressive arm ergometry to volitional exhaustion. Subsequently, they completed 25 min of continuous exercise at 45%PPO.

OUTCOME MEASURES

Respiratory exchange ratio (RER), fat and CHO oxidation, and blood lactate concentration (BLa) were assessed.

RESULTS

Data showed a similar RER (P = 0.98) during exercise in SCI (0.97 ± 0.04) versus AB (0.97 ± 0.03) reflecting high CHO use and no differences in BLa (3.5 ± 1.1 and 3.0 ± 0.9 vs. mM, P = 0.56) or fat and CHO oxidation between groups (P > 0.05). However, participants with SCI exercised at a higher relative intensity (P < 0.01, 84 ± 7 vs. 75 ± 7%HRpeak) versus AB.

CONCLUSION

Data confirm high reliance on CHO during arm ergometry in persons with SCI. To better compare substrate utilization to AB adults, we recommend that exercise be prescribed according to peak heart rate due to differences in cardiorespiratory fitness between groups.

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.

Informal caregivers' self-identified roles in facilitating health-promoting behaviours for weight management in community-dwelling care recipients living with spinal cord injury in the United States

Health providers often focus on secondary conditions and spend less time prioritising overweight/obesity care. Informal caregivers are well positioned to facilitate health-promoting behaviours of healthy eating and physical activity among community-dwelling care recipients with spinal cord injury (SCI) for prevention and management of overweight/obesity. Literature has typically focused on caregiver adjustment post-injury and burden related to their roles in secondary condition care. The novel objective of this study was to describe informal caregivers' perspectives of their roles in facilitating health-promoting weight management behaviours, healthy eating and physical activity, for care recipients with SCI. This was a qualitative study that used semi-structured interviews with informal caregivers for data collection in 2019. Braun & Clarke's established thematic phases were used for analysis. Participants included informal caregivers of individuals with SCI living in the community (n = 24). Caregivers identified eight themes to describe their role in facilitating weight management for care recipients. Themes included: (1) meal planning/shopping, (2) meal preparation/cooking, (3) using portion control, (4) serving/feeding, (5) helping the care recipient with physical activity and/or leisure activities, (6) mutually participating in weight management activities, (7) providing motivation and encouragement and (8) being an information liaison. In summary, informal caregivers have an intimate understanding of care recipients' needs and have insights on obstacles and enablers to health-promoting behaviours, making their involvement in facilitating weight management in individuals with SCI vital. Caregivers self-identified several significant roles for promoting weight management. This is especially valuable for conditions such as overweight/obesity for which prevention and treatment involve health-promoting behaviours that need consistent attention in the community setting. It is important to ensure that informal caregivers and care recipients have the information required in order to facilitate healthy eating and physical activity in persons with SCI and have opportunities for mutual dyadic participation when both partners are interested.

Pathophysiology, Classification and Comorbidities after Traumatic Spinal Cord Injury

The spinal cord is a conduit within the central nervous system (CNS) that provides ongoing communication between the brain and the rest of the body, conveying complex sensory and motor information necessary for safety, movement, reflexes, and optimization of autonomic function. After a spinal cord injury (SCI), supraspinal influences on the spinal segmental control system and autonomic nervous system (ANS) are disrupted, leading to spastic paralysis, pain and dysesthesia, sympathetic blunting and parasympathetic dominance resulting in cardiac dysrhythmias, systemic hypotension, bronchoconstriction, copious respiratory secretions and uncontrolled bowel, bladder, and sexual dysfunction. This article outlines the pathophysiology of traumatic SCI, current and emerging methods of classification, and its influence on sensory/motor function, and introduces the probable comorbidities associated with SCI that will be discussed in more detail in the accompanying manuscripts of this special issue.

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.

Physical activity and cardiometabolic risk factors in individuals with spinal cord injury: a systematic review and meta-analysis

Physical inactivity in individuals with spinal cord injury (SCI) has been suggested to be an important determinant of increased cardiometabolic disease (CMD) risk. However, it remains unclear whether physically active SCI individuals as compared to inactive or less active individuals have truly better cardiometabolic risk profile. We aimed to systematically review and quantify the association between engagement in regular physical activity and/or exercise interventions and CMD risk factors in individuals with SCI. Four medical databases were searched and studies were included if they were clinical trials or observational studies conducted in adult individuals with SCI and provided information of interest. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was applied to rate the certainty of evidence. Of 5816 unique citations, 11 randomized clinical trials, 3 non-randomized trial and 32 cross-sectional studies comprising more than 5500 SCI individuals were included in the systematic review. In meta-analysis of RCTs and based on evidence of moderate certainty, physical activity in comparison to control intervention was associated with: (i) better glucose homeostasis profile [WMD of glucose, insulin and Assessment of Insulin Resistance (HOMA-IR) were - 3.26 mg/dl (95% CI - 5.12 to - 1.39), - 3.19 μU/ml (95% CI - 3.96 to - 2.43)] and - 0.47 (95% CI - 0.60 to - 0.35), respectively], and (ii) improved cardiorespiratory fitness [WMD of relative and absolute oxygen uptake relative (VO2) were 4.53 ml/kg/min (95% CI 3.11, 5.96) and 0.26 L/min (95% CI 0.21, 0.32) respectively]. No differences were observed in blood pressure, heart rate and lipids (based on evidence of low/moderate certainty). In meta-analysis of cross-sectional studies and based on the evidence of very low to low certainty, glucose [WMD - 3.25 mg/dl (95% CI - 5.36, - 1.14)], insulin [- 2.12 μU/ml (95% CI - 4.21 to - 0.03)] and total cholesterol [WMD - 6.72 mg/dl (95% CI - 13.09, - 0.34)] were lower and HDL [WMD 3.86 mg/dl (95% CI 0.66, 7.05)] and catalase [0.07 UgHb-1 (95% CI 0.03, 0.11)] were higher in physically active SCI individuals in comparison to reference groups. Based on limited number of cross-sectional studies, better parameters of systolic and diastolic cardiac function and lower carotid intima media thickness were found in physically active groups. Methodologically sound clinical trials and prospective observational studies are required to further elaborate the impact of different physical activity prescriptions alone or in combination with other life-style interventions on CMD risk factors in SCI individuals.

Exploring the vagus nerve and the inflammatory reflex for therapeutic benefit in chronic spinal cord injury

PURPOSE OF REVIEW

To describe features and implications of chronic systemic inflammation in individuals with spinal cord injury (SCI) and to summarize the growing therapeutic possibilities to explore the vagus nerve-mediated inflammatory reflex in this context.

RECENT FINDINGS

The discovery of the inflammatory reflex provides a rationale to explore neuromodulation modalities, that is, electrical vagus nerve stimulation and pharmacological cholinergic modalities to regulate inflammation after SCI.

SUMMARY

Inflammation in individuals with SCI may negatively impact functional recovery and medical consequences after SCI. Exploring the potential of the vagus nerve-based inflammatory reflex to restore autonomic regulation and control inflammation may provide a novel approach for functional improvement in SCI.

Acute Spinal Cord Injury Is Associated With Prevalent Cardiometabolic Risk Factors

OBJECTIVES

To (1) describe the prevalence of cardiometabolic disease (CMD) at spinal cord injury (SCI) rehabilitation discharge; (2) compare this with controls without SCI; and (3) identify factors associated with increased CMD.

DESIGN

Multicenter, prospective observational study.

SETTING

Five National Institute on Disability, Independent Living, and Rehabilitation Research Model SCI Rehabilitation Centers.

PARTICIPANTS

SCI (n=95): patients aged 18-70 years, with SCI (neurologic levels of injury C2-L2, American Spinal Injury Association Impairment Scale grades A-D), and enrolled within 2 months of initial rehabilitation discharge. Control group (n=1609): age/sex/body mass index-matched entries in the National Health and Nutrition Examination Education Survey (2016-2019) (N=1704).

INTERVENTIONS

None MAIN OUTCOME MEASURES: Percentage of participants with SCI with CMD diagnosis, prevalence of CMD determinants within 2 months of rehabilitation discharge, and other significant early risk associations were analyzed using age, sex, body mass index, insulin resistance (IR) by fasting glucose and Homeostasis Model Assessment (v.2), fasting triglycerides, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol, total cholesterol, and resting blood pressure (systolic and diastolic).

RESULTS

Participants with SCI had significantly higher diastolic blood pressure and triglycerides than those without SCI, with lower fasting glucose and HDL-C. A total of 74.0% of participants with SCI vs 38.5% of those without SCI were obese when applying population-specific criteria (P<.05). Low HDL-C was measured in 54.2% of participants with SCI vs 15.4% of those without (P<.05). IR was not significantly different between groups. A total of 31.6% of participants with SCI had ≥3 CMD determinants, which was 40.7% higher than those without SCI (P<.05). Interplay of lipids and lipoproteins (ie, total cholesterol:HDL-C ratio and triglyceride:HDL-C ratio) were associated with elevated risk in participants with SCI for myocardial infarction and stroke. The only significant variable associated with CMD was age (P<.05).

CONCLUSIONS

Individuals with SCI have an increased CMD risk compared with the general population; obesity, IR, and low HDL-C are the most common CMD risk determinants; age is significantly associated with early CMD.

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.

Exercise to mitigate cardiometabolic disorders after spinal cord injury

The cardiometabolic disorder (CMD) is a syndrome caused by coalescing of cardiovascular, endocrine, pro-thrombotic, and inflammatory health risks. Together, these risks confer a hazard as health-threatening as coronary artery disease or type2 diabetes, whether an individual has a diagnosis of coronary disease or diabetes, or not. CMD is most often defined by three or more of five clinically assessed risk components, notably obesity, insulin resistance, hypertension, hypertriglyceridemia, and depressed high-density lipoprotein cholesterol. Evidence currently suggests that worldwide CMD is expanding at a pandemic rate, and it is known that people living with spinal cord injuries (SCI) qualify for the diagnosis at more than 50% of the prevalence of a non-disabled cohort. A recent evidence-based guideline warned of the current state of CMD following SCI and recommended early lifestyle intervention incorporating exercise and prudent nutrition as a first-line disease countermeasure. This monograph will define the CMD following SCI, explore its underlying pathophysiology, and provide evidence that recommends exercise for CMD health hazards after SCI.

Comparison of Various Indices in Identifying Insulin Resistance and Diabetes in Chronic Spinal Cord Injury

The purpose of this screening and diagnostic study was to examine the accord among indices of glucose metabolism, including the Homeostatic Model Assessment for Insulin Resistance (HOMA), HOMA2, Matsuda Index, Quantitative Insulin-sensitivity Check Index (QUICKI), hemoglobin A1C (HbA1C), and fasting plasma glucose (FPG) against intravenous glucose tolerance test-measured insulin sensitivity (Si) in individuals with chronic motor complete SCI. Persons with chronic (≥12-months post-injury) SCI (n = 29; 79% men; age 42.2 ± 11.4; body mass index 28.6 ± 6.4 kg/m2; C4-T10) were included. Measures were compared using adjusted R2 from linear regression models with Akaike information criterion (AIC, a measure of error). QUICKI had the greatest agreement with Si (adjusted R2 = 0.463, AIC = 91.1, p = 0.0001), followed by HOMA (adjusted R2 = 0.378, AIC = 95.4, p = 0.0008), HOMA2 (adjusted R2 = 0.256, AIC = 99.7, p = 0.0030), and the Matsuda Index (adjusted R2 = 0.356, AIC = 95.5, p = 0.0004). FPG (adjusted R2 = 0.056, AIC = 107.5, p = 0.1799) and HbA1C (adjusted R2 = 0.1, AIC = 106.1, p = 0.0975) had poor agreement with Si. While HbA1C and FPG are commonly used for evaluating disorders of glucose metabolism, QUICKI demonstrates the best accord with Si compared to the other measures.

What Are Personal Meanings of Healthy Eating and Physical Activity in Individuals Living With Spinal Cord Injury? A Qualitative Exploration

Objectives: To explore the personal meanings of healthy eating and physical activity among individuals living with spinal cord injury (SCI) and the information and resources they find beneficial. Methods: We conducted in-depth semistructured individual interviews to understand the personal meanings of healthy eating and physical activity among individuals with SCI. We completed a thematic analysis of qualitative data. Results: Participants were 11 Veterans and 14 civilians, predominantly male, non-Hispanic White, and with paraplegia. Data were described across two categories, including the personal meaning of healthy eating and the personal meaning of physical activity/exercise. Individuals with SCI described their meaning of healthy eating around four themes: types of food, amounts/portions of food, conscious/mindful eating, and eating to enhance health. Individuals wanted information on tailored diets for individuals with paraplegia and tetraplegia and healthy foods that are easy to prepare by people with SCI. Their personal meaning of physical activity/exercise focused on four themes: types of physical activity and exercise, staying active, moving/movement, and differences from non-SCI. Desired information around physical activity included cardiovascular workouts that are effective and possible to do in a wheelchair so that people with SCI can burn enough of the calories they consume to lose or maintain weight. Conclusion: Results provide a better understanding of what healthy eating and physical activity mean to people with SCI and information they desire toward these goals, which can be used to guide patient-provider discussions, develop health promotion programs, and tailor interventions to capitalize on meaningful concepts and beliefs that facilitate healthy behaviors.

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.

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.

Spinal cord injury: A multisystem physiological impairment/dysfunction

Spinal cord injury (SCI) is a complex disease that affects not only sensory and motor pathways below the neurological level of injury (NLI) but also all the organs and systems situated below this NLI. This multisystem impairment implies comprehensive management in dedicated SCI specialized centers, by interdisciplinary and multidisciplinary teams, able to treat not only the neurological impairment, but also all the systems and organs affected. After a brief history of the Spinal Cord Medicine, the author describes how to determine the level and severity of a SCI based on the International Standards for Neurological Classification of Spinal Cord Injury and the prognosis factors of recovery. This article provides also a review of the numerous SCI-related impairments (except for urinary, sexual problems and pain treated separately in this issue), their principles of management and related complications.

Anthropometric Prediction of Visceral Adiposity in Persons With Spinal Cord Injury

Over two-thirds of persons with spinal cord injury (SCI) experience neurogenic obesity-induced cardiometabolic syndrome (CMS) and other chronic comorbidities. Obesity is likely to impede social and recreational activities, impact quality of life, and impose additional socioeconomic burdens on persons with SCI. Advances in imaging technology facilitate the mapping of adiposity and its association with the cardiometabolic profile after SCI. Central adiposity or central obesity is characterized by increased waist (WC) and abdominal circumferences (AC) as well as visceral adipose tissue (VAT). A number of studies, while relying on expensive imaging techniques, have reported direct associations of both central obesity and VAT in imposing significant health risks after SCI. The mechanistic role of central obesity on cardiometabolic heath in persons with SCI has yet to be identified, despite the knowledge that it has been designated as an independent risk factor for cardiometabolic dysfunction and premature mortality in other clinical populations. In persons with SCI, the distribution of adipose tissue has been suggested to be a function of sex, level of injury, and age. To date, there is no SCI-specific WC or AC cutoff value to provide anthropometric prediction of VAT and diagnostic capability of persons at risk for central obesity, CMS, and cardiovascular disease after SCI. The purpose of the current review is to summarize the factors contributing to visceral adiposity in persons with SCI and to develop an SCI-specific anthropometric prediction equation for this population. Furthermore, a proposed WC cutoff will be discussed as a surrogate index for central obesity, CMS, and cardiovascular disorders after SCI.

Upper Extremity Overuse Injuries and Obesity After Spinal Cord Injury

Persons with spinal cord injury (SCI) are at high risk for developing neurogenic obesity due to muscle paralysis and obligatory sarcopenia, sympathetic blunting, anabolic deficiency, and blunted satiety. Persons with SCI are also at high risk for shoulder, elbow, wrist, and hand injuries, including neuromusculoskeletal pathologies and nociceptive pain, as human upper extremities are poorly designed to facilitate chronic weight-bearing activities, including manual wheelchair propulsion, transfers, self-care, and day-to-day activities. This article reviews current literature on the relationship between obesity and increased body weight with upper extremity overuse injuries, detailing pathology at the shoulders, elbows, and wrists that elicit pain and functional decline and stressing the importance of weight management to preserve function.

Substrate metabolism during recovery from circuit resistance exercise in persons with spinal cord injury

INTRODUCTION

Whole body energy expenditure and lipid oxidation (Lox) are upregulated during and after exercise. Persons with spinal cord injury (SCI) generally have a blunted ability to utilize fat during exercise, but it is unknown if their substrate partitioning is affected during recovery from exercise.

PURPOSE

To determine the effect of a single session of upper body circuit resistance exercise (CRE) on energy expenditure and Lox during exercise recovery in persons with and without SCI.

METHODS

Twenty four persons (3 groups; 7 male and 1 female per group) without paralysis (neurologically intact; N) or with chronic (≥ 1 yr) paraplegia (P) or tetraplegia (T) participated. Energy expenditure and substrate partitioning were assessed via indirect calorimetry before, during, and three times after (up to 120 min after) a single session of CRE, or time-matched seated control (CON).

RESULTS

During CRE, all groups experienced a similar relative increase in oxygen consumption (49 ± 13, 55 ± 11, and 48 ± 15% VO_2peak for N, P, and T, respectively). The Post_0-120 energy expenditure was greater following CRE vs. CON (P < 0.01) and independent of injury characteristics (10.6, 22.6, and 14.3% higher than CON for N, P, and T; P = 0.21). The absolute increase in Lox above CON during recovery was similar for N, P, and T (5.74 ± 2.81, 6.62 ± 3.10, and 4.50 ± 3.91 g, respectively; P = 0.45).

CONCLUSIONS

Energy expenditure and lipid utilization was increased similarly following circuit exercise in persons without and with spinal cord injury in a manner independent of level of injury.

Neurogenic Obesity and Skeletal Pathology in Spinal Cord Injury

Spinal cord injury (SCI) results in dramatic changes in body composition, with lean mass decreasing and fat mass increasing in specific regions that have important cardiometabolic implications. Accordingly, the recent Consortium for Spinal Cord Medicine (CSCM) released clinical practice guidelines for cardiometabolic disease (CMD) in SCI recommending the use of compartmental modeling of body composition to determine obesity in adults with SCI. This recommendation is guided by the fact that fat depots impact metabolic health differently, and in SCI adiposity increases around the viscera, skeletal muscle, and bone marrow. The contribution of skeletal muscle atrophy to decreased lean mass is self-evident, but the profound loss of bone is often less appreciated due to methodological considerations. General-population protocols for dual-energy x-ray absorptiometry (DXA) disregard assessment of the sites of greatest bone loss in SCI, but the International Society for Clinical Densitometry (ISCD) recently released an official position on the use of DXA to diagnose skeletal pathology in SCI. In this review, we discuss the recent guidelines regarding the evaluation and monitoring of obesity and bone loss in SCI. Then we consider the possible interactions of obesity and bone, including emerging evidence suggesting the possible influence of metabolic, autonomic, and endocrine function on bone health in SCI.

Exercise Interventions Targeting Obesity in Persons With Spinal Cord Injury

Spinal cord injury (SCI) results in an array of cardiometabolic complications, with obesity being the most common component risk of cardiometabolic disease (CMD) in this population. Recent Consortium for Spinal Cord Medicine Clinical Practice Guidelines for CMD in SCI recommend physical exercise as a primary treatment strategy for the management of CMD in SCI. However, the high prevalence of obesity in SCI and the pleiotropic nature of this body habitus warrant strategies for tailoring exercise to specifically target obesity. In general, exercise for obesity management should aim primarily to induce a negative energy balance and secondarily to increase the use of fat as a fuel source. In persons with SCI, reductions in the muscle mass that can be recruited during activity limit the capacity for exercise to induce a calorie deficit. Furthermore, the available musculature exhibits a decreased oxidative capacity, limiting the utilization of fat during exercise. These constraints must be considered when designing exercise interventions for obesity management in SCI. Certain forms of exercise have a greater therapeutic potential in this population partly due to impacts on metabolism during recovery from exercise and at rest. In this article, we propose that exercise for obesity in SCI should target large muscle groups and aim to induce hypertrophy to increase total energy expenditure response to training. Furthermore, although carbohydrate reliance will be high during activity, certain forms of exercise might induce meaningful postexercise shifts in the use of fat as a fuel. General activity in this population is important for many components of health, but low energy cost of daily activities and limitations in upper body volitional exercise mean that exercise interventions targeting utilization and hypertrophy of large muscle groups will likely be required for obesity management.