Neurogenic obesity and systemic inflammation following spinal cord injury: A review

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.

Risk factors for pressure injuries in individuals with spinal cord injuries who have sarcopenic obesity: A comparison of time-dependent changes in sacral region pressure between individuals with and without sarcopenic obesity

OBJECTIVE

To identify the risk factors for pressure injuries in individuals with spinal cord injuries (SCIs) who have sarcopenic obesity, comparing time-dependent changes in sacral region pressure in individuals with and without sarcopenic obesity.

DESIGN

An experimental time series study.

SETTING

Single-center hospital.

PARTICIPANTS

Twenty-five adult participants with subacute and chronic paraplegia who visited our rehabilitation center, Republic of Korea, between May 2021 and June 2022.

INTERVENTIONS

Whole-body dual-energy X-ray absorptiometry was performed to diagnose sarcopenic obesity. After the participants were placed in the supine position for 1 hour, the average pressure (mmHg), peak pressure (mmHg), and total contact area (cm2) of the sacral region were measured using the pressure-mapping system.

RESULTS

Compared with the non-sarcopenic obesity group, the sarcopenic obesity group showed significant before-and-after differences in peak pressure. Furthermore, the risk factors that were significantly associated with peak pressure in the sarcopenic obesity group were the American Spinal Injury Association Impairment Scale score and the fat mass index.

CONCLUSION

Among participants with SCIs, the risk of pressure injuries is higher in the sarcopenic obesity group than in the non-sarcopenic obesity group. Notably, the risk of pressure injuries increases in participants who have complete injury and an increased fat mass index, indicating the importance of close monitoring and more active management to prevent pressure injuries in this subpopulation.

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.

Roles of Plasminogen Activator Inhibitor-1 in Heterotopic Ossification Induced by Achilles Tenotomy in Thermal Injured Mice

Heterotopic ossification (HO) is the process by which ectopic bone forms at an extraskeletal site. Inflammatory conditions induce plasminogen activator inhibitor 1 (PAI-1), an inhibitor of fibrinolysis, which regulates osteogenesis. In the present study, we investigated the roles of PAI-1 in the pathophysiology of HO induced by trauma/burn treatment using PAI-1-deficient mice. PAI-1 deficiency significantly promoted HO and increased the number of alkaline phosphatase (ALP)-positive cells in Achilles tendons after trauma/burn treatment. The mRNA levels of inflammation markers were elevated in Achilles tendons of both wild-type and PAI-1-deficient mice after trauma/burn treatment and PAI-1 mRNA levels were elevated in Achilles tendons of wild-type mice. PAI-1 deficiency significantly up-regulated the expression of Runx2, Osterix, and type 1 collagen in Achilles tendons 9 weeks after trauma/burn treatment in mice. In in vitro experiments, PAI-1 deficiency significantly increased ALP activity and mineralization in mouse osteoblasts. Moreover, PAI-1 deficiency significantly increased ALP activity and up-regulated osteocalcin expression during osteoblastic differentiation from mouse adipose-tissue-derived stem cells, but suppressed the chondrogenic differentiation of these cells. In conclusion, the present study showed that PAI-1 deficiency promoted HO in Achilles tendons after trauma/burn treatment partly by enhancing osteoblast differentiation and ALP activity in mice. Endogenous PAI-1 may play protective roles against HO after injury and inflammation.

Piloting the effectiveness of the Workout on Wheels Internet Intervention (WOWii) program among individuals with mobility disabilities

BACKGROUND

Doing any amount of moderate-to-vigorous physical activity yields health benefits. Individuals with mobility disabilities are among the least physically active Americans and limited evidence indicates effective strategies to promote physical activity among this group.

OBJECTIVE

Examine whether a 16-week virtual intervention program (Workout on Wheels internet intervention, WOWii) increases exercise engagement among mobility impaired individuals.

METHODS

Participants recruited through community organizations that provide services to individuals with disabilities. The WOWii program is comprised of 3 core components: 16 weeks of virtual intervention delivery and access to the WOWii website; staff and peer support; an exercise package that included an activity tracker and heart rate monitor, pedal exerciser, and therabands.

RESULTS

Ten people enrolled. Participants demonstrated good program engagement, attending an average of 14.1 ± 2.1 of the 16 virtual meetings and completing an average of 10.6 ± 5.6 weekly activities. Exercise data revealed that participants increased their time spent in aerobic exercise from an average of two days a week performing 32 ± 22 min during week one to an average of five days a week doing 127 ± 143 min in the final WOWii week. Only half continued to exercise over the two months once WOWii virtual meetings ended.

CONCLUSIONS

WOWii program delivery successfully promoted increased exercise participation for people with mobility disabilities over the 16 intervention weeks. Future studies should investigate approaches to promote exercise maintenance beyond program delivery.

Tissue-specific genetic variation suggests distinct molecular pathways between body shape phenotypes and colorectal cancer

It remains unknown whether adiposity subtypes are differentially associated with colorectal cancer (CRC). To move beyond single-trait anthropometric indicators, we derived four multi-trait body shape phenotypes reflecting adiposity subtypes from principal components analysis on body mass index, height, weight, waist-to-hip ratio, and waist and hip circumference. A generally obese (PC1) and a tall, centrally obese (PC3) body shape were both positively associated with CRC risk in observational analyses in 329,828 UK Biobank participants (3728 cases). In genome-wide association studies in 460,198 UK Biobank participants, we identified 3414 genetic variants across four body shapes and Mendelian randomization analyses confirmed positive associations of PC1 and PC3 with CRC risk (52,775 cases/45,940 controls from GECCO/CORECT/CCFR). Brain tissue-specific genetic instruments, mapped to PC1 through enrichment analysis, were responsible for the relationship between PC1 and CRC, while the relationship between PC3 and CRC was predominantly driven by adipose tissue-specific genetic instruments. This study suggests distinct putative causal pathways between adiposity subtypes and CRC.

Monitoring outcome measures for cardiometabolic disease during rehabilitation and follow-up in people with spinal cord injury

STUDY DESIGN

Controlled pragmatic intervention with follow-up.

OBJECTIVES

To describe cardiometabolic risk outcomes after a pragmatic intervention implemented into standard spinal cord injury (SCI) rehabilitation.

SETTING

Inpatient SCI rehabilitation in East-Denmark.

PARTICIPANTS

Inpatients, >18 years, having sustained a SCI within the last 12 months at admission to rehabilitation, regardless of etiology, neurological level or completeness of the lesion or mobility status.

METHODS

Patient education on health promotion was guided by evidence and included feedback on peak oxygen uptake (VO2peak) (primary outcome measure), body mass index (BMI), Dual energy X-ray absorptiometry and metabolic profile (secondary outcome measures). Paired t-tests, non-parametric tests and Analysis of Variance (ANOVA) were used for analyzes. VO2peak and BMI were compared to historical data.

RESULTS

VO2peak increased significantly from admission to discharge but did not exceed historical data despite a minimal clinical important difference. BMI decreased significantly during rehabilitation (p < 0.001) followed by a significant increase after discharge (p = 0.006). There was a trend that people with American Spinal Injury Association Impairment Scale (AIS) D SCI increased lean mass to nearly normal values. Criteria for pre-diabetes or diabetes were present in 28.5% and dyslipidemia in 45% of the participants 44.2 days after time of injury.

CONCLUSIONS

Despite improvements during rehabilitation, outcome measures were worse than recommended, and most outcome measures worsened at follow up, even in people with an AIS D SCI. Meaningful support regarding exercise and diet when tackling altered life circumstances is needed after discharge.

Characteristics of the gut microbiome of Swiss elite athletes with a spinal cord injury: An exploratory study

OBJECTIVES

To illustrate and explore associations between the gut microbiome and spinal cord injury (SCI) characteristics, physical training, dietary intake, body composition, and blood biomarkers of elite Swiss athletes.

DESIGN AND SETTING

Baseline data analysis of athletes with SCI who participated in a pilot trial (NCT04659408) in the Swiss Paraplegic Center, Nottwil, Switzerland.

PARTICIPANTS

Elite athletes, five males, and six females, with SCI who competed internationally.

OUTCOME MEASURES

We conducted a differential abundance analysis and measured the alpha and beta diversity of the gut microbiome.

RESULTS

The athletes' median age was 34.5 years. Six had traumatic SCI and five had a spina bifida. The athletes competed in para-cycling (5), wheelchair athletics (3), and wheelchair tennis (3). A higher duration of training per week was positively associated with Akkermansia and Akkermansiaceae but negatively associated with Prevotellaceae. Muribaculaceae was negatively associated with the average number of trainings per week. Waist circumference is negatively associated with Butyricimonas. Significant differences in the alpha diversity were found with sex, gastrointestinal quality of life index (GIQLI) scores, total caloric intake, total fat intake, total carbohydrate intake, and high-sensitivity C-reactive protein (hs-CRP). Beta diversity differences were found with impairment of the sympathetic nervous system of the gut at the genus level and HbA1c at the family level.

CONCLUSIONS

This study provides insight into the gut microbiome of athletes with SCI. Our results were similar to those found in athletes without SCI. Further replication is needed to confirm the relationships of organisms observed in the gut of athletes 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.

System failure: Systemic inflammation following spinal cord injury

Spinal cord injury (SCI) affects hundreds of thousands of people in the United States, and while some effects of the injury are broadly recognized (deficits to locomotion, fine motor control, and quality of life), the systemic consequences of SCI are less well-known. The spinal cord regulates systemic immunological and visceral functions; this control is often disrupted by the injury, resulting in viscera including the gut, spleen, liver, bone marrow, and kidneys experiencing local tissue inflammation and physiological dysfunction. The extent of pathology depends on the injury level, severity, and time post-injury. In this review, we describe immunological and metabolic consequences of SCI across several organs. Since infection and metabolic disorders are primary reasons for reduced lifespan after SCI, it is imperative that research continues to focus on these deleterious aspects of SCI to improve life span and quality of life for individuals with SCI.

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.

Aging with spinal cord injury: A narrative review of consequences and challenges

Given the increase in life expectancy, aging with a pre-existing spinal cord injury (SCI) is becoming more common. This condition is challenging as compromised health status and functional independence can worsen. We aimed to provide an updated overview of the consequences of aging with SCI, highlighting the main challenges facing this population in a narrative review of the current literature we retrieved from the PubMed database from 2000 to 2022 on any aspect related to aging in persons with SCI. Here we address adverse circumstances that increase disability and hinder an active lifestyle, such as progressive physical deterioration, secondary health conditions, limitations in personal activity, changes in family and social support structures, aging of caregivers, and depletion of economic resources. Favorable changes are also observed, including psychosocial adjustments that improve quality of life. Additionally, various interventions are discussed to promote well-being, health, and social participation. Due to the relevance of this issue, people with SCI and all those who take care of them must have up-to-date information to carry out the necessary measures to promote healthy aging in a more inclusive social environment.

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.

The Physiology of Neurogenic Obesity: Lessons from Spinal Cord Injury Research

BACKGROUND

A spinal cord injury (SCI) from trauma or disease impairs sensorimotor pathways in somatic and autonomic divisions of the nervous system, affecting multiple body systems. Improved medical practices have increased survivability and life expectancy after SCI, allowing for the development of extensive metabolic comorbidities and profound changes in body composition that culminate in prevalent obesity.

SUMMARY

Obesity is the most common cardiometabolic component risk in people living with SCI, with a diagnostic body mass index cutoff of 22 kg/m2 to account for a phenotype of high adiposity and low lean mass. The metameric organization of specific divisions of the nervous system results in level-dependent pathology, with resulting sympathetic decentralization altering physiological functions such as lipolysis, hepatic lipoprotein metabolism, dietary fat absorption, and neuroendocrine signaling. In this manner, SCI provides a unique opportunity to study in vivo the "neurogenic" components of certain pathologies that otherwise are not readily observable in other populations. We discuss the unique physiology of neurogenic obesity after SCI, including the altered functions mentioned above as well as structural changes such as reduced skeletal muscle and bone mass and increased lipid deposition in the adipose tissue, skeletal muscle, bone marrow, and liver.

KEY MESSAGE

The study of neurogenic obesity after SCI gives us a unique neurological perspective on the physiology of obesity. The lessons learned from this field can guide future research and advancements to inform the study of obesity in persons with and without SCI.

A longitudinal analysis of resting energy expenditure and body composition in people with spinal cord injury undergoing surgical repair of pressure injuries: a pilot study

BACKGROUND

Data informing energy needs of people with spinal cord injury (SCI) and pressure injuries are scarce, the impact of surgical repair unknown, and the role of body composition in healing unexplored. The study aims were to investigate resting energy expenditure (REE) over the course of pressure injury surgical repair, compare with available energy prediction equations, and explore associations between body composition and wound healing.

METHODS

Indirect calorimetry measured REE pre-surgery, post-surgery, at suture removal and hospital discharge. A clinically significant change was defined as +/-10% difference from pre-surgery. Eight SCI-specific energy prediction equations were compared to pre-surgery REE. Wound breakdown (Yes/No), weight, waist circumference (WC), and body composition (fat mass [FM], fat-free mass [FFM], bioimpedance spectroscopy) were measured.

RESULTS

Twenty people underwent pressure injury surgical repair (95% male, mean age 56 ± 12 years, 70% paraplegia). Between pre-surgery and discharge, mean REE increased (+118 kcal/d, p = 0.005), but with <10% change at any timepoint. An energy prediction equation incorporating FFM showed greatest agreement (r_c = 0.779, 95% CI: 0.437, 0.924). Those with wound breakdown (65%) had a higher weight (12.7 kg, 95% CI: -4.0, 29.3), WC (17.8 cm, 95% CI: -5.1, 40.7), and FM % (36.0% [IQR 31.8, 40.2] vs 26.0% [IQR 15.6, 41.3]) than those without wound breakdown, although statistical significance was not reached.

CONCLUSION

The presence of pressure injuries and subsequent surgical repair did not impact REE and energy prediction equations incorporating FFM performed best. While not statistically significant, clinically important differences in body composition were observed in those with wound breakdown.

Consequences of spinal cord injury on the sympathetic nervous system

Spinal cord injury (SCI) damages multiple structures at the lesion site, including ascending, descending, and propriospinal axons; interrupting the conduction of information up and down the spinal cord. Additionally, axons associated with the autonomic nervous system that control involuntary physiological functions course through the spinal cord. Moreover, sympathetic, and parasympathetic preganglionic neurons reside in the spinal cord. Thus, depending on the level of an SCI, autonomic function can be greatly impacted by the trauma resulting in dysfunction of various organs. For example, SCI can lead to dysregulation of a variety of organs, such as the pineal gland, the heart and vasculature, lungs, spleen, kidneys, and bladder. Indeed, it is becoming more apparent that many disorders that negatively affect quality-of-life for SCI individuals have a basis in dysregulation of the sympathetic nervous system. Here, we will review how SCI impacts the sympathetic nervous system and how that negatively impacts target organs that receive sympathetic innervation. A deeper understanding of this may offer potential therapeutic insight into how to improve health and quality-of-life for those living with SCI.

Predictors of lower extremity fracture-related amputation in persons with traumatic spinal cord injury: a case-control study

STUDY DESIGN

This is a retrospective case-control study.

OBJECTIVES

To identify predictors of lower extremity (LE) long bone fracture-related amputation in persons with traumatic spinal cord injury (tSCI).

SETTING

US Veterans Health Administration facilities (2005-2015).

METHODS

Fracture-amputation sets in Veterans with tSCI were considered for inclusion if medical coding indicated a LE amputation within 365 days following an incident LE fracture. The authors adjudicated each fracture-amputation set by electronic health record review. Controls with incident LE fracture and no subsequent amputation were matched 1:1 with fracture-amputation sets on site and date of fracture (±30 days). Multivariable conditional logistic regression determined odds ratios (OR) and 95% confidence intervals (CI) for potential predictors (motor-complete injury; diabetes mellitus (DM); peripheral vascular disease (PVD); smoking; primary (within 30 days) nonsurgical fracture management; pressure injury and/or infection), controlling for age and race.

RESULTS

Forty fracture-amputation sets from 37 Veterans with LE amputations and 40 unique controls were identified. DM (OR = 26; 95% CI, 1.7-382), PVD (OR = 30; 95% CI, 2.5-371), and primary nonsurgical management (OR = 40; 95% CI, 1.5-1,116) were independent predictors of LE fracture-related amputation.

CONCLUSIONS

Early and aggressive strategies to prevent DM and PVD in tSCI are needed, as these comorbidities are associated with increased odds of LE fracture-related amputation. Nonsurgical fracture management increased the odds of LE amputation by at least 50%. Further large, prospective studies of fracture management in tSCI are needed to confirm our findings. Physicians and patients should consider the potential increased risk of amputation associated with non-operative management of LE fractures in shared decision making.

Health care provider views on the magnitude of overweight/obesity in spinal cord injury and awareness of evidence-based guidance for weight management

BACKGROUND

Literature shows that large proportions of people with a spinal cord injury (SCI) continue to experience challenges and limitations in weight management (WM) efforts in the health care setting. Despite the need, evidence-based research on effective and practical WM practices for persons with SCI is inconsistent and not widely used by health care providers (HCPs).

OBJECTIVE

The objectives were twofold: (1) to explore HCP perspectives of the extent of the problem of overweight/obesity in individuals with SCI and (2) HCPs awareness of and beliefs about availability of literature or evidence-based guidelines that discuss WM in SCI.

DESIGN

Qualitative study using semistructured interviews with HCPs and thematic analysis to identify themes.

PARTICIPANTS/SETTING

SCI HCPs (n = 25) from Veterans Health Administration and Midwest Regional SCI Care System.

INTERVENTION

Not applicable.

RESULTS

SCI HCPs (88%) emphasized the large scope of the problem of overweight and obesity in persons with SCI. HCPs noted the multiple associated negative consequences, specifically 84% highlighted the impact on chronic conditions (cardiometabolic, respiratory) and 48% discussed the impact on secondary/associated conditions (skin, bowel, bladder, musculoskeletal). HCPs noted other impacts of excess weight as greater disability in later life (28%), challenges with mobility and function (60%), self-care (24%), and equipment safety (28%). This sample of HCPs (76%) indicated being unaware of published or available information about WM efforts that work in SCI populations.

CONCLUSION

Our findings indicate that HCPs believe that overweight and obesity is a significant problem in persons with SCI but that this sample of HCPs are not aware of published work and easily accessible SCI-specific WM evidence-based guidance. This suggests the need for more education and proactive efforts to improve awareness of appropriate information within interprofessional HCPs.

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.

Fat to lean mass ratio in spinal cord injury: Possible interplay of components of body composition that may instigate systemic inflammation and metabolic syndrome

OBJECTIVE

To investigate the relationships between percentage fat mass (%FM), percentage lean mass (%LM), and the ratio of %FM to %LM with pro-inflammatory adipokines and metabolic syndrome in individuals with chronic spinal cord injury (SCI).

DESIGN

Observational, cross-sectional. Linear and logistic regression were used to examine the associations between the %FM, %LM, and the %FM to %LM ratio with inflammatory markers and metabolic syndrome, respectively.

PARTICIPANTS

Seventy chronic SCI men and women.

MAIN OUTCOME MEASURES

%FM, %LM, %FM to %LM ratio; fasting lipids, glucose, and tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and high-sensitivity c-reactive protein (hs-CRP); metabolic syndrome as determined by The International Diabetes Federation criteria.

RESULTS

There were significant correlations between %FM, %LM and the %FM to %LM ratio with hs-CRP. The %LM beta coefficient value was negative and greater than the beta coefficient value for %FM. The %FM to %LM ratio had the strongest correlation with hs-CRP and showed the only significant relationship with IL-6. There were strong significant correlations between %FM, %LM and the %FM to %LM ratio with metabolic syndrome. However, the %FM to %LM ratio, again, showed the strongest relationship indicating that it may be the best predictor of metabolic syndrome.

CONCLUSION

Both higher %FM and lower %LM affect cardiometabolic health and can be used as predictors for metabolic syndrome. However, the %FM to %LM ratio was the best predictor of systemic inflammation and cardiometabolic disorders in this group of SCI participants, suggesting that they both contribute to the statistical model.

Inflammaging and bone loss in a rat model of spinal cord injury

Spinal cord injury (SCI) results in significant loss of sublesional bone, adding to the comorbidity of SCI with an increased risk of fracture and post-fracture complications. Unfortunately, the effect of SCI on skeletal health is also likely to rise as the average age of SCI has increased and there are well-known negative effects of age on bone. To date, however, the impact of age and age-associated inflammation (inflammaging) on skeletal health after SCI remains largely unknown. To address this, we compared bone parameters in young (3 month) and middle-aged (9 month) male and female rats with a moderate thoracic contusion injury, to age and sex matched sham-operated controls. Skeletal parameters, locomotor function and serum cytokine levels were assessed at both subchronic (30 days) and chronic (180 days) time points post injury. We hypothesized that SCI would lead to a dramatic loss of bone immediately after injury in all SCI-groups, with inflammaging leading to greater loss in middle-aged SCI rats. We also predicted that while younger rats may re-establish bone properties in more chronic phases of SCI, middle-aged rats would not. Supporting these hypothesis, trabecular bone volume was significantly lower in male and young female SCI rats early after injury. Contrary to our hypothesis, however, there was greater loss of trabecular bone volume, relative to age-matched shams, in young compared to middle-aged SCI rats with no effects of SCI on trabecular bone volume in middle-aged female rats. Moreover, despite recovery of weight-supported locomotor activity, bone loss persisted into the chronic phase of injury for the young rats. Bone formation rates were lower in young male SCI rats, regardless of the time since injury, while both young and middle-aged female SCI rats had lower bone formation in the subchronic but not chronic phase of SCI. In middle-aged rats, SCI-induced higher osteoclast surfaces, which also persisted into the chronic phase of SCI in middle-aged females. Neither age nor SCI-induced increases in inflammation seemed to be associated with bone loss. In fact, SCI had more dramatic and persistent effects on bone in male rats, while aging and SCI elevated serum cytokines only in female rats. Overall, this study demonstrates SCI-induced loss of bone and altered bone turnover in male and female rats that persists into the chronic phase post-injury. The sex and age dependent variations in bone turnover and serum cytokines, however, underscore the need to further explore both mechanisms and potential therapeutics in multiple demographics.

Development and evaluation of an educational curriculum for healthcare providers on overweight/obesity management in individuals with spinal cord injury based on diverse stakeholder engagement

BACKGROUND

Spinal cord injury (SCI) healthcare providers are aware of the harmful consequences of overweight/obesity in persons with SCI, but many are unaware of available information and lack training to guide weight management care in the SCI population.

OBJECTIVE

Describe the development and content of an educational curriculum for healthcare providers to help individuals with SCI prevent or manage overweight/obesity.

METHODS

The biopsychoecological framework guided curriculum planning, data collection, and product development. Thematic analysis of interviews conducted with individuals with SCI, informal caregivers, and SCI healthcare providers pinpointed central educational curriculum topics. SCI healthcare providers evaluated the curriculum.

RESULTS

Seven comprehensive topics were developed: 1. Scope and consequences of overweight/obesity in SCI; 2. Classifying and measuring overweight/obesity in SCI; 3. Guidelines related to weight management in SCI; 4. Identifying challenges (and solutions) to weight management in SCI; 5. Strategies for providers to facilitate weight management; 6. Understanding goals, motivators, and desired feedback for weight management; and 7. Knowing how informal caregivers are affected by weight and weight management of care recipients with SCI. High ratings (>80% strong agreement) were achieved on content, word choice, organization, relevance, and actionability. Modification needs were identified and subsequently made to layout, visual aids, and provision of tangible resources. Providers described the curriculum as a scientifically rigorous resource that addresses a knowledge gap, provides population-specific content, and is useful across interdisciplinary teams.

CONCLUSION

We developed a self-directed learning educational curriculum addressing topics most salient to stakeholders involved in overweight/obesity management of persons with SCI.

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.

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.

The interaction of macronutrients and body composition among individuals with chronic spinal cord injury

Changes in body composition and dietary intake occur following spinal cord injury (SCI). The Geometric Framework for Nutrition (GFN) is a tool that allows the examination of the complex relationships between multiple nutrition factors and health parameters within a single model. This study aimed to utilize the GFN to examine the associations between self-reported macronutrient intakes and body composition in persons with chronic SCI. Forty-eight individuals with chronic SCI were recruited. Participants completed and returned 3- or 5-day self-reported dietary recall sheets. Dietary intake of macronutrients (fats, proteins, and carbohydrates) were analysed. Anthropometric measures (circumferences), dual-energy x-ray absorptiometry (DXA), and magnetic resonance imaging (MRI) were used to assess whlole-body composition. Associations between all circumference measures and carbohydrates were observed. Among MRI measures, only significant associations between subcutaneous adipose tissue and protein x carbohydrate as well as carbohydrates alone were identified. Carbohydrates were negatively associated with several measures of fat mass as measured by DXA. Overall, carbohydrates appear to play an important role in body composition among individuals with SCI. Higher carbohydrate intake was associated with lower fat mass. Additional research is needed to determine how carbohydrate intake influences body composition and cardiometabolic health after SCI.

Assessing Visceral Obesity and Abdominal Adipose Tissue Distribution in Healthy Populations Based on Computed Tomography: A Large Multicenter Cross-Sectional Study

Objective

Abdominal adipose is closely related to many endocrine and metabolic diseases. The aim of this study was to analyze the distribution of abdominal adipose tissue in a healthy population in northern China determined by abdominal computed tomography (CT).

Methods

Data for this study were obtained from a multicenter, retrospective, cross-sectional study that collected abdominal CT scans of 1787 healthy individuals from 4 representative cities in northern China. Areas of visceral adipose tissue (VATA) and subcutaneous adipose tissue (SATA) were obtained by measuring CT images at the level of the 3rd lumbar vertebra. Visceral adipose tissue index (VATI) and subcutaneous adipose index (SATI) were obtained by normalizing the square of height to analyze the distribution of the above indexes and visceral obesity among different body mass index (BMI), gender and age.

Results

The mean age of this healthy population was 45.3 ± 15.2 years and the mean BMI was 23.5 ± 3.2 kg/m², with 902 men and 885 women. Compared with women, men had a significantly higher median VATA (120.9 vs. 67.2 cm²), VATI (39.1 vs. 25.6 cm²/m²) and a significantly higher percentage of visceral adiposity (VATA ≥ 100 cm²) (60.8 vs. 30.4%), while women had significantly higher SATA (116.9 vs. 146.7 cm²) and SATI (38.8 vs. 55.8 cm²/m²) than men. Whether men or women, VATI was positively correlated with age. Interestingly, SATI was weakly positively correlated with age in women, while SATI was weakly negatively correlated with age in men. In persons with a normal BMI, the proportion of visceral adiposity increases with age, whereas in men with a normal BMI, the proportion of visceral adiposity decreases after the age of 60 years but remains >50%.

Conclusions

The distribution of abdominal visceral and subcutaneous adipose tissue parameters measured by CT differed among gender, age, and BMI. Even men and women with normal BMI have a high proportion of visceral obesity.

Inflammation and Oxidative Stress as Common Mechanisms of Pulmonary, Autonomic and Musculoskeletal Dysfunction after Spinal Cord Injury

Simple Summary

When a spinal cord injury occurs, the neurons that regulate our voluntary movements, those involved in environment and somatic perception and those that regulate vegetative functions are affected. Once neuronal damage is established, the cells of other tissues are also affected in their functions, altering the interaction between organs and altering the proper functioning of the organism. Multiple studies in animal models, as well as in humans, have recognized as factors involved in organ damage the imbalance between the formation of highly reactive molecules called pro-oxidants and defensive mechanisms called antioxidants. Closely associated with this phenomenon, the inflammatory response is also pathologically activated. In this narrative review, we have analyzed the information involving these pathological processes at the level of the lung, the autonomic nervous system and the skeletal musculature after spinal cord injury. Knowing the abnormal functioning mechanisms that occur after a spinal cord injury not only offers a better understanding of the organic events but also offers future possibilities for therapeutic interventions that may benefit the thousands of patients suffering this pathology.

Abstract

One of the etiopathogenic factors frequently associated with generalized organ damage after spinal cord injury corresponds to the imbalance of the redox state and inflammation, particularly of the respiratory, autonomic and musculoskeletal systems. Our goal in this review was to gain a better understanding of this phenomenon by reviewing both animal and human studies. At the respiratory level, the presence of tissue damage is notable in situations that require increased ventilation due to lower thoracic distensibility and alveolar inflammation caused by higher levels of leptin as a result of increased fatty tissue. Increased airway reactivity, due to loss of sympathetic innervation, and levels of nitric oxide in exhaled air that are similar to those seen in asthmatic patients have also been reported. In addition, the loss of autonomic control efficiency leads to an uncontrolled release of catecholamines and glucocorticoids that induce immunosuppression, as well as a predisposition to autoimmune reactions. Simultaneously, blood pressure regulation is altered with vascular damage and atherogenesis associated with oxidative damage. At the muscular level, chronically elevated levels of prooxidants and lipoperoxidation associated with myofibrillar atrophy are described, with no reduction or reversibility of this process through antioxidant supplementation.

Effects of Resistance Circuit Training on Health-Related Physical Fitness in People With Paraplegia: A Pilot Randomized Controlled Trial

OBJECTIVE

To evaluate the efficacy and safety of 8 weeks of resistance circuit training in people with paraplegia due to spinal cord injury.

METHODS

Participants were randomized into experimental and control groups. Although the intensity and sequence of movements of the exercise programs were identical in both groups, the resting time between sets was limited to 1 minute in the experimental group. In the control group, the participants were allowed to rest until they were comfortable. Both groups received 8 weeks of training twice per week. Before and after the program, muscle mass, body fat percentage, fat mass, blood pressure, heart rate, muscle strength and muscular endurance were evaluated, and 6-minute propulsion test was conducted. Additionally, the safety of the program was assessed.

RESULTS

Twenty-two individuals with paraplegia were enrolled (11 in each group). After the training program, the experimental group showed a significant decrease in the resting blood pressure and improvement in the upper extremity muscle mass, strength, and endurance (p<0.05). Each variable showed significant inter-group differences (p<0.05). Furthermore, none of the participants showed autonomic adverse events, musculoskeletal side effects, or discomfort.

CONCLUSION

The results show that resistance circuit training programs with short resting intervals are superior to the usual resistance exercise programs in improving the blood pressure and physical strength and are safe for people with upper thoracic level injuries at T6 or higher.

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.

Visceral Adiposity, Inflammation, and Testosterone Predict Skeletal Muscle Mitochondrial Mass and Activity in Chronic Spinal Cord Injury

Background

Mitochondrial health is an important predictor of several health-related comorbidities including obesity, type 2 diabetes mellitus, and cardiovascular disease. In persons with spinal cord injury (SCI), mitochondrial health has been linked to several important body composition and metabolic parameters. However, the complex interplay of how mitochondrial health is affected has yet to be determined in this population.

Objective

In this study, we examined the contribution of visceral adiposity, inflammatory biomarkers, testosterone and circulating serum growth factors as predictors of mitochondrial health in persons with chronic SCI.

Participants

Thirty-three individuals with chronic SCI (n = 27 Males, n = 6 Females, age: 40 ± 13.26 years, level of injury: C4-L1, BMI: 23 ± 5.57) participated in this cross-sectional study.

Methods

Visceral adipose tissue (VAT) was measured via magnetic resonance imaging (MRI). After an overnight fast, serum testosterone, inflammatory biomarkers [interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), c-reactive protein (CRP)], and anabolic growth factors [insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3)] were measured. Skeletal muscle biopsies were obtained from the vastus lateralis muscle to measure citrate synthase (CS) and Complex III activity. Regression analyses were used to examine predictors of mitochondrial mass and activity.

Results

CS activity was negatively associated with VAT (r² = 0.360, p < 0.001), CRP (r² = 0.168, p = 0.047), and positively associated with testosterone (r² = 0.145, p = 0.042). Complex III activity was negatively associated with VAT relative to total lean mass (VAT:TLM) (r² = 0.169, p = 0.033), trended for CRP (r² = 0.142, p = 0.069), and positively associated with testosterone (r² = 0.224, p = 0.010). Multiple regression showed CS activity was significantly associated with VAT + CRP (r² = 0.412, p = 0.008) and VAT + Testosterone (r² = 0.433, p = 0.001). Complex III activity was significantly associated with VAT relative to total trunk cross-sectional area (CSA) + CRP (VAT:total trunk CSA + CRP; r² = 0.286, p = 0.048) and VAT + Testosterone (r² = 0.277, p = 0.024).

Conclusion

Increased visceral adiposity and associated inflammatory signaling (CRP) along with reduced testosterone levels predict mitochondrial dysfunction following SCI. Specifically, lower VAT_CSA and higher testosterone levels or lower VAT_CSA and lower CRP levels positively predict mitochondrial mass and enzyme activity in persons with chronic SCI. Future research should investigate the efficacy of diet, exercise, and potentially testosterone replacement therapy on enhancing mitochondrial health in chronic SCI.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier: [NCT02660073].

Systematic review of the changes in the microbiome following spinal cord injury: animal and human evidence

Study design

Systematic review.

Objectives

To investigate the changes in the microbiome among human and animal populations with spinal cord injury (SCI).

Methods

Four databases (EMBASE, Medline (Ovid), Web of Science, Cochrane Central Register of Trials (CENTRAL)) and Google Scholar were searched. No language restrictions were applied. Data extraction was done in parallel and independently by two reviewers. The search was last conducted on 07 April 2021.

Results

There were 6869 studies retrieved, 43 full-text studies reviewed, and 19 studies included. There were seven animal gut studies, six human gut studies, and six urinary tract studies identified. There were no publications found on other body sites. Among the included studies, we observed a consistent and significant difference in gut microbiome composition between populations with SCI and able-bodied populations. This is characterized by a decrease in beneficial butyrate-producing bacteria (Faecalbacterium, Megamonas, Roseburia) and an increase in inflammation-associated bacteria (Alistipes, Anaerotruncus, and Lachnoclostridium). On the other hand, the urine of individuals with SCI was polymicrobial and members of Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae) were frequently observed. Probiotics were shown to induce a significant but transient shift in the urinary tract microbiome. The studies had low to moderate risks of bias.

Conclusions

There are limited studies on the changes in microbiome among SCI populations. The gut microbiome was characterized by bacterial profiles associated with chronic inflammation and metabolic disorder while the studies of the urinary tract microbiome show the dominance of bacterial genera associated with urinary tract infection.

An observational study on body mass index during rehabilitation and follow-up in people with spinal cord injury in Denmark

STUDY DESIGN

Observational study OBJECTIVE: To describe body mass index (BMI) during rehabilitation in people with a newly sustained spinal cord injury (SCI).

SETTING

Inpatient SCI rehabilitation in Denmark.

PARTICIPANTS

Inpatients, >18 years, having sustained a SCI within the last 12 months at admission to primary rehabilitation, inclusive of various SCI etiology, neurological level, completeness of the lesion or mobility status.

METHODS

Measures of BMI were obtained at admission and discharge as part of standard care. At one SCI center measures of BMI were sampled at follow up 9.5 months after discharge as well. BMI was described by mean and standard deviation (SD). Paired t-test was used to test difference in BMI between admission and discharge. Repeated measures Analysis of Variance (ANOVA) was used for analyzing BMI deriving from three time points.

RESULTS

Overall BMI was stable with no change (25.4 kg/m² at admission and 25.6 kg/m² at discharge) during rehabilitation at the two national centers. In participants with an American Spinal Injury Association (ASIA) Impairment Scale (AIS) D classification, BMI was higher during rehabilitation compared to the other groups and increased significantly (p = 0.008) from discharge to follow up.

CONCLUSIONS

Overall BMI was stable but higher than recommended in people with SCI undergoing rehabilitation at the two national centers in Denmark. Participants with an AIS D SCI were obese according to SCI adjusted BMI and the World Health Organization (WHO) recommendations during rehabilitation and at follow up.

Exoskeleton Training and Trans-Spinal Stimulation for Physical Activity Enhancement After Spinal Cord Injury (EXTra-SCI): An Exploratory Study

After spinal cord injury (SCI) physical activity levels decrease drastically, leading to numerous secondary health complications. Exoskeleton-assisted walking (EAW) may be one way to improve physical activity for adults with SCI and potentially alleviate secondary health complications. The effects of EAW may be limited, however, since exoskeletons induce passive movement for users who cannot volitionally contribute to walking. Trans-spinal stimulation (TSS) has shown the potential to enable those with even the most severe SCI to actively contribute to movements during EAW. To explore the effects of EAW training on improving secondary health complications in persons with SCI, participants with chronic (n = 8) were enrolled in an EAW program 2-3 times per week for 12 weeks. Anthropometrics (seated and supine waist and abdominal circumferences (WC and AC), body composition assessment (dual exposure x-ray absorptiometry-derived body fat percent, lean mass and total mass for the total body, legs, and trunk), and peak oxygen consumption (VO2 during a 6-minute walk test [6MWT]) were assessed before and after 12 weeks of EAW training. A subset of participants (n = 3) completed EAW training with concurrent TSS, and neuromuscular activity of locomotor muscles was assessed during a 10-m walk test (10MWT) with and without TSS following 12 weeks of EAW training. Upon completion of 12 weeks of training, reductions from baseline (BL) were found in seated WC (-2.2%, P = 0.036), seated AC (-2.9%, P = 0.05), and supine AC (-3.9%, P = 0.017). Percent fat was also reduced from BL for the total body (-1.4%, P = 0.018), leg (-1.3%, P = 0.018), and trunk (-2%, P = 0.036) regions. No effects were found for peak VO2. The addition of TSS for three individuals yielded individualized responses but generally increased knee extensor activity during EAW. Two of three participants who received TSS were also able to initiate more steps without additional assistance from the exoskeleton during a 10MWT. In summary, 12 weeks of EAW training significantly attenuated markers of obesity relevant to cardiometabolic health in eight men with chronic SCI. Changes in VO2 and neuromuscular activity with vs. without TSS were highly individualized and yielded no overall group effects.

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.

Leisure-time physical activity, anthropometrics, and body composition as predictors of quality of life domains after spinal cord injury: an exploratory cross-sectional study

The objective of the current work was to examine the relationships between quality of life (QOL) domains in persons with spinal cord injury (SCI) and their levels of weekly leisure-time physical activity (LTPA), anthropometric variables, and body composition variables. This exploratory cross-sectional study consisted of baseline data collected as part of a randomized clinical trial at a VA Medical Center and SCI center. A convenience sample of 36 community-dwelling persons with SCI participated in the current study. Outcome measures included the World Health Organization Quality of Life Short Form (WHOQOL-BREF), Leisure-Time Physical Activity Questionnaire for People with Spinal Cord Injury (LTPAQ-SCI), anthropomorphic measures (waist, hip, and abdominal circumference), and dual-energy x-ray absorptiometry (DXA) to quantify regional and total body composition. Multiple regression models suggested that engagement in LTPA accounted for 35.7% of the variance in physical health QOL, 33.5% in psychological QOL, 14.2% in social relationships QOL, and 38.2% in environmental QOL. Anthropometric measures accounted for 11.3%, 3.1%, 12.0%, and 6.7% of the variance in these QOL indices, respectively, and DXA indices accounted for 18.7%, 17.5%, 27.4%, and 21.9%. Within these models, the number of minutes of heavy LTPA per day uniquely predicted physical health QOL, the number of mild LTPA days per week uniquely predicted psychological QOL, and the amount of mild LTPA per day uniquely predicted environmental QOL. Bivariate analyses also suggested that android and trunk fat, as well as supine waist and abdominal circumferences, were positively associated with social relationships QOL. Encouraging individuals with SCI to engage in LTPA may robustly enhance multiple aspects of QOL while reducing the risk for cardiovascular and metabolic morbidities associated with SCI. Moreover, this may lead to a further understanding of how QOL may impact longitudinal intervention trials. The study protocol and procedures were reviewed and approved by the McGuire VA Research Institutional Review Board (IRB# 02152, approval date August 9, 2015; IRB# 02375, approval date May 2, 2018).

Effects of intensity-matched exercise at different intensities on inflammatory responses in able-bodied and spinal cord injured individuals

Objective: To compare the effects of intensity-matched acute exercise at different intensities on proinflammatory and anti-inflammatory cytokines between able-bodied (AB) and spinal cord injured (SCI) individuals.Design: Non-Randomized Controlled Trial.Setting: Community settings in São Paulo - Brazil.Participants: Eight AB and nine SCI paraplegic.Interventions: Participants underwent three exercise sessions at different relative intensities: at ventilatory threshold 1 intensity (VT1), 15% below VT1, and 15% above VT1. Similar energy expenditures were established from exercises with different intensities for each volunteer. The AB group was tested on a conventional treadmill, whereas the SCI group was tested on a treadmill adapted for wheelchair use. Blood samples were collected at baseline, immediately after, and 30 min after the exercise sessions.Outcome measures: Interleukin 1 receptor antagonist, interleukin 1 beta, interleukin 2, interleukin 4, interleukin 6, interleukin 10 and tumoral necrosis factor alpha were measured.Results: When groups were compared, interleukin - 2 was found higher, whereas interleukin - 4 and interleukin - 10 were found lower in the SCI group at all collection times in the three exercise intensities (all P < 0.05). Interleukin - 1 receptor antagonist was found higher immediately after exercise at VT1, 15% above VT1 and 30 min after 15% below VT1 in the AB group (all P < 0.05). In the AB group, an increase in interleukin - 6 immediately after the exercise at VT1 compared with baseline was found (P = 0.01).Conclusion: Individuals with SCI may have to perform physical exercise at a higher volume or energy expenditure than AB individuals to obtain similar anti-inflammatory benefits of acute exercise.Trial registration: Uniform Trial Number identifier: U1111-1232-8142.

Bone mesenchymal stem cell-derived extracellular vesicles deliver microRNA-23b to alleviate spinal cord injury by targeting toll-like receptor TLR4 and inhibiting NF-κB pathway activation

Bone mesenchymal stem cell-derived extracellular vesicles (BMSC-EVs) are known for recovery of injured tissues. We investigated the possible mechanism of BMSC-EVs in spinal cord injury (SCI). EVs were isolated from BMSCs and injected into SCI rats to evaluate the recovery of hindlimb motor function. The spinal cord tissue was stained after modeling to analyze spinal cord structure and inflammatory cell infiltration and detect microRNA (miR)-23b expression. The activity of lipopolysaccharide (LPS)-induced BV2 inflammatory cells was detected. The protein contents of interleukin (IL)-6, IL-1β, IL-10 and tumor necrosis factor-α (TNF-α) in spinal cord and BV2 cells were measured. Western blot analysis was used to detect the level of toll-like receptor (TLR)4, p65, p-p65, iNOS, and Arg1 in spinal cord tissue and cells. TLR4 was overexpressed in rats and cells to evaluate the content of inflammatory cytokines. After EV treatment, the motor function of SCI rats was improved, SCI was relieved, and miR-23b expression was increased. After treatment with EV-miR-23b, iNOS, IL-6, IL-1β, and TNF-α contents were decreased, while Arg1 and IL-10 were increased. The levels of TLR4 and p-p65 in spinal cord and BV2 cells were decreased. The rescue experiments verified that after overexpression of TLR4, the activity of BV2 cells was decreased, the contents of IL-6, IL-1β, TNF-α, and p-p65 were increased, IL-10 was decreased, and SCI was aggravated. To conclude, The miR-23b delivered by BMSC-EVs targets TLR4 and inhibits the activation of NF-κB pathway, relieves the inflammatory response, so as to improve SCI in rats.

Peripheral Immune Dysfunction: A Problem of Central Importance after Spinal Cord Injury

Simple Summary

Spinal cord injury can result in an increased vulnerability to infections, but until recently the biological mechanisms behind this observation were not well defined. Immunosuppression and concurrent sustained peripheral inflammation after spinal cord injury have been observed in preclinical and clinical studies, now termed spinal cord injury-induced immune depression syndrome. Recent research indicates a key instigator of this immune dysfunction is altered sympathetic input to lymphoid organs, such as the spleen, resulting in a wide array of secondary effects that can, in turn, exacerbate immune pathology. In this review, we discuss what we know about immune dysfunction after spinal cord injury, why it occurs, and how we might treat it.

Abstract

Individuals with spinal cord injuries (SCI) exhibit increased susceptibility to infection, with pneumonia consistently ranking as a leading cause of death. Despite this statistic, chronic inflammation and concurrent immune suppression have only recently begun to be explored mechanistically. Investigators have now identified numerous changes that occur in the peripheral immune system post-SCI, including splenic atrophy, reduced circulating lymphocytes, and impaired lymphocyte function. These effects stem from maladaptive changes in the spinal cord after injury, including plasticity within the spinal sympathetic reflex circuit that results in exaggerated sympathetic output in response to peripheral stimulation below injury level. Such pathological activity is particularly evident after a severe high-level injury above thoracic spinal cord segment 6, greatly increasing the risk of the development of sympathetic hyperreflexia and subsequent disrupted regulation of lymphoid organs. Encouragingly, studies have presented evidence for promising therapies, such as modulation of neuroimmune activity, to improve regulation of peripheral immune function. In this review, we summarize recent publications examining (1) how various immune functions and populations are affected, (2) mechanisms behind SCI-induced immune dysfunction, and (3) potential interventions to improve SCI individuals’ immunological function to strengthen resistance to potentially deadly infections.

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.

Strategies used by providers to support individuals with spinal cord injury in weight management: a qualitative study of provider perspectives

STUDY DESIGN

This is a descriptive qualitative study.

OBJECTIVES

To explore recommended strategies employed by healthcare providers to support individuals with SCI in weight management.

SETTING

Fourteen veteran administration hospitals in the United States and the Shirley Ryan AbilityLab (SRALab) SCI Model Systems in Illinois.

METHODS

Semi-structured interviews were conducted with interprofessional SCI providers involved in weight management with individuals living with SCI. Thematic analysis methods were used.

RESULTS

A total of 25 interprofessional providers were interviewed. Providing clinical expertise to assist in weight management included (1) checking progress or status of weight over time, (2) monitoring and tracking other health-related indicators, (3) stressing weight-related health risks, (4) providing education, (5) encouraging healthy behaviors, and (6) identifying and accessing resources. Fostering provider-patient relationships included (1) establishing and maintaining rapport and (2) tailoring/individualizing weight management treatment. Coordinating a team approach included (1) involving a dietitian or nutritionist, (2) communicating the same message, and (3) involving the informal caregiver/family.

CONCLUSION

Weight management strategies should incorporate patient preferences and goals, informed through provider expert and personalized clinical advice, and supported within the context of interprofessional team collaboration that includes caregivers and family.

The impact of body mass index on one-year mortality after spinal cord injury

Objective: Evaluate the association between body mass index (BMI, kg/m²) and one-year mortality among people who survived the first 90 days after spinal cord injury (SCI).Design: Cohort study.Setting: Eighteen SCI Model Systems centers throughout the United States.Participants: 6640 participants (men, 79.6%; mean age, 42.8 ± 17.7y; Whites, 62.3%) who had an SCI between October 2006 and March 2017.Interventions: Not applicable.Outcome Measures: All-cause mortality and causes of death. Life table method was used to estimate mortality rates, while Cox proportional hazard model was conducted to assess the impact of BMI on mortality after adjusting for demographic and injury-related factors.Results: Based on BMI obtained during initial rehabilitation, participants were classified into underweight (4.2%), normal weight (41.2%), overweight (30.9%) and obese (23.8%) groups, and their corresponding one-year mortality rates were 2.6%, 1.8%, 3.1%, 3.5%, respectively (P = 0.002). After adjusting for potential confounding factors, people with obesity had a higher mortality risk than those with normal weight (hazard ratio, 1.51; 95% confidence interval, 1.00-2.28). The most frequent causes of death for people with obesity were infective and parasitic diseases and respiratory diseases, while respiratory diseases were the most frequent for people with other BMI statuses.Conclusion: People with obesity who incur an SCI need special attention to prevent early mortality. Future studies should explore factors that contribute to such a higher mortality after SCI, such as preexisting conditions and comorbidities. The effects of BMI on long-term mortality also deserve further investigation.

MicroRNA-488 inhibits neural inflammation and apoptosis in spinal cord injury through restraint on the HMGB1/TLR4/NF-κB signaling pathway

OBJECTIVES

Secondary spinal cord injury (SCI), a reversible pathological change, involves neural inflammation and apoptosis. This study explored how microRNA (miR)-488, an inflammatory regulator as reported affected secondary SCI.

METHODS

In vivo, Wistar rats were clipped on the spinal cord for SCI induction. In vitro, PC-12 cells were treated with lipopolysaccharide (LPS) to induce cell injuries to mimic the environment during the secondary SCI. Cell viability and apoptosis were measured by CCK-8 assay and flow cytometry. The levels of inflammation-related factors (interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α) in the serum and PC-12 cells were determined by ELISA. The expressions of miR-488, high mobility group box 1 (HMGB1), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), cleaved caspase-3, toll-like receptor 4 (TLR4), phosphorylated (p)-p65 and total-p65 in rat spinal cord or PC-12 cells were analyzed by quantitative reverse transcription PCR or western blot.

RESULTS

After SCI induction, rats exhibited low Basso-Beattie-Bresnahan scores, promoted the release of inflammation-related factors and downregulated miR-488. LPS treatment decreased cell viability, enhanced apoptosis and downregulated miR-488. Upregulating miR-488 neutralized LPS-induced releases of inflammation-related factors and expressions of Bax and cleaved caspase-3 and counteracted LPS-induced inhibition on Bcl-2 expression. MiR-488 directly targeted HMGB1 and miR-488 mimic decreased LPS-induced HMGB1 expression. Overexpressing HMGB1 counteracted miR-488 mimic-induced decreases in the expressions of TLR4 and p-p65 and the ratio of p-p65 to Total-p65 in LPS-treated PC-12 cells.

CONCLUSION

MiR-488 inhibited neural inflammation and apoptosis in SCI via its binding with HMGB1-mediated restraint on the TLR4/NF-κB signaling pathway.

Demonstrating the vital role of physiatry throughout the health care continuum: Lessons learned from impacts of the COVID-19 pandemic on the disability community

COVID White Paper Series

Acute exercise improves glucose effectiveness but not insulin sensitivity in paraplegia

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Role of exercise on visceral adiposity after spinal cord injury: a cardiometabolic risk factor

PURPOSE

Visceral adipose tissue (VAT) is associated with cardiometabolic disease risk in able-bodied (AB) populations. However, the underlying mechanisms of VAT-induced disease risk are unknown in persons with spinal cord injury (SCI). Potential mechanisms of VAT-induced cardiometabolic dysfunction in persons with SCI include systemic inflammation, liver adiposity, mitochondrial dysfunction, and anabolic deficiency. Moreover, how exercise interventions impact these mechanisms associated with VAT-induced cardiometabolic dysfunction are still being explored.

METHODS

A search for relevant scientific literature about the effects of exercise on VAT and cardiometabolic health was conducted on the PubMed database. Literature from reference lists was also included when appropriate.

RESULTS

Both aerobic and resistance exercise training beneficially impact health and VAT mass via improving mitochondrial function, glucose effectiveness, and inflammatory signaling in SCI and AB populations. Specifically, aerobic exercise appears to also modulate cellular senescence in AB populations and animal models, while resistance exercise seems to augment anabolic signaling in persons with SCI.

CONCLUSIONS

The current evidence supports regular engagement in exercise to reduce VAT mass and the adverse effects on cardiometabolic health in persons with SCI. Future research is needed to further elucidate the precise mechanisms by which VAT negatively impacts health following SCI. This will likely facilitate the development of rehabilitation protocols that target VAT reduction in persons with SCI.