Diabetes mellitus in individuals with spinal cord injury or disorder

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.

Low-frequency electrically induced exercise after spinal cord injury: Physiologic challenge to skeletal muscle and feasibility for long-term use

CONTEXT

Skeletal muscle has traditionally been considered a "force generator": necessary for purposes of locomotion, but expendable for non-ambulators who use wheelchairs, such as people with a spinal cord injury (SCI). Active skeletal muscle plays an indispensable role in regulating systemic metabolic functions, even in people with paralysis, but because of severe osteoporosis, high tetanic muscle forces induced with high frequency electrical stimulation may be risky for some individuals. The purpose of this study was to compare the physiologic muscle properties incurred by two low force/low frequency repetitive stimulation protocols (1 and 3 Hz); and, to assess the acceptability of each protocol among people with SCI.

METHODS

Ten individuals with chronic SCI (12.9 years) and 11 individuals without SCI (NonSCI) participated in the study. Participants received either 1 or 3 Hz stimulation to the quadriceps muscle on Day 1, then the converse on Day 2. Each session consisted of 1000 stimulus pulses.

RESULTS

The initial and maximum forces were similar for the 1 and 3 Hz frequencies. The fatigue index (FI) for SCI and NonSCI groups were lower (P < 0.007) for 3 Hz than for 1 Hz (0.34 ± 0.17 versus 0.65 ± 0.16 and 0.72 ± 0.14 versus 0.87 ± 0.07, respectively).

CONCLUSION

The 3 Hz stimulation offered the greatest physiological challenge and was perceived as more acceptable for long term use among people with SCI.

The effect of level of injury on diabetes incidence and mortality after spinal cord injury - a longitudinal cohort study

STUDY DESIGN

Retrospective longitudinal cohort study of veterans with SCI.

OBJECTIVES

Spinal cord injury (SCI) is associated with an increased risk of developing diabetes mellitus (DM), likely due to body composition alterations and autonomic nervous system dysfunction. These factors are more pronounced in persons with tetraplegia (TP) versus paraplegia (PP). However, the effect of level of injury (LOI) on DM incidence is largely unknown. Therefore, the objective is to examine the effect of LOI on DM incidence in persons with SCI.

SETTING

South Texas Veterans Health Care System.

METHODS

We obtained electronic record data on age, sex, race/ethnicity, LOI and HbA1c concentration from January 1st 2001 through December 31st 2021. Cox proportional hazard regression analyses were used to assess the association between LOI, DM and all-cause mortality.

RESULTS

Among 728 non-diabetic veterans with SCI (350 TP/ 378 PP, 52 ± 15 years, 690 male/38 female) 243 developed DM, of which 116 with TP and 127 with PP. Despite chronological variations between TP and PP, DM risk over the entire follow-up did not differ between the groups (hazard ratio (HR): 1.06, 95% CI: 0.82-1.38). Mortality was higher in TP versus PP (HR: 1.40, 95% CI: 1.09-1.78). However, developing DM did not increase the risk of death, regardless of LOI (HR: 1.07, 95% CI: 0.83-1.37).

CONCLUSION

Despite chronological variations between both groups, the level of injury had minimal effect on long-term DM development in this cohort of veterans with SCI. Sponsorship NIH (DK105379; MS), RR&D SPiRE (I21RX003724-01A1; MT and SH).

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.

Type 2 Diabetes Increases the Risk of Serious and Life-Threatening Conditions Among Adults With Traumatic Spinal Cord Injury

Objective

To compare the incidence of and adjusted hazards for serious and life-threatening morbidities among adults with traumatic spinal cord injury (TSCI) with and without type 2 diabetes (T2D).

Participants and Methods

A retrospective longitudinal cohort study was conducted from September 1, 2022 to February 2, 2023, among privately insured beneficiaries if they had an International Classification of Diseases, 9th Revision or 10th Revision, Clinical Modification diagnostic code for TSCI (n=9081). Incidence estimates of serious and life-threatening morbidities, and more common secondary and long-term health conditions, were compared at 5 years of enrollment. Survival models were used to quantify unadjusted and adjusted hazard ratios for serious and life-threatening morbidities.

Results

Adults living with TSCI and T2D had a higher incidence of all of the morbidities assessed as compared with nondiabetic adults with TSCI. Fully adjusted survival models reported that adults with TSCI and T2D had a greater hazard for most of the serious and life-threatening conditions assessed, including sepsis (hazard ratio [HR]: 1.65), myocardial infarction (HR: 1.63), osteomyelitis (HR: 1.9), and stroke or transient ischemic attack (HR: 1.59). Rates for comorbid and secondary conditions were higher for individuals with TSCI and T2D, such as pressure sores, urinary tract infections, and depression, even after controlling for sociodemographic and comorbid conditions.

Conclusion

Adults living with TSCI and T2D have a significantly higher incidence of and risk of developing serious and life-threatening morbidities as compared with nondiabetic adults with TSCI.

Denervation impacts muscle quality and knee bone mineral density after spinal cord injury

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

To compare muscle size, body composition, bone mineral density (BMD), and metabolic profiles in denervated versus innervated individuals with spinal cord injury (SCI).

SETTING

Hunter Holmes McGuire Veterans Affairs (VA) Medical Center.

METHODS

Body composition, bone mineral density (BMD), muscle size, and metabolic parameters were collected in 16 persons with chronic SCI (n = 8 denervated, n = 8 innervated) using dual-energy x-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and fasting blood samples. BMR was measured by indirect calorimetry.

RESULTS

Percent differences of the whole thigh muscle cross-sectional area (CSA; 38%), knee extensor CSA (49%), vasti CSA (49%), and rectus femoris CSA (61%) were smaller in the denervated group (p < 0.05). Leg lean mass was also lower (28%) in the denervated group (p < 0.05). Whole muscle intramuscular fat (IMF%; 15.5%), knee extensor IMF% (22%), and % fat mass (10.9%) were significantly greater in the denervated group (p < 0.05). Knee distal femur and proximal tibia BMD were lower in the denervated group, 18-22% and 17-23%; p < 0.05. Certain indices of metabolic profile were more favorable in the denervated group though were not significant.

CONCLUSIONS

SCI results in skeletal muscle atrophy and dramatic changes in body composition. Lower motor neuron (LMN) injury results in denervation of the lower extremity muscles which exacerbates atrophy. Denervated participants exhibited lower leg lean mass and muscle CSA, greater muscle IMF, and reduced knee BMD compared to innervated participants. Future research is needed to explore therapeutic treatments for the denervated muscles after SCI.

We Got Your Back: Evaluating Recovery Following Spinal Cord Injury After High-Voltage Electric Burns

Delayed spinal cord injury (SCI) is a relatively rare consequence of high voltage electrical burns, but it holds significant implications for patient quality of life. Due to the uncommon nature of delayed SCI and variable time of onset following injury, providers are currently unable to provide a prognosis for functional recovery and optimize a therapy process tailored to treat this patient populace. In this study, we aim to better map the pattern of recovery in these patients to better inform future rehabilitation practices. A retrospective chart review of five patients who experienced delayed SCI secondary to an electrical burn was conducted. The majority of patients displayed an upward trajectory in motor function following acute hospitalization and inpatient rehabilitation, with four of the five patients able to achieve complete motor strength in multiple extremities. In addition, rehabilitation was shown to have a noticeable impact in improving functional independence in tasks related to nursing. In conclusion, the clinical and functional outcomes of these delayed SCI patients point to the need for multidisciplinary management following injury and highlight the importance of early rehabilitation in regaining function.

The use of alkaline phosphatase as a bone turnover marker after spinal cord injury: A scoping review of human and animal studies

BACKGROUND

Serum alkaline phosphatase (ALP) is measured as an indicator of bone or liver disease. Bone-specific alkaline phosphatase (B-ALP) is an isoform of ALP found in the bone tissue which can predict fractures and heterotopic ossification.

OBJECTIVE

The aim of this scoping review was to explore the current use of ALP and B-ALP in studies using humans or animal models of SCI, and to identify ways to advance future research using ALP and B-ALP as a bone marker after SCI.

RESULTS

HUMAN STUDIES: 42 studies were included. The evidence regarding changes or differences in ALP levels in individuals with SCI compared to controls is conflicting. For example, a negative correlation between B-ALP and total femur BMD was observed in only one of three studies examining the association. B-ALP seemed to increase after administration of teriparatide, and to decrease after treatment with denosumab. The effects of exercise on ALP and B-ALP levels are heterogeneous and depend on the type of exercise performed. ANIMAL STUDIES: 11 studies were included. There is uncertainty regarding the response of ALP or B-ALP levels after SCI; levels increased after some interventions, including vibration protocols, curcumin supplementation, cycles in electromagnetic field or hyperbaric chamber. Calcitonin or bisphosphonate administration did not affect ALP levels.

CONCLUSION

Researchers are encouraged to measure the bone-specific isoform of ALP rather than total ALP in future studies in humans of animal models of 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.

Altered chronic glycemic control in a clinically relevant model of rat thoracic spinal contusion

The lifetime risk for Type 2 diabetes mellitus remains higher in people with spinal cord injuries (SCIs) than in the able-bodied population. However, the mechanisms driving this disparity remain poorly understood. The goal of the present study was to evaluate the impact of a palatable high-fat diet (HFD) on glycemic regulation using a rodent model of moderate thoracic contusion. Animals were placed on either Chow or HFD and tolerance to glucose, insulin, and ENSURE mixed meal were investigated. Important targets in the gut-brain axis were investigated. HFD consumption equally induced weight gain in SCI and naïve rats over chow (CH) rats. Elevated blood glucose was observed during intraperitoneal glucose tolerance test in HFD-fed rats over CH-fed rats. Insulin tolerance test (ITT) was unremarkable among the three groups. Gavage of ENSURE resulted in high glucagon-like peptide 1 (GLP-1) release from SCI rats over naïve controls. An elevation in terminal total GLP-1 was measured, with a marked reduction in circulating dipeptidyl peptidase 4, the GLP-1 cleaving enzyme, in SCI rats, compared with naïve. Increased glucagon mRNA in the pancreas and reduced immunoreactive glucagon-positive staining in the pancreas in SCI rats compared with controls suggested increased glucagon turnover. Finally, GLP-1 receptor gene expression in the ileum, the primary source of GLP-1 production and release, in SCI rats suggests the responsivity of the gut to altered circulating GLP-1 in the body. In conclusion, the actions of GLP-1 and its preprohormone, glucagon, are markedly uncoupled from their actions on glucose control in the SCI rat. More work is required to understand GLP-1 in the human.

Fat Oxidation during Exercise in People with Spinal Cord Injury, and Protocols Used: A Systematic Review

BACKGROUND

The aim of this study was to summarize evidence on energy metabolism through peak fat oxidation (PFO) and maximum fat oxidation (Fat_max), as well as to analyze the protocols used in people with spinal cord injury (SCI) and to examine the main factors related to fat oxidation ability (i.e., age, sex, level of physical activity, and level and degree of injury).

METHODS

Studies to determine PFO and Fat_max using indirect calorimetry with an arm exercise protocol for SCI patients were included after a systematic search. Other endpoints included study design, sample size, control group, demographic data, level of injury, physical condition, protocol, outcomes measured, and statistical findings.

RESULTS

Eight studies (n = 560) were included. The mean value of VO_2peak was 1.86 L∙min^-1 (range 0.75-2.60 L∙min^-1) (lowest value in the tetraplegic subjects). The PFO ranged between 0.06 and 0.30 g∙min^-1 (lowest rates: the non-trained subjects with cervical SCI; highest: the tetraplegic subjects). Two types of exercise protocol were found: arm cycle ergometer, and wheelchair propulsion with a computerized ergometer. Five studies used an incremental protocol (2-3 min/stage, different load increments); the rest performed tests of 20 min/stage at three intensities.

CONCLUSION

There are few existing studies measuring fat oxidation in SCI, many of which used small and heterogeneous samples. PFO was lower in SCI subjects when compared with non-injured people performing lower-limb exercise; however, comparing upper-limb exercise, people with SCI showed higher values.

Do Patients With Chronic Diabetes Have Worse Motor Outcomes After Cervical ASIA C Traumatic Spinal Cord Injury?

STUDY DESIGN

This was a level IV retrospective prognostic study.

OBJECTIVE

The objective of this study was to determine if patients with chronic diabetes have worse functional outcomes and motor recovery after cervical traumatic spinal cord injury (TSCI).

SUMMARY OF BACKGROUND DATA

Diabetes mellitus has multiple deleterious neurological effects and has been shown to worsen elective cervical spine surgery outcomes. Prior literature has scarcely characterized the impact of chronic diabetes on motor and functional outcomes after TSCI.

METHODS

The National Spinal Cord Injury Statistical Center (NSCISC) database was utilized to retrospectively collect data on cervical American Spinal Injury Association (ASIA) C TSCI between 2011 and 2016. Patients were divided into diabetes and nondiabetes groups. Primary outcomes included wheelchair requirement and ambulatory status 1 year after injury. Secondary outcomes were motor score collected at the time of rehab admission, rehab discharge, and 1-year follow-up. All outcome variables were analyzed using univariate and multivariate regression to assess for differences between diabetes and nondiabetes groups and possible confounders.

RESULTS

A total of 219 patients met the inclusion criteria for the study: 193 without diabetes and 26 with diabetes (12.0%). After controlling for confounders, patients with diabetes had had significantly increased wheelchair requirement (83.3% vs. 51.8%, relative risk=1.63, 95% confidence interval: 1.20-1.83, P =0.009 multivariate) and decreased ambulatory rates (50% vs. 67.9%, relative risk=0.55, 95% confidence interval: 0.25-0.98, P =0.042 multivariate) at 1 year. They also had no difference in average total motor scores at rehab admission but significantly worse total motor scores at rehab discharge (50.6±23.3 vs. 60.3±21.4, P =0.033 univariate, P =0.002 multivariate).

CONCLUSIONS

Patients with diabetes have increased wheelchair requirement and decreased ambulatory ability at 1 year after the injury as well as diminished recovery in motor scores after motor-incomplete cervical TSCI. These patients may be targets for aggressive diabetic screening and intervention to minimize negative outcomes.

Testosterone and long pulse width stimulation (TLPS) for denervated muscles after spinal cord injury: a study protocol of randomised clinical trial

INTRODUCTION

Long pulse width stimulation (LPWS; 120-150 ms) has the potential to stimulate denervated muscles and to restore muscle size in denervated people with spinal cord injury (SCI). We will determine if testosterone treatment (TT)+LPWS would increase skeletal muscle size, leg lean mass and improve overall metabolic health in persons with SCI with denervation. We hypothesise that the 1-year TT+LPWS will upregulate protein synthesis pathways, downregulate protein degradation pathways and increase overall mitochondrial health.

METHODS AND ANALYSIS

Twenty-four male participants (aged 18-70 years with chronic SCI) with denervation of both knee extensor muscles and tolerance to the LPWS paradigm will be randomised into either TT+neuromuscular electrical stimulation via telehealth or TT+LPWS. The training sessions will be twice weekly for 1 year. Measurements will be conducted 1 week prior training (baseline; week 0), 6 months following training (postintervention 1) and 1 week after the end of 1 year of training (postintervention 2). Measurements will include body composition assessment using anthropometry, dual X-ray absorptiometry and MRI to measure size of different muscle groups. Metabolic profile will include measuring of basal metabolic rate, followed by blood drawn to measure fasting biomarkers similar to hemoglobin A1c, lipid panels, C reactive protein, interleukin-6 and free fatty acids and then intravenous glucose tolerance test to test for insulin sensitivity and glucose effectiveness. Finally, muscle biopsy will be captured to measure protein expression and intracellular signalling; and mitochondrial electron transport chain function. The participants will fill out 3 days dietary record to monitor their energy intake on a weekly basis.

ETHICS AND DISSEMINATION

The study was approved by Institutional Review Board of the McGuire Research Institute (ID # 02189). Dissemination plans will include the Veteran Health Administration and its practitioners, the national SCI/D services office, the general healthcare community and the veteran population, as well as the entire SCI community via submitting quarterly letters or peer-review articles.

TRIAL REGISTRATION NUMBER

NCT03345576.

Nutrient composition influences the gut microbiota in chronic thoracic spinal cord-injured rats

Chronic spinal cord injury (SCI) results in an increased predisposition to various metabolic problems that can be exacerbated by consuming a diet rich in calories and saturated fat. In addition, gastrointestinal symptoms have been reported after SCI, including intestinal dysbiosis of the gut microbiome. The effects of both diet and SCI on the gut microbiome of adult male Long Evans rats euthanized 16 wk after injury were investigated. The rats were either thoracic spinal contused or received sham procedures. After 12 wk of either a low-fat or high-fat diet, cecal contents were analyzed, revealing significant microbial changes to every taxonomic level below the kingdom level. Shannon α diversity analyses demonstrated a significant difference in diversity between the groups based on the surgical condition of the rats. SCI produced a unique signature of changes in commensal bacteria that were significantly different than Sham. Specific changes in commensal bacteria as a result of diet manipulation had high fidelity with reports in the literature, such as Clostridia, Thiohalorhabdales, and Pseudomonadales. In addition, novel changes in commensal bacteria were identified that are unique dietary influences on SCI. Linear regression analysis on body fat and lean mass showed that a consequence of chronic SCI produces uncoupled associations between some commensal bacteria and body composition. In conclusion, despite tightly controlling the protein content and varying the carbohydrate and fat contents, Sham and SCI rats respond uniquely to diet. These data provide potential direction for therapeutic modulation of the microbiome to improve health and wellness following SCI.

Spinal electrical stimulation to improve sympathetic autonomic functions needed for movement and exercise after spinal cord injury: a scoping clinical review

Spinal cord injury (SCI) results in sensory, motor and autonomic dysfunction. Obesity, cardiovascular and metabolic diseases are highly prevalent after SCI. Although inadequate voluntary activation of skeletal muscle contributes, it is absent or inadequate activation of thoracic spinal sympathetic neural circuitry and sub-optimal activation of homeostatic (cardiovascular, temperature) and metabolic support systems that truly limits exercise capacity, particularly for those with cervical SCI. Thus, when electrical spinal cord stimulation (SCS) studies aimed at improving motor functions began mentioning effects on exercise-related autonomic functions, a potential new area of clinical application appeared. To survey this new area of potential benefit, we performed a systematic scoping review of clinical SCS studies involving these spinally mediated autonomic functions. Nineteen studies were included, 8 used transcutaneous and 11 used epidural SCS. Improvements in BP at rest or in response to orthostatic challenge were investigated most systematically, whereas reports of improved temperature regulation, whole body metabolism and peak exercise performance were mainly anecdotal. Effective stimulation locations and parameters varied between studies, suggesting multiple stimulation parameters and rostrocaudal spinal locations may influence the same sympathetic function. Brainstem and spinal neural mechanisms providing excitatory drive to sympathetic neurons that activate homeostatic and metabolic tissues that provide support for movement and exercise and their integration with locomotor neural circuitry are discussed. A unifying conceptual framework for the integrated neural control of locomotor and sympathetic function is presented which may inform future research needed to take full advantage of SCS for improving these spinally mediated autonomic functions.

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.

Preventative Services Use and Risk Reduction for Potentially Preventative Hospitalizations among People with Traumatic Spinal Cord Injury

OBJECTIVE

To examine the risk of potentially preventable hospitalizations (PPHs) for adults (18 years or older) with traumatic spinal cord injury (TSCI) to identify the most common types of preventable hospitalizations and their associative risk factors.

DESIGN

Cohort study.

SETTING

Using 2007-2017 U.S. claims data from the Optum Clinformatics Data Mart, we identified adults (18 years or older) with diagnosis of TSCI (n=5380). Adults without TSCI diagnosis were included as controls (n=1,074,729). Using age and sex, we matched individuals with and without TSCI (n=5173) with propensity scores to address potential selection bias. Generalized linear regression was applied to examine the risk of TSCI on PPHs. Models were adjusted for age; sex; race and ethnicity; Elixhauser comorbidity count; any cardiometabolic, psychological, and musculoskeletal chronic conditions; U.S. Census Division; socioeconomic variables; and use of certain preventative care services. Adjusted odds ratios were compared within a 4-year follow-up period.

PARTICIPANTS

Adults with and without TSCI (N=5,173).

INTERVENTION

Not applicable.

MAIN OUTCOMES MEASURES

Any PPH and specific PPHs RESULTS: Adults with TSCI had higher risk for any PPH (odds ratio [OR], 1.67; 95% CI,1.20-2.32), as well as PPHs because of urinary tract infection (UTI) (OR, 3.78; 95% CI, 2.47-5.79), hypertension (OR, 3.77; 95% CI, 1.54-9.21), diabetes long-term complications (OR, 2.54; 95% CI, 1.34-4.80), and pneumonia (OR, 1.71; 95% CI. 1.21-2.41). Annual wellness visit was associated with reduced PPH risk compared with cases and controls without annual wellness visit (OR, 0.57; 95% CI, 0.46-0.71) and among people with TSCI (OR, 0.69; 95% CI, 0.55-0.86) compared with cases without annual wellness visit.

CONCLUSIONS

Adults with TSCI are at a heightened risk for PPH. They are also more susceptible to certain PPHs such as UTIs, pneumonia, and heart failure. Encouraging the use of preventative or health-promoting services, especially for respiratory and urinary outcomes, may reduce PPHs among adults with TSCI.

The effects of spasticity on glucose metabolism and soft tissue body composition in patients with spinal cord injury

Objectives

The aim of this study was to assess the effects of spasticity on glucose metabolism and percentage of fat-free mass (FFM%) in patients with spinal cord injury (SCI).

Patients and methods

A total of 33 patients (22 males, 11 females; mean age: 38.6±12.5 years; range, 20 to 64 years) with SCI defined by the American Spinal Injury Association Impairment Scale Grades A to D were included between September 2014 and May 2018. We assessed spasticity with the Modified Ashworth Scale (MAS) and evaluated spasms with the Penn Spasm Frequency Scale (PSFS). We assessed the glucose metabolism by calculating the Matsuda and HOMA-IR index, and measured FFM% by dual-energy X-ray absorptiometry.

Results

Fourteen patients had motor complete, and 19 had motor incomplete SCI. The neurological injury levels of the patients were C4-T12. There was a positive correlation between hip adductor muscle MAS and trunk, android, and gynoid FFM% and between hip extensor muscle MAS and android FFM% in patients with motor complete SCI. Hip extensor and knee flexor muscle MAS showed a negative correlation with the HOMA-IR. Hip adductor and extensor muscle MAS, as well as knee flexor and extensor muscle MAS, had a positive correlation with the Matsuda index in these patients. There was a positive correlation between knee extensor muscle MAS and gynoid FFM% and between PSFS and arms, trunk, gynoid, and total FFM% in patients with motor incomplete SCI. There was a negative correlation between hip adductor and extensor muscle MAS, PSFS, and level of fasting glucose in these patients.

Conclusion

This study supports the notion that spasticity has positive effects on the FFM% and glucose metabolism in patients with motor complete and incomplete SCI.

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].

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.

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.

Cause of Death Trends Among Persons With Spinal Cord Injury in the United States: 1960-2017

OBJECTIVE

To identify trends in causes of death after spinal cord injury (SCI) that could enhance understanding of why life expectancy after SCI has not improved in the last 3 decades.

DESIGN

Cohort study.

SETTING

Twenty-nine SCI Model Systems and 3 Shriners Hospitals.

PARTICIPANTS

Individuals with traumatic SCI (N=49,266) enrolled in the SCI Collaborative Survival Study Database between 1973 and 2017.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Age-standardized cause-specific SCI mortality rates and 95% confidence intervals were calculated for 5 time intervals (1960-1979, 1980-1989, 1990-1999, 2000-2009, and 2010-2017).

RESULTS

A total of 17,249 deaths occurred in 797,226 person-years of follow-up. Since 2010, the highest mortality rate was for respiratory diseases, followed by heart disease, cancer, infective and parasitic diseases (primarily septicemia), and unintentional injuries. Mortality rates for respiratory diseases, cancer, stroke, urinary diseases, and digestive diseases, initially decreased significantly but remained relatively stable since 1980, whereas essentially no progress occurred for infective and parasitic diseases. Mortality rates for heart disease, pulmonary embolus, and suicide decreased significantly throughout the entire study period, but were offset by increases in mortality rates for endocrine (primarily diabetes), nutritional, and metabolic diseases, as well as unintentional injuries. From 2010 to 2017, the overall age-standardized mortality rate was 3 times higher for individuals with SCI than the general population, ranging from 27% higher for cancer to 9 times higher for infective and parasitic diseases.

CONCLUSION

Improving life expectancy after SCI will require: (1) reducing mortality rates from respiratory diseases and septicemia that have remained high, (2) reversing current trends in diabetes and unintentional injury deaths, and (3) continuing to reduce mortality from heart disease and other leading causes.

Advances in the Relationship Between Pyroptosis and Diabetic Neuropathy

Pyroptosis is a novel programmed cell death process that promotes the release of interleukin-1β (IL-1β) and interleukin-18 (IL-18) by activating inflammasomes and gasdermin D (GSDMD), leading to cell swelling and rupture. Pyroptosis is involved in the regulation of the occurrence and development of cardiovascular and cerebrovascular diseases, tumors, and nerve injury. Diabetes is a metabolic disorder characterized by long-term hyperglycemia, insulin resistance, and chronic inflammation. The people have paid more and more attention to the relationship between pyroptosis, diabetes, and its complications, especially its important regulatory significance in diabetic neurological diseases, such as diabetic encephalopathy (DE) and diabetic peripheral neuropathy (DPN). This article will give an in-depth overview of the relationship between pyroptosis, diabetes, and its related neuropathy, and discuss the regulatory pathway and significance of pyroptosis in diabetes-associated neuropathy.

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.

The Potential Role of Inflammation in Modulating Endogenous Hippocampal Neurogenesis After Spinal Cord Injury

Currently there are approximately 291,000 people suffering from a spinal cord injury (SCI) in the United States. SCI is associated with traumatic changes in mobility and neuralgia, as well as many other long-term chronic health complications, including metabolic disorders, diabetes mellitus, non-alcoholic steatohepatitis, osteoporosis, and elevated inflammatory markers. Due to medical advances, patients with SCI survive much longer than previously. This increase in life expectancy exposes them to novel neurological complications such as memory loss, cognitive decline, depression, and Alzheimer's disease. In fact, these usually age-associated disorders are more prevalent in people living with SCI. A common factor of these disorders is the reduction in hippocampal neurogenesis. Inflammation, which is elevated after SCI, plays a major role in modulating hippocampal neurogenesis. While there is no clear consensus on the mechanism of the decline in hippocampal neurogenesis and cognition after SCI, we will examine in this review how SCI-induced inflammation could modulate hippocampal neurogenesis and provoke age-associated neurological disorders. Thereafter, we will discuss possible therapeutic options which may mitigate the influence of SCI associated complications on hippocampal neurogenesis.

Spinal Cord Injury Reduces Serum Levels of Fibroblast Growth Factor-21 and Impairs Its Signaling Pathways in Liver and Adipose Tissue in Mice

Spinal cord injury (SCI) results in dysregulation of carbohydrate and lipid metabolism; the underlying cellular and physiological mechanisms remain unclear. Fibroblast growth factor 21 (FGF21) is a circulating protein primarily secreted by the liver that lowers blood glucose levels, corrects abnormal lipid profiles, and mitigates non-alcoholic fatty liver disease. FGF21 acts via activating FGF receptor 1 and ß-klotho in adipose tissue and stimulating release of adiponectin from adipose tissue which in turn signals in the liver and skeletal muscle. We examined FGF21/adiponectin signaling after spinal cord transection in mice fed a high fat diet (HFD) or a standard mouse chow. Tissues were collected at 84 days after spinal cord transection or a sham SCI surgery. SCI reduced serum FGF21 levels and hepatic FGF21 expression, as well as β-klotho and FGF receptor-1 (FGFR1) mRNA expression in adipose tissue. SCI also reduced serum levels and adipose tissue mRNA expression of adiponectin and leptin, two major adipokines. In addition, SCI suppressed hepatic type 2 adiponectin receptor (AdipoR2) mRNA expression and PPARα activation in the liver. Post-SCI mice fed a HFD had further suppression of serum FGF21 levels and hepatic FGF21 expression. Elevated serum free fatty acid (FFA) levels after HFD feeding were observed in post-SCI mice but not in sham-mice, suggesting defective FFA uptake after SCI. Moreover, after SCI several genes that are implicated in insulin's action had reduced expression in tissues of interest. These findings suggest that downregulated FGF21/adiponectin signaling and impaired responsiveness of adipose tissues to FGF21 may, at least in part, contribute to the overall picture of metabolic dysfunction after SCI.

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

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

Liver inflammation at the time of spinal cord injury enhances intraspinal pathology, liver injury, metabolic syndrome and locomotor deficits

The current high obesity rates mean that neurological injuries are increasingly sustained on a background of systemic pathology, including liver inflammation, which likely has a negative impact on outcomes. Because obesity involves complex pathology, the effect of hepatic inflammation alone on neurological recovery is unknown. Thus, here we used a gain-of-function model to test if liver inflammation worsens outcome from spinal cord injury (SCI) in rats. Results show liver inflammation concomitant with SCI exacerbated intraspinal pathology and impaired locomotor recovery. Hepatic inflammation also potentiated SCI-induced non-alcoholic steatohepatitis (NASH), endotoxemia and insulin resistance. Circulating and cerebrospinal levels of the liver-derived protein Fetuin-A were higher in SCI rats with liver inflammation, and, when microinjected into intact spinal cords, Fetuin-A caused macrophage activation and neuron loss. Thus, liver inflammation functions as a disease modifying factor to impair recovery from SCI, and Fetuin-A is a potential neuropathological mediator. Since SCI alone induces acute liver inflammation, the liver may be a novel clinical target for improving recovery from SCI.

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.

Neurogenic Obesity-Induced Insulin Resistance and Type 2 Diabetes Mellitus in Chronic Spinal Cord Injury

The population with SCI is at a significant risk for both insulin resistance and type 2 diabetes mellitus (T2DM) secondary to neurogenic obesity. The prevalence of insulin resistance and T2DM in persons with SCI suggests that disorders of carbohydrate metabolism are at epidemic proportions within the population. However, the true frequency of such disorders may be underestimated because biomarkers of insulin resistance and T2DM used from the population without SCI remain nonspecific and may in fact fail to identify true cases that would benefit from intervention. Furthermore, diet and exercise have been used to help mitigate neurogenic obesity, but results on disorders of carbohydrate metabolism remain inconsistent, likely because of the various ways carbohydrate metabolism is assessed. The objective of this article is to review current literature on the prevalence and likely mechanisms driving insulin resistance and T2DM in persons with SCI. This article also explores the various assessments and diagnostic criteria used for insulin resistance and T2DM and briefly discusses the effects of exercise and/or diet to mitigate disorders of carbohydrate metabolism brought on by neurogenic obesity.

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.

Dietetics After Spinal Cord Injury: Current Evidence and Future Perspectives

Following spinal cord injury (SCI), individuals are at high risk for obesity and several chronic cardiometabolic disorders due to a deterioration in body composition, hypometabolic rate, and endometabolic dysregulation. Countermeasures to the consequences of an SCI include adopting a healthy diet that provides adequate nutrition to maintain good body habitus and cardiometabolic health. A proper diet for individuals with SCI should distribute carbohydrates, protein, and fat to optimize a lower energy intake requirement and should stress foods with low caloric yet high nutrient density. The purpose of this article is to present available evidence on how nutritional status after SCI should advance future research to further develop SCI-specific guidelines for total energy intake, as it relates to percent carbohydrates, protein, fat, and all vitamins and minerals, that take into consideration the adaptations after SCI.

Sex and gender gap in spinal cord injury research: Focus on cardiometabolic diseases. A mini review

Cardiometabolic disease (CMD) is among the leading causes of morbidity and mortality in people with a spinal cord injury (SCI). Despite well-acknowledged sex and gender differences in CMD in the general population, they remain insufficiently studied in persons with SCI. To describe the landscape of sex and gender in SCI research, we searched the literature for systematic reviews on cardiometabolic health in this population. Out of 15 systematic reviews identified, only 9 provided meaningful information on sex. Although one-quarter to one-fifth of the SCI population is female, women comprised only one-eighth to a quarter of study participants. A number of clinical studies purposively excluded women, to make the study population more homogenous. For those studies which included both sexes, in general, no sex-specific analyses were performed due to small sample sizes. All these reasons have contributed to the underrepresentation of females in the current body of evidence. Therefore, future studies should adopt a more sex- and gender-sensitive research framework to address cardiometabolic risk in SCI. Novel and advanced epidemiological methods should also be used, considering small sample sizes. Finally, collaborative research (through consortia and multi-center studies) should be encouraged to include more females. More inclusive research will ensure that everyone will benefit from scientific advancements, regardless of sex and gender.

Association of Secondary Health Conditions With Future Chronic Health Conditions Among Persons With Traumatic Spinal Cord Injury

Background

Secondary health conditions (SHC) are physical and mental health conditions that are causally related to disabilities. Studies have found that SHC increase risk of negative health outcomes among people with traumatic spinal cord injury (TSCI). However, little has been done to assess the association of SHC with the risk of chronic health conditions (CHC) after TSCI.

Objectives

To identify the prevalence of CHC in adults with TSCI, changes in CHC at follow-up, and the associations of baseline SHC with future CHC.

Methods

Participants included 501 adults with TSCI of at least 1-year duration, identified through a population-based surveillance system. Baseline and follow-up self-report assessments were completed. We measured seven SHC: fatigue, spasticity, pain, pressure ulcers, subsequent injury, fracture, and anxiety disorder, and measured seven CHC: diabetes, heart attack, coronary artery disease, stroke, cancer, hypertension, and high blood cholesterol. Control variables included gender, race/ethnicity, age at injury, years post injury, injury severity, smoking status, binge drinking, and taking prescription medication. We implemented a Poisson regression model for the multivariate analyses.

Results

The total number of CHC, the percentage of participants having at least one CHC, and prevalence of three individual CHC (diabetes, cancer, and high cholesterol) increased from baseline to follow-up. After controlling for demographic, injury characteristics, and behavioral factors, pain interference and anxiety disorder at baseline were associated with the total number of CHC at follow-up.

Conclusion

CHC are common among adults with TSCI and increase significantly over time. Pain and anxiety disorders appear to be risk factors for future CHC.

Systemic Inflammation and the Breakdown of Intestinal Homeostasis Are Key Events in Chronic Spinal Cord Injury Patients

Our aim was to investigate the subset distribution and function of circulating monocytes, proinflammatory cytokine levels, gut barrier damage, and bacterial translocation in chronic spinal cord injury (SCI) patients. Thus, 56 SCI patients and 28 healthy donors were studied. The levels of circulating CD14^+highCD16^-, CD14^+highCD16⁺, and CD14^+lowCD16⁺ monocytes, membrane TLR2, TLR4, and TLR9, phagocytic activity, ROS generation, and intracytoplasmic TNF-α, IL-1, IL-6, and IL-10 after lipopolysaccharide (LPS) stimulation were analyzed by polychromatic flow cytometry. Serum TNF-α, IL-1, IL-6 and IL-10 levels were measured by Luminex and LPS-binding protein (LBP), intestinal fatty acid-binding protein (I-FABP) and zonulin by ELISA. SCI patients had normal monocyte counts and subset distribution. CD14^+highCD16^- and CD14^+highCD16⁺ monocytes exhibited decreased TLR4, normal TLR2 and increased TLR9 expression. CD14^+highCD16^- monocytes had increased LPS-induced TNF-α but normal IL-1, IL-6, and IL-10 production. Monocytes exhibited defective phagocytosis but normal ROS production. Patients had enhanced serum TNF-α and IL-6 levels, normal IL-1 and IL-10 levels, and increased circulating LBP, I-FABP, and zonulin levels. Chronic SCI patients displayed impaired circulating monocyte function. These patients exhibited a systemic proinflammatory state characterized by enhanced serum TNF-α and IL-6 levels. These patients also had increased bacterial translocation and gut barrier damage.

An exploration of attitudes and preferences towards medications among healthcare providers and persons with spinal cord injury/dysfunction: a qualitative comparison

PURPOSE

To compare the attitudes and preferences of persons with spinal cord injury/dysfunction (SCI/D) and healthcare providers regarding prescription medications, over-the-counter medications, and natural health products (NHPs).

MATERIALS AND METHODS

A qualitative study involving semi-structured interviews with healthcare providers (n = 32) and persons with SCI/D (n = 19) in Canada. Inductive descriptive and interpretive analyses were conducted using data display matrices and a constant comparative approach.

RESULTS

Participants described differing perceptions of therapeutic benefits based on medication type, with shared attitudes about the therapeutic benefits of prescription medications and differing views about the effectiveness of NHPs. Despite the perceived effectiveness of prescription medications, persons with SCI/D preferred to avoid them due to concerns about side effects, safety, and stigma. Persons with SCI/D were often concerned about the long-term safety of prescription medications, whereas providers focused more on medication-related addictions. Participants discussed stigma relating to prescription medications, NHPs, and medicinal marijuana.

CONCLUSION

Healthcare providers and persons with SCI/D described different attitudes about and preferences for pharmacotherapeutic products, contributing to challenges in optimizing medication management. Strategies to improve medication management include shared decision-making to incorporate patient preferences into care plans and explicit discussions about long-term medication safety. Further, steps are needed to combat the stigma associated with medication use.Implications for rehabilitationFollowing a person-centered approach to shared decision-making, prescribers should initiate explicit conversations about patient medication preferences, short and long-term prescription medication side effects, and alternative treatment options.Regarding prescription medication safety, persons with spinal cord injury/dysfunction focused on the long term impact of medications, while providers focused on medication-related addictions, highlighting a disconnect that should be discussed during initiation, continuation, or discontinuation of a medication.Providers should be mindful of the stigma associated with taking multiple prescription medications, including medicinal marijuana, as well as the stigma associated with over-the-counter medications and natural health products.Providers could benefit from education about spinal cord injury/dysfunction-specific prescription medications and could benefit from increased education about natural health products.

Effects of a High-Fat Diet on Tissue Mass, Bone, and Glucose Tolerance after Chronic Complete Spinal Cord Transection in Male Mice

Spinal cord injury (SCI) is associated with obesity and is a risk factor for type 2 diabetes mellitus (T2DM). Immobilization, muscle atrophy, obesity, and loss of sympathetic innervation to the liver are believed to contribute to risks of these abnormalities. Systematic study of the mechanisms underlying SCI-induced metabolic disorders has been limited by a lack of animal models of insulin resistance following SCI. Therefore, the effects of a high-fat diet (HFD), which causes weight gain and glucose intolerance in neurologically intact mice, was tested in mice that had undergone a spinal cord transection at thoracic vertebra 10 (T10) or a sham-transection. At 84 days after surgery, Sham-HFD and SCI-HFD mice showed impaired intraperitoneal glucose tolerance when compared with Sham control (Sham-Con) or SCI control (SCI-Con) mice fed a standard control chow. Glucose tolerance in SCI-Con mice was comparable to that of Sham-Con mice. The mass of paralyzed skeletal muscle, liver, and epididymal, inguinal, and omental fat deposits were lower in SCI versus Sham groups, with lower liver mass present in SCI-HFD versus SCI-Con animals. SCI also produced sublesional bone loss, with no differences between SCI-Con and SCI-HFD groups. The results suggest that administration of a HFD to mice after SCI may provide a model to better understand mechanisms leading to insulin resistance post-SCI, as well as an approach to study pathogenesis of glucose intolerance that is independent of obesity.

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

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

Interdisciplinary bodyweight management program for persons with SCI

Objective: Persons with spinal cord injury (SCI) have a higher prevalence of being overweight than the general population, which is thought to be due to a variety of metabolic, physiologic and psychological changes. The quality improvement project described in this work was designed to help overweight persons with SCI lose bodyweight through nutrition, exercise, and behavioral management strategies.Methods: Eighteen persons with SCI who were overweight were enrolled in a 12-week interdisciplinary weight management program. Participants were limited to persons at least one-year post-acute SCI with an established overweight status. Measurements, including a person's weight, body mass index, and waist circumference (WaC), were taken at the program's start, at its end, and six months post program.Results: Seventeen out of 18 participants experienced weight loss, (WaC) decreased (P < 0.001), and the program was effective at reducing weight (P < 0.001). Six months following participation in the program participants did experience a significant change in weight or waist size six months post program, thus indicating that subjects did not regain weight after completion of the program.Conclusion: This quality improvement project provided indications of the benefits of an SCI-specific interdisciplinary weight management program. Clinical research evaluating methods for helping persons with SCI achieve a healthy bodyweight is indicated.

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

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

Lifestyle modifications and pharmacological approaches to improve sexual function and satisfaction in men with spinal cord injury: a narrative review

STUDY DESIGN

A narrative review describing various components of sexual dysfunction in men with spinal cord injury (SCI), as well as addressing potential therapeutic approaches.

OBJECTIVES

Restoration of sexual function is considered one of the most important health priorities for individuals with SCI. The purpose of this review is to provide information regarding the factors that are less appreciated when considering changes to sexual function in men with SCI. We also propose therapeutic approaches, with a focus on lifestyle modifications, which have been shown to improve sexual function.

METHODS

A literature search was performed and limited evidence for therapeutic approaches in individuals with SCI was supplemented by consistent findings from the able-bodied population.

RESULTS

We evaluated the less addressed factors known to contribute to sexual dysfunction in men with SCI, including hormonal influences (i.e., testosterone deficiency, thyroid hormone, and cortisol), psychological factors (i.e., pain, fatigue, depression, and body image), and secondary SCI complications (i.e., urinary tract infection, pressure sores, and autonomic dysreflexia). To address these factors beyond standard medical treatments for sexual dysfunction, options include physical activity/exercise, diet, and specific medications for symptom relief (i.e., testosterone replacement therapy and selective serotonin reuptake inhibitors for depression).

CONCLUSIONS

Physical activity's potential application, efficacy across multiple aspects of sexuality, and the lack of side effects, suggests that long-term exercise is a viable solution to directly or indirectly improve sexual function in males with SCI. Diet and supplemental medications may further promote body composition changes, which more broadly affect sexuality.

Utilizing a low-carbohydrate/high-protein diet to improve metabolic health in individuals with spinal cord injury (DISH): study protocol for a randomized controlled trial

Background

Metabolic disorders (e.g., impaired glucose tolerance, insulin resistance, and type 2 diabetes) are more prevalent in people with spinal cord injury (SCI) than able-bodied individuals. Dietary modification is a more cost-effective treatment option than pharmacological therapies for reducing the risk of metabolic dysfunction. Lowering carbohydrate, increasing protein, and maintaining a proper dietary fat intake are expected to induce favorable adaptations in glucose control, body fat distribution, and the composition of the gut microbiome. However, dietary modification has not been rigorously investigated in people with SCI. The purpose of this study is to determine if an 8-week low-carbohydrate/high-protein (LC/HP) dietary intervention will show improvements in clinically important metrics of metabolic function, body composition, the composition of gut bacteria, and quality of life.

Methods/design

We intend to recruit 100 participants with chronic traumatic SCI (3 years postinjury, C5–L2, American Spinal Injury Association impairment scale A–D, and aged 18–65 years) and insulin resistance, impaired glucose tolerance or untreated type 2 diabetes and randomly assign them to an 8-week LC/HP dietary intervention group or a control group. The daily LC/HP dietary intervention includes ~ 30% total energy as protein (1.6 g/kg per day) with a carbohydrate-to-protein ratio < 1.5 and fat intake set at ~ 30% of the total energy intake. The control group does not receive any dietary intervention and are continuing with their regular daily diets. Glucose tolerance, insulin sensitivity, β-cell function, body composition, gut microbiome composition, and quality of life measures are assessed at week 1, before starting the LC/HP dietary intervention, and at week 8, after completion of the LC/HP dietary intervention.

Discussion

New information derived from this project will result in the development of a low-cost, simple, self-administered LC/HP dietary intervention for improving metabolic function in individuals with chronic SCI, improved understanding of the composition of gut bacteria in SCI, and how a LC/HP dietary intervention alters gut bacteria composition. In addition, this project will improve our understanding of the relationship between metabolic function and quality of life in individuals with long-standing SCI.

Trial registration

ClinicalTrials.gov, NCT03207841. Registered on 5 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3520-3) contains supplementary material, which is available to authorized users.

Biomarkers of cardiometabolic health are associated with body composition characteristics but not physical activity in persons with spinal cord injury

OBJECTIVE

To examine (i) the associations between physical activity dimensions, cardiorespiratory fitness and body composition and, (ii) the associations between physical activity dimensions, cardiorespiratory fitness, body composition and biomarkers of cardiometabolic health in persons with spinal cord injury (SCI).

METHODS

A cross-sectional prospective cohort study with 7-day follow-up was conducted. Body composition, cardiorespiratory fitness and biomarkers of cardiometabolic health were measured in thirty-three participants with SCI (> 1 year post injury). Physical activity dimensions were objectively assessed over 7-days.

RESULTS

Activity energy expenditure (r =.43), physical activity level (r =.39), and moderate-to-vigorous physical activity (MVPA) (r =.48) were significantly (P < 0.001) associated with absolute (L/min) peak oxygen uptake (⩒O₂ peak). ⩒O₂ peak was significantly higher in persons performing ≥150 MVPA minutes/week compared to <40 minutes/week (P = 0.003). Individual physical activity dimensions were not significantly associated with biomarkers of cardiometabolic health. However, body composition characteristics (BMI, waist and hip circumference) showed significant (P < 0.04), moderate (r >.30) associations with parameters of metabolic regulation, lipid profiles and inflammatory biomarkers. Relative ⩒O₂ peak (ml/kg/min) was moderately associated with only insulin sensitivity (r = 0.37, P = 0.03).

CONCLUSIONS

Physical activity dimensions are associated with cardiorespiratory fitness; however, stronger and more consistent associations suggest that poor cardiometabolic health is associated with higher body fat content. Given these findings, the regulation of energy balance should be an important consideration for researchers and clinicians looking to improve cardiometabolic health in persons with SCI.

Comprehensive Care for Persons with Spinal Cord Injury

Spinal cord injury results in multiple secondary comorbidities, which vary based on injury severity and other characteristics. Persons with spinal cord injury are at lifelong risk for many complications, most of which are at least partially preventable with proper medical care. The Veterans Health Administration Spinal Cord Injury and Disorders (SCI&D) System of Care offers these evaluations to all persons in their registries. Annual evaluations are performed at any of the 24 SCI&D Veterans Administration Centers nationwide. This allows veterans to receive the care from an interdisciplinary team that specializes in the care of veterans with spinal cord injury.

TRPV1 neurons regulate β-cell function in a sex-dependent manner

There is emerging evidence to support an important role for the transient receptor potential vanilloid type 1 (TRPV1) sensory innervation in glucose homeostasis. However, it remains unknown whether the glucoregulatory action of these afferent neurons is sex-biased and whether it is pancreatic β-cell-mediated.

OBJECTIVE

We investigated in male and female mice whether denervation of whole-body or pancreas-projecting TRPV1 sensory neurons regulates adult functional β-cell mass and alters systemic glucose homeostasis.

METHODS

We used a combination of pharmacological and surgical approaches to ablate whole-body or pancreatic TRPV1 sensory neurons and assessed islet β-cell function and mass, aspects of glucose and insulin homeostasis, and energy expenditure.

RESULTS

Capsaicin-induced chemodenervation of whole-body TRPV1 sensory neurons improved glucose clearance and enhanced glucose-stimulated insulin secretion without alterations in β-cell proliferation and mass, systemic insulin sensitivity, body composition, and energy expenditure. Similarly, denervation of intrapancreatic TRPV1 afferents by pancreas intraductal injection of capsaicin or surgical removal of the dorsal root ganglia projecting into the pancreas lowered post-absorptive glucose levels and increased insulin release upon glucose stimulation. The beneficial effects of TRPV1 sensory denervation on glucose tolerance and β-cell function were observed in male but not female mice.

CONCLUSION

Collectively, these findings suggest that TRPV1 neurons regulate glucose homeostasis, at least partly, through direct modulation of glucose-induced insulin secretion and that this regulation operates in a sex-dependent manner.

Body composition changes with testosterone replacement therapy following spinal cord injury and aging: A mini review

Context Hypogonadism is a male clinical condition in which the body does not produce enough testosterone. Testosterone plays a key role in maintaining body composition, bone mineral density, sexual function, mood, erythropoiesis, cognition and quality of life. Hypogonadism can occur due to several underlying pathologies during aging and in men with physical disabilities, such as spinal cord injury (SCI). This condition is often under diagnosed and as a result, symptoms undertreated. Methods In this mini-review, we propose that testosterone replacement therapy (TRT) may be a viable strategy to improve lean body mass (LBM) and fat mass (FM) in men with SCI. Evidence Synthesis Supplementing the limited data from SCI cohorts with consistent findings from studies in non-disabled aging men, we present evidence that, relative to placebo, transdermal TRT can increase LBM and reduce FM over 3-36 months. The impact of TRT on bone mineral density and metabolism is also discussed, with particular relevance for persons with SCI. Moreover, the risks of TRT remain controversial and pertinent safety considerations related to transdermal administration are outlined. Conclusion Further research is necessary to help develop clinical guidelines for the specific dose and duration of TRT in persons with SCI. Therefore, we call for more high-quality randomized controlled trials to examine the efficacy and safety of TRT in this population, which experiences an increased risk of cardiometabolic diseases as a result of deleterious body composition changes after injury.

Pancreatic-islet microvascular vasomotion dysfunction in mice with spinal cord injury

Patients with spinal cord injury (SCI) have an increased risk for developing type 2 diabetes. It is unknown whether the pancreatic-islet microvascular vasomotion is involved. We used female C57BL/6 mice and a 100-kilodyne T10 Infinite Horizons contusion SCI (or T10 laminectomy) to detect blood glucose and pancreatic-islet microvascular vasomotion. Blood glucose obtained from tail vein was detected using one Touch UltraEasy glucometer. Glucose tolerance test was performed by d-glucose administration intraperitoneally. Functional status of pancreatic-islet microvascular vasomotion was determined by laser Doppler monitoring. Expressions of insulin and glucagon were determined by immunohistochemistry. Expression of VEGF-A was determined by immunohistochemistry and Western blotting. Our result demonstrated that blood glucose was significantly increased at 4 h postinjury compared to that in sham group, with continuous higher blood glucose until 4 days postinjury (p < 0.05). SCI mice at day 7 and day 14 had significantly impaired glucose tolerance following glucose administration (p < 0.01). Average blood perfusion, amplitude, frequency, and relative velocity of vasomotion were significantly lower at 6 h postinjury than those in the sham group (p < 0.05), which were gradually upregulated over time. The expression of insulin was decreased, while the expression of glucagon was increased at 6 h postinjury. Similarly, the expression of VEGF-A was significantly decreased at 6 h postinjury, compared to that in sham group (p < 0.05), with slight increases by 14 days postinjury. Our study suggests that the functional status of pancreatic-islet microvascular vasomotion is impaired after injury, which may have implications for developing effective therapeutic interventions for SCI.