Cardiometabolic changes and disparities among persons with spinal cord injury: a 17-year cohort study

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.

Cardiometabolic risk profiling during spinal cord injury rehabilitation: A longitudinal analysis from Swiss Spinal Cord Injury cohort (SwiSCI)

BACKGROUND

Early screening is important in individuals with spinal cord injury (SCI) as they were deemed high-risk for cardiometabolic diseases. Few studies explored changes in cardiometabolic risk profile in the early phase of the injury. Thus, it remains unclear how early the cardiometabolic status deteriorates after injury.

OBJECTIVE

We determined the longitudinal changes in the cardiometabolic risk profile and examined the association between injury characteristics and cardiometabolic status in subacute SCI.

SETTING

Multicenter Swiss Spinal Cord Injury Cohort.

PARTICIPANTS

Adults with traumatic SCI without history of cardiovascular disease or type 2 diabetes.

MAIN OUTCOME MEASURES

Blood pressure (BP), lipid profile, fasting glucose, waist circumference (WC), weight, body mass index (BMI) and Framingham risk score (FRS) were compared across time and according to the injury characteristics.

RESULTS

We analyzed the data of 258 individuals with traumatic SCI (110 tetraplegia and 148 paraplegia, 122 motor complete and 136 incomplete). The median age was 50 years (IQR 32-60), with 76.36% (n=197) of the population being male. The median rehabilitation duration was 5.5 months (IQR 3.2-7.1). At admission to rehabilitation, fully-adjusted linear regression models showed higher baseline weight (β 0.06, 95% CI 0.005, 0.11), systolic BP (β 0.05, 95% CI 0.008, 0.09), diastolic BP (β 0.05 95% CI 0.004, 0.10), and triglycerides (β 0.27 95% CI 0.13, 0.42) in paraplegia than tetraplegia. Systolic BP, diastolic BP, HDL-C were higher in incomplete than complete injury. In our main analysis, we observed an increase in cholesterol and HDL-C and lipid ratio when comparing the beginning and end of rehabilitation. Individuals with paraplegia had a higher increase in BMI than tetraplegia, while no differences in other cardiometabolic risk factors were detected when comparing motor incomplete and complete injury. Trajectories of each participant showed that the majority of individuals with SCI decreased FRS score at follow-up compared to baseline and no significant changes in prevalence of cardiometabolic syndrome were observed. At discharge, one-third of study participants were classified as moderate to high risk of CVD, 64% were overweight, and 39.45% had cardiometabolic syndrome.

CONCLUSION

We observed a modest improvement in lipid profile and FRS during the first inpatient rehabilitation hospitalization. Injury characteristics, such as level and completeness, were not associated with changes in cardiometabolic risk factors in the subacute phase of the injury. Despite this, a significant proportion of study participants remained at risk of cardiometabolic disease at discharge, suggesting that early cardiometabolic preventive strategies may be initiated as early as during the first inpatient rehabilitation hospitalization. This article is protected by copyright. All rights reserved.

Markers of susceptibility to cardiac arrhythmia in experimental spinal cord injury and the impact of sympathetic stimulation and exercise training

Injury to descending autonomic (sympathetic) pathways is common after high-level spinal cord injury (SCI) and associated with abnormal blood pressure and heart rate regulation. In individuals with high-level SCI, abnormal sympathovagal balance (such as during autonomic dysreflexia; paroxysmal hypertension provoked by sensory stimuli below the injury) is proarrhythmogenic. Exercise training is a key component of SCI rehabilitation and management of cardiovascular disease risk, but it is unclear whether exercise training influences susceptibility to cardiac arrhythmia. We aimed to evaluate: (i) whether susceptibility to arrhythmia increases in a rodent-model of SCI; (ii) the impact of the sympathomimetic drug dobutamine (DOB) on arrhythmia risk; (iii) whether exercise training ameliorates arrhythmia risk. Twenty-one Wistar rats were divided into 3 subgroups: T2-contusive SCI (T2, n = 7), T2-contusive SCI completing passive hindlimb cycling training (PHLC, n = 7), and T10-contusive SCI (T10, n = 7). Known electrocardiographic arrhythmia markers and heart rate variability parameters were evaluated before (PRE), 1-week (POST) and 5-weeks post-SCI (TERM) at baseline and during DOB infusion (30 μg/kg/min). Baseline markers of arrhythmia risk were increased in both T2 and T10 animals. DOB decreased R-R interval (p < 0.001), and increased markers of risk for ventricular arrhythmia, particularly in high-level (T2) animals (p < 0.05). Exercise training blunted the exacerbation of markers of arrhythmia risk in the presence of DOB. Markers of risk for cardiac arrhythmia are increased in experimental SCI, and DOB further increases arrhythmia risk in high-level SCI. Exercise training did not improve markers of arrhythmia risk at rest, but did ameliorate markers of arrhythmia risk during sympathetic stimulation.

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.

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

OBJECTIVE

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

DESIGN

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

SETTING

Research university.

PARTICIPANTS

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

INTERVENTIONS

Not applicable.

RESULTS

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

CONCLUSION

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

Associations of human skeletal muscle fiber type and insulin sensitivity, blood lipids, and vascular hemodynamics in a cohort of premenopausal women

PURPOSE

Cardiometabolic disease remains a leading cause of morbidity and mortality in developed nations. Consequently, identifying and understanding factors associated with underlying pathophysiological processes leading to chronic cardio metabolic conditions is critical. Metabolic health, arterial elasticity, and insulin sensitivity (SI) may impact disease risk, and may be determined in part by myofiber type. Therefore, the purpose of this study was to test the hypothesis that type I myofiber composition would be associated with high SI, greater arterial elasticity, lower blood pressure, and blood lipids; whereas, type IIx myofibers would be associated with lower SI, lower arterial elasticity, higher blood pressure, blood lipids.

METHODS

Muscle biopsies were performed on the vastus lateralis in 16 subjects (BMI = 27.62 ± 4.71 kg/m², age = 32.24 ± 6.37 years, 43% African American). The distribution of type I, IIa, and IIx myofibers was determined via immunohistochemistry performed on frozen cross-sections. Pearson correlation analyses were performed to assess associations between myofiber composition, SI, arterial elasticity, blood pressure, and blood lipid concentrations.

RESULTS

The percentage of type I myofibers positively correlated with SI and negatively correlated with systolic blood pressure SBP, diastolic blood pressure, and mean arterial pressure (MAP); whereas, the percentage of type IIx myofibers were negatively correlated with SI and large artery elasticity, and positively correlated with LDL cholesterol, SBP, and MAP.

CONCLUSIONS

These data demonstrate a potential link between myofiber composition and cardiometabolic health outcomes in a cohort of premenopausal women. Future research is needed to determine the precise mechanisms in which myofiber composition impacts the pathophysiology of impaired glucose and lipid metabolism, as well as vascular dysfunction.

Ischemic Bowel Syndrome in Patients with Spinal Cord Injury: A Nationwide Study

Purpose

The aim of this study was to determine whether spinal cord injuries (SCI) is associated with increased risk of ischemic bowel syndrome (IBS) in an Asian population by analyzing data from the National Health Insurance Research Database (NHIRD) in Taiwan.

Methods

Patients aged ≥20 years in the inpatient database with newly identified SCI from 2000 to 2011 were selected as the SCI cohort. For the non-SCI cohort, patients were selected based on a 1:4 risk-set sampling. Hospitalization with a new diagnosis of IBS during the follow-up was the main outcome measure. We used the standard univariable and multivariable Cox proportional hazard regression models to determine adjusted subhazard ratios (SHR) and 95% confidence interval (CI) in the SCI and non-SCI cohorts.

Results

Patients with SCI were at significant risk for IBS, with an adjusted SHR (aSHR) of 1.25, 95% CI = 1.04–1.51. Multivariable analysis showed individuals with SCI were associated with a greater risk of IBS than individuals without SCI among males (aSHR = 1.47, 95% CI = 1.16–1.86), all age groups (≤49 y: aSHR = 2.15, 95% CI = 1.24–3.74; 50–65 y: aSHR = 1.82, 95% CI = 1.15–2.88; >65 y: aSHR = 1.39, 95% CI = 1.11–1.74) and those without comorbidities (aSHR = 1.41, 95% CI = 1.04–1.93). Comorbidities including diabetes, hypertension, heart failure, coronary artery disease (CAD), Stroke, and end stage renal disease (ESRD) significantly increased the risk of IBS.

Conclusion

Patients hospitalized for SCI have increased risks of developing IBS. Though the mechanism that predisposes SCI patients to IBS is unclear, we suggest that physicians promptly identify and treat correctable risk factors.

Inflammatory Stress Effects on Health and Function After Spinal Cord Injury

Background: Injury to the spinal cord produces immediate, adaptive inflammatory responses that can exacerbate the initial injury and lead to secondary damage. Thus far, researchers and clinicians have focused on modulating acute inflammation to preserve sensorimotor function. However, this singular approach risks overlooking how chronic inflammation negatively impacts the broader health of persons with a spinal cord injury (SCI). Objective: The aim of this monograph was to discuss interrelated processes causing persistent inflammatory stress after SCI, along with associated health risks. We review archetypal factors that contribute to a chronic inflammatory state, including response to injury, acute infection, and autonomic dysreflexia. Secondary complications producing and exacerbating inflammation are also discussed, including pain, depression, obesity, and injury to the integumentary and skeletal systems. Finally, we discuss the role of bacteria and the gut microbiome in this process and then conclude with a discussion on how a pro-inflammatory phenotype promotes an elevated risk for cardiovascular disease after injury. Conclusions: Effectively managing chronic inflammation should be a high priority for clinicians and researchers who seek to improve the health and life quality of persons with SCI. Chronic inflammation worsens secondary medical complications and amplifies the risk for cardiometabolic disorders after injury, directly impacting both the quality of life and mortality risk after SCI. Inflammation can worsen pain and depression and even hinder neurological recovery. It is, therefore, imperative that countermeasures to chronic inflammation are routinely considered from the point of initial injury and proceeding throughout the lifespan of the individual with SCI.

The natural course of spinal cord injury: changes over 40 years among those with exceptional survival

OBJECTIVES

To identify 40-year longitudinal changes in health, activity, employment, life satisfaction and self-rated adjustment after spinal cord injury.

STUDY DESIGN

Longitudinal, mailed self-report.

METHODS

Participants were identified from outpatient records of a Midwestern USA university hospital in 1973. Follow-ups were conducted in 1984 and approximate 10-year intervals thereafter. A total of 49 participants completed each of the five assessments. Data were reviewed and analyzed by research team members and a research associate with experience in biostatistics at a medical university in Southeastern USA. Life Situation Questionnaire included the following: (1) demographic and injury characteristics, (2) educational status and employment, (3) community participation, (4) life satisfaction, (5) adjustment, and (6) recent medical history.

RESULTS

Proportion of individuals with 10+ non-routine physician visits increased from consistently <10% to >40% during the 40 years. Proportion who spent a week or more in hospital increased from a low of 10% at 20-year follow-up to 43% at 40-year follow-up. Percentage employed and average hours employed initially improved over time but decreased substantially during the last two times of measurement. Satisfaction with health, sex life and social life declined over time, whereas satisfaction with employment improved initially and was maintained over time. Self-rated current adjustment remained stable, whereas predicted future adjustment declined steadily over 40 years.

CONCLUSIONS

Age-related declines were apparent for need of physician visits and hospitalizations, with notable declines in satisfaction with sex life, social life and health. However, not all indices declined over time. Participants appeared to maintain stability when rating their own adjustment.

Metabolic syndrome in people with a long-standing spinal cord injury: associations with physical activity and capacity

This study investigated (i) the prevalence of the metabolic syndrome (MetS) in people with a long-standing spinal cord injury (SCI); (ii) whether personal or lesion characteristics are determinants of the MetS; and (iii) the association with physical activity or peak aerobic capacity on the MetS. In a cross-sectional study, persons with SCI (N = 223; time since injury of ≥10 years) were tested. The individual components of the MetS were assessed together with the physical activity measured by the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD), while peak aerobic capacity was tested during a graded wheelchair exercise test on a treadmill. Thirty-nine percent of the participants had MetS. In a multivariate logistic regression analyses and after performing a backward regression analysis, only age and education were significant determinants of the MetS. A 10-year increase in age leads to a 1.5 times more chance to have the MetS. Furthermore, people with a low education will multiply the relative risk of MetS compared with people with high education by almost 2. With and without correcting for confounders, no significant relationship was found between PASIPD or peak aerobic capacity and the MetS. It can be concluded that the prevalence of the MetS is high (39%) in people with a long-standing SCI but is comparable to the general Dutch population. Older people and those with a lower education level are most at risk for the MetS. Physical activity and peak aerobic fitness were not related to the MetS in this group with a long-standing SCI.

The association between metabolic syndrome and pressure ulcers among individuals living with spinal cord injury

OBJECTIVE

The objective of this study was to identify the relationship between metabolic syndrome (MetS) and pressure ulcers (PrU), after controlling for demographic and injury characteristics, socioeconomic factors, health behaviors and fatigue among participants with spinal cord injury (SCI).

METHODS

This cross-sectional study recruited 350 participants with SCI from a hospital in the western region of the USA. Blood tests and physical examination were performed. Waist circumference, high-density cholesterol, triglycerides, blood pressure and fasting glucose were used to diagnose MetS according to Criteria for Clinical Diagnosis of Metabolic Syndrome defined by the American Heart Association. All other variables were self-reported. Three-stage multivariate logistic regression models were conducted to evaluate the effects of three sequential sets of predictors, including demographic/injury, socio-environmental/behavioral and health factors, basing the order of analysis on the Theoretical Risk and Prevention Model.

RESULTS

The prevalence of PrU and MetS was 11.0% (n=36) and 35.3% (n=115), respectively. Ethnicity, smoking, alcohol consumption and MetS were statistically associated with PrU in the full model. Participants who were non-Hispanic (odds ratio (OR)=10.30, 95% confidence interval (CI): 3.46-30.65), smokers (OR=2.69, 95% CI: 1.00-7.27) and drank over 30 drinks per month (OR=5.26, 95% CI: 1.24-22.26) had greater odds of having a PrU compared with those who were Hispanic, non-smokers and non-drinkers, respectively. We also observed a positive association between MetS and PrU (OR_MetS=3.71, 95% CI: 1.45-9.52), even after controlling for all other factors.

CONCLUSION

Participants who had MetS had higher odds of PrU than those without MetS after adjusting for multiple covariates. Unhealthy behaviors such as smoking and excess drinking were positively associated with PrU.