Visceral adiposity in persons with chronic spinal cord injury determined by dual energy X-ray absorptiometry

Correlates of metabolic syndrome in people with chronic spinal cord injury

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Preliminary observations on the administration of a glucagon-like peptide-1 receptor agonist on body weight and select carbohydrate endpoints in persons with spinal cord injury: A controlled case series

CONTEXT/OBJECTIVE

To describe the effect of semaglutide, a glucagon-like peptide-1 (GLP-1) agonist, to reduce body weight and improve glycemic control in overweight or obese individuals with spinal cord injury (SCI).

DESIGN

Open-label, randomized drug intervention case series.

SETTING

This study was performed at James J. Peters VA Medical Center (JJP VAMC) and Kessler Institute for Rehabilitation (KIR).

PARTICIPANTS

Five individuals with chronic SCI meeting criteria for obesity and abnormal carbohydrate metabolism.

INTERVENTION

Administration of semaglutide (subcutaneously once per week) versus no treatment (control) for 26 weeks.

OUTCOME MEASURES

Change in total body weight (TBW), fat tissue mass (FTM), total body fat percent (TBF%), and visceral adipose tissue volume (VATvol) was determined at baseline and after 26 weeks using Dual energy X-ray absorptiometry; fasting plasma glucose (FPG) concentration and serum glycated hemoglobin (HbA1C) values were obtained at the same two time points.

RESULTS

In 3 participants, after 26 weeks of semaglutide administration, TBW, FTM, TBF%, and VATvol decreased, on average, by 6, 4.4 kg, 1.7%, and 674 cm3, respectively. In addition, values for FPG and HbA1c decreased by 17 mg/dl and 0.2%, respectively. After 26 weeks of observation in the 2 control participants, TBW, FTM, TBF% and VATvol increased on average by 3.3 , 4.5 kg, 2.5%, and 991 cm3, respectively. The average values for FPG and HbA1c also increased by 11 mg/dl and 0.3%, respectively.

CONCLUSIONS

Administration of semaglutide for 26 weeks resulted in favorable changes in body composition and glycemic control, suggesting a reduced risk for the development of cardiometabolic disease in obese individuals with SCI.Trial registration: ClinicalTrials.gov identifier: NCT03292315.

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.

Independent association of hypovitaminosis d with non-alcoholic fatty liver disease in people with chronic spinal cord injury: a cross-sectional study

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) and hypovitaminosis D are highly prevalent in people with spinal cord injury (SCI) and could exert an unfavorable influence on cardiovascular profile and rehabilitation outcomes. We aimed to assess the independent association between low 25-hydroxy vitamin D (25(OH)D) levels and NAFLD in people with chronic (> 1 year) SCI.

METHODS

One hundred seventy-three consecutive patients with chronic SCI (132 men and 41 women) admitted to a rehabilitation program underwent clinical/biochemical evaluations and liver ultrasonography.

RESULTS

NAFLD was found in 105 patients (60.7% of the study population). They were significantly older and exhibited a poorer leisure time physical activity (LTPA) and functional independence in activities of daily living, a greater number of comorbidities and a higher prevalence of metabolic syndrome (MetS) and its correlates, including lower HDL and higher values of body mass index (BMI), systolic blood pressure, HOMA-index of insulin resistance and triglycerides. 25(OH)D levels were significantly lower in NAFLD (median: 10.6 ng/ml, range: 2.0-31.0) than in non-NAFLD group (22.5 ng/ml, 4.2-51.6). When all these variables were included in a multiple logistic regression analysis, a significant independent association with NAFLD only persisted for lower 25(OH)D levels, a greater number of comorbidities and a poorer LTPA. The ROC analysis revealed that 25(OH)D levels < 18.25 ng/ml discriminated patients with NAFLD with a sensitivity of 89.0% and a specificity of 73.0% (AUC: 85.7%; 95%CI: 79.6-91.7%). NAFLD was exhibited by 83.9% of patients with 25(OH)D levels < 18.25 ng/ml and by 18% of those with 25(OH)D levels ≥ 18.25 ng/ml (p < 0.0001).

CONCLUSION

In people with chronic SCI, 25(OH)D levels < 18.25 ng/ml may represent a marker of NAFLD independent of MetS-related features. Further studies are warranted to define the cause-effect relationships of this association.

Exercise prescription for persons with spinal cord injury: a review of physiological considerations and evidence-based guidelines

Persons with spinal cord injury (SCI) experience gains in fitness, physical and mental health from regular participation in exercise and physical activity. Due to changes in physiological function of the cardiovascular, nervous, and muscular systems, general population physical activity guidelines and traditional exercise prescription methods are not appropriate for the SCI population. Exercise guidelines specific to persons with SCI recommend progressive training beginning at 20 min of moderate to vigorous intensity aerobic exercise twice per week transitioning to 30 min three times per week, with strength training of the major muscle groups two times per week. These population-specific guidelines were designed considering the substantial barriers to physical activity for persons with SCI and can be used to frame an individual exercise prescription. Rating of perceived exertion (i.e., perceptually regulated exercise) is a practical way to indicate moderate to vigorous intensity exercise in community settings. Adapted exercise modes include arm cycle ergometry, hybrid arm-leg cycling, and recumbent elliptical equipment. Body weight-supported treadmill training and other rehabilitation modalities may improve some aspects of health and fitness for people with SCI if completed at sufficient intensity. Disability-specific community programs offer beneficial opportunities for persons with SCI to experience quality exercise opportunities but are not universally available.

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

CONTEXT/OBJECTIVE

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

APPROACH

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

RESULTS

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

CONCLUSION

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

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.

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

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

Cardiovascular and metabolic morbidity following spinal cord injury

BACKGROUND CONTEXT

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

PURPOSE

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

STUDY DESIGN/SETTING

Longitudinal cohort from a nationwide insurance claims database.

PATIENT SAMPLE

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

OUTCOME MEASURES AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Predicting Cardiometabolic Risk From Visceral Abdominal Adiposity in Persons With Chronic Spinal Cord Injury

Persons with spinal cord injury (SCI) have increased adiposity that may predispose to cardiovascular disease compared to those who are able-bodied (AB). The purpose of this study was to determine the relationships between dual energy X-ray absorptiometry (DXA)-derived visceral adipose tissue (VAT) and biomarkers of lipid metabolism and insulin resistance in persons with chronic SCI. A prospective observational study in participants with chronic SCI and age- and gender-matched AB controls. The study was conducted at a Department of Veterans Affairs Medical Center and Private Rehabilitation Hospital. The quantification of DXA-derived VAT volume (VAT_vol) and blood-derived markers of lipid and carbohydrate metabolism were determined in 100 SCI and 51 AB men. The VAT_vol was acquired from a total body DXA scan and analyzed using iDXA enCore CoreScan software (GE Lunar). Blood samples were collected for the serum lipid profile and plasma and glucose concentrations, with the latter two values used to calculate a measure of insulin resistance. In the SCI and AB groups, VAT% was significantly correlated with most cardiometabolic biomarkers. The results of the binary logistic regression analysis revealed that participants who had a VAT_vol above the cutoff value of 1630 cm³ were 3.1-, 4.8-, 5.6-, 19.2-, and 16.7-times more likely to have high serum triglycerides (R²_N= 0.09, p = 0.014), low serum high density lipoprotein cholesterol (R²_N = 0.16, p < 0.001), HOMA2-IR (R²_N = 0.18, p < 0.001), metabolic syndrome (R²_N = 0.25, p < 0.001), and a 10-yr Framingham Risk Score ≥ 10% (R²_N = 0.16, p = 0.001), respectively, when compared to participants below this VAT_vol cutoff value. Our findings reveal that persons with chronic SCI have a higher VAT_vol than that of AB controls, and VAT_vol correlates directly with biomarkers of lipid and carbohydrate metabolism that are strong predictors of cardiometabolic disorders.

Assessment of body composition in spinal cord injury: A scoping review

The objective of this scoping review was to map the evidence on measurement properties of body composition tools to assess whole-body and regional fat and fat-free mass in adults with SCI, and to identify research gaps in order to set future research priorities. Electronic databases of PubMed, EMBASE and the Cochrane library were searched up to April 2020. Included studies employed assessments related to whole-body or regional fat and/or fat-free mass and provided data to quantify measurement properties that involved adults with SCI. All searches and data extractions were conducted by two independent reviewers. The scoping review was designed and conducted together with an expert panel (n = 8) that represented research, clinical, nutritional and lived SCI experience. The panel collaboratively determined the scope and design of the review and interpreted its findings. Additionally, the expert panel reached out to their professional networks to gain further stakeholder feedback via interactive practitioner surveys and workshops with people with SCI. The research gaps identified by the review, together with discussions among the expert panel including consideration of the survey and workshop feedback, informed the formulation of future research priorities. A total of 42 eligible articles were identified (1,011 males and 143 females). The only tool supported by studies showing both acceptable test-retest reliability and convergent validity was whole-body dual-energy x-ray absorptiometry (DXA). The survey/workshop participants considered the measurement burden of DXA acceptable as long as it was reliable, valid and would do no harm (e.g. radiation, skin damage). Practitioners considered cost and accessibility of DXA major barriers in applied settings. The survey/workshop participants expressed a preference towards simple tools if they could be confident in their reliability and validity. This review suggests that future research should prioritize reliability and validity studies on: (1) DXA as a surrogate 'gold standard' tool to assess whole-body composition, regional fat and fat-free mass; and (2) skinfold thickness and waist circumference as practical low-cost tools to assess regional fat mass in persons with SCI, and (3) females to explore potential sex differences of body composition assessment tools. Registration review protocol: CRD42018090187 (PROSPERO).

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.

Effect of Paraplegia on the Time Course of Exogenous Fatty Acid Incorporation Into the Plasma Triacylglycerol Pool in the Postprandial State

Spinal cord injury (SCI) results in disordered fat metabolism. Autonomic decentralization might contribute to dyslipidemia in SCI, in part by influencing the uptake of dietary fats through the gut-lymph complex. However, the neurogenic contributions to dietary fat metabolism are unknown in this population. We present a subset of results from an ongoing registered clinical trial (NCT03691532) related to dietary fat absorption. We fed a standardized (20 kcal⋅kgFFM^–1) liquid meal tolerance test (50% carb, 35% fat, and 15% protein) that contained stable isotope lipid tracer (5 mg⋅kgFFM^–1 [U-¹³C]palmitate) to persons with and without motor complete thoracic SCI. Blood samples were collected at six postprandial time points over 400 min. Changes in dietary fatty acid incorporated into the triacylglycerol (TAG) pool (“exogenous TAG”) were used as a marker of dietary fat absorption. This biomarker showed that those with paraplegia had a lower amplitude than non-injured participants at Post₂₄₀ (52.4 ± 11.0 vs. 77.5 ± 16.0 μM), although this failed to reach statistical significance (p = 0.328). However, group differences in the time course of absorption were notable. The injury level was also strongly correlated with time-to-peak exogenous TAG concentration (r = −0.806, p = 0.012), with higher injuries resulting in a slower rise in exogenous TAG. This time course documenting exogenous TAG change is the first to show a potential neurogenic alteration in SCI dietary fat absorption.

Neurogenic Obesity and Skeletal Pathology in Spinal Cord Injury

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

Exercise Interventions Targeting Obesity in Persons With Spinal Cord Injury

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

Body Composition and Metabolic Assessment After Motor Complete Spinal Cord Injury: Development of a Clinically Relevant Equation to Estimate Body Fat

Background: Obesity is at epidemic proportions in the population with spinal cord injury (SCI), and adipose tissue (AT) is the mediator of the metabolic syndrome. Obesity, however, has been poorly appreciated in SCI because of the lack of sensitivity that body mass index (BMI) conveys for obesity risk in SCI without measuring AT. Objectives: The specific objectives were to compare measures of body composition assessment for body fat with the criterion standard 4-compartment (4C) model in persons with SCI, to develop a regression equation that can be utilized in the clinical setting to estimate fat mass (FM), and to determine cardiometabolic risk using surrogates of obesity in a current model of metabolic syndrome. Methods: Seventy-two individuals with chronic (>1 year) motor complete (AIS A and B) C5-L2 SCI were recruited over 3 years. Subjects underwent assessment with 4C using hydrostatic (underwater) weighing (UWW), dual-energy x-ray absorptiometry (DXA), and total body water (TBW) assessment to determine percent body fat (%BF); fasting glucose and lipid profiles, and resting blood pressure were also obtained. BMI, DXA, bioelectrical impedance analyses (BIA), BodPod, circumferences, diameters, lengths, and nine-site skinfold (SF) were assessed and validated against 4C. A multiple linear regression model was used to fit %BF (dependent variable) using anthropometric and demographic data that had the greatest correlations with variables, followed by a combined forward/backward stepwise regression with Akaike information criterion (AIC) to identify the variables most predictive of the 4C %BF. To allow for a more practical model for use in the clinical setting, we further reduced the AIC model with minimal loss of predictability. Surrogate markers of obesity were employed with metabolic biomarkers of metabolic syndrome to determine prevalence in persons with SCI. Results: Subject characteristics included age 44.4 ± 11.3 years, time since injury (TSI) 14.4 ± 11.0 years, BMI 27.3 ± 5.9 kg/m2; 59 were men and 13 were women. Sitting waist circumference (WCSit ) was 95.5 ± 13.1 cm, supine waist circumference (WCSup) was 93.4 ± 12.7 cm, and abdominal skinfold (ABDSF) was 53.1 ± 19.6 mm. Findings showed 4C %BF 42.4 ± 8.6%, UWW %BF 37.3 ± 9.7%, DXA %BF 39.1 ± 9.4%, BodPod %BF 33.7 ± 11.4%, nine-site SF %BF 37.8 ± 9.3%, and BIA %BF 27.6 ± 8.6%. A regression equation using age, sex, weight, and ABDSF provided R2 correlation of 0.57 with 4C %BF (p < .0001). Metabolic syndrome was identified in 59.4% of the sample. Conclusion: Body composition techniques to determine body fat are labor intensive and expensive for persons with SCI, and the regression equation developed against the criterion standard 4C model may allow clinicians to quickly estimate %BF and more accurately demonstrate obesity-induced cardiometabolic syndrome in this population.

Effect of Exoskeletal-Assisted Walking on Soft Tissue Body Composition in Persons With Spinal Cord Injury

OBJECTIVE

To determine the effect of overground walking using a powered exoskeleton on soft tissue body composition in persons with spinal cord injury (SCI).

DESIGN

A prospective, single group observational pilot study.

SETTING

Medical center.

PARTICIPANTS

Persons (N=8) with chronic (>6mo) SCI between 18 and 65 years old who weighed less than 100 kg.

INTERVENTIONS

Overground ambulation training using a powered exoskeleton (ReWalk) for 40 sessions, with each session lasting up to 2 hours, with participants training 3 times per week.

MAIN OUTCOME MEASURE(S)

Dual-energy x-ray absorptiometry (DXA) was used to measure lean mass (LM) and fat mass (FM) from the whole body, arms, legs and trunk. DXA was also used to assess visceral adipose tissue (VAT). Walking performance was measured by 6-minute walk test.

RESULTS

Participants significantly lost total body FM (-1.8±1.2kg, P=.004) with the loss of adiposity distributed over several regional sites. Six of the 8 participants lost VAT, with the average loss in VAT trending toward significance (-0.141kg, P=.06). LM for the group was not significantly changed.

CONCLUSIONS

Sustained and weekly use of powered exoskeletons in persons with SCI has the potential to reduce FM with inferred improvements in health.

Relationships between T-scores at the hip and bone mineral density at the distal femur and proximal tibia in persons with spinal cord injury

Objective: To identify T-score values at the total hip (TH) and femoral neck (FN) that correspond to the cutoff value of <0.60 g/cm² for heightened risk of fracture at the distal femur (DF) and proximal tibia (PT).Design: Retrospective analysis of data in a research center's database. Setting: Community-based individuals with spinal cord injury (SCI). Participants: 105 unique individuals with SCI. Outcome Measurements: DXA derived areal BMD (aBMD) and T-score of the DF, PT, TH, and FN. Results: The aBMD at the DF and PT regions were predictors of T-scores at the TH (R² = 0.63, P < 0.001 and R² = 0.65, P < 0.001) and FN (R² = 0.55, P < 0.001 and R² = 0.58, P < 0.001). Using the DF and PT aBMD of 0.60 g/cm² as a value below which fractures were more likely to occur, the predicted T-score was -3.1 and -3.5 at the TH and -2.6 and -2.9 at the FN, respectively. However, when the predicted and observed T-score values disagree outside the 95% limit of agreement, the predicted T-score values are lower than the measured T-score values, overestimating the measured values between -2.0 and -4.0 SD. Conclusion: The DF and PT cutoff value for aBMD of 0.60 g/cm² was a moderate predictor of T-score values at the TH and FN, with considerable inaccuracies outside the clinically acceptable limits of agreement. As such, the direct measurement of knee aBMD in persons with SCI should be performed, whenever possible, prior to prescribing weight bearing upright activities, such as robotic exoskeletal-assisted walking.

Psychological Morbidity and Chronic Disease Among Adults With Traumatic Spinal Cord Injuries: A Longitudinal Cohort Study of Privately Insured Beneficiaries

OBJECTIVE

To compare the longitudinal incidence of psychological morbidities and multimorbidity and estimates of chronic diseases among adults with spinal cord injuries (SCIs) as compared with adults without SCIs.

METHODS

Privately insured beneficiaries who had medical coverage at any time between January 1, 2001, and December 31, 2017 were included if they had an International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic code for a traumatic SCI (n=6,847).

RESULTS

Adults with SCIs (n=6847) had a higher incidence of adjustment reaction (7.2% [n=493] vs 5.0% [n=42,862]), anxiety disorders (19.3% [n=1,322] vs 14.1% [n=120,872]), depressive disorders (29.3% [n=2,006] vs 9.3% [n=79,724]), alcohol dependence (2.4% [n=164] vs 1.0% [n=8,573]), drug dependence (2.3% [n=158] vs 0.8% [n=6,858]), psychogenic pain (1.0% [n=69] vs 0.2% [n=1,715]), dementia (6.5% [n=445] vs 1.5% [n=12,859]), insomnia (10.9% [n=746] vs 7.2% [n=61,722]), and psychological multimorbidity (37.4% [n=2,561] vs 23.9% [n=204,882]) as compared with adults without SCIs (n=857,245). The adjusted hazard ratios (HRs) of each psychological outcome were significantly higher for individuals with SCI and ranged from 1.18 (95% CI, 1.08-1.29) for anxiety disorders to 3.32 (95% CI, 1.93-5.71) for psychogenic pain. Adults with SCIs also had a significantly higher prevalence of all chronic diseases and chronic disease multimorbidity (51.1% vs 14.1%), except human immunodeficiency virus infection/AIDS. After propensity matching for age, education, race, sex, and chronic diseases (n=5884 matched pairs), there was still a significantly higher incidence of most psychological disorders and psychological multimorbidity among adults with SCIs.

CONCLUSION

Adults with traumatic SCIs experienced an increased incidence of psychological morbidities and multimorbidity as compared with adults without SCIs. Clinical efforts are needed to improve mental health screening and targeted interventions to reduce the risk for psychological disease onset in the traumatic SCI population.

Caloric Intake Relative to Total Daily Energy Expenditure Using a Spinal Cord Injury-Specific Correction Factor: An Analysis by Level of Injury

OBJECTIVE

The aims of the study were to evaluate the influence of level of spinal cord injury (SCI) on caloric intake relative to total daily energy expenditure (TDEE) and body composition, and to develop a SCI-specific correction factor for the TDEE estimation.

DESIGN

Individuals with paraplegia (PARA, n = 28) and tetraplegia (TETRA, n = 13) were analyzed. Daily caloric intake, basal metabolic rate, and TDEE were obtained using dietary recall, indirect calorimetry, and prediction equations, respectively. Caloric intake and TDEE were adjusted to bodyweight. Body composition was assessed using dual-energy x-ray absorptiometry.

RESULTS

Total caloric (PARA 1516.4 ± 548.4, TETRA 1619.1 ± 564.3 kcal/d), fat (PARA 58.6 ± 27.4, TETRA 65.8 ± 29.7 g), and protein (PARA 62.7 ± 23.2, TETRA 71.5 ± 30.9 g) intake were significantly higher in TETRA versus PARA (P < 0.05) when adjusted for bodyweight. Adjusted and unadjusted TDEE (unadjusted: PARA 1851.0 ± 405.3, TETRA 1530.4 ± 640.4 kcal/d) and basal metabolic rate (unadjusted: PARA 1516.6 ± 398.0, TETRA 1223.6 ± 390.2 kcal/d) were significantly higher in PARA versus TETRA (P < 0.05). Bone mineral content (PARA 3.17 ± 0.6, TETRA 2.71 ± 0.5 g), lean body mass (PARA 50.0 ± 8.6, TETRA 40.96 ± 8.8 kg), and regional percent body fat (PARA 36.45 ± 8.0, TETRA 41.82 ± 9.1) were different between groups (P < 0.05). The SCI-specific correction factor was 1.15.

CONCLUSIONS

A dichotomy exists in caloric intake, TDEE, and body composition among TETRA and PARA. The SCI-specific correction factor of 1.15 is a promising tool to estimate TDEE in SCI.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Understand the influence of spinal cord level of injury on energy expenditure and body composition; (2) Appreciate that equations used to estimate total daily energy expenditure overestimate energy expenditure in individuals with spinal cord injury; and (3) Understand the importance of normalizing caloric intake to bodyweight after spinal cord injury.

LEVEL

Advanced.

ACCREDITATION

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

Contusion spinal cord injury upregulates p53 protein expression in rat soleus muscle at multiple timepoints but not key senescence cytokines

To determine whether muscle disuse after a spinal cord injury (SCI) produces elevated markers of cellular senescence and induces markers of the senescence-associated secretory phenotypes (SASPs) in paralyzed skeletal muscle. Four-month-old male Sprague-Dawley rats received a moderate-severe (250 kiloDyne) T-9 contusion SCI or Sham surgery and were monitored over 2 weeks, and 1-, 2-, or 3 months. Animals were sacrificed via isoflurane overdose and terminal exsanguination and the soleus was carefully excised and snap frozen. Protein expression of senescence markers p53, p27, and p16 was determined from whole soleus lysates using Western immunoblotting and RT-qPCR was used to determine the soleus gene expression of IL-1α, IL-1β, IL-6, CXCL1, and TNFα. SCI soleus muscle displayed 2- to 3-fold higher total p53 protein expression at 2 weeks, and at 1 and 2 months when compared with Sham. p27 expression was stable across all groups and timepoints. p16 protein expression was lower at 3 months in SCI versus Sham, but not earlier timepoints. Gene expression was relatively stable between groups at 2 weeks. There were Surgery x Time interaction effects for IL-6 and TNFα mRNA expression but not for IL-1α, IL-1β, or CXCL1. There were no main effects for time or surgery for IL-1α, IL-1β, or CXCL1, but targeted t tests showed reductions in IL-1α and CXCL1 in SCI animals compared to Sham at 3 months and IL-1β was reduced in SCI animals compared to Sham animals at the 2-month timepoint. The elevation in p53 does not appear consistent with the induction of SASP because mRNA expression of cytokines associated with senescence was not uniformly upregulated and, in some instances, was downregulated in the early chronic phase of SCI.

Measurement of Visceral Adipose Tissue in Persons With Spinal Cord Injury by Magnetic Resonance Imaging and Dual X-Ray Absorptiometry: Generation and Application of a Predictive Equation

PURPOSE

Dual energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) permits quantification of visceral adipose tissue (VAT). However, DXA has not been validated against MRI in persons with chronic spinal cord injury (SCI). A predictive equation was generated from the measurement of VAT by MRI, a "gold" standard to quantitate VAT, compared to that of DXA, a method with several practical advantages.

METHOD

DXA and MRI scans were performed in 27 participants with SCI. MRI multiaxial images were captured for VAT analysis. DXA-VAT was quantified at the android region (DXA-VAT_ANDROID-VOL) using enCore software. Android regions of DXA and MRI were matched using android height. Volumes of multiaxial MRI-VAT and subcutaneous adipose tissue (SAT) were quantified for the android region (MRI-VAT_ANDROID-VOL, MRI-SAT_ANDROID-VOL) and total trunk (MRI-VAT_ANDROID-VOL). Linear regression analysis was used to establish the proposed predication equations. The prediction equations were then applied to an independent sample that consisted of 98 participants with SCI. Bland-Altman analysis was used to determine the limits of agreement.

RESULTS

DXA-VAT_ANDROID-VOL predicted 92% of the variance in MRI-VAT_ANDROID-VOL (SEE = 252.5, p < 0.0005) and 85% of the variance in MRI-VAT_TRUNK-VOL (SEE = 1526.9, p < 0.0005). DXA-SAT_ANDROID-VOL predicted 81.5% of the variance in MRI-SAT_ANDROID-VOL (SEE = 458.2, p < 0.0005). Bland-Altman analysis revealed a high level of agreement between MRI-VAT_ANDROID-VOL and DXA-VAT_ANDROID-VOL (mean bias = 58.45 cm³). A predicted mean DXA-VAT_ANDROID-VOL of 995.2 cm³ was estimated as the population-specific cut-off point for high levels of VAT.

CONCLUSION

DXA-VAT_ANDROID-VOL may accurately predict MRI-VAT_ANDROID-VOL in persons with SCI. The ability of DXA to detect VAT changes in longitudinal studies in persons with SCI should be performed.

Psychological morbidity and chronic disease among adults with nontraumatic spinal cord injuries: a cohort study of privately insured beneficiaries

BACKGROUND

Individuals living with a spinal cord injury (SCI) are at heightened risk for a number of chronic health conditions such as secondary comorbidities that may develop or be influenced by the injury, the presence of impairment, and/or the process of aging. However, very little is known about the development of secondary comorbidities among individuals living with nontraumatic SCIs (NTSCIs).

PURPOSE

The objective of this study was to compare the prevalence of psychological morbidities and chronic diseases among adults with and without NTSCIs.

DESIGN

Cross-sectional cohort from a nationwide insurance claims database.

METHODS

Privately insured beneficiaries were included if they had an ICD-9-CM diagnostic code for a NTSCI and accompanying diagnosis of paraplegia, tetraplegia, quadriplegia, or unspecified paralysis (n=10,006). Adults without SCIs were also included (n=779,545). Prevalence estimates of common psychological morbidities, chronic diseases, and multimorbidity (≥2 conditions) were compared.

RESULTS

Adults with NTSCIs had a higher prevalence of adjustment reaction (11.4% vs 5.1%), anxiety disorders (23.7% vs 14.5%), depressive disorders (31.6% vs 9.6%), drug dependence (3.4% vs 0.8%), episodic mood disorders (15.9% vs 5.4%), central pain syndrome (1% vs 0%), psychogenic pain (1.9% vs 0.2%), dementia (5.2% vs 1.5%), and psychological multimorbidity (29.3% vs 11.6%), as compared to adults without SCIs. The adjusted odds of psychological multimorbidity were 1.86 (95% confidence interval: 1.76-2.00). Adults with NTSCIs also had a significantly higher prevalence of all chronic diseases and chronic disease multimorbidity (73.5% vs 18%), except HIV/AIDS. After propensity matching for age, education, race, sex, and the chronic diseases (n=7,419 matched pairs), there was still a higher prevalence of adjustment reaction (9.2% vs 5.4%), depressive symptoms (23.5% vs 16.0%), central pain syndrome (1% vs 0%), psychogenic pain (1.5% vs 0.3%), and psychological multimorbidity (20.2% vs 17.4%) among adults with NTSCIs.

CONCLUSIONS

Adults with NTSCIs have a significantly increased prevalence of psychological morbidities, chronic disease, and multimorbidity, as compared to adults without SCIs. Efforts are needed to facilitate the development of improved clinical screening algorithms and early interventions to reduce risk of disease onset/progression in this higher risk population.

Quantification of trunk and android lean mass using dual energy x-ray absorptiometry compared to magnetic resonance imaging after spinal cord injury

OBJECTIVE

To determine whether dual energy x-ray absorptiometry (DXA) compared to magnetic resonance imaging (MRI) may accurately quantify trunk lean mass (LM) after chronic spinal cord injury (SCI) and to investigate the relationships between trunk LM, visceral adiposity, trunk fat mass and basal metabolic rate (BMR).

DESIGN

Cross-sectional design and correlational analysis.

SETTING

Research setting in a medical center.

PARTICIPANTS

Twenty-two men with motor complete paraplegia (n = 14; T4-T11) and tetraplegia (n = 8; C5-C7) were recruited as part of a clinical trial.

INTERVENTIONS

Not applicable.

OUTCOME MEASURES

Trunk and android LM were measured using DXA. The volume of six trunk muscle groups were then measured using MRI to quantify trunk LM-MRI. Subcutaneous and visceral adipose tissue (VAT) cross-sectional areas were also measured using MRI. After overnight fast, BMR was evaluated using indirect calorimetry.

RESULTS

Trunk LM-DXA (24 ± 3.3 kg) and android LM-DXA (3.6 ± 0.7 kg) overestimated (P < 0.0001) trunk LM-MRI (1.7 ± 0.5 kg). Trunk LM-MRI = 0.088* log (trunk LM-DXA)-0.415; r2=0.29, SEE= 0.44 kg, P = 0.007. Trunk LM-MRI = 1.53* android LM-DXA + 0.126; r2=0.26, SEE= 0.21 kg, P = 0.018. Percentage trunk LM-MRI was inversely related to VAT (r=-0.79, P < 0.0001) and trunk fat mass (r=-0.83, P < 0.001). Only trunk LM-DXA was related to BMR (r = 0.61, P = 0.002). Persons with tetraplegia have 13% smaller trunk muscle cross-sectional areas (P = 0.036) compared to those with paraplegia.

CONCLUSIONS

Trunk LM-DXA and android LM-DXA overestimated trunk LM-MRI. Percentage trunk LM-MRI, but not LM-DXA, was inversely related to trunk central adiposity. The findings highlight the importance of exercising trunk LM to attenuate cardio-metabolic disorders after SCI.

Epidural stimulation with locomotor training improves body composition in individuals with cervical or upper thoracic motor complete spinal cord injury: A series of case studies

CONTEXT

Four individuals with motor complete SCI with an implanted epidural stimulator who were enrolled in another study were assessed for cardiovascular fitness, metabolic function and body composition at four time points before, during, and after task specific training. Following 80 locomotor training sessions, a 16-electrode array was surgically placed on the dura (L1-S1 cord segments) to allow for electrical stimulation. After implantation individuals received 160 sessions of task specific training with epidural stimulation (stand and step).

OUTCOME MEASURES

Dual-energy X-ray absorptiometry (DXA), resting metabolic rate and peak oxygen consumption (VO₂peak) were measured before locomotor training, after locomotor training but before epidural stimulator implant, at mid-locomotor training with spinal cord epidural stimulation (scES) and after locomotor training with scES.

FINDINGS

Participants showed increases in lean body mass with decreases on percentage of body fat, particularly android body fat, and android/gynoid ratio from baseline to post training; resting metabolic rate and VO₂peak also show increases that are of clinical relevance in this population.

CONCLUSIONS

Task specific training combined with epidural stimulation has the potential to show improvements in cardiovascular fitness and body composition in individuals with cervical or upper thoracic motor complete SCI.

Associations between vitamin D, adiposity, and respiratory symptoms in chronic spinal cord injury

Context/Objective Persons with chronic spinal cord injury (SCI) have an increased risk of respiratory-related morbidity and mortality and chronic respiratory symptoms are clinical markers of future respiratory disease. Therefore, we sought to assess potentially modifiable factors associated with respiratory symptoms, with a focus on circulating vitamin D and measures of body fat. Design Cross-sectional study. Setting Veterans Affairs Medical Center. Participants Three hundred forty-three participants (282 men and 61 women) with chronic SCI participating in an epidemiologic study to assess factors influencing respiratory health recruited from VA Boston and the community. Methods Participants provided a blood sample, completed a respiratory health questionnaire, and underwent dual x-ray absorptiometry (DXA) to assess % body fat. Logistic regression was used to assess cross-sectional associations between respiratory symptoms and plasma vitamin D and measures of body fat with adjustment for a number of potential confounders. Outcome Measures Chronic cough, chronic phlegm, any wheeze, persistent wheeze. Results After adjustment for a number of confounders (including smoking), participants with greater %-android, gynoid, trunk, or total body fat had increased odds ratios for any wheeze and suggestive associations with persistent wheeze, but not with chronic cough or phlegm. Vitamin D levels were not associated with any of the respiratory symptoms. Conclusion Increased body fat, but not vitamin D, was associated with wheeze in chronic SCI independent of a number of covariates.

Obesity cutoff values in Korean men with motor complete spinal cord injury: body mass index and waist circumference

STUDY DESIGN

Cross-sectional.

OBJECTIVES

To determine the obesity cutoff values for body mass index (BMI) and waist circumference (WC) in Korean men with motor complete spinal cord injury (SCI).

SETTING

Tertiary level hospital in Seoul, Korea.

METHODS

BMI (kg/m²) was calculated and WC (cm) was measured in each participant in the supine position. Percentage of total body fat (%) was determined using whole-body dual-energy X-ray absorptiometry. Receiver operating characteristic curves were generated to determine the obesity cutoff values for BMI and WC. The optimal cutoff values were determined using the Youden index. Identified cutoff values were compared with those of 195 age- and BMI-matched men in the general population (GP), obtained from the Korea National Health and Nutrition Examination Survey.

RESULTS

This study included 52 Korean men with motor complete SCI. A BMI of 20.2 kg/m² and WC of 81.3 cm were identified as obesity cutoff values in Korean men with motor complete SCI. The area under the curve (AUC) was 0.928, specificity was 100%, and sensitivity was 84.8% according to the ROC curve of BMI for participants. AUC was 0.964, specificity was 100%, and sensitivity was 84.8% in the ROC curve of WC for participants. A BMI of 22.5 kg/m² and WC of 85.5 cm were identified as obesity cutoff values in age- and BMI-matched men in the GP.

CONCLUSIONS

The obesity cutoff values in Korean men with motor complete SCI that were determined in this study were lower than those of the Korean GP and western people with SCI.

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

CONTENT

Spinal Cord Injury (SCI) results in physiological changes that markedly reduces whole-body metabolism, resulting in neurogenic obesity via adipose tissue accumulation. Adipose tissue has been implicated in the release of proinflammatory adipokines that lead to chronic, systemic inflammation, and evidence suggests these adipokines contribute to the pathogeneses of metabolic diseases that often accompany obesity. In this review, we propose the concept of neurogenic obesity through paralysis-induced adiposity as the primary source of systemic inflammation and metabolic dysfunction reported in chronic SCI. We also briefly discuss how exercise in SCI can attenuate the negative consequences of obesity-induced inflammation and its comorbidities.

METHODS

A MEDLINE, PubMed, Google Scholar, and ClinicalKey search was performed using the following search terms: obesity, adiposity, adipose tissue, proinflammatory adipokines, proinflammatory cytokines, metabolic dysfunction, exercise, physical activity, and spinal cord injury. All papers identified were full-text, English language papers. The reference list of identified papers was also searched for additional papers.

RESULTS

Research suggests that obesity in SCI results in a state of chronic, systemic inflammation primarily through proinflammatory adipokines secreted from excess adipose tissue. The reduction of adipose tissue through the use of diet and exercise demonstrates promise to combat neurogenic obesity, inflammation, and cardiometabolic dysfunction in SCI.

CONCLUSION

Proinflammatory adipokines may serve as biomarkers for the development of obesity-related complication in SCI. Mechanistic and interventional studies on neurogenic obesity-induced inflammation in chronic SCI are warranted.

The influence of level of spinal cord injury on adipose tissue and its relationship to inflammatory adipokines and cardiometabolic profiles

OBJECTIVE

Level of injury (LOI) and the role of adipose tissue and its proinflammatory adipokines in cardiometabolic dysfunction following spinal cord injury (SCI) remains poorly understood. We aim to examine the influence of LOI on adipose tissue and its relationship to proinflammatory adipokines and cardiometabolic profiles following SCI.

DESIGN

Cross sectional and correlational study.

SETTING

Clinical hospital and academic setting.

PARTICIPANTS

Forty-seven individuals with chronic motor complete SCI (age 43.8±11.5 y, BMI: 27.3±5.3) were classified as having tetraplegia (TSCI; n=12) or paraplegia (PSCI; n=35).

INTERVENTION

Non applicable.

OUTCOME MEASURES

Visceral (VAT) and subcutaneous (SAT) adipose tissue volumes were measured using magnetic resonance imaging. Proinflammatory adipokines (tumor neurosis factor-α, interleukin-6 (IL-6), plasminogen activatable inhibitor-1, thrombin-activatable fibrinolysis inhibitor, and high-sensitivity c-reactive protein) and cardiovascular, carbohydrate, and lipid profiles were assessed according to standard techniques.

RESULTS

VAT volume was greater in TSCI versus PSCI (p=0.042); however, after covarying for age this significance was lost (p>0.05). IL-6 was significantly elevated in TSCI (p<0.05), while other markers of inflammation generally were elevated, but did not reach statistical significance (p>0.05). Systolic blood pressure and total cholesterol were significantly lower in TSCI (p<0.05), while fasting glucose was significantly lower in PSCI (p<0.05). A number of proinflammatory adipokines and cardiometabolic markers significantly correlated with adipose tissue depots by LOI (p<0.05).

CONCLUSION

The results show that LOI does not influence the distribution of adipose tissue, but does influence proinflammatory adipokines and cardiometabolic profiles following SCI. Further research is needed to evaluate impact of lean body mass on these findings.

Anthropometric Prediction of Visceral Adipose Tissue in Persons With Motor Complete Spinal Cord Injury

BACKGROUND

Spinal cord injury (SCI) results in increased accumulation of visceral adipose tissue (VAT). Anthropometrics may provide an alternative to estimate VAT cross-section area (CSA) compared to magnetic resonance imaging (MRI).

OBJECTIVE

To validate the use of anthropometrics, including abdominal circumference and skinfold thickness (SF_T) measurements against MRI to predict subcutaneous adipose tissue (SAT) and VAT cross-sectional areas in persons with SCI.

DESIGN

Cross-sectional.

SETTING

Clinical research center PARTICIPANT: Twenty-two men with motor complete SCI METHODS: Anthropometric measurements and MRI were taken during a single visit. Abdominal circumference and SF_T were used to derive prediction equations for subcutaneous adipose tissue (SAT_Anthro-CSA) and VAT (VAT_Anthro-CSA). Three-axial MRI at the level of umbilicus was used to establish the prediction equations. VAT_Anthro-CSA was compared against body mass index (BMI), waist circumference, and SF_T. Bland-Altman plots were used to determine limits of agreement between prediction equations and MRI.

MAIN OUTCOME MEASUREMENTS

SAT and VAT cross-sectional areas.

RESULTS

SAT_Anthro-CSA explained 76% of the variance in SAT cross-sectional area (r² = 0.76, standard error of the estimate [SEE] = 49.5 cm², P <.001). VAT_Anthro-CSA explained 72% of VAT cross-sectional area (r² = 0.72, SEE = 45.8 cm², P <.001). Compared to VAT_Anthro-CSA, BMI, waist circumference, and SF_T explained only 37%, 63%, and 31%, respectively, in the variance of VAT MRI.

CONCLUSION

Abdominal circumference and SF_T demonstrated an alternative way to predict VAT CSA. VAT_Anthro-CSA estimated VAT_MRI more accurately than BMI, waist circumference, and SF_T in individuals with chronic SCI.

LEVEL OF EVIDENCE

I.

Participation in moderate-to-vigorous leisure time physical activity is related to decreased visceral adipose tissue in adults with spinal cord injury

Increased visceral adiposity places individuals with chronic spinal cord injury (SCI) at increased risk of cardiometabolic disease. The purpose of this study was to identify if people with chronic SCI who participate in any moderate- to vigorous-intensity leisure time physical activity (LTPA) have lower visceral adipose tissue (VAT) area compared with those who report none. Participants included 136 adult men (n = 100) and women (n = 36) with chronic (mean (±SD) 15.6 ± 11.3 years post-injury) tetraplegia (n = 66) or paraplegia (n = 70) recruited from a tertiary rehabilitation hospital. VAT area was assessed via whole-body dual-energy X-ray absorptiometry using a Hologic densitometer and the manufacturer's body composition software. Moderate-to-vigorous LTPA was assessed using the Leisure Time Physical Activity Questionnaire for People with SCI (LTPAQ-SCI) or the Physical Activity Recall Assessment for People with SCI (PARA-SCI). Summary scores were dichotomized into any or no participation in moderate-to-vigorous LTPA to best represent the intensity described in current population-specific physical-activity guidelines. Data were analyzed using univariate and multiple regression analyses to identify the determinants of VAT. Overall, the model explained 67% of the variance in VAT area and included time post-injury, age-at-injury, android/gynoid ratio, waist circumference, and moderate-to-vigorous LTPA. Participation in any moderate-to-vigorous LTPA was significantly (95% confidence interval: -34.71 to -2.61, p = 0.02) associated with VAT after controlling for injury-related and body-composition correlates. Moderate-to-vigorous LTPA appears to be related to lower VAT area, suggesting potential for LTPA to reduce cardiometabolic disease risk among individuals with chronic SCI.

Health status of regularly physically active persons with spinal cord injury

Study design

A non-controlled cross-sectional study.

Objectives

To make a descriptive examination of health status in persons with paraplegia and tetraplegia who exercise regularly according to Canadian guidelines.

Settings

Sunnaas Rehabilitation Hospital and the Norwegian School of Sport Sciences.

Methods

Eighteen persons (men/women = 9/9), aged 41‒72 years with spinal cord injury (SCI), who exercise regularly were included. Post-injury years ranged from 4 to 48 years. Clinical examination of body composition, bone mineral density (BMD), forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), diffusion capacity (DL_CO), cardiorespiratory fitness (VO_2max), and self-reported quality of life (QOL) obtained by questionnaire was performed. Lung function results are presented as % predicted and VO_2max as absolute values relative to body weight. All results are given as median and range.

Results

Persons with paraplegia (n = 13) were defined as overweight with fat mass 42% (25‒51). BMD 1.047 g cm⁻² (0.885‒1.312) was within normal range. FVC 95% predicted (60‒131), FEV₁ 90% predicted (61‒119), DL_CO 77% predicted (56‒103), and VO_2max 16.66 ml kg⁻¹ min⁻¹ (12.15‒25.28) defined good aerobic capacity according to age controlled reference values (18). Persons with tetraplegia (n = 5) were slightly overweight with fat mass 35% (26‒47). BMD 1.122 g cm⁻² (1.095‒1.299) was within normal range. FVC 72% predicted (46‒91), FEV₁ 75% predicted (43‒83), DL_CO 67% predicted (56‒84), and VO_2max 16.70 ml kg⁻¹ min⁻¹ (9.91‒21.01) defined excellent aerobic capacity according to reference values (18). QOL was ranked as median 7.5 (0‒10 scale).

Conclusions

Persons with SCI who exercise regularly following the Canadian guidelines responded with rather positive associations for health outcomes. Additional research is needed to strengthen our findings.

Clinical factors associated with C-reactive protein in chronic spinal cord injury

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

Determine clinical factors associated with plasma C-reactive protein (CRP) in persons with chronic spinal cord injury (SCI).

SETTING

Veterans Affairs Medical Center in Boston, MA, USA.

METHODS

Participants provided a blood sample, completed a respiratory health questionnaire and underwent dual X-ray absorptiometry (DXA) to assess total and regional body fat. Linear regression models were used to assess cross-sectional associations with plasma CRP.

RESULTS

In multivariable models, factors associated with a higher CRP included a greater BMI, urinary catheter use, a respiratory illness in the past week and non-white race. Mean CRP also increased with decreasing mobility (motorized wheelchair >hand-propelled wheelchair >walk with an assistive device >walk independently). Results were similar when adjusting for percentage android, gynoid, trunk or total fat mass in place of BMI. Level and completeness of SCI was not associated with CRP in multivariable models.

CONCLUSIONS

Clinical characteristics common in chronic SCI are associated with plasma CRP. These factors are more important than the level and completeness of SCI and some are potentially modifiable.

Effect of functional sympathetic nervous system impairment of the liver and abdominal visceral adipose tissue on circulating triglyceride-rich lipoproteins

Background

Interruption of sympathetic innervation to the liver and visceral adipose tissue (VAT) in animal models has been reported to reduce VAT lipolysis and hepatic secretion of very low density lipoprotein (VLDL) and concentrations of triglyceride-rich lipoprotein particles. Whether functional impairment of sympathetic nervous system (SNS) innervation to tissues of the abdominal cavity reduce circulating concentrations of triglyceride (TG) and VLDL particles (VLDL-P) was tested in men with spinal cord injury (SCI).

Methods

One hundred-three non-ambulatory men with SCI [55 subjects with neurologic injury at or proximal to the 4^th thoracic vertebrae (↑T4); 48 subjects with SCI at or distal to the 5^th thoracic vertebrae (↓T5)] and 53 able-bodied (AB) subjects were studied. Fasting blood samples were obtained for determination of TG, VLDL-P concentration by NMR spectroscopy, serum glucose by autoanalyzer, and plasma insulin by radioimmunoassay. VAT volume was determined by dual energy x-ray absorptiometry imaging with calculation by a validated proprietary software package.

Results

Significant group main effects for TG and VLDL-P were present; post-hoc tests revealed that serum TG concentrations were significantly higher in ↓T5 group compared to AB and ↑T4 groups [150±9 vs. 101±8 (p<0.01) and 112±8 mg/dl (p<0.05), respectively]. VLDL-P concentration was significantly elevated in ↓T5 group compared to AB and ↑T4 groups [74±4 vs. 58±4 (p<0.05) and 55±4 μmol/l (p<0.05)]. VAT volume was significantly higher in both SCI groups than in the AB group, and HOMA-IR was higher and approached significance in the SCI groups compared to the AB group. A linear relationship between triglyceride rich lipoproteins (i.e., TG or Large VLDL-P) and VAT volume or HOMA-IR was significant only in the ↓T5 group.

Conclusions

Despite a similar VAT volume and insulin resistance in both SCI groups, the ↓T5 group had significantly higher serum TG and VLDL-P values than that observed in the ↑T4 and the AB control groups. Thus, level of injury is an important determinate of the concentration of circulating triglyceride rich lipoproteins, which may play a role in the genesis of cardiometabolic dysfunction.

The influence of a home-based exercise intervention on human health indices in individuals with chronic spinal cord injury (HOMEX-SCI): study protocol for a randomised controlled trial

BACKGROUND

Spinal cord injury (SCI) creates a complex pathology that can lead to an increase in sedentary behaviours and deleterious changes in body composition. Consequently, individuals with SCI are at increased risk of developing cardiovascular disease and type-2 diabetes mellitus. While the role of physical activity on the reduction of chronic disease risk is well documented in non-disabled individuals the evidence is less conclusive for persons with SCI. The aim of this methodological paper is to outline the design of a study that will assess the role of a home-based exercise intervention on biomarkers of metabolic and cardiovascular health in persons with SCI: the HOMEX-SCI study.

METHODS/DESIGN

Eligible participants will be inactive (physical activity level ≤1.60) individuals, with a chronic (more than 1 year) spinal cord lesion between the second thoracic and the fifth lumbar vertebrae, and aged between 18 and 65 years. Following baseline laboratory testing and lifestyle monitoring, participants will be randomly allocated to a control (CON) group or a 6-week home-based exercise intervention (INT) group. The INT consists of 45 minutes of moderate-intensity (60-65 % peak oxygen uptake) arm-crank exercise four times per week. Participants assigned to the CON group will be asked to maintain their normal lifestyle. The main outcomes of this study (biomarkers of metabolic and cardiovascular health) are obtained from venous blood samples, collected in the fasted and postprandial state. Eight other measurement categories will be assessed: (1) body composition, (2) physical activity, (3) energy intake, (4) measures of health and wellbeing, (5) resting metabolic rate, heart rate and blood pressure, (6) aerobic capacity, (7) immune function, and (8) adipose tissue gene expression.

DISCUSSION

This study will explore the feasibility of home-based moderate-intensity exercise and ascertain its impact on metabolic and cardiovascular health in comparison to a lifestyle maintenance CON group. Findings from this study may help to inform new evidence-based physical activity guidelines and also help to elucidate the physiological mechanisms whereby exercise might exert beneficial effects in persons with chronic SCI. The results will also act as a scientific platform for further intervention studies in other diverse and at-risk populations.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number: ISRCTN57096451 . Registered on 11 July 2014.