Associations of the trunk skeletal musculature and dietary intake to biomarkers of cardiometabolic health after spinal cord injury

Mapping of Dietary Interventions Beneficial in the Prevention of Secondary Health Conditions in Spinal Cord Injured Population: A Systematic Review

OBJECTIVES

Individuals with spinal cord injury are at risk of secondary health conditions (SHC) that develop as a consequence of autonomic dysfunction, prolonged oxidative stress and inflammation, and physical inactivity coupled with inadequate energy and nutritional intake. SHC can be debilitating and even life-threatening, and its prevention remains one of the major challenges in the continuum of medical care of aging SCI population. An unhealthy diet is a major driver of inflammation, oxidative stress, and unfavourable metabolic status and may be a practical preventive target to tackle increased SHC risk post-injury.

AIMS

To provide a catalogue of dietary interventions beneficial in prevention of SHC among individuals with SCI by conducting a systematic review of the literature on dietary interventions and dietary supplementation in promoting health and well-being after the injury. In addition, we aimed to provide a summary of observational studies exploring the association between habitual diet (macro- and micronutrients intake and dietary patterns) and health patterns following the injury.

METHOD

This review was registered at PROSPERO (University of York) with registration number CRD42022373773. Four medical databases (EMBASE.com, MEDLINE [Ovid], Cochrane CENTRAL, and Web of Science Core Collection) and Google Scholar were searched from inception until 11th July 2022. Studies were included if they were clinical trials or observational studies conducted in adult individuals with SCI and provided information of interest. Based on strength of the study design and risk of bias assessment (using the NIH tool), we classified studies from Level 1 (most reliable studies) to Level 4 (least reliable studies).

RESULTS

Of 12,313 unique citations, 47 articles (based on 43 original studies) comprising 32 interventional (22 RCTs, 3 NRCT, and 7 pre-post studies) and 11 observational studies (2 cohort studies, 2 case-control, 1 post-intervention follow-up study, and 6 cross-sectional studies) were included in the present systematic review. Twenty studies (46.5%) were classified as Level 1 or 2, indicating high/moderate methodological quality. Based on those studies, dietary strategies including high protein diet, intermittent fasting, balanced diet in combination with physical conditioning and electrical stimulation, and dietary supplementation including alpha-lipoic acid, creatine, vitamin D, and cranberry-derived supplements and probiotics were mapped as the most promising in prevention of SHC among individuals with SCI.

CONCLUSIONS

To develop timely and effective preventive strategies targeting major SHC (e.g., cardiometabolic diseases, urinary tract infections) in SCI, further research is warranted to confirm the effectiveness of dietary strategies/interventions identified through the current systematic review of the literature.

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

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

The 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.

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].

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.

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.

A secondary analysis of testosterone and electrically evoked resistance training versus testosterone only (TEREX-SCI) on untrained muscles after spinal cord injury: a pilot randomized clinical trial

STUDY DESIGN

Secondary analysis of a clinical trial.

OBJECTIVES

To perform a secondary analysis on the effects of neuromuscular electrical stimulation resistance training (RT) combined with testosterone replacement therapy (TRT) compared with TRT on the untrained muscles after spinal cord injury (SCI).

SETTING

Medical research center.

METHODS

Twenty-two men with chronic motor complete SCI were randomized into TRT + RT group (n = 11) or TRT group (n = 11). Both groups received 16 weeks of TRT (2-6 mg/day) via testosterone patches. The TRT + RT group received twice weekly progressive RT of the knee extensor muscles using electrical stimulation and ankle weights. Magnetic resonance images were captured to measure cross-sectional areas (CSAs) of trunk, glutei, and leg muscles.

RESULTS

Total and absolute gluteus maximus m. (14%, P = 0.003 and 16%, P = 0.001), gluteus medius m. (10%; P = 0.008 and 14%; P = 0.02), and total glutei m. (8%, P = 0.01 and 11%, P = 0.005) CSAs increased overtime for the TRT + RT group. Mean between-group differences of 2.86 (95% CI: 0.30, 5.4), 1.89 (95% CI: 0.23, 3.58) and 5.27 (95% CI: 0.90, 9.69) cm² were noted for absolute gluteus maximus, total gluteus medius and total glutei CSAs, respectively (P < 0.05). Trunk muscle CSAs showed a trend towards an interaction between groups.

CONCLUSIONS

RT combined with low-dose TRT results in significant hypertrophy compared with TRT only on the adjacent untrained glutei muscles. Trunk muscles may require direct stimulation to evoke hypertrophy. These exploratory findings may be of clinical relevance in the reduction of incidence and severity of pelvic pressure injuries.

Low-Dose Testosterone and Evoked Resistance Exercise after Spinal Cord Injury on Cardio-Metabolic Risk Factors: An Open-Label Randomized Clinical Trial

The purpose of the work is to investigate the effects of low-dose testosterone replacement therapy (TRT) and evoked resistance training (RT) on body composition and metabolic variables after spinal cord injury (SCI). Twenty-two individuals with chronic motor complete SCI (ages 18-50 years) were randomly assigned to either TRT+RT (n = 11) or TRT (n = 11) for 16 weeks following a 4 -week delayed entry period. TRT+RT men underwent twice weekly progressive RT using electrical stimulation with ankle weights. TRT was administered via testosterone patches (2-6 mg/day). Body composition was tested using anthropometrics, dual energy x-ray absorptiometry, and magnetic resonance imaging. After an overnight fast, basal metabolic rate (BMR), lipid panel, serum testosterone, adiponectin, inflammatory and anabolic biomarkers (insulin-like growth factor-1 and insulin-like growth factor-binding protein 3 [IGFBP-3]), glucose effectiveness (Sg), and insulin sensitivity (Si) were measured. Total body lean mass (LM; 2.7 kg, p < 0.0001), whole muscle (p < 0.0001), and whole muscle knee extensor cross-sectional areas (CSAs; p < 0.0001) increased in the TRT+RT group, with no changes in the TRT group. Visceral adiposity decreased (p = 0.049) in the TRT group, with a trend in the TRT+RT (p = 0.07) group. There was a trend (p = 0.050) of a 14-17% increase in BMR following TRT+RT. Sg showed a trend (p = 0.07) to improvement by 28.5-31.5% following both interventions. IGFBP-3 increased (p = 0.0001) while IL-6 decreased (p = 0.039) following both interventions, and TRT+RT suppressed adiponectin (p = 0.024). TRT+RT resulted in an increase in LM and whole thigh and knee extensor muscle CSAs, with an increase in BMR and suppressed adiponectin. Low-dose TRT may mediate modest effects on visceral adipose tissue, Sg, IGFBP-3, and IL-6, independent of changes in LM.

Dietary manipulation and testosterone replacement therapy may explain changes in body composition after spinal cord injury: A retrospective case report

BACKGROUND

Reduced level of physical activity, high-fat diet and skeletal muscle atrophy are key factors that are likely to contribute to deleterious changes in body composition and metabolic following spinal cord injury (SCI). Reduced caloric intake with lowering percentage macronutrients of fat and increasing protein intake may likely to improve body composition parameters and decrease ectopic adiposity after SCI.

AIM

To highlight the effects of dietary manipulation and testosterone replacement therapy (TRT) on body composition after SCI

METHODS

A 31-year-old male with T5 SCI was administered transdermal TRT daily for 16 wk. Caloric intake and percentage macronutrients were analyzed using dietary recalls. Magnetic resonance imaging and dual-energy x-ray absorptiometry were used to measure changes in body composition.

RESULTS

Caloric intake and fat percentage were reduced by 445 kcal/d and 6.5%, respectively. Total body weight decreased by 8%, body fat decreased by 29%, and lean mass increased by 7%. Thigh subcutaneous adipose tissue cross-sectional area was reduced by 31%.

CONCLUSION

Manipulation of caloric intake, fat percentage, and protein percentage may have influenced body composition after SCI.

Serum testosterone levels may influence body composition and cardiometabolic health in men with spinal cord injury

Study Design:

Cross-sectional study

Objective

To establish the association between serum testosterone (T) levels, biomarkers of cardiometabolic health and regional body composition variables after spinal cord injury (SCI).

Setting:

Medical research center

Methods

Metabolic and body composition measurements were collected from thirty-six men with chronic motor complete SCI. Serum T, carbohydrate and lipid profiles were measured after an overnight fast. Body composition was measured using anthropometrics, dual energy x-ray absorptiometry and magnetic resonance imaging. Participants were evenly classified into tertiles based on their serum T levels into low, mid-normal and normal ranges.

Results

Low, mid-normal and normal range serum T were 288.8 ± 84.9ng/dL, 461.0 ± 52.5ng/dL and 648.0 ± 53.5ng/dL, respectively. Low range serum T group had greater total (9.6%, P= 0.04) percentage fat mass and visceral adipose tissue (VAT) area (72%, P= 0.01) compared to normal range serum T group. Serum T was related to the absolute whole thigh muscle area (r= 0.40, P< 0.05) after controlling for body mass index. Serum T was negatively related to fasting plasma glucose (r= −0.46, P= 0.006) and insulin (r= −0.42, P= 0.01), HbA1c (r= −0.39, P= 0.02) and triglycerides (r= −0.36, P= 0.03).

Conclusion

Men with low serum T have more unfavorable body composition and cardiometabolic health outcomes after SCI. Testosterone replacement therapy may serve as a potential strategy in preventing cardiometabolic disorders after SCI.