Skeletal muscle mitochondrial health and spinal cord injury

Mitochondria are the main source of cellular energy production and are dynamic organelles that undergo biogenesis, remodeling, and degradation. Mitochondrial dysfunction is observed in a number of disease states including acute and chronic central or peripheral nervous system injury by traumatic brain injury, spinal cord injury(SCI), and neurodegenerative disease as well as in metabolic disturbances such as insulin resistance, type Ⅱ diabetes and obesity. Mitochondrial dysfunction is most commonly observed in high energy requiring tissues like the brain and skeletal muscle. In persons with chronic SCI, changes to skeletal muscle may include remarkable atrophy and conversion of muscle fiber type from oxidative to fast glycolytic, combined with increased infiltration of intramuscular adipose tissue. These changes contribute to a proinflammatory environment, glucose intolerance and insulin resistance. The loss of metabolically active muscle combined with inactivity predisposes individuals with SCI to type Ⅱ diabetes and obesity. The contribution of skeletal muscle mitochondrial density and electron transport chain activity to the development of the aforementioned comorbidities following SCI is unclear. A better understanding of the mechanisms involved in skeletal muscle mitochondrial dynamics is imperative to designing and testing effective treatments for this growing population. The current editorial will review ways to study mitochondrial function and the importance of improving skeletal muscle mitochondrial health in clinical populations with a special focus on chronic SCI.

Exercise awareness and barriers after spinal cord injury

Exercise is an essential element in managing several of the non-communicable diseases after spinal cord injury(SCI).Awareness of the importance of prescribing a customized exercise program that meets the goals of persons with SCI should be highly considered in the rehabilitation community.The barriers of implementing specific exercise program as well as the factors that may mask the outcomes of regular exercise regimen need to be continuously addressed as a part of patients’rehabilitation care.The focus of this editorial is to encourage the medical community to consider routine physical activity as one of the necessary vital signs that needs to be routinely checked in patients with SCI.Providing education tips,nutritional counseling and engaging in recreational programs may provide motivational route to the community of SCI.This may result in reinforcing active lifestyle in survivors with SCI as well as to reduce the impact of chronic life threatening medical disorders.

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.

Skeletal muscle conditioning may be an effective rehabilitation intervention preceding functional electrical stimulation cycling

In our recent effort,we introduced a submaximal index that utilized ventilatory efficiency relative to CO2 production（VE/CO2）to evaluate the cardiovascular effectiveness to functional electrical stimulation lower-extremity cycling（FESLEC）in persons with spinal cord injury（SCI）（Gorgey and Lawrence,2016）.