Metabolic and Endocrine Changes in Persons Aging with Spinal Cord Injury

Persons with spinal cord injury (SCI) have secondary medical disabilities that impair their ability to function. With paralysis, dramatic deleterious changes in body composition occur acutely with further adverse changes ensuing with increasing duration of injury. Lean mass, composed of skeletal muscle and bone, is lost and adiposity is relatively increased. The body composition changes may be further exacerbated by associated reductions in anabolic hormones, testosterone, and growth hormone. Individuals with SCI also have decreased levels of activity. These body composition and activity changes are associated with insulin resistance, disorders in carbohydrate and lipid metabolism, and may be associated with premature cardiovascular disease. Although limited information is available, upper body exercise and cycle ergometry of the lower extremities by functional electrical stimulation (FES) have been reported to have a salutary effect on these body composition and metabolic sequelae of paralysis. Perhaps other innovative, externally mediated forms of active exercise of the paralyzed extremities will result in an increased functional capacity, metabolic improvement, and reduction of atherosclerotic vascular disease.