Several body composition and metabolic-associated disorders such as glucose intolerance, insulin resistance, and lipid abnormalities occur prematurely after spinal cord injury (SCI) and at a higher prevalence compared to able-bodied populations. Within a few weeks to months of the injury, there is a significant decrease in total lean mass, particularly lower extremity muscle mass and an accompanying increase in fat mass. The infiltration of fat in intramuscular and visceral sites is associated with abnormal metabolic profiles. The current review will summarize the major changes in body composition and metabolic profiles that can lead to comorbidities such as type 2 diabetes mellitus and cardiovascular diseases after SCI. It is crucial for healthcare specialists to be aware of the magnitude of these changes. Such awareness may lead to earlier recognition and treatment of metabolic abnormalities that may reduce the co-morbidities seen over the lifetime of persons living with SCI.

Prolonged, uninterrupted sitting negatively impacts markers of peripheral vascular health, particularly, vasodilatory function of leg arteries. Whether sitting can similarly impact measures of central vascular health, as well as overall leg vasoreactivity (i.e., vaso-dilatory and vasoconstrictor function) remains unknown. To address this, measurements were made in relatively healthy participants (i.e., free of overt disease; n = 20, age = 26 § 7; body mass index = 30 § 7 kg/m2; 7 female) pre, during and post 3 hours of uninterrupted sitting. Measures of central vascular health included arterial wave reflection (augmentation index and Reflection Magnitude-RM%) and aortic vascular stiffness (aortic pulse wavevelocity). Local vasoreactivity of the distal, posterior tibialartery was measured using flow-mediated dilation-FMD, coupled with low-flow mediated constriction, and microvascular function was assessed through the total hyperemic blood velocity (area-under-curve) response during FMD. After sitting, there was a significant increase in aortic pulse wave velocity (pre sit = 5.7 § 0.3 vs post sit = 6.1 § 0.3 m/s; p=0.009, d = 0.36), whereas, augmentation index decreased (pre sit=13 § 3 vs post sit=3 § 1%; p < 0.001, d = 0.71). Albeit a moderate effect for decrease, RM % was not significantly altered during sitting (p = 0.13, d = 0.3). Vasodilatory (i.e., FMD pre sit = 0.5 § 0.04 vs post sit =0.3 § 0.04 mm; p = 0.014, d = 0.29) and micro vascular function (i.e., Microvascular area-under-curve: pre sit = 2,196 § 333 vs1, 157 §172 AU; p = 0.003, d = 0.31) decreased, but vasoconstrictor function (low-flow mediated constriction; p = 0.85, d = 0.005) was unaffected by sitting. In conclusion, these data demonstrate that a prolonged bout of uninterrupted sitting negatively impacts markers of peripheral and central vascular health in relatively healthy adults.

Diet and exercise are cornerstones in the management of obesity and associated metabolic complications, including insulin resistance, type 2 diabetes, and disturbances in the lipid profile. However, the role of exercise in managing body composition adaptations and metabolic disorders after spinal cord injury (SCI) is not well established. The current review summarizes evidence about the efficacy of using neuromuscular electrical stimulation or functional electrical stimulation in exercising the paralytic lower extremities to improve body composition and metabolic profile after SCI. There are a number of trials that investigated the effects on muscle cross-sectional area, fat-free mass, and glucose/lipid metabolism. The duration of the intervention in these trials varied from 6 weeks to 24 months. Training frequency ranged from 2 to 5 days/week. Most studies documented significant increases in muscle size but no noticeable changes in adipose tissue. While increases in skeletal muscle size after twice weekly training were greater than those trials that used 3 or 5 days/week, other factors such as differences in the training mode, i.e. resistance versus cycling exercise and pattern of muscle activation may be responsible for this observation. Loading to evoke muscle hypertrophy is a key component in neuromuscular training after SCI. The overall effects on lean mass were modest and did not exceed 10% and the effects of training on trunk or pelvic muscles remain unestablished. Most studies reported improvement in glucose metabolism with the enhancement of insulin sensitivity being the major factor following training. The effect on lipid profile is unclear and warrants further investigation.

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.