Effects of Exercise in People With Paraplegia

Obesity and obesity-related secondary complications are pandemic health hazards that are highly prevalent among persons with spinal cord injuries (SCI). Accumulation of body fat disposes persons with SCI to accelerated endocrine and cardiovascular diseases, as well as pain, functional decline, and diminished health-related quality of life (HRQoL). While use of combined resistance and endurance exercise by persons without disability can remedy many of the problems associated with these disorders, their widespread use for persons with spinal cord injuries (SCI) must first satisfy scientific burdens of effectiveness.

The investigators have adopted the term "obesity-related secondary complications" to describe accumulation of body fat clustering with other secondary CVD risks, while recognizing that a threshold criterion for diagnosis of obesity in persons with SCI remains ill-defined. For purposes of this proposal, the "-related" part of the term confers physical deconditioning, hypertension, fasting dyslipidemia, post-prandial lipemia (PPL), and impaired insulin sensitivity, all of which have been reported in persons with SCI. Contextualized, any of these risks occurring independently or in clusters would be cause for immediate therapeutic lifestyle intervention (TLI), if not frank medical treatment. Given our early understanding of effective treatments for these risks, any improvement in their severity would be CVD risk-reducing and thus life-benefiting and function-preserving.

The investigators expect that the research findings will improve the understanding of risks for obesity and obesity-related secondary complications so that future interventions can be better targeted, identify an exercise intervention that can attend to current health risks, clarify whether nutrient supplementation improves risk-lessening benefits of exercise, identify exercise timing and intensities that best enhance fat utilization, and expand the understanding of the interrelated nature of risk factors after SCI.

Inclusion criteria

• SCI resulting in paraplegia between T5 and L1
• injury for more than one year
• American Spinal Injury Association Impairment Scale (AIS) grade A-C injuries
• BMI ≥ 23 kg/m2 (defined by studies as the equivalent to the WHO criterion of 25 kg/m2 as 'overweight', and the point at which health risks begin to increase), plus any two or more of the following conditions on screening:

• prehypertension (BP ≥ 120/80 mmHg) by updated AHA and ADA criteria
• dyslipidemia (HDL-C ≥ 40 mg/dL or TG ≤ 150 mg/dL) by NCEP ATP III Guidelines,44 or
• impaired fasting glucose (≥ 100 mg/dL) by 2006 ADA criteria.

Exclusion criteria

• surgery within 6 months
• pressure ulcer within 3 months
• upper limb pain that limits exercise
• recurrent acute infection or illness requiring hospitalization or IV antibiotics
• pregnancy
• previous myocardial infarction or cardiac surgery
• 6 month history of glucose lowering and lipid-lowering drug therapy
• Type I or II diabetes (by WHO criteria)
• daily intake of vitamin supplements exceeding 100% RDA
• The following medications and drug therapies will disqualify subjects from participating: beta-adrenergic antagonists, maintenance alpha-blockers, Methyldopa, thiazide and loop diuretics, parasympatholytic agents, zinc, estrogen/hormone replacement therapy excluding oral contraceptives, insulin-sensitizing drugs, and maintenance use of aspirin and nonsteroidal anti-inflammatory drugs.