Effects of Exercise in People With Tetraplegia

Much as in the general population, cardiovascular disease (CVD) is a leading cause of death
in persons with spinal cord injury. However, CVD occurs earlier in life for those with SCI,
progresses silently, and manifests atypical symptoms which fail to warn of impending
ischemic damage. This accelerated development of CVD is multimodal in cause, including, but
not limited to: a sedentary lifestyle, decreased muscle mass, increased fat mass, and
physiologic alterations in lipid metabolism, all attributable in part to SCI. Traditional
methods of dietary modification and exercise intervention are likely insufficient to elicit
adequate modification of post-SCI physiology to prevent CVD. Secondary to our purposes, but
of immediate importance to an individual with SCI is the impact of a sedentary lifestyle and
increased obesity on their ability to remain independent. A quarter of young persons with
SCI possess levels of fitness which are inadequate to complete essential activities of daily
living. Thus, a sedentary lifestyle, as measured by fitness, is a correlate if not
perceptive of morbidity and mortality in persons with SCI.

Atherosclerosis has recently been defined as an inflammatory disease. C-reactive protein has
emerged as a general marker of inflammation and is elevated in persons with SCI. We have
demonstrated persons with SCI have a pathophysiologic lipid uptake response to a high fat
meal, the endpoint of which is increased vascular oxidative stress, a precursor to CVD,
indexed by endothelial microparticles. We have also demonstrated circuit resistance training
favorably alters lipid profiles of persons with paraplegia. Research in able-bodied
individuals suggests acute bouts of exercise accelerate postprandial lipid metabolism (PPL).
Post-exercise supplementation has been demonstrated to improve gains in both lean muscle
mass and performance over exercise alone in both the able-bodied and individuals with spinal
cord injury.

Targeting inflammation, post-prandial lipidemia, and altering lipid profiles through dietary
and exercise interventions may be a method to reverse or pre-empt the development of CVD in
persons with SCI. Increasing muscle mass and physical performance through the same
interventions may improve physical performance and thus independence in activities of daily
living in persons with SCI. In addition, exercise may serve to decrease depression and
anxiety in persons with SCI, much as in non-disabled persons. Targeted exercise plus timed
supplementation may decrease the accelerated morbidity and mortality of persons with SCI.

Inclusion Criteria:

- SCI resulting in tetraplegia at C5-C8

- injury for more than one year

- American Spinal Injury Association Impairment Scale (AIS) grade A-C injuries

Exclusion Criteria:

- Surgery within 6 months;

- pressure ulcer within 3 months;

- upper limb pain that limits completion of exercise;

- recurrent acute infection or illness requiring hospitalization or IV antibiotics;

- pregnancy;

- previous myocardial infarction or cardiac surgery;

- history of glucose-lowering and lipid-lowering drug therapy;

- Type I or II diabetes (by World Health Organization criteria). The following
medications and drug therapies will disqualify subjects from participating in the
study: beta-adrenergic antagonists, maintenance alpha-adrenergic blockers,
Methyldopa, thiazide and loop diuretics, parasympatholytic agents, zinc,
estrogen/hormone replacement therapy excluding oral contraceptives,
insulin-sensitizing drugs, aspirin, and non-steroidal anti-inflammatory drugs.