Clinical Trial Summary
Each year, 11,000 people suffer a spinal cord injury (SCI) in the U.S. Within the first year,
there are profound declines in physiologic function, forming the underlying substrate for
future cardiovascular disease . In fact, acquired cardiovascular disease is an increasingly
recognized consequence of SCI and is the leading cause of death in SCI. Though incompletely
understood, the almost 10-fold prevalence of cardiovascular disease results in part from
profound physiologic 'detraining' resulting from motor impairment and immobility. Currently,
effective interventions preventing acute declines that lead to cardiovascular compromise and
increased risk in SCI are lacking - exercise therapy for those with SCI is challenging and
when employed, is typically limited to the upper body. Recently, the investigators refined a
unique form of exercise for those with SCI that specifically mirrors exercise performed by
those without SCI. Functional Electrical Stimulation (FES) Row Training (RT) couples
volitional arm and electrically controlled leg exercise, resulting in a hemodynamic profile
that produces the beneficial cardiac loading conditions of large muscle mass exercise. As
such, FES-RT may be a safe and effective way to attenuate cardiovascular declines following
SCI. The investigators aims are to test the overall hypotheses that FES-RT will: 1) mitigate
against increased visceral adiposity and reduced insulin sensitivity, 2) prevent worsening
lipid profile and compromised baroreflex function, and 3) counter ventricular wall thickening
and declining ventricular function occurring with acute SCI, and that these effects will be
greater than that observed with an arms-only exercise group. Changes with FES-RT will be
compared to a time (wait-list) control and to arms-only-RT. Individuals with an SCI within
the last 3-6 months will be randomized to FES-RT, to a time control, or arms-only-RT.
Measures will be made at baseline and 6 months. The investigators work will provide results
that clearly delineate potential health benefits of FES-RT, and if FES-RT is effective in a
majority of those with SCI, its application, implementation, and integration could be easily
replicated.
We will enroll approximately 60 individuals within three to six months post SCI to obtain
data on 50 individuals. One-half of the subjects (N=25) will be randomized to immediately
enroll in 6 months of FES-RT. One third (N=18) will be randomized to a wait-list to provide
time control data from baseline to 6 months. A wait-list control group is routine in exercise
studies because most volunteers are interested in participating in an exercise program.
Hence, time controls are difficult to capture since many of those randomized to receive no
exercise either drop from the study entirely, or end up pursuing some form of exercise on
their own. Therefore, a vehicle for enrollment of a time control group that is acceptable to
most volunteers is a wait-list. Therefore, a six month time control will provide data on
expected declines and then subjects will be randomized to six months exercise.
Training Protocols for Each Study Group
1. FES-RT GROUP
Subjects will begin with short intervals of FES-RT interspersed with rest intervals
and/or arms-only rowing intervals depending on fitness level and the response to the
FES. A maximum FES-rowing test will be performed at baseline. This will be repeated
after three months of training and training intensity will be adjusted to maintain the
training stimulus at the same relative intensity. The goal is for each volunteer to
achieve an exercise intensity of 75-85% maintained for a continuous 30 minutes performed
three times each week. A maximum FES-rowing test will be performed at the end of the six
months of FES-RT to determine increases in fitness.
2. ARMS-ONLY-RT GROUP
Training sessions will be 3 times per week for 26 weeks. To parallel the FES-RT, the
initial training sessions will also consist of 6 sets of arms-only rowing for five
minutes at 60% of VO2peak with a work-to-rest ratio of 2:1 and progress over the six
months to an exercise intensity of 75-85% maintained for 30 minutes performed three
times each week. A maximum arms-only rowing test will be performed at baseline. This
will be repeated after three months of training and training intensity will be adjusted
to maintain the training stimulus at the same relative intensity. A maximum arms-only
rowing test will be performed at the end of the six months of training to determine
increases in fitness.
3. WAIT-LIST GROUP
The wait list group will not participate in any training for 6 months. A maximum arms-only
rowing test will be performed immediately after enrollment, after initial familiarization
with arms-only-RT equipment (usually 2-3 sessions) and will be repeated after 3 and 6 months