Lower-extremity muscle atrophy and fat infiltration after chronic spinal cord injury.
BACKGROUND
Atrophy and fatty-infiltration of lower-extremity muscle after spinal cord injury (SCI) predisposes individuals to metabolic disease and related mortality.


OBJECTIVE
To determine the magnitude of atrophy and fatty-infiltration of lower-extremity muscles and related factors in a group of individuals with chronic SCI and diverse impairment.


METHODS
Muscle cross-sectional area and density were calculated from peripheral quantitative computed tomography scans of the 66% site of the calf of 70 participants with chronic SCI [50 male, mean age 49 (standard deviation 12) years, C2-T12, AIS A-D] and matched controls. Regression models for muscle area and density were formed using 16 potential correlates selected a priori.


RESULTS
Participants with motor-complete SCI had ≈ 32% lower muscle area, and ≈ 43% lower muscle density values relative to controls. Participants with motor-incomplete SCI had muscle area and density values that were both ≈ 14% lower than controls. Body mass (+), tetraplegia (+), motor function (+), spasticity (+), vigorous physical activity (+), wheelchair use (-), age (-), and waist circumference (-) were associated with muscle size and/or density in best-fit regression models.


CONCLUSIONS
There are modifiable factors related to muscle size, body composition, and activity level that may offer therapeutic targets for preserving metabolic health after chronic SCI.
Brain and Spinal Cord Rehabilitation Program, Toronto Rehabilitation Institute, University Health Network.
C D
CD
Moore
B C
BC
Craven
L
L
Thabane
A C
AC
Laing
A W
AW
Frank-Wilson
S A
SA
Kontulainen
A
A
Papaioannou
J D
JD
Adachi
L M
LM
Giangregorio
D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D000368:Aged; D001823:Body Composition; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D009133:Muscular Atrophy / Q000209:etiology / Q000473:pathology*; D013119:Spinal Cord Injuries / Q000150:complications*; D014057:Tomography, X-Ray Computed