Non-invasive assessment of lower extremity muscle composition after incomplete spinal cord injury.
METHODS
Cross-sectional study.


OBJECTIVE
(1) To quantify intramyocellular lipid (IMCL) content of the soleus muscle. (2) To assess the T(2) relaxation rates in the lower extremity skeletal muscles in persons with incomplete spinal cord injury (SCI).


METHODS
Academic Institution, Florida.


METHODS
Eight subjects (42+/-10 years old; 70+/-12 kg; 176+/-10 cm) with chronic (17+/-9 months post injury) motor SCI (C4-T12; ASIA C or D) and eight matched healthy controls were tested. Localized unsuppressed proton spectroscopy (H-MRS) was performed to estimate total lipid content and individual lipid components; IMCL and extramyocellular lipid (EMCL) from the soleus muscle. T(2)-weighted imaging of lower extremity muscles yielded muscle T(2) rates.


RESULTS
The IMCL content of the soleus muscle was 3.3 times higher in the patient group as compared to controls (P=0.002; 0.0401 (0.0234-0.0849) versus 0.0123 (0.0090-0.0175)). Similarly, EMCL measures were 4.5 times higher as compared to the controls (P=0.002). Significant differences were observed in the T(2) relaxation times of the soleus and gastrocnemius muscles (P<0.05).


CONCLUSIONS
The increased levels of IMCL might interfere with the glucose uptake in skeletal muscle; potentially predisposing persons with incomplete SCI to the development of peripheral insulin resistance. Marked elevations in the T(2) relaxation times of the locomotor muscles are reflective of an altered muscle composition.
Shah
P K
PK
Department of Physical Therapy, University of Florida, Gainesville, FL 32610, USA.
Gregory
C M
CM
Stevens
J E
JE
Pathare
N C
NC
Jayaraman
A
A
Behrman
A L
AL
Walter
G A
GA
Vandenborne
K
K
D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001823:Body Composition / Q000502:physiology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004576:Electromyography; D005260:Female; D006801:Humans; D050356:Lipid Metabolism / Q000502:physiology*; D035002:Lower Extremity / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D011522:Protons; D013119:Spinal Cord Injuries / Q000473:pathology* / Q000503:physiopathology; D018709:Statistics, Nonparametric
D011522:Protons