1. ¹Department of Exercise Science, The University of Georgia, Athens, GA, USA
2. ²Departments of Physiology and Radiology, Molecular Imaging Research Center, Michigan State University, East Lansing, MI, USA
3. ³Crawford Research Institute, Shepherd Center, Atlanta, GA, USA
4. ⁴Department of Physical Therapy, Louisiana State University Health Sciences Center, New Orleans, LA, USA

Correspondence: GA Dudley, 115 M Ramsey Center, Dept of Exercise Science, University of Georgia, 300 River Rd, Athens, GA 30602, USA

Abstract

Study design: Survey.

Objective: Determine intramuscular fat (IMF) in affected skeletal muscle after complete spinal cord injury using a novel analysis method and determine the correlation of IMF to plasma glucose or plasma insulin during an oral glucose tolerance test.

Setting: General community of Athens, GA, USA.

Methods: A total of 12 nonexercise-trained complete spinal cord injured (SCI) persons (10 males and two females 4012 years old (meanSD), range 26–71 years, and 85 years post SCI) and nine nonexercise-trained nondisabled (ND) controls 299 years old, range 23–51 years, matched for height, weight, and BMI, had T₁ magnetic resonance images of their thighs taken and underwent an oral glucose tolerance test (OGTT) after giving consent.

Results: Average skeletal muscle cross-sectional area (CSA) (meanSD) was 58.621.6 cm² in spinal cord subjects and 94.132.5 cm² in ND subjects. Average IMF CSA was 14.56.0 cm² in spinal cord subjects and 4.72.5 cm² in nondisabled subjects, resulting in an almost four-fold difference in IMF percentage of 17.34.4% in spinal cord subjects and 4.62.6% in nondisabled subjects. The 60, 90 and 120 min plasma glucose or plasma insulin were higher in the SCI group. IMF (absolute and %) was related to the 90 or 120 min plasma glucose or plasma insulin (r ²=0.71–0.40).

Conclusions: IMF is a good predictor of plasma glucose during an OGTT and may be a contributing factor to the onset of impaired glucose tolerance and type II diabetes, especially in SCI. In addition, reports of skeletal muscle CSA should be corrected for IMF.