 Sample size calculation is based on a recent report showing that TBS is lower in diabetic vs. control subjects 1.228 vs. 1.298 with a standard deviation of 0.140. To observe a normalization of TBS in EXE participants with a statistical power of 90 α0.05 by unpaired t-test, 85 patients per arm are needed 170 total. A sample size of 200 patients will allow to support a dropout rate up to 15. 