Aim: This work explores underlying microstructural fiber differences in the calf muscles of individuals with and without type 2 diabetes mellitus (DM) at rest and during an isometric exercise.

Methods: Twenty-one subjects were examined in a 3T MRI scanner. Two groups were tested: 8 participants without DM (WDM) and 13 participants with DM. We used a custom-made MRI compatible ergometer that consisted of a brake-like pedal with an adjustable pressure gauge. Diffusion tensor imaging was performed on calf at rest and during a plantarflexion exercise. Regions of interests (ROI) were manually drawn on medial and lateral gastrocnemius (MG and LG), as well as on soleus (SOL).

Results: In the MG, the fiber length changes (%) were -29.07±6.71 for the WDM, and -52.53±15.for the DM group (P<.001). Exercise fiber density (P<.01) and angle (P<.05) changes were also significantly different between groups. The DM resulted in more fiber disarrays with loss of fiber during exercise (Fig 1).

Conclusions: While more changes in the fiber indices were observed in the DM during exercise, significant difference was shown in the MG muscle. These changes may reflect diabetic damage by altering muscle microstructure.


M. Edalati: None. C.J. Sorensen: None. M. Hastings: None. M.A. Zayed: None. M.J. Mueller: None. J. Zheng: None.

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at