Muscle Modification in Asymptomatic Diabetic Neuropathy: a Surface Electromyographic Study

Carmelo Chisari, Alberto Piaggesi, Fabio Baccetti, Rosaria Licitra, Bruno Rossi
2002 Basic Appl Myol   unpublished
In 24 non insulin-dependent diabetic patients [NIDDM-12 with (ND+) and 12 without (ND-) asymptomatic polyneuropathy] in stable metabolic control, and in 12 age-matched controls (C), we studied the functional properties of tibialis anterior muscle (TA) through an electrically elicited contraction. We recorded the surface EMG signal and analysed the median frequency of power spectrum (MDF), the average rectified value of amplitude (ARV) and the muscle fibers conduction velocity (CV). At the
more » ... ing MDF, ARV and CV were significantly decreased in ND+ compared both to ND-and controls. After 23 and 43 sec from the beginning of the stimulation a statistically significant decrease in CV was observed in ND+ compared to ND-and controls (-26% and-49% in ND+,-9% and-28% in ND- ,-12% and-30% in C p<0.01). No significant differences emerged as regard MDF and ARV among three groups, either after 23 and 43 sec of electrical stimulation. Our main findings are consistent with a decrease in mean size of muscle fibers in ND+ respect to ND-and controls. This data suggest a muscle fibers hypotrophy even in non den-ervated ones. Moreover we can suppose a shift of fiber composition toward the type II fibers in asymptomatic neuropathic diabetic patients. In conclusion, we observed a myopathic involvement in TA of asymptomatic NIDDM patients. So, it seems very important to early detect muscle function impairment in these patients in order to advise them appropriate rehabilitative program.