Functional predictors of treatment induced diabetic neuropathy (TIND): a prospective pilot study using clinical and neurophysiological functional tests

BACKGROUND: A treatment-induced drop in HbA1c has been suggested to be a risk factor for TIND. METHODS: From 60 included patients with severe diabetes mellitus (HbA1c over 8.5) only 21 patients adhered to the study protocol over 1 year with a battery of autonomic nervous system tests scheduled before and after starting antidiabetic treatment. RESULTS: In patients with a drop of HbA1c greater than 2 per cent points only some neurophysiologic tests and lab values tended to deteriorate with a trend to improve at later time points along the study. None of these changes were statistically significant, most likely because the study failed to reach the planned number of patients. CONCLUSION: Poor adherence to diabetes treatment and to following the study protocol were the assumed obstacles in our patient cohort selected for very high HbA1c levels. In future studies a multi-center trial and case numbers of up to 500 patients may be needed to account for drop outs in the range observed here. Moreover, the number of tests in each patient at each visit may have to be reduced and special educational group sessions are warranted to cope with the limited adherence. Trial registration Ethic Committee University of Leipzig 439/15-ek. Registered 22 April 2016