In this prospective, double-blind, placebo-controlled trial, 90 patients with type 2 diabetes on metformin treatment for at least four years, and both peripheral and autonomic diabetic neuropathy were randomized to an active treatment group (n=44) receiving B12, and a control group (n=46) receiving placebo. All patients had B12 levels less than 400 pmol/L. Subjects underwent measurement of sural nerve conduction velocity and amplitude, vibration perception threshold, and performed cardiovascular autonomic reflex tests (CARTs: Mean Circular Resultant, Valsalva test, postural index and orthostatic hypotension]). Sudomotor function was assessed with the SUDOSCAN that measures electrochemical skin conductance in hands and feet. The Michigan Neuropathy Screening Instrument Questionnaire and Examination and questionnaires to evaluate quality of life and level of pain were also used.
This prospective double-blind placebo-controlled trial aims to investigate the safety and efficacy of oral dispersible tablet of vitamin B12 for 1 year, in 90 patients with diabetes mellitus type 2 and neuropathy.