ORIGINAL ARTICLE   

Minerva Endocrinologica 2018 March;43(1):11-8

DOI: 10.23736/S0391-1977.16.02505-0

Copyright © 2016 EDIZIONI MINERVA MEDICA

language: English

Differential efficacy of methylcobalamin and alpha-lipoic acid treatment on symptoms of diabetic peripheral neuropathy

Yajuan HAN ¹, Min WANG ², Jie SHEN ¹, Zhen ZHANG ³, Min ZHAO ¹, Jing HUANG ⁴, Youming CHEN ⁴, Zhi CHEN ¹, Yulan HU ¹, Yubing WANG ⁵ ✉

¹ Department of Endocrinology and Metabolism, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China; ² Department of Endocrinology and Tuberculosis, Guangzhou Chest Hospital, Guangzhou, China; ³ Department of Thoracic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China; ⁴ Department of Clinical Laboratory, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China; ⁵ Department of Thoracic Surgery, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China

BACKGROUND: Diabetic hyperglycemia damages peripheral nerves by triggering ischemia, oxidative stress, and inflammation. Alpha-lipoic acid (ALA) and methylcobalamin (MC) are known to improve signs of diabetic peripheral neuropathy (DPN), possibly by enhancing neural and vascular endothelial cell metabolism and antioxidant capacity. We evaluated differences in efficacy following short-term MC or ALA treatment on DPN symptoms to guide clinical drug selection.
METHODS: Forty DPN patients were randomly divided into MC and ALA treatment groups (both N.=20) and assessed by the Toronto Clinical Neuropathy Scoring System (TCSS), total symptom score (TSS), visual analog scale (VAS) of positive symptoms, and easy sensory test (EST) for negative symptoms before and after 2 weeks of treatment. Serum malondialdehyde (MDA) and superoxide dismutase (SOD) were also measured.
RESULTS: Neuropathy as measured by TCSS, TSS, and VAS scores was significantly reduced by both treatments (P<0.05) but magnitude varied by symptom. The VAS score reductions for burning and pain were significantly greater following ALA (P<0.01), while MC reduced numbness and paresthesia VAS scores to a slightly greater extent than ALA (P>0.05). Numbers of abnormal (low-response) points for pressure and pinprick sensation were reduced by MC but not by ALA, while both treatments induced a significant reduction in vibratory perception threshold (P<0.01). Neither MC nor ALA improved temperature sensation or tendon reflexes (P>0.05). Alpha-lipoic acid, increased SOD and reduced MDA (P<0.05), indicating enhanced antioxidant capacity, while MC had no effect.
CONCLUSIONS: Due to differences in efficacy, MC or ALA should be chosen according to the symptoms of individual patients.

KEY WORDS: Type 2 diabetes mellitus - Diabetic neuropathies - Methylcobalamin - Thioctic acid