Alpha Lipoic Acid Improves Sensory Symptoms of Diabetic Sensorimotor Peripheral Neuropathy

by | Sep 25, 2023 | 2023, Alpha Lipoic Acid, Diabetes

Written by Taylor Woosley, Staff Writer. Results of the systematic review and meta-analysis of 10 RCTs shows that administration of ALA significantly improved total symptoms’ score and neurological disability score outcomes in diabetic subjects with DSPN. 

diabetesDiabetes mellitus (DM) is a worldwide public health challenge and the World Health Organization (WHO) estimates that around 422 million people are currently living with diabetes1. Among the complications of diabetes, a group of clinical syndromes caused by damage to the peripheral and autonomic nervous systems are the most prevalent2. Diabetic sensorimotor peripheral neuropathy (DSPN) is a major cause of reduced quality of life due to pain, sensory loss, instability, fall-related injury, and foot ulceration and amputation3.

Α-lipoic acid (ALA) is an organosulfur compound commonly found in mitochondria that has been researched for its use to reduce neuropathy symptoms of diabetes4. Many studies have indicated its potential role in the regulation of glucose metabolism, highlighting its effects on insulin sensitivity, insulin secretion, the reduction of circulating lipid levels, and the increase on nitric oxygen5. Furthermore, it is a powerful antioxidant cofactor that could help stimulate nerves and regenerative nerve fibers, thus preventing disease progression6.

Hsieh et al. conducted a systematic review and meta-analysis to analyze the effects of oral administration of ALA compared to a placebo in subjects with DSPN. Study inclusion consisted of following a randomized controlled trial (RCT) design, with adult patients diagnosed with DSPN who were consuming oral ALA, with outcome measures including total symptoms’ score (TSS), neuropathy impaired score (NIS), NIS-lower limb (NIS-LL), neurological disability score (NDS), visual analogue scale of pain (VAS), vibration perception threshold (VPT), nerve conduction study (NCS) results, and a global satisfaction score.

A total of 10 RCTs were included in the final meta-analysis. Study samples ranged from 20 to 454 subjects, with a total of 1242 participants (mean age 46.88 to 61.3 years). Subject duration of diabetes mellitus was between 10.13 and 14.55 years. ALA dosage varied across studies; 7 RCTs used 600 mg/day, 4 studies utilized 1200 mg/day, and 3 RCTs prescribed 1800 mg/day. The Risk of Bias 2 tool was utilized to assess the methodological quality of individual studies. A subgroup analysis of ALA dosages (600, 1200, and 1800 mg/day) was conducted to analyze whether different doses of ALA produced different effects compared to placebo. Significant findings of the study are as follows:

  • Results of 6 RCTs reporting TSS outcomes shows that ALA supplementation led to significantly improved TSS outcomes compared to the control (MD, -1.69; 95% CI [-1.57, -1.08]).
  • 2 RCTs reporting NDS outcomes show significant improvements in neurological disability score outcomes compared to the control (MD, -0.98; 95% CI [-1.29, -0.67]).
  • Results of 4 RCTs reporting on changes on global satisfaction show that the pooled odds ratio of ALA administration at 600, 1200, and 1800 mg/day was 2.15 (95% CI [1.58, 2.92]), 3.2 (95% CI [1.33, 7.71]), and 6.56 (95% CI [2.60, 16.54]), respectively.

Results of this systematic review and meta-analysis shows that ALA is an effective approach to improve sensory symptoms related to DPSN. Furthermore, a dose-dependent response was noted between ALA dosage and improvement in TSS and global satisfaction scores. Study limitations include the small number of studies used in the meta-analysis, the use of a myriad of outcomes for assessing DSPN with many included RCTs using different measurements, and the low subject participation in studies.

Source: Hsieh, Ruey-Yu, I-Chen Huang, Chiehfeng Chen, and Jia-Ying Sung. “Effects of Oral Alpha-Lipoic Acid Treatment on Diabetic Polyneuropathy: A Meta-Analysis and Systematic Review.” Nutrients 15, no. 16 (2023): 3634.

© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

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Posted September 25, 2023.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

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