-Lipoic Acid for Diabetic Neuropathy

This antioxidant supplement (which is unregulated in the U.S.) reduced pain scores.

The antioxidant -lipoic acid has shown some promise in treating diabetic neuropathy. In this industry-sponsored, double-blind randomized trial — a collaboration among researchers at Mayo Clinic and in Israel, Russia, and Germany — 181 diabetic patients with symptomatic diabetic neuropathy received either -lipoic acid (at oral doses of 600, 1200, or 1800 mg daily) or placebo. The primary outcome was change in a total symptom score (TSS; possible range, 0–14.64) that reflected stabbing pain, burning pain, paresthesia, and numbness.

At 5 weeks, the mean TSS had decreased (from a baseline of about 9 points) by 2.9 points in the placebo group and by 4.9, 4.5, and 4.7 points, respectively, in the three -lipoic acid groups. In addition, a clinical response (defined as reduction in the TSS score of 50%) occurred in 26% of placebo recipients and in 62%, 50%, and 56%, respectively, of patients in the three -lipoic acid groups. Differences between each dose of -lipoic acid and placebo were significant. Higher doses were associated with more nausea than the lowest dose.

Comment: According to this study, 600 mg daily of -lipoic acid reduces symptoms in some patients with diabetic neuropathy. In the U.S., -lipoic acid is available only as a nonprescription dietary supplement and thus is not regulated. An interesting next step would be to compare it with commonly prescribed medications for neuropathy (e.g., anticonvulsants and antidepressants).

— Allan S. Brett, MD

Published in Journal Watch General Medicine December 12, 2006

Citation(s):

Ziegler D et al. Oral treatment with alpha-lipoic acid improves symptomatic diabetic polyneuropathy: The SYDNEY 2 trial. Diabetes Care 2006 Nov; 29:2365-70.