Palmitoylethanolamide in Add-On to Alpha Lipoic Acid for Control of Symptoms of Diabetic Peripheral Neuropathy

Background: Palmitoylethanolamide (PEA) is an amide with “autacoid local inflammation antagonism” effects, protecting nerve degeneration due to mast cell degranulation. PEA add-on to alpha-lipoic acid (ALA) is successfully used as treatment of neuropathic pain, but there are no data in diabetic peripheral neuropathy (DPN) specifically.

Aim: To evaluate whether PEA in add-on to ALA has potentials in controlling DPN symptoms.

Methods: In this pilot longitudinal observational study, clinical and biochemical data from ninety-eight consecutive subjects with type 1 diabetes (T1D) evaluated for DPN symptoms between January and July 2017 in our outpatient clinic were retrospectively retrieved. DPN symptoms were assessed by Neuropathy Symptoms Score (NSS). Follow-up data were retrieved for patients with NSS ≥3 and receiving treatment with ALA 600mg/daily ± PEA 600mg/daily or receiving no treatment.

Results: NSS was ≥3 in 34 (34.7%) subjects. Of these, 17 were treated with ALA ± PEA (9 with ALA in monotherapy and 8 with PEA in add-on to ALA), and 17 were not treated. After a mean follow-up of 8.1±3.4 months, NSS was ≥3 in 76.5% of non-treated subjects vs. 29.4% of treated subjects (p<0.01). The percentage of subjects with NSS≥3 did not differ between subjects treated with ALA vs. those treated with ALA+PEA (p=0.62). The mean time for symptoms resolution (NSS<3) was lower in subject treated with ALA+PEA than in those treated with ALA in monotherapy (14.0±8.6 vs. 25.0±9.1 days, p<0.05). Among treated subjects, baseline HDL-cholesterol was inversely related to the time to symptoms resolution (p=0.026)

Conclusions: PEA add-on to ALA accelerates the resolution of neuropathic symptoms in T1D subjects with DPN. This study also suggests HDL-cholesterol may be a biomarker for the response to treatment with ALA ± PEA.