Real-World Effectiveness of Different Nutraceutical Formulations on Pain Intensity of Subjects with Diabetic Peripheral Neuropathy: An Observational, Retrospective, Case–Control Study

<b>Background/Objectives</b>. Diabetic peripheral neuropathy is a debilitating disease-related complication with a significant impact on quality of life. Its management represents a therapeutic challenge. Antioxidant agents such as α-lipoic acid, N-acetyl cysteine, and glutatione may be useful treatment strategies. <b>Methods</b>. A real-world, observational, retrospective, case-control study involving consecutive subjects with type 2 diabetes with diabetic peripheral neuropathy was performed. Participants who were supplemented with three different formulations for 12 weeks (high-dose α-lipoic acid (800 mg); low-dose α-lipoic acid (100 mg) plus glutathione (200 mg) plus Vitamin D (800 IU); N-acetyl cysteine (600 mg) plus glutathione (200 mg) plus Vitamin D (800 IU)) were compared with a non-treated control group. Questionnaires aimed at investigating the degree of disability and quality of life were administered. The primary endpoint was the change in neuropathic pain intensity measured by the Numerical Rating Scale (NRS). <b>Results</b>. Among 750 consecutive screened subjects with type 2 diabetes, 98 (13%) had diabetic neuropathy (mean age 66.7 ± 7.6 years, diabetes duration 11.3 ± 6.7 years, HbA1c 8.1 ± 1.5%, 43.8% insulin-treated). When comparing the differences between treatment groups in the changes in individual questionnaire scores between baseline and follow-up, all three supplements showed significant reductions compared to the control group in the NRS scale scores. No side effects have been reported during the study. <b>Conclusions</b>. As well as lipoic acid, other substances with specific activity on the genesis of neuropathic pain, such as N-acetyl cysteine and glutathione, have proved effective in reducing the intensity of pain.