Safety and efficacy of alpha lipoic acid during 4 years of observation: A retrospective, clinical trial in healthy subjects in primary prevention

Aim: To evaluate the safety of four different dosages of alpha lipoic acid (400, 600, 800, and 1200 mg) as food supplement on adverse events related to alpha lipoic acid consumption and efficacy on glycemic status and lipid profile in subjects with euglycemia or dysglycemia. Methods: We conducted a retrospective, observational study enrolling 322 patients, 83 taking 400 mg/day, 78 taking 600 mg/day, 80 taking 800 mg/day, and 81 taking 1200 mg/day alpha lipoic acid, respectively. Results: In the groups treated with alpha lipoic acid 800 and 1200 mg/day, we registered a reduction of FPG, TC, LDL-C, and Tg compared to baseline (p < 0.05 for all with alpha lipoic acid 800 mg/day, and p < 0.01 for all with alpha lipoic acid 1200 mg/day). The values recorded in the group treated with alpha lipoic acid 1200 mg/day were significantly lower compared to the ones obtained with alpha lipoic acid 400 mg/day. Moreover, alpha lipoic acid 1200 mg/day reduced Hs-CRP levels compared to baseline and compared to 400 mg/day (p < 0.05 for both). In the group treated with alpha lipoic acid at 800 mg/day, 5 subjects with IFG and 1 subject with IGT returned euglycemic. In the group treated with alpha lipoic acid at 1200 mg/day, 11 subjects with IFG and 3 subjects with IGT returned euglycemic. Adverse events of patients during alpha lipoic acid treatment included nausea, vomiting, dizziness, cutaneous rash, hypoglycemia, and hypotension. Adverse events did not differ among the four groups. Conclusion: The chronic use (4 years) of a food supplement containing alpha lipoic acid is well tolerated, without significant differences between lower and higher dosages and improves glycemic status and lipid profile but only if administered at high dosage.