Evaluation of effectiveness of different modes of per os therapy of painful diabetic peripheral polyneuropathy with alpha-lipoic acid

Abstract

Aim.
To evaluate effectiveness of different modes of per os therapy of painful diabetic peripheral polyneuropathy with alpha-lipoic acid.
Materials and methods.
This work is a prospective open randomized comparative clinical study including 4 parallel groups of patients. Group 1(n=31) comprised patients given 600 mg ALA daily (two 300 mg tablets at a time), group 2 (n=28) 600 mg ALA daily (two 300 mg tablets in succession),group 3 (n=35) 900 mg ALA daily (three 300 mg tablets at a time in the morning), group 4 (n=27) 900 mg ALA daily (three 300 mg tablets in succession30-40 min before meals). Active treatment lasted 3 months.
Results.
Beneficial effect of 3 ALA tablets on neurologic symptoms estimated by NTSS-6 and 9 scales was significantly more pronounced than that oftwo 300 mg tablets taken either once or twice a day. The groups were analysed in terms of the number of patients who achieved or failed to achievethe end point of therapy (responders, n=86 and non-responders, n=29). The HbA_1c level and the degree of sensory deficit were shown to begood predictors of therapeutic efficiency. There was moderate correlation between HbA_1c level (>8%), NIS LL and NIS LL-sensory function points,and frequency of response to ALA therapy (r=0.251; p=0.007 // r=0.32; p=0.00077 // r=0.32; p=0.0015 respectively). Patients having HbA_1c<7.0% showed maximum dynamics of NTSS-6 and 9 points.
Conclusion.
Intake of ALA tablets (300 mg thrice daily) causes marked reduction of neurologic symptoms estimated by NTSS-6 and 9 scales. Thefrequency of pain relapses depends on the initial HbA_1c level rather than on the previous scheme of ALA therapy. High HbA_1c (>8.0%) and severedisturbances of sensory function (e.g. monofilament resistance) may be used as predictors of therapeutic efficiency.