Alpha Lipoic Acid for Symptomatic Peripheral Neuropathy in Patients with Diabetes: A Meta-Analysis of Randomized Controlled Trials

Table 3

Overview of the included randomized, placebo-controlled studies with alpha lipoic acid in persons with symptomatic peripheral diabetic neuropathy.

Study; 1st author, year; study name	Research group		Length of study	Alpha lipoic acid dosage	Administration route	Primary outcome measure	Findings		Difference intervention versus control* (Significance)	level of evidence
	Patient type	Number of patients (Intervention/control)					Intervention	Control
Ziegler 1995 ALADIN [15]	DM2; 18–70 yr	328 (65/63/66/66)	3 weeks	(a) 100 mg daily; (b) 600 mg daily; (c) 1200 mg daily	Intravenous	TSS	(a) 7.6 → 4.3; (b) 7.8 → 2.8; (c) 7.6 → 3.1	6.8 → 4.2	−0.7 (ns); −2.4 (𝑃<0.001); −1.9 (𝑃=0.003)	1b
Ruhnau 1999 ORPIL [16]	DM2; 18–70 yr	24 (12/12)	3 weeks	3dd600 mg	Oral	TSS	7.99 → 4.24	8.18 → 6.24	−1.81 (𝑃=0.021)	1b
Ametov 2003 SYDNEY [17]	DM1+ DM2; 18–74 yr	120 (60/60)	3 weeks	600 mg daily for 14 days	Intravenous	TSS	−5.72	−1.83	−3.89(𝑃<0.001)	1b
Ziegler 2006 SYDNEY 2 [18]	DM1+ DM2; 18–74 yr	181 (45/47/46 /43)	5 weeks	(a) 600 mg daily; (b) 1200 mg daily; (c) 1800 mg daily	Oral	TSS	(a) 9.44 → 4.59; (b) 9.40 → 4.90; (c) 9.02 → 4.32	9.27 → 6.35	−1.93 (𝑃<0.05); −1.58 (𝑃<0.05); −1.78 (𝑃<0.05)	1b

*Calculated differences between intervention and control groups: not controlled.
DM: diabetes mellitus.
ns: not significant.
TSS: Total Symptom Score.