Efficacy and safety of prostaglandin E1 plus lipoic acid combination therapy versus monotherapy for patients with diabetic peripheral neuropathy

• Compared with prostaglandin E1 (PGE1) or lipoic acid (LA) monotherapy, PGE1 plus LA (PGE1 + LA) combination therapy can significantly improve clinical efficacy in patients with diabetic peripheral neuropathy (DPN).
• PGE1 + LA combination therapy can significantly elevate nerve conduction velocities in patients with DPN compared with PGE1 or LA monotherapy.
• There were no serious adverse events in PGE1 + LA treatment group.

The aim of this report was to evaluate the efficacy and safety of prostaglandin E1 (PGE1) plus lipoic acid (LA) for the treatment of diabetic peripheral neuropathy (DPN) compared with that of PGE1 or LA monotherapy. Randomized controlled trials (RCT) published up to 3 August 2014 were reviewed. A random or fixed effect model was used to analyze outcomes expressed as risk ratios (RR) or mean difference (MD) with a 95% confidence interval (CI). I2 statistic was used to assess heterogeneity. Subgroup and sensitivity analyses were performed. The outcomes measured were as follows: clinical efficacy, median motor nerve conduction velocity (MNCV), median sensory nerve conduction velocity (SNCV), peroneal MNCV, peroneal SNCV and adverse effects. Thirty-one RCT with 2676 participants were included. Clinical efficacy of PGE1 + LA combination therapy was significantly better than monotherapy (p < 0.00001, RR = 1.32, 95% CI 1.26 to 1.38). Compared with monotherapy, PGE1 + LA combination therapy led to significant improvements in median MNCV (p < 0.00001, MD = 4.69, 95% CI 3.16 to 6.23), median SNCV (p < 0.00001, MD = 5.46, 95% CI 4.04 to 6.88), peroneal MNCV (p < 0.00001, MD = 5.19, 95% CI 3.71 to 6.67) and peroneal SNCV (p < 0.00001, MD = 5.50, 95% CI 3.30 to 7.70). There were no serious adverse events associated with drug intervention. PGE1 + LA combination therapy is superior to PGE1 or LA monotherapy for improvement of neuropathic symptoms and nerve conduction velocities in patients with DPN. These findings should be further validated by larger well-designed and high-quality RCT.