Efficacy of Rong Dan oral liquid for intervention of diabetic peripheral neuropathy

Abstract

Objective To evaluate the efficacy of a pure Chinese herbal product, Rong Dan oral liquid, in intervention of diabetic peripheral neuropathy (DPN). Methods This was a prospective study from July 2013 to February 2014. Thirty-one patients with DPN-complicating type 2 diabetes, who visited Endocrinology clinic at the First Affiliated Hospital, Guangzhou Medical University and met the inclusion criteria, were included. In addition to their dietary modification, exercise program and hypoglycemic scheme, the patients received Rong Dan oral liquid (20 ml, 3 times daily) for 12 weeks. Michigan Neuropathy Screening Instrument (MNSI) symptom scores and nerve conduction velocity (NCV) were assessed to evaluate the efficacy of Rong Dan oral liquid in improving subjective symptoms and objective measures of DPN. Meanwhile, the body weight, blood pressure, heart rate, fasting plasma glucose (FPG) , glycosylated hemoglobin (HbA1c) , liver and kidney functions, ECG, lipid profile, fundus and albuminuria excretion of the patients were compared before and after treatment. Correlation analysis was used to determine the relationship between MNSI scores and NCV. Results After 12 weeks of intervention, patients showed various degree of symptomatic improvents in drying cracks skin, toe numbness, tingling, burning sensation and hyperesthesia compared with before the intervention. In particular, there were statistically significant differences in reduction of drying cracks skin (32.2% vs 87.1%) and hypersensitivity (3.2% vs 25.8% ) (both P 0.05). Urinary albumin excretion rate was reduced compared with that before the intervention [(1.09±0.62) μg/min vs (1.27±0.67) μg/min, P=0.001]. Correlation analysis showed that MNSI scores were negatively correlated with and NCV (r=-0.429, P=0.05). Conclusion Rong Dan oral liquid may help improve a number of symptoms related to DPN, especially in dry/cracking skin and hyperesthesia of the feet. To a certain extent, Rong Dan oral liquid may also effectively improve the nerve conduction velocity at affected sites of the body, and reduce urinary albumin excretion rate. Rong Dan oral liquid is well-tolerated. Key words: Dan Rong oral liquid; Diabetic neuropathy; Michigan neuropathy screening instrument; Nerve conduction velocity