Objective: To evaluate the efficacy of oral mixed tocotrienols for patients with diabetic peripheral neuropathy.
Design, Setting, and Participants: The Vitamin E in Neuroprotection Study (VENUS) was a parallel, double-blind, placebo-controlled trial that recruited participants from January 30, 2011, to December 7, 2014, with 12 months of follow-up. This trial screened 14 289 patients with diabetes from 6 health clinics and ambulatory care units from 5 public hospitals in Malaysia. A total of 391 patients who reported neuropathic symptoms were further assessed with Total Symptom Score (TSS) and Neuropathy Impairment Score (NIS). Patients 20 years or older with a TSS of 3 or higher and an NIS of 2 or higher were recruited.
Interventions: Patients were randomized to receive 200 mg of mixed tocotrienols twice daily or matching placebo for 12 months. Patients with hyperhomocysteinemia (homocysteine level ≥2.03 mg/L) received oral folic acid, 5 mg once daily, and methylcobalamin, 500 μg thrice daily, in both groups.
Main Outcomes and Measures: The primary outcome was patient-reported neuropathy TSS (lancinating pain, burning pain, paresthesia, and asleep numbness) changes at 12 months. The secondary outcomes were NIS and sensory nerve conduction test result.
Results: Of 391 eligible patients, 300 were recruited (130 [43.3%] male; mean [SD] age, 57.6 [8.9] years; mean [SD] duration of diabetes, 11.4 [7.8] years) and 229 (76.3%) completed the trial. The TSS changes between the tocotrienols and placebo groups at 12 months (-0.30; 95% CI, -1.16 to 0.56; P = .49) were similar. No significant differences in NIS (0.60; 95% CI, -1.37 to 2.65; P = .53) and sensory nerve conduction test assessments were found between both groups. In post hoc subgroup analyses, tocotrienols reduced lancinating pain among patients with hemoglobin A1C levels greater than 8% (P = .03) and normohomocysteinemia (homocysteine level <2.03 mg/L; P = .008) at 1 year. Serious adverse events in both groups were similar, except more infections were observed in the tocotrienols group (6.7% vs 0.7%, P = .04). Results reported were of modified intention-to-treat analyses.
Conclusions and Relevance: Supplementation of oral mixed tocotrienols, 400 mg/d for 1 year, did not improve overall neuropathic symptoms. The preliminary observations on lancinating pain among subsets of patients require further exploration.
Trial Registration: National Medical Research Registry Identifier: NMRR-10-948-7327 and clinicaltrials.gov Identifier: NCT01973400.
METHOD: Rats divided into four groups: control group, diabetic group, the diabetic group treated with CeO2nanoparticle at a dose of 65mg/kg and diabetic group received CeO2nanoparticle at a dose of 85mg/kg. Diabetes was induced by single intraperitoneal injection of 65mg/kg streptozotocin (STZ). 8 weeks after the induction of diabetes, body weight and pain sensitivity in all groups were measured. The blood sample was collected for biochemical analysis. The dorsal root ganglion (DRG) neurons were isolated for histopathological stain and morphometric parameters studies.
RESULTS: Reduction of body weight, total thiol molecules (TTM), total antioxidant power (TAP) and ADP/ATP ratio in diabetic rat was reversed by CeO2nanoparticles administration. We showed that lipid peroxidation (LPO) and nociception latency were significantly increased in STZ-treated rats and decreased after CeO2nanoparticles administration. DRG neurons showed obvious vacuole and various changes in diameter, area and the count of A and B cells in STZ-diabetic rat. CeO2nanoparticles improved the histopathology and morphological abnormalities of DRG neurons.
CONCLUSION: Our study concluded the CeO2nanoparticles have a protective effect against the development of DN.
FUNDING: Pfizer.