METHODS: This study will be a pilot, interventional, randomized, 2-armed, parallel, singled-masked, controlled trial. A total of 40 diabetes mellitus patients with peripheral neuropathy will be recruited and assigned randomly into 2 groups (moxibustion group and waiting group) at a 1:1 ratio. This trial consists of an 8-week intervention period and a 4-week follow-up period. During the intervention period, the moxibustion group will take 3 moxibustion sessions per week, whereas no intervention will be done on the waiting group to act as the control group. The outcome will be assessed by an outcome assessor who is unaware of the group assignment. The primary outcome will be pain assessment measured with algometry, Leeds Assessment of Neuropathic Symptoms and Signs pain scale, visual analogue scale, and neuropathy pain scale. The secondary outcome will be an evaluation of functional performance capacity with 6 minutes walking test, evaluation of the Foot and Ankle Ability Measure, and serum HbA1c and albumin levels.
DISCUSSION: We hope that this trial will provide valuable insights on the efficacy of moxibustion in the management of diabetic peripheral neuropathy.
TRIAL REGISTRATION: ClinicalTrials.gov Registry No.: NCT04894461 (URL: https://clinicaltrials.gov/ct2/show/NCT04894461?term=NCT04894461&draw=2&rank=1) Registered on May 20, 2021.
Methods: Thirty Sprague-Dawley rats were randomly assigned to control (non-diabetic), PDN and non-PDN groups (n = 10). The rats were induced with diabetes by streptozotocin injection (60 mg/kg). Tactile allodynia and thermal hyperalgesia were assessed on day 0, 14 (week 2) and 21 (week 3) in the rats. The rats were sacrificed and the spinal cord tissue was collected for the measurement of oxidative stress (malondialdehyde (MDA), superoxide dismutase (SOD) and catalase) and pro-inflammatory markers (interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α)).
Results: PDN rats demonstrated a marked tactile allodynia with no thermal hyperalgesia whilst non-PDN rats exhibited a prominent hypo-responsiveness towards non-noxious stimuli and hypoalgesia towards thermal input. The MDA level and pro-inflammatory TNF-α was significantly increased in PDN rats whilst catalase was reduced in these rats. Meanwhile, non-PDN rats demonstrated reduced SOD enzyme activity and TNF-α level and increased MDA and catalase activity.
Conclusion: The changes in oxidative stress parameters and pro-inflammatory factors may contribute to the changes in behavioural responses in both PDN and non-PDN rats.
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.