A dietary intervention for chronic diabetic neuropathy pain: a randomized controlled pilot study

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SCIENCE
A dietary intervention for chronic diabetic neuropathy pain: a randomized controlled pilot study
Key Take-Away: 
  • Following 20 weeks, there was a reduction in body weight by a mean of 7.0 kg in intervention as compared with 0.6 kg in the control.
  • A reduction in pain by 9.1 points was seen in the intervention group and 0.9 points in control group measured by the Short Term McGill Pain Questionnaire.

Diabetic neuropathy is a type of nerve damage that occurs as a result of diabetes. It occurs in up to 60% of individuals with type 2 diabetes accompanied with morbidity, including gait disturbances, amputations, depression, anxiety and reduced quality of life, in which pain occurs in 15-30% of cases. 

ABSTRACT: 
Background: 

Diabetic neuropathy is a type of nerve damage that occurs as a result of diabetes. It occurs in up to 60% of individuals with type 2 diabetes accompanied with morbidity, including gait disturbances, amputations, depression, anxiety and reduced quality of life, in which pain occurs in 15-30% of cases. Low-fat-plant based dietary interventions have shown improvement in glycemic and other complications related to type 2 diabetes. In intervention trials utilizing plant-based diets, improvements in glycemic control, blood lipid concentrations and blood pressure have been reliably observed, and diet is similar to other therapeutic diets.

  • Rationale behind research
  1. Two uncontrolled diet intervention studies showed promising results in individuals with diabetic neuropathy
  2. Therefore, a hypothesis was postulated that a plant-based dietary intervention can reduce diabetic neuropathy pain and a randomized, controlled, pilot study was conducted to test this hypothesis.
  • Objective

To investigate the efficacy of plant-based dietary intervention and the suitability of the overall method, permitting larger trials to follow

Methods: 

 

Study outcomes

  • Primary outcome
  • The pain and sensory symptoms were measured by visual analog ‘worst pain’ scale, global impression scale, Short Form McGill pain Questionnaire, Michigan Neuropathy Screening instrument questionnaire (MNSI), Neuropathy Total Symptom Score, a weekly pain diary, and Norfolk Quality of Life Questionnaire
  • The patient’s global impression of change (PGIC)question was assessed to rate pain on a scale of 1-7
  • Secondary outcome: Mood and depression were measured by the Beck Depression Inventory (BDI) and the Center for Epidemiological Studies Depression revised scale

NOTE: For missing data, values from previous period were calculated

  • Time points
  • Efficacy: Baseline, 10 weeks, 20 weeks
Results: 

 

Baseline: Treatment groups were well balanced with no significant baseline differences except Neuropathy Impairment Score Lower Limb

Figure 1: Visual Analogue Worst Pain Scale

  • At 20 weeks, a reduction in pain by 9.1 points as measured by the Short Form McGill Pain Questionnaire in the intervention group versus 0.9 points in the control group (P = 0.14)
  • Pain as measured by the Neuropathy Total Symptom Score and visual analog pain scale declined in both groups (P= 0.70 and 0.39, respectively)
  • The intervention group had significant improvements for seven of the ten items on the Neuropathic Pain Scale
  • For the MNSI-Q, the improvement for the intervention group was significantly greater than that for the control group
  • For the Neuropathy Impairment Score-Lower Limb, the intervention group improved slightly. Body weight declined by a mean of 7.0 kg over 20 weeks in the intervention group, as compared with 0.6 kg in the control group (P = 0.001)
  • Mean HbA1c declined in the intervention group by 0.8 percentage point over 20 weeks, but remained unchanged in the control group (P = 0.07)
  • Secondary outcome: No significant changes were seen in the Beck Depression Inventory or the Center for Epidemiological Studies Depression over 20-weeks
Conclusion: 

This study recommends the potential value of plant-based diet intervention, including week after week support classes, for treating painful diabetic neuropathy.

Nutrition & Diabetes 2015 May