The Effect of Mindfulness Based Stress Reduction in Patients With Painful Diabetic Peripheral Neuropathy

By 2020, it is estimated that 3.7 million Canadians will have diabetes mellitus, with type 2 diabetes (T2DM) accounting for more than 90% of cases. Estimates of the prevalence of diabetic peripheral neuropathy among adults with T2DM range from 26% to 47%. It increases with patient age and duration of disease and it can be as high as 60 to 70% in older cohorts. Diabetic peripheral neuropathy is documented in most studies as numbness, tingling, pain and/or objective sensory changes. Pain is an early manifestation of neuropathy and may be the presenting symptom of diabetes. Even the best medications and procedures rarely relieve more than 30% of the discomfort of chronic painful conditions. Diabetic patients continue to experience debilitating and disabling pain. Pain affects our ability to work, our ability to participate in recreational activities, our mood and our relationships. It is well-established that an interdisciplinary approach is key to the treatment of some types of chronic pain, but little research has been done on the effectiveness of interdisciplinary treatments for patients suffering from painful diabetic peripheral neuropathy. The investigators will evaluate the effectiveness of an interdisciplinary approach combining medical treatment and mindfulness-based stress reduction (MBSR) to reduce disability and improve quality of life among patients with painful diabetic peripheral neuropathy. The investigators will also evaluate the impact of the program on psychological distress, pain cognitions, and biomarkers of stress and glycemic function.

The investigators will recruit 110 adults with painful diabetic peripheral neuropathy. All will have their medical treatment optimized by a pain medicine specialist before being randomly assigned to either an 8-week group MBSR program or a wait-list. All participants will complete self-report questionnaires, provide a hair sample for cortisol measurements and a blood sample to measure glycemic index. We will be collecting outcome data for both groups. Patients randomized to MBSR will have data collected at 4 time points: 1) before medical optimization; 2) after medical optimization and before the MBSR group intervention begins, 3) 2 weeks after the group intervention; and 4) 3 months following completion of MBSR. Patients randomized to control will have data collected at 6-7 time points depending on when are participants enrolled in the trial: 1) before medical optimization; 2) after medical optimization and before the MBSR group intervention begins; 3) 2 weeks after the group intervention; 4) 3 months following completion of MBSR; 5) Re-test before control group intervention begins; 6) 2 weeks after control group intervention; and 7) 3 months after control group intervention.

The primary hypothesis is that after all patients are medically optimized, those randomized to MBSR will have a 30% higher incidence of clinically significant (≥1.0 decrease in mean BPI interference score) improvement (responders) compared to controls measured 3 months following completion of MBSR. A significant change is defined as ≥ 1 decrease in BPI interference score. A one point change on the Interference Scale, has been recommended by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) group as a minimally clinically important change. This design controls for the effect of time and disease fluctuation, regression to the mean, and the effect of testing. In this preliminary research, where our primary goal is to establish proof of concept and obtain data needed to plan a comparative trial, we are not controlling for the placebo effect. We believe that a wait-list controlled study is the necessary foundation on which to build a rigorous program of research.

Eligibility Criteria:
Inclusion Criteria:

* Patient aged \> 18 years
* Type 1 or Type 2 Diabetes Mellitus (receiving insulin or not)
* HbA1c 6.5%-9.9%
* Diagnosis of Diabetic Peripheral Neuropathy (DPN) \> 1 year
* Report of pain \> 6 months
* Score \>3 on Douleur Neuropathique-4 Questionnaire
* VAS completed 5/7 days; Average VAS score \>4 and \<9 (i.e., moderate to severe pain).
* Ability to attend a minimum of 7 of 9 MBSR workshops

Exclusion Criteria:

* Peripheral vascular disease requiring revascularization of lower limb or amputation
* Pregnant or lactating
* Active alcohol or drug abuse/dependence
* Previous MBSR training
* Co-morbidity preventing assessment or understanding of questionnaires
* Inability to speak English or French