BETHESDA, MD. — Despite little evidence backing their efficacy, complementary and alternative medicine therapies are used regularly by more than 40% of patients with painful diabetic neuropathy, Dr. Martin Stevens said at a meeting sponsored by the National Institute of Health's Pain Consortium.
Well-designed, prospective, randomized trials of complementary and alternative medicine (CAM) therapies have been relatively few and far between. Many of the CAM approaches—which range from α-lipoic acid and benfotiamine to biofield therapies, near-infrared phototherapy, and static- and pulsed-magnetic field therapies—pose “significant challenges” for adequate blinding and determination of a placebo response, said Dr. Stevens, professor of medicine at the University of Birmingham (England).
Overall, the literature shows that about 25% of patients taking CAM therapies for painful diabetic neuropathy report a response, “which is very close to what we'd consider a placebo response,” he said. Yet surveys suggest that only about one-third of patients with painful diabetic neuropathy respond to conventional pharmacologic therapies, such as nonsteroidal drugs, antidepressants, and nonaddicting analgesics, which explains the growing popularity of CAM approaches, Dr. Stevens said.
A recently published study of Reiki, a hands-on therapy based on the theoretical existence of a bioenergy field intrinsic to the human body, suggests how powerful the placebo response and the therapeutic effects of ongoing involvement with a health care provider can be, Dr. Stevens noted.
Just over 200 patients with type 2 diabetes and painful diabetic neuropathy were randomized to receive Reiki, mimic Reiki, or usual care. Patients in the Reiki and mimic-Reiki groups underwent two treatments in the first week, followed by weekly treatments, for a total of 12 weeks. Patients in the usual-care group were assessed at the start and end of the 12-week period, said Dr. Stevens, one of the study investigators.
Global pain scores and walking distance improved from baseline in both the Reiki and mimic-Reiki groups, but not in the usual-care group.
There were no significant differences between the two groups at the final visit, indicating that the reduction in pain is consistent with the notion that “a sustained partnership between the health care provider and the patient can have direct therapeutic benefits,” Dr. Stevens and his coinvestigators wrote (Diabetes Care 2007:30;999–1001).
“Seeing the patient on a regular basis clearly does help their perception and their pain … whatever else you chose to do to them,” he said at the NIH meeting.
The etiology of pain complicating diabetes is still poorly understood, he noted. It may result from the dysfunction of pain-signaling pathways at multiple levels, such as cutaneous nociceptors, afferent neurons, and the spinal and supraspinal pathways, he said.
A survey of 180 consecutive outpatients with diabetic neuropathy and other peripheral neuropathies found that the most frequently used CAM therapies were megavitamins (35%), magnetics (30%), acupuncture (30%), herbal remedies (22%), and chiropractic manipulation (21%).
Almost 50% had tried more than one form of alternative treatment, and almost half did not consult a physician before starting CAM. Patients with diabetic neuropathy used CAM more frequently than patients with other neuropathies, the survey showed (J. Neurol. Sci. 2004;218:59–66).
Dr. Stevens and other investigators at the University of Birmingham are recruiting patients for a 12-week, randomized, double-blind, controlled study of taurine, a ubiquitous β-amino acid found in high concentrations in the central and peripheral nervous systems. The amino acid—probably one of the better-studied CAM therapies for painful diabetic neuropathy—functions as an antioxidant, calcium modulator, analgesic, and neuromodulator, Dr. Steven said.
He hopes to recruit 180 patients to participate in the investigation and expects it to take at least another year to complete.