Background Diabetic neuropathic pain can severely influence quality of life, and patients may be dissatisfied with treatment.
Objective To carry out an observational study of the effects of acupuncture for the treatment of diabetic neuropathic pain, in preparation for a full study.
Methods Nine patients with diabetic neuropathic pain were recruited from a Korean diabetic clinic and given 12 sessions of acupuncture over 4 weeks. Their symptoms were evaluated using the Total Symptom Score (TSS) and Michigan Neuropathy Screening Instrument (MNSI) at baseline and 4 weeks after the last treatment.
Results Mean TSS scores reduced from 7.99 (SD 3.55) at baseline to 4.95 (SD 4.41), at the 8-week follow-up—a statistically non-significant change (p=0.057). The MNSI scores improved from 6.33 (SD 1.31) before treatment to 4.33 (SD 3.00) after acupuncture treatment—a significant improvement (p=0.010). One participant experienced an exacerbation of diabetic neuropathy symptoms, but two patients gained complete relief of their diabetic peripheral neuropathy (DPN) symptoms.
Conclusions The results of this study justify further investigations into the effects of acupuncture on DPN.
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Diabetic peripheral neuropathy (DPN) is a common complication of diabetes, with diverse clinical manifestations. While it is often asymptomatic, it may be painful and debilitating and, in some cases, difficult to manage. In addition, neuropathic pain has a substantial impact on the quality of life, particularly by causing interference with sleep, daily activities and enjoyment of life.1 However, the exact pathophysiological mechanisms of neuropathic pain in diabetes remain unknown, and several experimental studies have suggested a multifactorial pathogenesis.2 ,3 Pharmacological management of DPN consists mostly in treatment of symptoms. First-line treatments for painful diabetic neuropathy are tricyclic antidepressants, selective serotonin reuptake inhibitors or anticonvulsants.1 ,4 ,5 Combinations of drugs may be considered if there is no response to first-line treatments. If the pain is inadequately controlled, opioids such as tramadol and oxycodone may be added. However, there are concerns about the safety or tolerability of many drugs.
Patients with DPN are often dissatisfied, finding that the relief of pain by pharmacological treatment at doses that do not cause significant adverse effects is inadequate. Lack of response and adverse effect of conventional drug treatments force many patients to try alternative non-pharmacological treatments such as acupuncture, near-infrared phototherapy, low-intensity light amplification by stimulated emission of radiation therapy and transcutaneous electrical stimulation.6–9 A recent pilot study reported that using acupuncture as an additional treatment for patients with long-term DPN was feasible in clinic and produced improvements in a variety of troublesome symptoms.10 Considering the increasing prevalence of diabetes, the role of acupuncture in DPN for treating pain should be further examined. The aim of this study was to evaluate the effect of acupuncture for the treatment of painful DPN in a Korean clinic setting.
An observational study was conducted on nine patients between September 2011 and February 2012 at the Daegu Catholic University Hospital of Korea. The study protocol was approved by the institutional review board of Daegu Catholic University Hospital. We obtained written informed consent from all participants.
Participants were recruited using bulletin boards in the clinic. The inclusion criteria were aged 18–70 years, history of type 2 diabetes, fasting plasma glucose concentrations of ≥126 mg/dL, or serum levels of 2 h postprandial glucose of ≥200 mg/dL. Subjects were defined as having painful DPN if they had a summary score of at least 2 on the Total Symptom Score (TSS) (table 1).11 ,12 Thirteen patients were screened at the outpatient clinic, one refused to participate and three did not meet the inclusion criteria.
Participants received 12 sessions of traditional acupuncture, delivered three times a week for 4 weeks. Acupuncture was applied at 11 acupuncture points bilaterally, as follows: EX-LE10 (Bafeng; four points of needle insertion), LR3, GB41, GB39, ST36, GB34, SP6 and SP9. The acupuncture needles used were sterile, disposable, stainless steel needles (30×0.25 mm; Dongbang Acupuncture Inc, Cungcheongnam-Do, Korea); a total of eight needles was used. The skin was swabbed with an alcohol prep pad before acupuncture was administered. Depending on the points selected, needles were inserted 10–20 mm deep into the skin and were gently manipulated manually to obtain de qi (needle sensation referring to pain, numbness and distension felt around the point after the needle is inserted to a certain depth as well as the operator’ s sensation of tension around the needle). After 10 min, the needle positions were controlled by gentle rotation without evoking needle sensation. The needles were retained for 25±3 min. No electrical stimulation or other interventions were used.
All drugs being taken before this study were maintained. At baseline, final treatment visit and 4-week follow-up, all subjects completed both TSS and the Michigan Neuropathy Screening Instrument (MNSI). An autonomic dysfunction test and other laboratory tests were performed but are not reported here.
Data were expressed as the mean±SD. Changes in group mean TSS and MNSI scores from baseline to 4 weeks after the final acupuncture session were tested using paired t tests. A p value of <0.05 was considered statistically significant.
The baseline characteristics and outcomes of the subjects are shown in table 2. A total of nine patients (five male, four female) with painful DPN were treated with acupuncture. The age range of the participants was 54–66 years. The average duration of DPN was 6.7 years. No adverse events were recorded and no subjects withdrew from the study.
The changes of TSS and MNSI for the individual patients are presented in figure 1A,B. Mean TSS scores reduced from 7.99 (SD 3.55) at baseline to 4.95 (SD 4.41) at the 8-week follow-up. This improvement was not statistically different (p=0.057). The MNSI scores improved from 6.33 (SD 1.31) before treatment to 4.33 (SD 3.00) after acupuncture treatment, which is a significant improvement (p=0.010). However, one participant (case 2) exhibited exacerbation of diabetic neuropathy symptoms, two patients experienced complete relief of DPN symptoms as assessed by TSS and MNSI.
Recently, Chen et al13 reported the results of systematic review of a total of 25 randomised controlled trials on the effect of manual acupuncture on DPN. Although they concluded that manual acupuncture had a beneficial effect for DPN, this could not be confirmed owing to the high risks of bias of the trials. Meta-analysis showed that manual acupuncture had a greater effect on global symptom improvement than mecobalamin (RR=1.31, 95% CI 1.21 to 1.42), vitamins B1 and B12 (RR=1.55, 95% CI 1.33 to 1.80) and no treatment (RR=1.56, 95% CI 1.28 to 1.90) and that the combination of manual acupuncture and mecobalamin had greater effect than mecobalamin alone (RR=1.56, 95% CI 1.28 to 1.90).
This study has some limitations. First, the sample was small and the study was conducted at a single centre. The relatively small and selective sample limits the ability to apply the results to the general population. Second, the follow-up period after the acupuncture treatment might not have been sufficient. Although the effects of acupuncture were maintained at a 4-week follow-up, long-term follow-up results are required to clarify the efficacy of acupuncture. Nevertheless, in view of this study we will continue to conduct large-scale, well-designed, randomised controlled trials in the future.
Our study suggests that acupuncture might be an effective treatment for the management of some patients with painful DPN, although its mechanism of action remains speculative. Further investigations, including controlled trials, are required to elucidate the role of acupuncture in the treatment of DPN.
Contributors EJ: wrote the paper. HK: carried out the acupuncture treatments. IS: performed the data analysis. SK: designed the study. HS: directed the paper work.
Funding This study was supported by a grant from the Ministry of Health and Welfare, Republic of Korea (project No: 20–11-0-090-091-3000-3033-320).
Competing interests None.
Patient consent Obtained.
Ethics approval The institutional review board at the Daegu Catholic University Hospital approved this study.
Provenance and peer review Not commissioned; externally peer reviewed.
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