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By Heather Bufford, MD, and Nassim Assefi, MD
Dysmenorrhea affects up to 90% of women; approximately 15% have severe symptoms.1 In addition to causing impaired quality of life, dysmenorrhea is associated with significant social impact, including absenteeism from work and school. Annually, this amounts to an estimated loss of $600 million in wages and $2 billion in lost productivity.2
Although first-line therapies including non-steroidal anti-inflammatory drugs (NSAIDs) and oral contraceptives often are effective, up to 10% of cases are refractory to such treatment.1 Acupuncture is an attractive treatment option given its benefits in the treatment of other pain syndromes, safety profile, and acceptability to some women who are reluctant to use medication. However, although the National Institutes of Health Consensus Statement on Acupuncture endorses the potential efficacy of acupuncture for many types of pain, such as acute dental pain, epicondylitis, and fibromyalgia,3 very little Western-based literature has documented the efficacy of acupuncture for painful gynecologic conditions, including dysmenorrhea.
Dysmenorrhea consists of painful cramps in the lower abdomen associated with the onset of menses. Associated features also may include sweating, tachycardia, headaches, nausea, vomiting, diarrhea, and tremulousness.
Primary dysmenorrhea usually begins six months to three years after menarche. Symptoms are typically most severe the first day or two of the menstrual cycle. There is strong evidence linking elevated prostaglandin levels with primary dysmenorrhea, including elevated levels of PGF2a in the menstrual fluid of symptomatic women. In addition, increased myometrial contractility in response to PGF2a, and the efficacy of NSAIDs (which inhibit synthesis of prostaglandins) in the treatment of this disorder argue for a prostaglandin relationship.1,4 Dysmenorrhea also can occur secondary to other gynecologic, gastrointestinal, and psychologic factors (see Table 1).
Common causes of secondary dysmenorrhea
• Gynecologic tumors
• Cervical stenosis
• Pelvic infections
• Inflammatory bowel disease
• Irritable bowel disease
Primary dysmenorrhea usually can be diagnosed by history and physical examination. Symptoms often are associated with early menarche, recent menarche, heavy flow, and positive family history. The timing of the pain, cycle length, and social history also can be helpful in differentiating this condition from endometriosis, pelvic inflammatory disease, and other secondary causes. Response to NSAIDs can confirm the diagnosis. Women with late or immediate onset relative to menarche, or severe or refractory symptoms merit careful evaluation by a gynecologist for secondary causes.
NSAIDs and OCPs are the conventional therapies for primary dysmenorrhea, alleviating symptoms in 40-90% of patients.1 Investigational therapies have included transcutaneous electrical nerve stimulation units, nitroglycerin, thiamine, magnesium, omega-3-fatty-acids, and laparascopic presacral neurectomy. Treatment of secondary dysmenorrhea may include surgery, antibiotics, counseling techniques, and acupuncture.
From a Western perspective, the mechanism of acupuncture is unclear. No unique anatomic structures corresponding to the acupoints have been found,5 but studies have consistently shown that acupuncture alters the concentrations of molecules that mediate pain and inflammatory pathways, such as endorphins, monoamines, and prostaglandins.6 Acupuncture’s documented effects on prostaglandin levels are of specific interest in dysmenorrhea treatment, providing a plausible physiologic mechanism for its effects.
According to traditional Chinese medicine (TCM), there are three major classifications for symptoms consistent with dysmenorrhea: stagnant qi (vital energy), cold damp, and deficient blood and qi.7,8 Needling is thought to improve circulation of qi and moxibustion (burning of the herb Artemesia vulgaris) is thought to warm the meridians and reinforce the effects of acupoint stimulation.
An English language literature search using "acupuncture" and "dysmenorrhea" as key words revealed one randomized controlled trial (RCT), one prospective trial, and a large body of mostly Chinese articles consisting of case reports, case series, and expert opinions.
The strongest data are from an RCT of 43 women with recurrent pain starting within two years of menarche without evidence of pelvic pathology.9 Four study groups were followed for one year, including real acupuncture at predetermined acupoints, sham acupuncture with needling at non-acupoints, standard therapy with extra visits to control for attention placebo effects, and usual care. Treatments involved needling at 12 points (either a standardized acupoint or non-acupoint protocol), once weekly for 30 minutes, three weeks of each month for three months. Results showed a significant difference in the proportion of patients with improved symptoms in the acupuncture group (90.9%) as opposed to other groups, and a trend toward significance in the magnitude of improvement. There also was a 41% reduction in the use of oral analgesics in the acupuncture group, with no change in medication use among other groups.
Limitations of this study include lack of investigator blinding (which may bias interpretation of efficacy); lack of credibility testing to show true blinding of sham acupuncture subjects (the sole physician-acupuncturist-investigator could have given subtle clues to make the sham needle group think they were receiving a placebo treatment); and the use of a non-standard pain scale. However, randomization, use of controls, and objective reduction in pill use make this study more rigorous than any other.
A prospective trial of 48 patients employing acupuncture at seven specified acupoints for five sessions before expected menses resulted in 28 patients (58.3%) with complete relief for at least six months, 12 (25%) with considerable relief, and four (8.3%) with no relief.10 Limitations of this trial included the lack of a control group, failure to distinguish between primary and secondary dysmenorrhea, potential investigator bias in interpreting results, and lack of standardized pain scales and objective measurements.
The largest case series published in English involved 100 patients.11 Selection of points varied according to syndrome, as did the use of moxibustion or electroacupuncture. The author of the study reported that 54% of patients had "complete relief" for six months, while 27% showed "marked improvement," 13% were "somewhat improved," and "failure of therapy" occurred in 6% of patients.
In another case series, 49 patients were treated between eight and 13 times with acupuncture according to a TCM diagnosis of dysmenorrhea type.12 Forty-two patients experienced "complete cure" and another six were "markedly improved." The single failure was complicated by fibroids. In another case series, 32 patients were treated according to TCM diagnosis of dysmenorrhea.13 Two standard points were used, along with a third that varied by type of dysmenorrhea; moxibustion also was used when indicated. The results showed that 20 patients were considered "cured," and 11 were "effectively treated."
The above case reports, and virtually all clinical trials of acupuncture, have methodological features that confound their interpretation. The methodological challenges of studying acupuncture have been previously described in Alternative Medicine Alert14 and are summarized in tabular form in Table 2.
TCM has at least three different diagnoses for dysmenorrhea, which do not correlate with the Western biomedical model of primary and secondary dysmenorrhea. In most of the dysmenorrhea studies mentioned above, a single acupuncturist-investigator delivered the treatments and assessed the outcomes in all patients. Furthermore, most of the Chinese studies did not use standard, objective pain outcomes, but instead used a gestalt-type clinical impression. These study features lend themselves to bias of interpretation and blinding (in the few cases where patients were given a control treatment).
The ideal acupuncture trial would be randomized and performed with appropriate controls, including needling at non-acupoints (sham acupuncture) and placebo-needling. Such a trial also would blind both patients and investigators assessing patient responses to treatment (dual blinding), with credibility testing to demonstrate patient blinding, as well as an assessment of patient beliefs about the healing powers of acupuncture to evaluate for self-efficacy (effect of positive belief).
The design would standardize treatment in a rational way to incorporate both TCM and Western biomedical classifications of dysmenorrhea, and determine adequate duration, course of treatment, and follow-up. Standardized outcomes such as validated pain scales and objective measures (such as analgesic pill counts and prostaglandin levels in menstrual fluid) should be used. To limit confounding effects, patients should be free of their usual therapies after a medicine wash-out period, or a more pragmatic approach may be to request that they not change any of their ongoing medical therapies.
Methodological challenges of acupuncture studies16,17
• Case definition and discrimination among etiologies
• Appropriate and adequate treatment (sufficient and appropriate points, duration, frequency, manipulation, use of additional stimulation such as electroacupuncture or
moxibustion, predetermined vs. individualized
• Appropriate comparison groups and evaluation of placebo effect
• Blinding of patients and independent physician/
• Adequate sample sizes
• Valid subjective and objective outcome measures
• Duration of follow-up
Acupuncture generally is a very safe form of treatment, especially the style in which it is performed in the United States (using disposable needles, limited depth of penetration, and gentle needling techniques). Minor side effects including pain at the insertion site, bleeding, and fatigue can transiently affect more than 40% of patients. Serious complications, such as infection, pneumothorax, and cardiac tamponade, are extremely rare.15
Dysmenorrhea is a very common problem for women that often can be treated easily with standard therapies. However, there are some women who are refractory to conventional medicines or who are not good candidates for standard therapies. It is difficult to assess the efficacy of acupuncture for dysmenorrhea, because there are few rigorously derived data and many challenges to constructing well-designed trials. A single randomized, controlled trial and a large body of mostly anecdotal literature suggest that acupuncture may have an effect beyond that of placebo in ameliorating the symptoms of dysmenorrhea.
Acupuncture may be useful for dysmenorrhea patients who have failed or are not candidates for standard therapy. Given the low side effect profile, referral to a licensed acupuncturist is reasonable for these patients. However, given the paucity of high-quality data, no recommendations can be made regarding the specific type of treatment. The studies indicate that 12 acupuncture treatments should be a sufficient trial for most patients’ dysmenorrhea symptoms.
Dr. Bufford is a second-year Obstetrics/Gynecology resident and Dr. Assefi is Attending (Clinician-Teacher), Departments of Medicine and Obstetrics/Gynecology, Complementary and Alternative Medicine Liaison, School of Medicine, University of Washington in Seattle.
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