An Analysis of Recent Oriental Medical Research on Dysmenorrhea

1. Data collection

All papers published from 2002 to 2012 were collected from the medical databases using keywords like ‘dysmenorrhea’, ‘traditional medicine’, ‘herb’, ‘acupuncture’, ‘CAM’, ‘complementary and alternative medicine’, ‘moxibustion’. For Korean papers, KISS (http://kiss.kstudy.com), Korean Traditional Knowledge Portal (http://www.koreantk.com), Journal of Korean Medicine (http://jkom.org) and affiliated journal sites were used. For overseas journals, Pubmed (http://www.ncbi.nlm.nih.gov/PubMed) was used. 32 Korean journal articles and 29 overseas journal articles were selected.

2. Study design

3. Classification by evaluation tool

Journals which used evaluation tools were classified by that.

4. Classification by therapy

Journals were classified by type of therapy, meridian point, and herbal medicine.

1. Classification by field (Fig 1,2)

Fig. 1.

Comparison of field on 32 journal articles in Korea

Fig. 2.

Comparison of field on 29 journal articles abroad

In Korean journals, there were 16 therapy, 14 diagnosis, 1 tool development, and 1 other journals (Fig 1). But among overseas journals, there were only 29 therapy journals (Fig 2).

2. Classification by typology (Fig 3,4) (Table 1,2)

Fig. 3.

Comparison of typology on 32 journal articles in Korea

Fig. 4.

Comparison of typology on 29 journal articles abroad

Table 1.

Classification of Journal Articles in Korea

Table 2.

Classification of Journal Articles Abroad

In Korean journals, there were 2 case reports, 12 clinical research, 12 sectional study, 3 systemic review study, 1 assessment, and 2 other journals (Fig 3). Clinical research journals included 6 RCT (Randomized-Controlled Trial) and 6 non-RCTs. In overseas journals, there were 1 case report, 21 clinical research, 4 systemic review study, and 3 experimental study journals (Fig 4). There were no sectional study, and clinical research journals were all RCTs.

3. Classification by evaluation tool (Fig 5,6) (Table 3,4)

Fig. 5.

Comparison of evaluation tool on 12 clinical journal articles in Korea

Fig. 6.

Comparison of evaluation tool on 21 clinical journal articles abroad

Table 3.

Summarized Information of Clinical studies in Korea

Table 4.

Summarized Information of Clinical studies Abroad

In Korean journals, all the 12 clinical research journals selected VAS (Visual Analogue Scale). 1 journal selected VRS (Verbal Rating Scale), 3 journals selected MVRS (Multidimensional Verbal Rating Scale), and 1 journal selected PGA (Patient’s Global Assessment). 2 journals selected DITI (Digital Infrared Thermal Imaging). VAS, VRS, MVRS are subjective evaluation tools, while DITI is an objective evaluation tool.

In overseas journals, more various subjective evaluation questionnaires like SF-MPQ (Short-form McGill Pain Questionnaire), SF-MDQ (Short-form Menstrual Distress Questionnaire), CMSS (Cox Menstrual Symptom Scale), CRSS (Cox Retrospective Symptom Scale), 4-point pain scale, and Blood stagnation scale were used. Objective evaluation tools were also used more variously such as pulsatility index, resistance index, and ratio of systolic peak/diastolic peak of uterine arteries, prostaglandin level, proportion of participants using analgesics, HRV (Heart Rate Variability).

4. Classification by therapy (Fig 7,8) (Table 1,2)

Fig. 7.

Comparison of therapy on journal articles in Korea

Fig. 8.

Comparison of therapy on journal articles abroad

In Korean journals, there were 4 herbal medicine, 5 acupuncture/moxibustion, 1 other clinical research journals, and 2 herbal medicine case report journals. In overseas journals, there were 6 herbal medicine, 13 acupuncture/moxibustion, and 2 other clinical research journals.

1. Discussion on field: Therapeutic-sided studies

The largest proportion of both Korean and overseas journals were therapeutic. Especially, all the overseas journals were therapeutic. More diverse types of research would have to be conducted such as development of evaluation tools or formula of herbal medicine, standards of diagnosis or therapy.

2. Discussion on typology: Absence of longitudinal study and Oriental medical differentiation of syndromes in clinical studies

There existed some cross-sectional studies, but no longitudinal studies. In longitudinal studies, long time follow-up observation is difficult and risk of subjects’ breaking away is high. But from an angle of medical expenses, two obstacles would be removed.

Also, in clinical studies, most of the research excluded Oriental medical differentiation of syndromes. If all subjects of the experimental group are given the same herbal medicine and therapies, the results of the clinical study are not trustworthy. Large number of RCTs were conducted abroad so positive effect on follow-up studies would be outstanding. But with the exception of Oriental medical differentiation of syndromes, these studies can’t provide reasonable evidence of therapeutic effects of Oriental medicine.

3. Discussion on evaluation tools: Absence of development of objective evaluation tools

Clinical studies are valuable for follow-up studies because these studies provide research protocols such as evaluation tools (outcome measurements), methods of setting experimental/control group, placebo-control, etc.

In evaluation of dysmenorrhea, patients’ own complaints of observable symptoms are important, so in clinical or case studies, selection of evaluation tool is important to diagnose or compare before and after the therapy. Especially, existence of objective evaluation tools is the core of research design.

VAS, MVRS, VRS, and Patient’s Global Assessment are subjective evaluation tools which assess patients’ own complaints of intensity of pain. These subjective evaluation tools have low reliability and stability because subjects’ condition (attitude, action, mood, knowledge, physical condition) changes with time⁴⁾. In other words, subjective evaluation tools are important but other objective evaluation tools which have high reliability and stability are needed.

In Korean journals, the only objective evaluation tool was DITI. DITI can give objective information if conditions (psychological stability, 15 minutes of adjusting to room temperature, no wind, maintaining the right room temperature (20–24°C), inhibition of physical therapy, drinking alcohol or using drugs, etc.) are properly controlled⁵⁾. But DITI is applicable only for the cold-damp stagnation type.

With evaluation tools in overseas journals, there’s one other point which calls for attention. There was no use of blood tests, ultrasound, HRV, or proportion of participants using analgesics among the systemic review studies⁶⁾ from 1979 to 2003.

Primary dysmenorrhea is thought to be caused by the increase of PG (prostaglandin) production in the endometrium. PG increases the level of tension and contraction strength of uterus and blood vessels, and this process may induce pain⁷⁾. So, the measure of PG level can be an indicator of intensity of dysmenorrhea. PG level is not the only cause of the intensity of dysmenorrhea, so there’s a limit to use of this evaluation tool, but PG level can show the therapeutic effect on dysmenorrhea objectively.

Secondly, measure of pulsatility index, resistance index, and ratio of systolic peak/diastolic peak of uterine arteries by ultrasound can also be an objective and direct evaluation tool.

Thirdly, HRV measures activity of the autonomic nervous system. If stress reaction increases, the sympathetic system is activated and parasympathetic system is inactivated. If this status continues, the autonomic nervous system loses its balance control, so neurotransmitter, neurosecretion, and immune systems lose their normal function. This process induces dysmenorrhea⁸⁾. Observation on change of HRV can thus assess the therapeutic effect on dysmenorrhea.

These three objective evaluation tools have been used by clinical studies only in the past 10 years, and are thought to be valuable tools for follow-up studies. More studies about development of new evaluation tools are needed, too. For example, it is known that acupuncture reduces headache, and once headache is reduced, increase of α wave on parieto-occipital and occipital area is observed on EEG (electroencephalography)⁹⁾. Objective evaluation tools used for general pain diseases have to be reviewed for whether they can be used for assessment of dysmenorrhea. Sectional studies are also needed to verify the validity.

4. Discussion of therapy: Absence of studies about diverse Oriental medical therapies

In Korean journals, Gyejibongnyeong-hwan, Jujadanggui-hwan, and Hyunburikyung-tang were used most frequently. Also, SP6 in experimental groups and GB39 in control groups were used most frequently. In auricular acupuncture, Uterus, Sympathetic nerve, Subcortex, and Endocrine points were used most frequently.

In overseas journals, Samul-tang (Siwu-tang) was used most frequently. Also, SP6 was used most frequently. In auricular acupuncture, Spirit gate, Uterus, Endocrine, Subcortex, Sympathetic nerve, and Kidney points were used most frequently. In electroacupuncture, SP6 was used most frequently, and in moxibustion, CV8 was used most frequently.

SP6 relieves stagnancy of ki of the liver, tonifies the kidneys and invigorates the spleen to resolve dampness, so SP6 is used for urogenital diseases. Also, it is commonly used for general gynecological diseases¹⁰⁾. Gyejibongnyeong-hwan and Samul-tang (Siwu-tang) cure stagnation of ki and stasis of blood, cold-damp stagnation, and deficiency of both ki and blood.

In therapeutic studies, almost all the journals were about acupuncture/moxibustion, or herbal medicine. Only one was about functional under inner-wear. Other studies about diverse therapies such as pharmacoacupuncture and herbal medicine steam bath on pelvis are thought to be needed.