• Overview
  • Forms of Treatment
  • Prevalence and Use in the U.S.
  • Costs and Coverage
  • Licensure and Credentials
  • Transmission of Chinese Medical Thought
  • East Asian Medical Theory and Diagnosis
• Interventions
  • Acupuncture
  • Chinese Herbal Medicine
  • Meditative Exercises
• Conditions
  • Acupuncture and Smoking Cessation
  • Acupuncture in the Treatment of Hypertension
  • Tai Chi and Cardiovascular Health

Acupuncture in the Treatment of Hypertension

Hypertension is a condition with significant public health and financial consequences. Approximately 50 million Americans have hypertension. Only 69% of hypertensive individuals are aware that they are hypertensive; approximately half take prescribed medications, but blood pressure is adequately controlled in only a quarter of those patients. [1], [2] The use of pharmaceutical antihypertensive agents is often associated with side effects, contributing to low compliance with recommended treatment regimens. Consequently, there is a growing interest in complementary and alternative medicine (CAM) to treat hypertension and related cardiovascular diseases. For example, the National Center for Complementary and Alternative Medicine (NCCAM) is funding research at both University of Michigan's Integative Medicine Cardioprotection Research Lab and the Maharishi University of Management's Institute for Natural Medicine and Prevention in Iowa. [3]

Acupuncture has been used to treat hypertension in clinical practice with very few reported adverse effects. However, to date the effectiveness of this treatment has not been explored adequately in published studies. A systematic literature review conducted by Y.E. Ren evaluating the benefits of acupuncture for treating hypertension in humans summarized 13 trials. Of these, only three were controlled and only one was single blinded and randomized. [4] The one randomized controlled trial (RCT) included in this review was of very poor quality. [5] Its design included ten subjects randomized to receive either active or sham acupuncture. Active treatments consisted of electro-acupuncture stimulation to four pre-determined acupuncture points. Sham treatments consisted of electro-acupuncture stimulation to so-called "non-acupuncture" locations. Treatments lasted only five minutes. Nevertheless, the results from this small study suggested significantly greater post-stimulation reductions in diastolic blood pressure in the active versus sham group. [5]

In another trial conducted in China not included in Ren's review, 216 patients with a diagnosis of primary hypertension were randomized into three active treatment groups: ear acupuncture (N=72); corporal acupuncture (N=72); and a combination of ear and corporal acupuncture (N=72). [6] Each group received a 20-minute treatment once a day for 10 days. A significant effective response was defined as either the diastolic pressure returning to the normal range, and the reduction was >10 mmHg, or the diastolic pressure reduction was greater then 20 mmHg even if the reduction did not return to the normal range. All three groups showed a statistically significant reduction of blood pressure. In the combination ear and corporal acupuncture group, a significant effective response was observed in 43 out of 72 patients with a total response rate of 86.1%. The total response rates for ear acupuncture and corporal acupuncture performed alone, however, were 53.8% and 55.4% respectively. There was no sham or non-acupuncture control administered in this trial.

Numerous other non-controlled case series have also been conducted to evaluate the efficacy of acupuncture in managing blood pressure. Overall, these less rigorous trials suggest acupuncture may be helpful. For example, in one study, 34 patients with stage I and II primary hypertension received 20 minute acupuncture treatments, once a day for 30 days. [7] The diastolic and systolic pressures were measured before and after the course of treatment. The mean of systolic pressure was reduced from 177 mmHg to 159 mmHg and the mean of diastolic pressure was reduced from 99 mmHg to 92 mmHg. Meanwhile, significant changes in blood viscosity parameters of patients were observed before and after the treatment. Other case studies are summarized in Ren’s review. [4]

Mechanistic animal studies conducted in China suggest that acupuncture could affect blood pressure regulation by influencing blood pressure regulating hormones. One study suggests that acupuncture reduces the renin, angiotensin II, and aldosterone levels in two-kidney, one-clip (2K1C) hypertensive rats. [8] Another study on spontaneous hypertensive rats found that the concentration of serum nitric oxide (NO) was significantly higher in electroacupuncture-treated group than that in the control group. [9]

While the results of some RCT and case series suggest some benefits of acupuncture for managing hypertension, the results must be treated with caution because of serious methodological limitations: (a) sample sizes have been small and generally inadequate; (b) randomization and the use of controls is rare and poorly characterized; (c) interventions often do not reflect traditional clinical practice; (d)the period of follow-up has generally been inadequate or unspecified; (e) the content of treatment is often poorly described; (f) the subjects of the studies are not well characterized; and (g) statistical analyses of the data obtained are often rudimentary.

To address these limitations, the NIH has recently funded a rigorously designed RCT: "Stop Hypertension with the Acupuncture Research Program (SHARP)." SHARP has enrolled 190 subjects with mild to moderate hypertension, and randomly allocated them to one of three treatments: individualized, standardized, or sham acupuncture. Unique to this study is the application of dual diagnosis (click for information about the study's design). Patients are diagnosed not only with respect to the severity of their hypertension, but also with respect to Traditional Chinese Medicine (TCM) patterns. According to TCM theory, subjects with identical blood pressure profiles may be diagnosed in at least five different ways (e.g. Liver Fire Rising, Kidney Yin Deficiency). This design will allow researchers to test two hypothesis: 1) that active treatments (individualized + standardized) are more effective than sham treatments; and 2) that individualized treatments tailored to specific TCM diagnoses are more effective than standardized treatments. Details of this acupuncture RCT are summarized in a paper characterizing the design and rationale of this study. [10]