Jillian Capodice, L.Ac examines the role of Traditional Oriental Medicine in aiding patients with hypertension.

by  Jillian L. Capodice, LAc

Background on the heart and hypertension (TCM and Biomedicine)

TCM

The heart organ and meridian in Traditional Chinese Medicine (TCM) is the considered the ruler of all the organ networks.  It is related to the characteristics of joy, fire, south and summer.  It is the seat of shen (spirit), controls the blood and commands the vessels.  In Chinese it is thus discussed as the principle fire of the body and all the meridians necessitate the heart qi to course through the body. 

The heart in TCM is also intimately connected with the kidney.  The Neijing says ‘the heart resides in the vessels. It rules the kidney network, not via a controlling position in the restraining circle of relationship between the organ networks [where the kidney actually restrains the heart], but simply because it is the general master of all organ networks. Before the heart fire can harmoniously blend with the kidney water, however, the kidney water must be sufficient. Otherwise the heart fire will flare out of control, and all kinds of heart and kidney ailments will arise.’

This classic medical view of the heart and kidney easily relates to modern anatomy and physiology of the function of the heart and kidney and their roles in maintaining the cardiovascular system and controlling blood pressure.  

Biomedicine

Hypertension (high blood pressure) doubles the risk of cardiovascular diseases, including coronary heart disease (CHD), congestive heart failure (CHF), ischemic and hemorrhagic stroke, renal failure, and peripheral arterial disease.  It is also often associated with additional cardiovascular disease risk factors.

In the United States 28.7% (age-adjusted prevalence) of U.S. adults, or ~58.4 million individuals, have hypertension (defined as any one of the following: systolic blood pressure ³140 mmHg; diastolic blood pressure ³ 90 mmHg; taking antihypertensive medications). Hypertension prevalence is 33.5% in non-Hispanic blacks, 28.9% in non-Hispanic whites, and 20.7% in Mexican Americans. The burden of hypertension also increases with age and of Americans >60 years of age, hypertension prevalence is 65.4%. It has also been implied that the prevalence of hypertension is increasing likely due to the increased prevalence of obesity.

Blood Pressure Classification

Systolic, mmHg

Diastolic, mmHg

Normal

<120

and <80 

Prehypertension

120–139

or 80–89 

Stage 1 hypertension

140–159

or 90–99 

Stage 2 hypertension

160

or 100 

Isolated systolic hypertension

140

and <90 

 
Depending on methods of ascertainment, ~80–95% of hypertensive patients are diagnosed as having “essential” hypertension (also referred to as primary or idiopathic hypertension) which has been suggested to be familial and also likely due to the combination of both environmental and genetic factors.  It is also postulated that essential hypertension represents a variety of potential disorders related to various pathophysiologies.  Conventional treatment of essential hypertension focuses on lowering and stabilizing the blood pressure (BP) and lifestyle modifications including diet, exercise and weight loss have all been shown to reduce BP.  Medications include a variety of antihypertensives including:

  1. ACE inhibitors
  2. Alpha blockers
  3. Antiotensin II antagonists
  4. Beta blockers
  5. Calcium channel blockers
  6. Diuretics
  7. Renin inhibitors

In 5–20% of hypertensive patients, a specific underlying disorder causing the elevation of blood pressure can be identified and termed “secondary” hypertension where a specific mechanism for elevation of the blood pressure elevation is more apparent and can include disorders such as metabolic syndrome and various renal diseases and treatment is aimed at controlling the BP with regard to the specific cause, e.g:  treatment for Cushing’s based on the primary cause for the excessive cortisol levels that may include surgery, radiation, chemotherapy, or the use of cortisol-inhibiting drugs.

Acupuncture and Hypertension

Basic science

The most recent study by Moazzami et al demonstrated that stimulation of somatic afferents during electroacupuncture (EA) inhibits sympathoexcitatory cardiovascular rostral ventrolateral medulla (rVLM) neurons and reflex responses in the brain.

Methods: Based on previous studies, animals were anesthetized, ventilated, and heart rate and blood pressure were monitored.  By careful procedure microinjection and recording electrodes were inserted into the rVLM and nucleus raphae pallidus (NRP). Via application of bradykinin (BK, 10 mug/ml) to the gallbladder Q10 minutes or stimulation of the splanchnic nerve, excitatory cardiovascular reflex responses were elicited.  Subsequent EA to the P5 and P6 acupoints bilaterally was then performed.

Results: Application of EA reduced the induced increase in blood pressure from 41+/-4 to 22+/-4 mmHg for more than 70 min. Inactivation of NRP with 50 nl of kainic acid reversed the EA-related inhibition of the cardiovascular reflex response. And the blockade of 5-HT1A (serotenergic) receptors with the antagonist WAY-100635 into the rVLM reversed the EA evoked inhibition.

In the absence of EA, NRP microinjection of d,l-homocysteic acid (to mimic EA), reduced the cardiovascular and rVLM neuronal excitatory reflex response during stimulation of the gallbladder and splanchnic nerve, respectively.

Finally blockade of 5-HT1A receptors in the rVLM reversed the NRP DLH-inhibition of the cardiovascular and neuronal reflex responses, demonstrating that activation of the NRP involves a serotonergic and 5-HT1A receptor mechanism in the rVLM during somatic stimulation and that in combination, EA is able to attenuate sympathoexcitatory cardiovascular reflexes.

Meta analysis of human clinical trials on acupuncture and blood pressure

Lee H et al recently conducted a systematic literature review to estimate the effect of acupuncture on blood pressure in hypertensive patients.

Methods: Electronic literature search for randomized controlled trials (RCTs) of acupuncture.

Results: Eleven RCTs testing acupuncture met the inclusion criteria although they showed a wide variety of methodological quality.  Of these studies three of the sham-controlled trials demonstrated no significant systolic BP (SBP) change was not (mean difference -5 mm Hg, 95% CI (-12, 1), P = 0.12) and acupuncture a small reduction in diastolic BP (DBP) by 3 mm Hg (95% CI (-6, 0), P = 0.05).

Second acupuncture combined with antihypertensive medication demonstrated significantly reduced SBP (-8 mm Hg, 95% CI (-10, -5), P < 0.00001) and DBP (-4 mm Hg, 95% CI (-6, -2), P < 0.0001).

In general the results of the intervention included acupuncture treatments 5 to 30 times (median 17) for a mean 5.4 weeks (ranging 1 to 8 weeks, median 5.7 weeks). It also demonstrated that the acupuncture techniques varied across the studies in terms of acupoint selection, manipulation of needles and frequency and duration of the treatment sessions.

The most frequently used acupuncture points were LR3 (7 studies out of 11), LI11 (7 studies), GB20 (7 studies), ST36 (6 studies), and ST40 (6 studies).

Qi Gong and Hypertension

Qi gong, a healing art that involves mediation, breathing and movement has also been studied in humans in order to ascertain whether in can be useful in lowering blood pressure.  A recent meta-analysis of trials by Guo et al demonstrated the following:

Results:  Nine (9) studies qualified for meta-analysis, comprising a total of 908 cases and the mean decrease of SBP in those practicing qigong was a 17.03 mm Hg reduction (95% confidence interval (CI) 11.53-22.52) compared with nonspecific intervention controls.  However this was not superior to patients acting as drug controls (1.19 mm Hg, 95% CI -5.40-7.79) and conventional exercise controls (-1.51 mm Hg, 95% CI -6.98-3.95).

Mean decrease of DBP in those practicing qigong was 9.98 mm Hg (95% CI 2.55-17.41) compared with nonspecific intervention controls, but again this was not superior to that in drug controls (2.49 mm Hg, 95% CI -0.16-5.13) or conventional exercise controls (-1.59 mm Hg, 95% CI -4.91-1.74).

The qi gong methods tested were also various an included: Guolin qi gong, dongjing jiehe gong, jinggong and shuzi jiangya gong, wuxin method qi gong, shuxinpinxue gong, and guolin qigong.

Finally, it appears that qi gong was safe and caused limited side effects and may be useful as a complementary treatment for patients with hypertension.

References

1.  Harrison’s Principles of Internal Medicine

2. National Health and Nutrition Examination Survey

3. Moazzami A, Tjen-A-Looi SC, Guo ZL, Longhurst JC. Serotonergic Projection from Nucleus Raphe Pallidus to Rostral Ventrolateral Medulla Modulates Cardiovascular Reflex Responses during Acupuncture. J Appl Physiol. 2010 Feb 4. [Epub ahead of print]

4.  Lee H, Kim SY, Park J, Kim YJ, Lee H, Park HJ. Acupuncture for lowering blood pressure: systematic review and meta-analysis. Am J Hypertens. 2009 Jan;22(1):122-8.

5. Guo X, Zhou B, Nishimura T, Teramukai S, Fukushima M.Clinical effect of qigong practice on essential hypertension: a meta-analysis of randomized controlled trials.  J Altern Complement Med. 2008 Jan-Feb;14(1):27-37.


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