Wednesday, June 20, 2007

Acupuncture study on hypertension

A new study regarding the effect of acupuncture and hypertension has recently been published in Circulation .As studies dealing with alternative modalities go, it is better designed than most. In essence, it concludes that acupuncture as practiced in Traditional Chinese Medicine (TCM) can reduce non complicated hypertension, actually approaching the effect of hypotensive drugs such as angiotensin. The authors state that acupuncture can be used as an adjunct or alternative to other forms of lowering blood pressure, and provides a promising avenue for a malady where management through more routine methods are either costly or are difficult to comply with.

As time passes, the merits and weakness of this study will be added to the general data base regarding acupuncture and whatever positive or negative contribution it offers will be duly assimilated. In the mean time, Orac provides interesting commentary and presents a series of concerns regarding the study. Overall, he states that even if there are some benefits to needling, the actions are likely due to physiological mechanisms not linked to the philosophies and beliefs of acupuncture and TCM.

“More specifically, if acupuncture has any real effects on pain or other medical conditions, it doesn't do it by altering any sort of mystical and unmeasurable "life energy." If there is a physiologic effect of acupuncture, it must derive from human physiology, not magic, be it placebo effect, release of endorphins, or a counter-irritant effect, all of which have been postulated by various investigators as possible mechanisms for whatever clinical effects have been reported for it. Whatever the true case is, the scientific method should be able to figure it out in time.”

This study is randomized but is single blinded in favor of the acupuncture physicians. That is, the Chinese physicians were not blinded. Admittedly this would be tough to do, but it opens the door to a potentially fatal bias possibly rendering any conclusions of the study pretty much dead on arrival. For example, the clinician’s formal demeanor and tactile skills in the context of the acupuncture application may have tremendous calming influence as well as other unexpected effects.

Additionally, the number and placement of needles may cause placebo/nocebo effects that may account for the variations in pulse values. It would be interesting to get more detail as to the exact placement and methodology beyond the text description as this may play an important role in psychological responses which can play an important role in relaxation or increased tension. For example, were the placements of the sham needles in more topically sensitive regions of the body? Because the study did reveal a response it would be prudent to do several follow up studies to improve the “definition” of the effect and build a larger body of evidence to better ascertain just what is being observed.

TCM philosophies have very little plausibility and reality based mechanisms of action. Additionally, there is a mounting data base of equivocal and negative results regarding acupuncture (There have been attempts to link neurophysiologic effects to putative regions of the body- not necessarily acupuncture points- especially using electricity, but even here many questions remain and at any rate they imply a different effect than acupuncture and needling). Allusion to the ancient wisdom of TCM implied in the study and acupuncture technique stands on very shaky ground historically. Therefore this is a case where just a little bit of evidence is not good enough.

Hypertension is variable and sensitive to environmental stimuli, and though these study results are interesting, the effects fall very closely into the natural waxing and waning variations that profile many chronic diseases even though the authors seem to have taken reasonable efforts to minimize many confounding factors. Incidentally, the study references an interesting article: “ Statistics Notes: Some examples of regression to the mean.” It is not clear that this phenomenon, among others, was clearly accounted for with respect to influencing the observations.

Also, though a tough situation for the authors, we need to take into account the possibility that the anti hypertensive medication played some confounding role. The study seems to have considered this issue, but the question still stands. Another point not clear is whether those monitoring blood pressure values were blinded as this can be another big problem when interpreting results a certain way.

In the background brief, the authors discuss the problems that western medicine has controlling hypertension mentioning pharmaceutical side effects, the cost of medication, and compliance problems regarding managing this condition. However, they also acknowledge in their conclusion that acupuncture training (implies cost), and compliance could be pivotal to the success or failure of acupuncture treatment. Interestingly they stress the importance that acupuncturist skill level plays in applying TCM based acupuncture correctly, adding a layer of obscurity to these results (i.e., the implication being that there is a "special" form of practicing needling that is hard to replicate, but that the chinese seem to possess in spades).

The problematic use of sham acupuncture as mentioned remains an issue. When the rubber hits the road, the act of needling seems to have some type of physiological effect, even if the body is simply reacting to a foreign body intrusion. Teasing out a proper control is difficult and placebo influence seems to pop up recurringly significantly confusing matters . Perhaps sensing some of the problematical issues in the study, the authors revealingly suggest that using acupuncture to manage hypertension may be best suited to those individuals that expressed an interest in the “spiritual” aspects of TCM and acupuncture.

Finally, it seems even the popular TCM practice of acupuncture continues to be riddled with basic foundational questions. Perhaps, one way or the other, improved quality research will offer more satisfactory answers. To rise above the background noise of random effects (as opposed to a clear specific point A that influences organ B) will take a significant number of higher quality studies. However, we need to keep in mind that there may come a point (pardon the pun) where effort and money spent researching modest effects in one modality could be better utilized in other areas of inquiry.

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