Hasty Conclusion About Acupuncture for Hypertension?
To the Editor:
In his editorial commentary, “Acupuncture for Hypertension,” Kaplan1 unequivocally concludes that, “acupuncture is of no value for the treatment of hypertension.” In their clinical trial, Macklin et al2 randomly assigned hypertensive subjects to 1 of 3 interventions using “individualized,” “standardized,” or “sham” acupuncture. Each intervention group experienced reductions in both systolic (at or more than −3.55 mm Hg) and diastolic (at or more than −2.81 mm Hg) blood pressures. Although not all of the improvements were statistically or clinically significant, acupuncture seems to be capable of moderating hypertension. The fact that changes in blood pressure did not differ among treatment arms suggests that the effects of acupuncture are not dependent on point location or needling technique, a conclusion reached in a review of 79 recent acupuncture trials.3
The real problem is that the clinical trial lacked internal validity insofar as the independent variable lacked meaningful variation. It is unreasonable to expect differences in outcomes if there are no differences among the intervention arms. Each intervention arm used “corporeal acupuncture” (ie, needles puncturing the body), and there was no physiological hypothesis to explain how the different maneuvers could have different effects. Thus, we can no more attribute the observed reduction in blood pressure to the needling than to any other aspect of the indistinguishable arms, and a placebo effect cannot be ruled out.
Acupuncture, twice referred to by Kaplan1 as “long needles stuck in strange places,” has been transmitted to us as anachronistic rituals without a clear scientific basis. But we should not make hasty conclusions about what acupuncture can and cannot do. Acupuncture has demonstrable physiological effects,4 which may have beneficial applications for patients. However, trials will be unreliable without testable hypotheses about how acupuncture might actually work.
Kaplan NM. Acupuncture for hypertension. Can 2500 years come to an end? Hypertension. 2006; 48: 815.
Macklin EA, Wayne PM, Kalish LA, Valaskatgis P, Thompson J, Pian-Smith MC, Zhang Q, Stevens S, Goertz C, Prineas RJ, Buczynski B, Zusman RM. Stop Hypertension With the Acupuncture Research Program (SHARP). Results of a randomized, controlled clinical trial. Hypertension. 2006; 48: 838–845.
Stux G, Hammerschlag R, eds. Clinical Acupuncture: Scientific Basis. Berlin, Germany: Springer-Verlag; 2001.