Research Review Corner: July-August 2012

Spinal Manipulation for the Treatment of Hypertension: A Systematic Qualitative Literature Review

BACKGROUND INFORMATION
Hypertension and its related diseases are a significant cause of morbidity and mortality in developed nations. In the United States, hypertension represents over five per cent of family medicine diagnoses, and it is the most commonly seen condition in family practice clinics.1 Further, roughly 25 per cent of adults have hypertension, increasing to 50 per cent in the elderly.2 Needless to say, direct and indirect health-care costs relating to this condition are very high. Although it is not normally the primary reason patients seek chiropractic care, we all have numerous hypertensive patients. As a component of a patient’s overall health, it is something we should all be aware of and monitor, particularly if patients have no one else to do so (in a rural region that is medically under-serviced, for example). 

To review, we should concern ourselves with blood pressure, as primary hypertension is a modifiable risk factor for numerous health problems including: coronary heart disease; stroke; angina; peripheral vascular disease; left ventricular and atrial fibrillation; left ventricular hypertrophy; retinopathy; renal failure and end-stage renal disease; and dementia.

Spinal manipulative therapy (SMT) has been reported to improve hypertension in case reports, anecdotal evidence and some clinical trials. As always, it is important that we evaluate and understand the overall state of the literature regarding this topic in order to avoid misinterpreting or overemphasizing the results of individual studies when speaking to patients and other health-care colleagues (which, unfortunately, we tend to do sometimes!). With this in mind, the authors of this study undertook the prudent and relevant task of amalgamating and critiquing this body of literature via qualitative systematic review to assess the efficacy of SMT for treating hypertension.

CONCLUSIONS AND PRACTICAL APPLICATIONS
Overall, the state of the literature on the efficacy of SMT for treating hypertension is not as strong as some of our colleagues would lead us to believe. Although some case studies have reported successful outcomes, larger trials have not been as promising when comparing SMT to other treatment options such as effleurage massage, or even waiting for five minutes! The biological plausibility of SMT as a treatment for hypertension remains controversial and requires further study. Remember, hypertension is a multifaceted problem, so it is unlikely to have a one-treatment cure! Therefore, clinicians should not strictly employ SMT as a stand-alone therapy for hypertension at the expense of other therapeutic options (i.e., dietary modifications, exercise, some anti-hypertensive medications, etc.).

Having said that, we shouldn’t abandon this topic just yet, since the literature on this topic is varied, of general low quality and subject to design flaws and moderate/high risks of bias. Future studies will hopefully improve upon these shortcomings and give us a more
concrete answer.

Dr. Shawn Thistle is the founder and president of Research Review Service Inc., an online, subscription-based service designed to help busy practitioners to integrate current, relevant scientific evidence into their practice. Shawn graduated from CMCC and holds an Honours Degree in Kinesiology from McMaster University. He also holds a certificate in Contemporary Medical Acupuncture from McMaster University, and is a Certified Active Release Techniques (ART®) Provider. For more information about the Research Review Service, visit www.researchreviewservice.com .