SPINAL MANIPULATION FOR THE TREATMENT OF HYPERTENSION: A SYSTEMATIC QUALITATIVE LITERATURE REVIEW

Objective: Spinal manipulative therapy (SMT) has been reported to successfully treat hypertension (HTN). The purpose of this study was to perform a qualitative literature review on the efficacy of SMT for treating HTN. Methods: The literature was systematically searched in PubMed, Medline, Allied and Complementary Medicine Database, Cumulative Index to Nursing and Allied Health Literature, and Index of Chiropractic Literature. Included articles were rated for bias using the Cochrane Collaboration's tool for assessing risk of bias. Studies reporting differing methodologies, types of SMT, frequency of treatment, and time of follow-up were considered too dissimilar for meta-analysis. Results: Of 208 articles identified, 10 were selected as relevant and were assessed. Risk of bias scores revealed 2 studies with low risk, 3 studies with unclear risk, and 5 studies with high risk. The maximum improvement observed in any SWT group, in low risk of bias studies was -9.7 (95% confidence interval [CI], -21.1 to 1.8) systolic improvement and -9.0 (95% CI, -16.8 to -1.2) diastolic; and in unclear risk of bias studies, it was -17.2 (95% CI, -20.7 to -13.7) systolic and -13.0 (95% CI, -15.4 to -10.6) diastolic. Statistically significant decreases in blood pressure were not observed in clinical trials with low bias when SMT was compared with effleurage massage and a 5-minute wait. The studies with more risk of bias showed a greater treatment effect. Conclusion: There is currently a lack of low bias evidence to support the use of SMT as a therapy for the treatment of HTN. Future investigations may clarify if SMT is effective for treating HTN, either by itself or as an adjunctive therapy, and by which physiologic mechanism this occurs. (J Manipulative Physiol Ther 2012;35:235-243)