Treatment of Hypertension with Alternative Therapies (THAT) Study: a randomized clinical trial

OBJECTIVES: To examine the effect of spinal manipulation on blood pressure. DESIGN: This randomized clinical trial compared the effects of chiropractic spinal manipulation and diet with diet alone for lowering blood pressure in participants with high-normal blood pressure or stage I hypertension. Blood pressure observers were blinded to treatment group. SETTING: The study was conducted at the Berman Center for Clinical and Outcomes Research in Minnesota. Chiropractic treatments were administered by chiropractic physicians within private practice settings.PARTICIPANTS One hundred and forty men and women, aged 25-60 years, with high-normal blood pressure or stage I hypertension, were enrolled. One hundred and twenty-eight participants completed the study. INTERVENTIONS: (i) A dietary intervention program administered by a dietitian or (ii) a dietary intervention program administered by a doctor of chiropractic in conjunction with chiropractic spinal manipulation. The frequency of treatment for both groups was three times per week for 4 weeks, for a total of 12 visits. MAIN OUTCOME MEASURES: The primary outcomes for this study were change from baseline in diastolic and systolic blood pressure. RESULTS: Study groups were comparable at baseline. Changes in potentially confounding covariates did not differ between groups. Average decreases in systolic/diastolic blood pressure were -4.9/5.6 mmHg for diet group and -3.5/4.0 mmHg for the chiropractic group. Between group changes were not statistically significant. CONCLUSIONS: For patients with high normal blood pressure or stage I hypertension, chiropractic spinal manipulation in conjunction with a dietary modification program offered no advantage in lowering either diastolic or systolic blood pressure compared to diet alone.