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.