AUGUST 10, 2013
Subject: Hypertension / Blood Pressure
Reference: Steven Roffers, Laura Huber, David Morris, Anquonette Stiles, Derek Barton, Therese House
Objective: Previous studies on the effects of chiropractic treatment on blood pressure (BP) and pulse rate (PR) have reported decreases in both systolic and diastolic BP,(1,2,3) as well as PR.(2,3) However, those studies have been criticized as being flawed, and accused of drawing erroneous conclusions, due to small sample size and various methodological concerns.(4,5,6,7) The purpose of this randomized controlled trial (RCT) was to measure the effects of specific thoracic (T5 to T1) chiropractic adjustments on BP and PR in a larger sample size of both normotensive and hypertensive humans.
Methods: Informed consent was obtained and 290 human subjects who met the inclusion criteria were randomly assigned to one of three groups: Control (N=95; no treatment, no placebo); Placebo Treatment (N=96; sham adjustment with inactive device); or Active Treatment (N=99; adjustment with active device). Subjects were seated in a relaxing climate-controlled room for a minimum of 15 minutes prior to obtaining a baseline blood pressure (BP) (systolic and diastolic) and pulse rate (PR) measurement with an electronic oscillometric BP monitor. The subjects were then moved to chairs stationed according to the study group in which they were assigned. Subjects had another BP and PR measured (“anxiety” BP and PR measurements) after being called upon for active treatment, placebo treatment, or no treatment at all. Active treatment involved the use of the Activator IV(8) adjusting instrument to correct subluxations detected according to the Activator Methods Chiropractic Technique(9) for thoracic vertebrae T5 to T1. Placebo treatment was performed with an Activator II(10) adjusting instrument in the “off” position which mimics all aspects of the treatment that is administered when in the “on” position but no manipulative force is delivered. Following active treatment (or placebo treatment or no treatment), subjects had their BP and PR measured once again.
Results: Subjects ranged in age from 18 to 100 years old (mean age = 52) and 66% of them were female. Systolic and diastolic BP decreased significantly (p<0.0001) in the active treatment group, whereas no significant changes occurred in the placebo treatment and control groups. Similarly, PR decreased significantly (p<0.0001) in the active treatment group, whereas no significant changes occurred in the placebo treatment and control groups.
Discussion: Previous smaller studies, with various weaknesses, served as the foundation for this larger and important RCT. The results of this RCT indicate, with strong statistical significance, that specific thoracic (T5 to T1) chiropractic adjustments decrease systolic and diastolic BP, as well as PR.
Conclusion: This important and significant RCT demonstrates that specific thoracic chiropractic adjustments decrease BP and PR. A follow-up longitudinal pilot study of both normotensive and hypertensive subjects is currently in progress by the authors to determine how long a decrease in BP and PR is sustained following specific chiropractic adjustments. Hypertension and its adverse effects are worldwide health problems warranting further studies on the effects of chiropractic adjustments on BP and PR.