Heart Rate Variability (HRV)
In the December 2019 issue of the Chiropractic Journal of Australia are the results of a study documenting that patients who were under continuous chiropractic care showed an improvement in Heart Rate Variability (HRV).
According to Marcelo Campos, MD, in his article in the Harvard Medical School’s Harvard Health Publishing, "HRV is simply a measure of the variation in time between each heartbeat. This variation is controlled by a primitive part of the nervous system called the autonomic nervous system (ANS)." He points out that a high rate of HRV indicates a better ability to adapt and a healthier functioning nerve system. Conversely a lower HRV is associated with conditions such as cardiovascular disease, inflammation, diabetic neuropathy, depression, sleep disorders, and cancer.
As this study points out, vertebral subluxations create nerve system interference that can then affect HRV. The study states, "The primary objective of chiropractic care is to optimize health and wellbeing through the enhancement of nervous system function by reducing nerve interference caused by vertebral subluxations." They continue by noting that the Australian Spinal Research Foundation defines vertebral subluxation as "a diminished state of being, comprising of a state of reduced coherence, altered biomechanical function, altered neurological function and altered adaptability."
In explaining the rationale for this study the researcher noted, "Research over the past 2 decades has shown that the chiropractic adjustment (also referred to as chiropractic spinal manipulation in the chiropractic research literature) results in changes in spinal biomechanics and structure, central nervous system function, motor output, and autonomic output. while under chiropractic care."
In this study, 6 patients between the ages of 25 and 55 started chiropractic care for correction of subluxations. The patients were specifically screened to assure that medications or stressful life events would not create any changes in their HRV during this study. The three men and three women each had their HRV monitored before they started chiropractic, and then routinely every 12 visits to see if correction of subluxations would affect their HRV. These results were also compared to HRVs from control patients who did not receive any chiropractic adjustments.
The results of the study showed a consistent and sustained improvement in HRV in each of the patients who received chiropractic care. There was not only an improvement in their HRV as compared to before starting chiropractic. There was also a demonstrable improvement between the 6 patients receiving chiropractic and the control patients who did not.
In discussing the results of the study, the authors noted, "This case series chronicles HRV changes of 6 adult patients receiving chiropractic care using (specific) adjusting techniques for the correction of vertebral subluxation. The data described here are consistent with immediate and long-lasting neurophysiological changes affected by chiropractic case management."
In the conclusion the authors wrote, "The data presented demonstrates a sustained improvement in HRV over a course of chiropractic care that is consistent with improved health outcomes."