While the management of musculoskeletal pain has long been the undisputed domain of the chiropractor, research is taking a steady march into the non-musculoskeletal aspects of our offering. With new studies emerging over the last few years revealing the impacts of chiropractic care on the brain and the way it drives the muscles, as well as advancements into using objective measurements to assess nervous system function, it’s an exciting time to be involved in chiropractic and chiropractic research.
A recent addition to the knowledge bank relating to chiropractic and cardiovascular health came from the Journal of the Canadian Chiropractic Association. In it, a paper examined pulse pressure findings in people who were receiving upper cervical chiropractic care – that is chiropractic care for the upper neck area [1].
Pulse pressure, while related to blood pressure, is unique. If someone’s blood pressure reading is 120/80, then the pulse pressure is the 40-point pressure difference between the two numbers. A “normal” pulse pressure measurement is between 40-60mm Hg [1]. It is also worth noting that “pulse pressure tends to increase after the age of 50. This is due to the stiffening of the arteries and blood vessels as you age [2].”
It has long been recognized that elevated pulse pressure (or a widened gap between systolic and diastolic blood pressure readings) is a “recognized cardiovascular risk factor and some studies have suggested it to be a marker for preclinical cardiovascular disease [1].” It is also thought that even a difference of 10mm HG may be significant for health outcomes.
It goes without saying that this is an important measure of health. So, can chiropractic have an impact on this measure of cardiovascular wellbeing? The study in question took in all new patients entering any of five participating chiropractic clinics (as long as they fit the criteria and consented to the study between March 15 and December 31 of 2014). Five attending chiropractors were involved in the study and were trained in a specific chiropractic technique for the upper cervical area (the Knee Chest Upper Cervical Specific Technique, for the chiropractors out there).
The study ended up taking in an impressive 130 participants, of which 81 were female. “The mean age for the patients was 46.7 years old…ranging from 8 to 81 years of age. Most patients (97 of the 130) were younger than 60 years of age. Through the course of six weeks care, the average number of office visits was 11.5 and the average number of upper cervical adjustments was 2.8.”
They were sorted into three groups:
- Low pulse pressure group with a difference of less than 40mm HG
- Medium pulse pressure with a difference of 40-49mm HG, and:
- High pressure of greater than 49mm HG difference
There are more specifics in the paper (which can be accessed at the link below) and the analysis includes a full statistical breakdown and details of care. It is important to note, however, that these patients were not included the study because of the issue for which they presented at the chiropractic clinics – this study simply looked at whether or not upper cervical adjustments might have an impact on pulse pressure findings.
So, here is the good news! While there were no statistically significant differences in the low to moderate groups, the mean change in the high pulse pressure group was “relatively large, where a reduction by 8.9mm HG was observed and this change was statistically significant with a large effect size of 0.8. Some important things to note here include the following:
- There were 47 people in the high pulse pressure group.
- Their mean age was 54.5 (remembering we typically start to see pulse pressure widen over the age of 50) [2].
- 22 of the participants in this group were female and 25 were male.
Researchers concluded that “in this study, we observed, through the application of an upper cervical chiropractic technique, lowered pulse pressure in patients determined to previously have had elevated pulse pressure.”
Given that the autonomic nervous system is responsible for all the functions in the body that we don’t think about in order to perform (i.e. breathing, heartbeat, blood pressure and more), it is quite plausible that this study is giving us a little insight into the impact that chiropractic may have on improved autonomic function.
In terms of limitations, it should be noted that this was clinical-grade data, not research-grade data, and it was not a randomized controlled trial where presenting conditions could be controlled for. However, the results are still quite significant, especially given the sample size. There is always room for more research, and this paper certainly presents a compelling case to take a closer look.
REFERENCES:
- Kessinger R, Qualls T, Hart J, Dallies H, Anderson M, Wayland J and Bradshaw L (2019), “Pulse Pressure Findings Following Upper Cervical Care: A Practice-Based Observational Study,” Journal of the Canadian Chiropractic Association, https://www.chiropractic.ca/wp-content/uploads/2019/04/112756-1_Chiro_63_1g_Kessinger.pdf retrieved 19 June 2020
- Seladi-Schulman J (2018), “Pulse Presure Calculation Explained,” Healthline, healthline.com/health/pulse-pressure retrieved 19 June 2020
