Breathwork as an Intervention for White Coat Hypertension
Internship project at Emory University Alphanumerics Lab
Cambridge High School, Atlanta, GA
May-July 2023
Abstract
This study described the result of breathwork on 16 participants’ blood pressures. The variability due to the small sample size of the study made it difficult to ascertain the contribution, if any, of breathwork in lowering blood pressure. Two participants, both older than 75 years, experienced a decrease in blood pressure which was not observed in the control group among participants of the same age.
Introduction
White coat hypertension is a phenomenon in which a patient’s blood pressure is higher in a clinical setting than in others such as his or her home. Up to 50% of patients suffer from white coat hypertension (Mancia G et al., 2021), which may lead to overtreatment for hypertension. Additionally, in the long-term, white coat hypertension may lead to other cardiovascular issues and organ damage.
In the United States alone, the American Heart Association states that about 122 million people have high blood pressure. Additionally, the number of patients affected by hypertension shows a positive trend and the number will likely continue to grow (Xiong P et al., 2021).
Relaxation techniques such as imagery and diaphragmatic breathing have been found to be helpful in diminishing pain, as well as cortisol levels (Manolaki S et al., 2021). Relaxation techniques can increase immune functioning and help control glycemic levels in patients with diabetes (Mohamed AA et al., 2021). Finally, such techniques have been shown to decrease anxiety, heart rate, and respiration rate (Chen YF et al., 2017).
Mindfulness meditation has been shown in previous studies to decrease blood pressure (Ponte Marquez PH et al., 2019), but there are few studies about the use of breathwork to decrease blood pressure. Breathwork is a stress management technique that can help calm the body and focus the mind. It usually involves focusing on the breath as one inhales and exhales for a specified duration. Among the myriad relaxation techniques that exist, we focused on breathwork, as it is straightforward to regulate and implement in a clinical setting. Furthermore, it requires no materials and involves a standardized method.
If breathwork proves to be helpful in lowering blood pressure, it could be implemented in hospitals and clinics to lower a patient’s blood pressure when he or she feels anxious, thus reducing the amount of overtreatment that may occur for hypertension.
Materials and Methods
This study was presented to the Institutional Review Board at Emory University School of Medicine at which it was determined not to require a formal review due to the small sample size. Nevertheless, informed consent was obtained from every subject.
We used an electronic blood pressure cuff from OMRON™, which has been deemed accurate within 3mmHg for blood pressure readings (Takahashi et al., 2013). Four participants measured their own blood pressure due to distance. In all other cases, blood pressures were measured by the researcher.
This study included 16 volunteers (4 male, 12 female). Ages of the subjects ranged from 15 to 20 years and 45 to 85 years.
The 16 participants were randomly divided by computer into test (n = 8) and control groups (n = 8).
The protocol included the following steps: Both groups sat at rest for five minutes before the initial blood pressure measurement. The test group were then shown a video (take a deep breath™) where they were instructed to inhale for 3 counts, hold for 2, exhale for 5, and hold for 2 more counts before repeating for a total duration of three minutes. Blood pressure was then measured for a second time. The control group sat at rest for three minutes before the second measurement. This process was repeated for a total of three measurements over three weeks with each participant.
Results
Tables 1A and 1B report blood pressure measurements in the 16 subjects in the three trials. The upper table represents the test group and the lower table represents the control group.
Table 1A - Experimental Group
| Subject ID | BP Before | BP After | BP Before | BP After | BP Before | BP After |
|---|---|---|---|---|---|---|
| Record pairs | 1st | 1st | 2nd | 2nd | 3rd | 3rd |
| 3F | 101/66 | 104/73 | 117/74 | 120/76 | 100/72 | 96/65 |
| 8F | 89/65 | 87/64 | 85/66 | 95/64 | 86/55 | 92/62 |
| 10F | 97/58 | 98/59 | 107/66 | 100/68 | 102/62 | 105/57 |
| 13F | 131/61 | 123/101 | 128/70 | 123/71 | – | – |
| 15M | 155/77 | 144/79 | 144/73 | 137/67 | 147/84 | 144/73 |
| 1F | 129/85 | 130/81 | 132/90 | 133/88 | 127/85 | 116/74 |
| 4F | 153/79 | 126/68 | 149/81 | 146/80 | 170/80 | 149/91 |
| 5M | 166/87 | 142/84 | 149/82 | 137/77 | 167/90 | 170/82 |
Table 1B - Control Group
| Subject ID | BP Before | BP After | BP Before | BP After | BP Before | BP After |
|---|---|---|---|---|---|---|
| Record pairs | 1st | 1st | 2nd | 2nd | 3rd | 3rd |
| 9F | 121/67 | 114/69 | 116/70 | 111/71 | 116/68 | 106/67 |
| 11F | 91/57 | 85/51 | 87/61 | 87/54 | 99/63 | 91/58 |
| 14F | 117/79 | 120/73 | 116/73 | 112/71 | 110/72 | 108/73 |
| 16F | 121/79 | 121/65 | 124/70 | 120/64 | 127/68 | 119/79 |
| 2M | 104/68 | 91/48 | 119/69 | 122/70 | 106/63 | 100/64 |
| 6F | 156/96 | 155/99 | 162/103 | 157/99 | 153/100 | 145/100 |
| 7M | 160/109 | 169/106 | 150/104 | 149/91 | 162/101 | 163/119 |
| 12F | 148/73 | 113/64 | 143/77 | 125/68 | 146/77 | 132/73 |
Legend:
- M=male
- F=female
The average MAP (mean arterial pressure) before the intervention in the experimental group was 92.3 mmHg with a standard deviation of 14.8. The MAP was calculated using the formula ⅓(SBP) + ⅔(DBP). After the intervention, the mean went down to 89.9 mmHg with a standard deviation of 13.6.
The average MAP of the control group before sitting for three minutes was 94.3 mmHg with a standard deviation of 17.5. The average MAP after sitting was 90.4 mmHg with a standard deviation of 15.3.
Since the means of both the control and experimental group decreased, it is difficult to say whether the intervention had an effect on the blood pressure readings of the experimental group. Additionally, the large standard deviation indicates a lot of variance in the data, making it harder to analyze the impact of the breathwork.
Due to the small sample size, there was too much variation in the data to analyze the effectiveness of the intervention. Some patients experienced an observable decrease in their blood pressure while others had no change or even an increase.
Discussion
Upon data analysis, the age group from 45-85 years was subdivided into a middle-aged group (45-65) and an elderly group (66-85). The difference was noted in the elderly group where data revealed that blood pressure improved after the intervention in two patients (as highlighted in the table). In contrast, no noticeable changes in blood pressure were observed in other age groups in both the control and test group.
Variability can be minimized in the future by repeating measurements over a shorter period of time than three weeks.
15 of 16 participants were Caucasian, so more research is needed to assess the applicability in other populations.
In the future, a larger and more diverse group is needed to determine the statistical significance of the intervention.
Limitations of this study include small sample size, lack of population diversity, geographic and time constraints, and inconsistency of the blood pressure determinations. We believe that introducing formal statistical considerations early in the study design, as well as statistical analysis of the results may demonstrate a consistent reduction in blood pressure after breathwork.
The results of this study may be useful not only in temporarily lowering blood pressure in the clinical setting, but also in mitigating long-term end-organ damage from sub-optimally controlled blood pressure.
References
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