Journal of Undergraduate Research
Volume 1, Issue 6 - March 2000

The Effect of Rhythmic Breathing on Blood Pressure in Hypertensive Adults

Jennifer Chodzinski

ABSTRACT

The purpose of this study is to explore the effect of a simplified version of Pranayama (rhythmic breathing exercise) on blood pressure. Six white female hypertensive adults were taught a 15-minute breathing technique. The third time subjects performed the breathing technique, they were able to significantly decrease their mean arterial pressure and heart rate. While more research is needed, this stress-reduction technique may help hypertensive persons to better control their blood pressure.

INTRODUCTION

In many studies of circadian blood pressure rhythms, researchers (Neutel & Smith, 1997; Muller, Tofler & Stone, 1989) report that responses to everyday activities cause peaks in blood pressure that may result in end-organ damage. Hypertensives maintain a persistently higher average blood pressure with significantly greater peaks, thus increasing their risk for severe end-organ degradation. While the most common methods of controlling hypertension involve pharmacological agents and encouragement to improve diet and exercise, these have little or no effect on short-term blood pressure variability (Floras, Hassan, Jones, Osikowska, Sever, & Sleight,1988; Mancia, Ferrari, Gregorini, Parati, Pomidossi, Grassi, et al., 1981). Hypertensives continue to display acute peaks in their circadian rhythm. Researchers have associated these peaks with chronic work stress (Peter & Siegrist, 1997) and psychobehavioral responses to stress that comprise anger, anxiety, guilt, tension, and nervousness (Munakata, Hiraizumi, Tomiie, et al., 1998; Raikkonen, Matthews, Flory, Owens & Gump, 1999).

Relaxation therapy decreases blood pressure by suppressing the sympathetic nervous system (Shapiro, 1977). The body's immediate response to relaxation (rather than the gradual response invoked by medication and/or diet and exercise) may be the key to reducing peak values for hypertensives. If hypertensives could adopt a simple relaxation technique that would reduce stress and its physiological effects, they may be able to control their blood pressure response during such psychologically stressful events.

Studies in Hatha Yoga have claimed that employment of certain breathing techniques may improve the body's visceral functions and decrease the effects of vascular-related disorders (Wenger & Bagchi, 1961; Udupa & Singh, 1972; Poppen, 1998). Yet, the classic routines of Hatha Yoga involve intricate regimens of spiritual meditation, intense physical postures, and advanced flexibility, which are impractical in today's lifestyle and health care system. Gopal, Anantharaman, Balachander, Nishith, 1973) and Iyengar (1998) suggest that the cardio-respiratory system can be toned through mere rhythmic breathing exercises. One type of rhythmic breathing is pranayama, defined by Udupa, Singh & Settiwar (1975) as a manipulation of breath movement. Although many forms of pranayama are practiced, they all encompass a series of inhalations, sustained breaths, and exhalations. This method of relaxation involves minimal training, can be learned quickly and easily, and more importantly, can be applied immediately to everyday situations. The focus of this study is to determine the effects of a simplified version of pranayama on blood pressure.

METHODOLOGY

Sample

This study was approved by the University of Florida's Institutional Review Board for the Protection of Human Subjects. Subjects were recruited via electronic mail announcements sent to faculty and staff and flyers posted throughout the UF campus. Subjects were included as hypertensive if they had blood pressure greater than 140/90 mmHg or were taking antihypertensive drugs. Subjects were excluded from the study if they were normotensive. All subjects signed informed consent to participate in a three-day trial of ambulatory blood pressure monitoring and a regimen of controlled breathing exercises. The study group consisted of a convenience sample of six hypertensive adults from the North Florida area.

Methods

Ambulatory blood pressure measurement. The Spacelabs Ambulatory Blood Pressure Monitor (ABPM)(Model #90207, Spacelabs Medical Inc, Redmond WA) used for this study "achieved B rating for both systolic and diastolic blood pressure according to the criteria of the British Hypertension Society protocol and satisfied the criteria of the Association for the Advancement of Medical Instrumentation" (O'Brien, 1991). The ABPM was cleaned with diluted dish soap and a sponge, and calibrated before each new subject's use. To determine proper cuff size, each subject's non-dominant, mid-arm circumference was measured in centimeters using a tape measure, and then matched to the corresponding Spacelabs cuff size (24-32cm Adult; 32-42cm Large Adult). The ABPM was then initialized through a personal computer to collect blood pressure (BP) and heart rate (HR) at 30-minute intervals between 0600h-200h (day) and at 60-minute intervals between 2000h-0600h (night). With the subject lying in the semi-supine position, three in-office BP's were taken with the Spacelabs monitor by manual activation. Using the same method, one BP measurement was also taken before and after each breathing exercise.

Subjects were encouraged to continue their normal daily activities while wearing the ABPM for one 24-hour period. A patient diary was provided to the subject with instructions to enter the time of each BP measurement, activity at that time, and the time when BP medications were taken. They were also instructed to manually activate the ABPM before and after the breathing exercise completed at home.

Breathing Exercise. Each subject completed two in-office breathing exercises and practiced the breathing exercise once outside the office. Lasting 15-minutes, the pranayama breathing technique was administered by a Light Transitions (Phoenix, AZ) cassette tape. Guided by music, the tape instructs the subject to inhale for six counts (seconds), hold for three, exhale for twelve, and hold for three; repeating the controlled breaths. This was a simplified version of pranayamic breathing that required minimal physical demand. The subject performed the breathing exercises alone, in our small, quiet, dimly lit office, while lying in the semi-supine position. The environment was not controlled during the subject's at-home practice session.

Data Processing. ABPM data were entered into the Microsoft Excel program to calculate daytime and nighttime mean and standard deviation of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and HR. The first three in-office blood pressures were averaged and used as a baseline. Nighttime SBP and DBP loads (load is the percent of measurements above 140/90mmHg during the day and the percent of measurements above 120/80mmHg during sleep hours) were also determined. Measurements taken before and after each breathing exercise (trials one through 3) included SBP, DBP, MAP, and HR, and were identified as the dependent variables. These variables were added to the MS Excel data and transferred to the SPSS program, along with each subject's demographic information.

RESULTS

The sample consisted of six white female hypertensive volunteers. Their mean age was 51 (range 30-61), weight 167lbs. (121-224), height 65 inches (range 61-67). Five of the six were taking antihypertensive medications. All were working full time in moderate to high stress jobs. Only four reported exercising regularly. The first time the subjects did the breathing exercise, SBP, DBP, MAP, and HR did not decrease significantly (see table 1). Trial 2 was not analyzed because it was a practice session in an uncontrolled environment at home. Results for trial 3 are shown in Table 2. MAP and HR decreased significantly; SBP and DBP did not. Individual changes for MAP are shown in figure 1; changes in HR are shown in figure 2.

 

Figure 1. Individual changes for MAP.

Figure 2. Changes in HR.

CONCLUSION

In one fifteen-minute session, subjects were quickly and easily taught the deep breathing exercise. After practicing at home once, the next trial in the office showed significant reductions in MAP and HR. The drop in the SBP approached significance (p=0.54). Had more subjects been studied, the drop in SBP and possibly DBP might also have been significant.

Major limitations of the study were the small number of subjects and lack of male participants. Other limitations involved whether or not the decreases measured occurred because of the pranayama breathing technique, the use of music in the exercise, or the mere act of lying in a quiet room with dim lights in the semi-supine position.

These findings are supported by work of other researchers. These authors propose that reactions of the parasympathetic nervous system remain the key to understanding the physiological effects of relaxation techniques. Bhargava, Gogate, and Mascarenhas (1988) reported drops in both SBP and DBP in 20 health young males that practiced a pranayama technique over a period of four weeks. Udupa et al. (1972) suggested that an increase in adrenocortical activity (observed in many yogis) might lead to an adaptive response resulting in an increase in stress competence. Future studies about the relationship between relaxation and the parasympathetic nervous system are necessary to address the physiological basis of meditative techniques.

---

REFERENCES

1. Bhargava, R., Gogate, M. G., & Mascarenhas, J. F. (1988). Autonomic responses to breath holding and its variations following pranayama. Indian Journal of Physiology and Pharmacology, 32 (4), 257-264.
2. Floras, J. S., Hassan, O., Jones, J. V., Osikowska, B. A., Sever, P. S., & Sleight, P. (1988). Factors influencing blood pressure and heart rate variability in hypertensive humans. Hypertension, 11, 273-281.
3. Gopal, K. S., Anantharaman, V., Balachander, S., & Nishith, S. D. (1973). The cardiorespiratory adjustments in 'pranayama', with and without 'bandhas', in 'vajrasana'. Indian Journal of Medical Science, 27, (9), 686-692.
4. Iyengar, B. K. S. (1998). Light on Pranayama: The Yogic Art of Breathing. New York: Crossroad.
5. Mancia, S., Ferrari, A., Gregorini, L., Parati, G., Pomidossi, G., Grassi, G., Bertinieri, G., & Zanchetti, A. (1981). Evaluation of a slow-release Clonidine preparation by direct continuous blood pressure recording in essential hypertensive patients. Journal of Cardiovascular Pharmacology, 3, 1193-1202.
6. Muller, J. E., Tofler, G. H., & Stone, P. H. (1989). Circadian variation and triggers of onset of acute cardiovascular disease. Circulation, 79, 733-743.
7. Munakata, M., Hiraizumi, T., Tomiie, T., Saito, Y., Ichii, S., Nunokawa, T., Ito, N., Taguchi, F., Yamauchi, Y., & Yoshinaga, K. (1998). Psychobehavioral factors involved in the isolated office hypertension: comparison with stress-incduced hypertension. Journal of Hypertension, 4, (16), 419-422.
8. Neutel, J. M., & Smith, D. H. G. (1997). The circadian pattern of blood pressure: cardiovascular risk and therapeutic opportunities. Current Opinion in Nephrology and Hypertension, 6, 250-256.
9. O'Brien, E., Mee, F., Atkins, N., & O'Malley, K. (1991). Accuracy of the Spacelabs 90207 determined by the British Hypertension Society protocol. Journal of Hypertension, 9, 573-574.
10. Peter, R., & Siegrist, J. (1997). Chronic work stress, sickness, absence, and hypertension in middle managers: general or specific sociological explanations? Social Science & Medicine, 45, (7), 1111-1120.
11. Poppen, R., (1998). Behavioral Relaxation Training and Assessment. Thousand Oaks: Sage.
12. Raikkonen, K., Matthews, K. A., Flory, J. D., Owens, J. F., & Gump, B. B. (1999). Effects of optimism, pessimism, and trait anxiety on ambulatory blood pressure and mood during everyday life. Journal of Personality and Social Psychology, 76, (1), 104-113.
13. Shapiro, A. P., Schwartz, G. E., Ferguson, D. C. E., Redmond, D. P., & Weiss, S. M. (1977). Behavioral methods in the treatment of hypertension: A review of their clinical status. Annals of Internal Medicine, 86, 626-636.
14. Udupa, K. N., & Singh, R. H. (1972). The scientific basis of yoga. Journal of the American Medical Society, 220, (10), 1365.
15. Udupa, K. N., Singh, R. H., & Settiwar, R. M. (1975). Studies on the effect of some yogic breathing exercises (pranayamas) in normal persons. Indian Journal of Medical Research, 63, (8), 1062-1065.
16. Wenger, M. A., & Bagchi, B. K. (1961). Studies of autonomic functions in practitioners of yoga in India. Behavioral Science, 6, 312-323.

---

--top--

Back to the Journal of Undergraduate Research