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Review Article
Effect of om chanting and yoga nidra on blood pressure and lipid
profile in hypertension eA randomized controlled trial
K. Anjana
a
, R. Archana
b
,
*
, J.K. Mukkadan
a
a
Department of Physiology, Little Flower Medical Research Center, Angamaly 683572, Kerala, India
b
Department of Physiology, Saveetha Medical College, Saveetha Institute of Technical and Medical Sciences (SIMATS), Thandalam, Chennai 602105 Tamil
Nadu, India
article info
Article history:
Received 17 March 2022
Received in revised form
28 September 2022
Accepted 7 October 2022
Available online xxx
Keywords:
Yoga
Meditation
Yoga nidra
OM chanting
Blood pressure
Lipid profile
abstract
Background: Hypertension (HTN) is a major public health concern, and elevated blood pressure (BP) is a
distinct risk factor for all - causes of morbidity and mortality.
Objectives: Considering the growing evidence of yoga interventions in the management of hypertension,
the objective of the current randomized controlled study is to assess the effect of OM chanting and Yoga
nidra (Relaxation technique) on BP and lipid profile in individuals with HTN.
Materials and methods: Eighty patients with diagnosed HTN were recruited and randomized equally to
either the experimental group or the control group. Patients in the experimental group received a
combination of OM chanting and Yoga nidra, five days a week for a period of 2 months and patients in
the control group continued with their regular conventional medications. BP and lipid profile parameters
were assessed at baseline, 30th day and 60th day for both the groups.
Results: After 2 months of intervention, a significant (p <0.05) reduction in the BP and lipid profile was
observed in the intervention group when compared to the control group. The reduction in systolic and
diastolic BP and LDL were significantly (p <0.001) higher in the experimental group. In addition, there is
a significant increase in HDL levels in the experimental group. No adverse events were reported during
the trial period.
Conclusion: The current study demonstrates the efficacy of Om chanting and Yoga nidra in reducing
blood pressure and improving lipid profiles in patients with HTN. These particular yoga interventions
could thus be considered a safer form of complementary therapy in the management of HTN, alongside
conventional management.
Registration: Clinical trial identifier- CTRI/2020/02/023400.
©2022 The Authors. Published by Elsevier B.V. on behalf of Institute of Transdisciplinary Health Sciences
and Technology and World Ayurveda Foundation. This is an open access article under the CC BY-NC-ND
license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction
Hypertension is a global public health challenge and elevated
blood pressure is one of the leading risk factors for mortality
globally [1]. Over 10.4 million deaths have been reported world-
wide due to hypertension (HTN) and it is the most preventable and
modifiable vascular risk factor for premature morbidity and mor-
tality as well [2,3]. Dyslipidemia is a common metabolic abnor-
mality observed in patients with hypertension. The pathological
abnormalities due to dyslipidemia and elevated blood pressure lead
to endothelial dysfunction, vascular inflammation, vascular
remodeling and atherosclerosis [4]. Reduction in blood pressure, as
little as 10 mm Hg in systolic blood pressure (SBP) and 4 mm Hg in
diastolic blood pressure (DBP), is reported to reduce the risk of
myocardial infarction and stroke by 23% and 30% respectively [5].
Thus, achieving even a smaller reduction in SBP and DBP through
non-pharmacological means such as diet, exercise and comple-
mentary therapies like yoga would be of greater significance in the
management of hypertension alongside conventional
management.
Yoga is one of the most popular mind-body therapies widely
practiced across the world. Various practices are involved in yoga
including physical movements (asanas), controlled respiration
(pranayama), relaxation and meditation (dhyana) [6]. The
*Corresponding author.
E-mail: professorarchana2017@gmail.com
Peer review under responsibility of Transdisciplinary University, Bangalore.
Contents lists available at ScienceDirect
Journal of Ayurveda and Integrative Medicine
journal homepage: http://elsevier.com/locate/jaim
https://doi.org/10.1016/j.jaim.2022.100657
0975-9476/©2022 The Authors. Published by Elsevier B.V. on behalf of Institute of Transdisciplinary Health Sciences and Technology and World Ayurveda Foundation. This is
an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Journal of Ayurveda and Integrative Medicine 13 (2022) 100657
beneficial effects of yoga on various aspects of hypertension are
well-documented, especially with pranayama (breathing tech-
niques), meditation and other relaxation techniques in the man-
agement of hypertension [7e9].
The American College of Cardiology/American Heart Association
(AHA) task force guidelines have emphasized on the importance of
lifestyle interventions such as regular exercise and yoga in the
effective management of hypertension [10]. Keeping in mind the
increase in cardiovascular mortality in low and middle income
countries, a community based intervention would be a more
effective strategy in the management of hypertension [11]. A simple
mind-body intervention like yoga would help patients to practice in
the comfort of their homes without much hassles. Most previous
studies have focused on asanas and pranayama. There are multiple
other simpler practices in yoga that could be performed across all
age groups irrespective of the flexibility of a practitioner. However,
these components of yoga are least explored scientifically. The
objective of the current study is to understand and scientifically
explore the effect of integrated relaxation practices of Yoga nidra
and Om meditation on blood pressure and lipid profile in patients
with elevated blood pressure.
2. Materials and Methods
2.1. Study design
This study was a prospective randomized controlled study
conducted on patients with diagnosed HTN. The study was con-
ducted in a private hospital and research center in rural Kerala,
South India. BP measurement and lipid profile parameters were
evaluated at baseline and after 2 months of intervention.
2.2. Subjects
Patients at Little Flower Medical Research Center, diagnosed
with HTN, with a BP range of 130e139/80e89 mmHg, between 25
and 60 years of age were selected. The subjects were under a hy-
pertension diet and taking essential pharmacological therapy.
Exclusion criteria were patients with cardio-respiratory diseases,
Neuroendocrine diseases, and patients who are practicing yoga or
any form of exercise more than 3 days a week. Recruitment was
done by giving fliers and were contacted by calling over the tele-
phone. 80 patients who fulfilled the inclusion and exclusion criteria
were recruited and randomly assigned to control group (n ¼40)
and experimental group (n ¼40).
2.3. Randomization
For the process of recruitment, 320 patients with HTN were pre-
screened. Out of which, 117 patients were screened for eligibility
and after applying further inclusion and exclusion criteria, 80 pa-
tients who provided informed written consents were randomly
allocated to either intervention group (40) or control group (40)
through block randomization method. Allocation concealment was
done in a sequentially numbered opaque and sealed envelope
(SNOSE method), handled by a researcher who was not directly
involved in the study. Six patients from the experimental group and
nine patients from the control group dropped out of the study.
2.4. Intervention
2.4.1. Om chanting
Patients were trained in ‘Om’chanting by an experienced yoga
trainer. The patients were trained to chant the vowel (O) part of the
‘Om’followed by the consonant (M) part of the ‘Om’for 20 s in each
chanting.The O part was chanted for a shorter duration (1/3 part)
followed by a prolonged M part (2/3 part). They were trained to
chant ‘Om’3 times per minute for a period of 5 min.
2.4.2. Yoga nidra
After ‘Om’, yoga nidra developed by Swami Satyananda Sar-
aswati, Bihar School of Yoga, India was given to the patients in a
supine position for a period of 20 min [12 ]. All patients were
instructed to remain in the lying down position and follow the
instructions of the yoga trainer. The practice starts with in-
structions to relax their entire body and mind as per the in-
structions provided. Followed by stating a resolve/sankalpa. The
sankalpa was given were same for all the subjects and was constant
throughout the study period. The subjects were instructed to rotate
their consciousness as per the instruction followed by breath
awareness. The subjects were instructed to experience the different
feelings and emotions and produce a creative visualization of im-
ages. They were asked to recollect the Sankalpa at this phase. The
subjects were instructed gradually and carefully to return to the
normal state.
No active intervention was scheduled for the control group and
they continued with their regular medications and usual activities.
They were asked to do the follow-up on every 30th and 60th day.
2.5. Outcome measures
BP measurement was carried out using a validated BP monitor
(Omron Inc., Japan). After 10 min of rest in a sitting position, BP was
estimated in the left arm. A fasting blood sample (5 mL) was
collected for assessment of lipid profile markers such as triglyceride
(TG), total cholesterol (TC), low-density lipoprotein (LDL), and high-
density lipoprotein (HDL) at baseline, on 30th day and 60th day for
all the patients.
2.6. Statistical analysis
Descriptive statistics were used to present the baseline charac-
teristics of the data. Normally distributed quantitative data was
presented by the mean and standard deviation (SD). Binary and
categorical variables were presented using counts and percentages.
Between group comparisons of study groups were analyzed using
Independent T test or Mann Whitney U test based on normality.
The corresponding p-value of less than 0.05 was considered sig-
nificant for each outcome. All the data entered in Microsoft Excel,
and analyzed using SPSS version 20.00.
3. Results
Baseline demographical details of the patients who participated
in the present study are shown in Table 1. In the experimental
Table 1
Baseline characteristics of the study participants.
Variables Control group
n¼31
Experimental group
n¼34
P value
Age (yrs, Mean, SD) 43.90 ±9.24 49.13 ±8.106 0.023*a
20-30 (n, %) 4 (13) 4 (13) 0.64#
30-40 (n, %) 10 (33.30) 12 (40)
40-50 (n, %) 15 (50) 14 (46.70)
50-60 (n, %) 2 (3.30) 4 (13.30)
Gender (n, %)
Male 14 (45.1) 15 (44.1) 0.34#
Female 17 (54.8) 19 (55.8)
BMI (kg/m2) 24.31 ±1.21 25.27 ±1.38 0.95*
*Unpaired t test; # chi-square test.
K. Anjana, R. Archana and J.K. Mukkadan Journal of Ayurveda and Integrative Medicine 13 (2022) 100657
2
group, the range of age varies from 34 to 60 years with an average of
49.13 ±8.11 years and in the control group age varies from 25 to 58
years with an average of 43.90 ±9.24 years. Gender is distributed
almost equally in both groups as more than half of the population
were females in both groups. BMI distribution shows that our study
population is overweight.
3.1. Blood pressure variables
Within group comparison of study groups shows that in
experimental group, compared to initial value, systolic blood
pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP),
mean arterial pressure (MAP), and rate pressure product (RPP)
showed a significant reduction on 30th day and it was consistent on
60th day (p <0.001). There was no statistically significant differ-
ence was obtained in control group during the study period.
(p >0.05). The changes in BP variables (SBP, DBP, PP, MAP and RPP)
in the experimental group at various time points with a significant
improvement (p <0.001) post-intervention. The improvement in
SBP (7.6 ±3.58 vs 0.88 ±1.01 mmHg), DBP (4.2 ±1.52 vs.
1.81 ±1.99 mmHg), PP (4.6 ±3.86 vs 2.06 ±2.12 mmHg), MAP
(4.62 ±1.68 vs 1.29 ±1.37 mmHg) and RPP (1347.2 ±459.58 vs.
128.69 ±153.3 mmHg) for the experimental group at 60th day were
significantly higher than control group (Table 2).
3.2. Lipid profile
There was significant improvement (Table 3) in serum lipid
markers (TGL, VLDL, LDL, HDL, LDL/HDL and TC/HDL and total
cholesterol) as well in the experimental group at the end of 30th
day (P <0.001) and 60th day of intervention (P <0.001). Difference
observed among the experimental group shows that Triglycerides
(mg/dl), VLDL (mg/dl), LDL (mg/dl), TC (mg/dl), LDL/HDL, TC/HDL
were showed statistically significant decrease on 30th day and on
60th day after receiving Om chanting and yoga nidra (p <0.05) The
HDL (mg/dl), values increased (p <0.05) significantly during the
study period. In the control group, there was no significant differ-
ences were observed during the study period. (p >0.05). The mean
difference of TGL (9.33 ±1.69 vs 0.16 ±0.63), VLDL (1.87 ±0.34 vs
0.03 ±0.13), HDL (4.43 ±1.72 vs. 0.34 ±0.87 mg/dl), LDL
(9.74 ±2.30 vs. 0.08 ±0.26 mg/dl), LDL/HDL (0.64 ±0.32 vs
0.04 ±0.09) ratio, TC (6.43 ±1.75 vs 0.46 ±0.89) and TC/HDL ratio
(0.79 ±0.4 vs 0.05 ±0.12) were significantly higher at the end of the
60th day.
4. Discussion
In the current study, the combination of the two relaxation
practices- ‘Om’chanting and Yoga nidra, showed a statistically
significant reduction in SBP, DBP, PP, MAP and, RPP. Similarly, an
improvement in the lipid profile was also observed in the inter-
vention group.
The mechanism of action and impact of ‘Om’chanting on
breathing pattern is well-documented. During Om chanting, the
breathing rate is slowed down and airway resistance is induced due
to the laryngeal contraction to generate the particular sound and
vibrational effects, thereby increasing the vagal tone, and resultant
physiological relaxation via parasympathetic arousal [13,14]. The
changes induced in the respiratory tract impact the ascending vagal
activity which would produce a widespread action in critical reg-
ulatory centers of the brain. The parasympathetic nervous system
(PNS) which gets stimulated by the neurotransmitter GABA from
the pre-frontal cortex and insular cortex reduces the hyper activity
of the amygdala [15]. Similarly, the changes in breathing patterns
will increase the release of hormones such as oxytocin, vasopressin
and prolactin, meanwhile reducing the stress markers such as
cortisol, via the hypothalamo pituitary adrenal (HPA) axis [16,17].
Mind-body therapies such as yoga have already been shown to
improve heart rate variability (HRV) in previous studies, especially
slow breathing is reported to influence cardiovagal centers [18].
Previous studies have reported that ‘Om’sound activates the
middle frontal cortex and right supramarginal gyrus which are
Table 2
Within group comparison of blood pressure parameters among the study groups.
Blood pressure parameters Experimental group Control Group
Initial,
Mean ±SD
30th day,
Mean ±SD
60th day,
Mean ±SD
P Value Initial,
Mean ±SD
30th day,
Mean ±SD
60th day,
Mean ±SD
P Value
SBP(mmHg) 137.53 ±3.70 134.53 ±4.66 129.93 ±5.97 <0.001 133.13 ±3.09 132.94 ±2.83 132.88 ±2.73 0.395
DBP(mmHg) 86.13 ±2.40 83.93 ±2.37 81.93 ±2.43 <0.001 84 ±4.42 83.69 ±4.04 84.69 ±2.57 0.051
PP(mmHg) 52.87 ±5.77 51.33 ±5.57 42.67 ±3.65 <0.001 48.33 ±4.55 48.13 ±5.04 46.93 ±3.27 0.221
MAP(mmHg) 103.72 ±2.56 100.97 ±2.81 99.23 ±3.65 <0.001 100.38 ±3.17 100.1 ±2.71 100.75 ±1.82 0.056
RPP (bpm-mmHg) 10446.67 ±1063.87 10012.13 ±967.53 9099.47 ±887.03 <0.001 9973.75 ±1293.86 9972.5 ±1232.06 9974.81 ±1188.13 0.869
Repeated measures ANOVA, P <0.05 shows statistical significance.
SBP- systolic blood pressure, DBP- diastolic blood pressure, PP-pulse pressure, MAP-mean arterial pressure, RPP-rate pressure product.
Table 3
Within group comparison of lipid profile among the study groups.
Lipid Profile Experimental group Control Group
Initial,
Mean ±SD
30th day,
Mean ±SD
60th day,
Mean ±SD
P Value Initial,
Mean ±SD
30th day,
Mean ±SD
60th day,
Mean ±SD
P Value
Triglycerides (mg/dl) 194.17 ±73.27 190.17 ±73.50 184.83 ±72.67 <0.001 245.16 ±45.22 244.94 ±45.03 245 ±45 0.097
VLDL (mg/dl) 38.8 ±14.66 38.03 ±14.59 37.03 ±14.59 <0.001 49.03 ±9.04 48.99 ±9.01 49 ±9 0.097
HDL (mg/dl) 40.10 ±4.58 41.23 ±4.47 44.53 ±3.86 <0.001 35.13 ±5.75 34.91 ±5.44 34.78 ±5.43 0.052
LDL (mg/dl) 164.9 ±34.421 159.90 ±34.39 155.93 ±34.39 <0.001 166.58 ±34.34 166.61 ±34.37 166.66 ±34.3 0.264
TC (mg/dl) 243.75 ±35.07 239.08 ±35.41 237.32 ±35.07 <0.001 250.73 ±35.5 250.51 ±35.5 250.44 ±35.5 0.326
LDL/HDL 4.17 ±0.98 3.83 ±0.91 3.50 ±0.777 <0.001 4.89 ±1.37 4.91 ±1.35 4.92 ±1.34 0.070
TC/HDL 6.13 ±1.104 5.8 ±0.92 5.37 ±0.765 <0.001 7.32 ±1.58 7.35 ±1.56 7.37 ±1.55 0.054
Repeated measures ANOVA, P <0.05 shows statistical significance.
TG-triglyceride, TC-total cholesterol, LDL-low density lipoprotein, HDL-high density lipoprotein.
K. Anjana, R. Archana and J.K. Mukkadan Journal of Ayurveda and Integrative Medicine 13 (2022) 100657
3
neural systems associated with the emotion of ‘empathy’[19]An
fMRI study has demonstrated that 15 s loud ‘Om’chanting stimu-
lates the auricular part of the vagus nerve [20].
Similar to ‘Om’chanting, Yoga nidra is also an equally effective
relaxation practice. Yoga nidra is considered to be a state of relax-
ation with an altered state of consciousness [21]. The integrated
response of Yoga nidra on the hypothalamus results in decreased
sympathetic nervous system activity and simultaneously increases
the parasympathetic activity as well, by possible activation of the
HPA axis [22]. EEG studies showed an initial increase in the beta
wave activity during the practice, indicating a calm state of mind
being induced in the practitioners [23].
Serum cholesterol levels may be elevated during sympathetic
overactivity. Chronic stress may raise cholesterol levels indepen-
dent of dietary measures [24].
Studies on yoga nidra proved that Yoga nidra effectively reduces
stress and anxiety [21].
Previous studies show that pranayama and yogasanas are
effective in patients with defective lipid metabolism [25]. This
might be due to the parasympathetic stimulatory activity of Om
chanting and Yoga nidra [9].
4.1. Strengths and limitations of the study
The major advantage of the study was the intervention, which
did not include any physical practices (such as asanas), which
makes the current intervention simpler and easier for elderly pa-
tients to practice. Having no adverse events being reported by any
of the participants is an added advantage. The intervention, in fact,
could also be considered as a limitation, because the intervention
used in the current study is a combination of two relaxation
practices and therefore, the observed beneficial effects could not be
attributed to any one single practice in particular.
4.2. Future direction
Future robust studies with adequate sample size would enable
to consolidate our findings and help in understanding the benefi-
cial effects of various individual components of yoga. The beneficial
effects observed with the two relaxation practices is nevertheless a
significant one and could be used as a complementary therapy in
the conventional management of hypertension.
5. Conclusion
Combination of the two well-known relaxation practices in yoga
has shown to be beneficial in the reducing high BP and lipid profile
in patients with hypertension. With no adverse events being re-
ported during the entire duration of the intervention, these specific
yogic relaxation practices could be used as a complementary
therapy alongside conventional management of hypertension.
Statement of ethics
This study was approved by institutional Ethical board (Ref: EC/
26/2018)) from Little flower hospital and research center Angamaly,
Kerala, and registered at clinical trial registry (CTRI/2020/02/
023400). Written Informed consent was obtained from all the pa-
tients before commencement of the intervention.
Funding sources
No external funding sources were involved in any stage of this
study.
Author contribution statement
Anjana.K: Conceptualization, Methodology, Formal analysis,
Investigation, Resources, Data curation, Validation, Writing - orig-
inal draft, Visualization. Archana. R: Conceptualization, Method-
ology, Formal analysis, Validation Writing - review &editing,
Supervision. Mukkadan. J.K: Conceptualization, Methodology,
Supervision.
Declaration of competing interest
The authors declare no conflict of interest.
Acknowledgements
Ms. Anitha Devi. T.S for all the help provided in statistical
analysis. We are also grateful to the subjects who are participated in
the study.
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