Impact of Hatha Yoga on the Airway Resistances in Healthy Individuals and Allergic Rhinitis Patients

Abstract

There have been limited studies on Hatha yoga training as a complementary therapy to manage the symptoms of Allergic Rhinitis. The main Aim of the study was to check the impact of Hatha yogasanas on the Airway resistances in Healthy volunteers, a baseline data can be established and also to study the impact of Hatha yogasanas on the Airway resistances in Allergic Rhinitis patients in Bangalore, India. This is a prospective case series of 51 healthy volunteers (18 Males and 33 Females) Group 1 and 51 Allergic Rhinitis patients (18 Males and 33 Females) Group 2. The Objective analysis of the upper airway resistance was measured using a rhinomanometer and the lower airway resistance was measured using a spirometer. Then the subjects practiced specific Hatha yogasanas for three months. Then the airway resistance tests were again done at 3 months interval. The subjective analysis was done pre yoga and post yoga using the Short form-12 (SF-12) and Sino Nasal Outcome Test (SNOT) Questionnaires to assess the quality of life. The data was analyzed by doing a Paired (2-tailed) T Test, using SPSS (Software Package for Social Sciences) version 16. Total Nasal Airway Resistance pre yoga and post yoga in 51 healthy volunteers had significantly reduced at 150 Pa and the Forced Vital Capacity(FVC) pre yoga and post yoga had significantly increased,Forced Expiratory volume (FEV1) & % Residual standard deviation (%RSD) had increased but not significant. The Physical component score (PCS) and Mental component score (MCS) of the SF-12 health survey questionnaire had significantly improved with and the SNOT questionnaire score had significantly reduced. The Total Nasal Airway Resistance in 51 Allergic Rhinitis had significantly reduced at 150 Pa and the FVC pre yoga and post yoga showed increase but change was not significant, FEV1 pre yoga and post yoga had significantly increased, %RSD pre yoga and post yoga had significantly increased. The PCS and MCS of the SF-12 health survey questionnaire had significantly increased and the SNOT questionnaire score had significantly decreased. The scientific documentation of the impact of Hatha Yoga on the airway resistances can be an eye opener in the management of several other diseases of the airways.

Introduction

Allergic Rhinitis (AR) is defined as inflammation of the membranes lining the nose, and is characterized by nasal congestion, rhinorrhea, sneezing, itching of the nose and/or post-nasal discharge [1]. It is often viewed, as a trivial disease but can significantly affect the quality of life (QOL) by causing fatigue, headache, sleep disturbances and cognitive impairment [2]. Allergic Rhinitis is also closely related to asthma and, 10–40% of people with rhinitis have concomitant asthma [2]. According to WHO (2007), the global burden of allergic rhinitis was estimated to be 400 million [3] and the prevalence among adults ranges between 10 and 32% in Asia Pacific region [4]. Despite the high burden, there is paucity of community based studies in India, determining the burden and factors associated with allergic rhinitis. Medications provide some relief, but improvement is only partial. Anti-IgE shots show better efficacy, but are still very expensive [5]. In developing countries such diseases pose a serious socio economic burden. Cost effective options and alternative therapy such as yoga will serve as a solution to manage Allergic rhinitis. The ancient science of yoga includes physical postures, voluntarily regulated breathing, and meditation, among other techniques [6]. Practicing yoga can bring positive effects on well-being and human health with respect to biological and physiological parameters [7]. Voluntarily regulated yoga breathing techniques have been found to increase the oxygen consumption (and correspondingly the metabolic rate) both as an immediate effect [8, 9] and as a longitudinal effect [8]. Certain yoga voluntarily regulated breathing techniques offer an opportunity to study the effects of changes in the respiratory pattern on metabolism [10]. Voluntary regulation of breathing in yoga alters autonomic activity with an improvement in cardiovascular and psychological health [11].

Nose is the main channel for the entry of air to the respiratory system, but this also exerts a resistance to the airflow. This nasal airflow resistance consists of half to 2/3rd of total airway resistance [12]. Nasal resistance is defined as resistance offered to the air entry by the nasal cavity [13]. This resistance is rather important as it prevents catastrophic collapse of lung [14]. Nasal airway resistance accounts for more than 50% of total airway resistance [15]. The nasal cavity has been modeled as 2 resistors in parallel [16, 17]. The 3 components of nasal resistance are as follows: the nasal vestibule, nasal valve, and nasal cavum [15]. Information regarding nasal resistance is essential for management of anatomic and physiologic diseases of the nasal airway. However, there are often inconsistencies between subjective nasal obstructive symptoms and the objective appearance of the nasal cavity [18]. Due to this discrepancy, objective diagnostic tools for the assessment of nasal patency or resistance are needed [19]. The upper airway resistance can be measured with the help of a rhinomanometer and lower airway resistance can be measured with a spirometer. Anterior active rhinomanometry is the most frequently used method in clinical practice according to the International Standardization Committee of Rhinomanometry, ICSR [20, 21]. The word rhinomanometry means ‘rhino’ for nose and ‘manometry’ for measurement of pressure [22]. Spirometry is a safe, practical and reproducible maximum breathing test that can be used in primary care to objectively determine the ventilatory capacity of the lungs. As already emphasised earlier in this article, it is the ‘gold standard’ for detecting and quantifying airflow obstruction [23]. A spirometer is a medical device that allows measurement of how much air is expelled and how quickly the lungs can be emptied, in a maximal expiration from full inflation [24]. The test is relatively quick to perform, well tolerated by most patients and the results are immediately available to clinician [25]. Till today there are no studies to explain the effect of Hatha yogasanas on the airway resistances in healthy volunteers and Allergic rhinitis patients. In the present study the effect of Hatha yogasanas on the airway resistances in the healthy volunteers and Allergic rhinitis patients of Bangalore was studied.

Materials and Methods

This study was conducted at the Department of Otorhinolaryngology, St. John’s national academy of health sciences, Bangalore. The study is a prospective non blinded study. 51 healthy volunteers (Group 1) and 51 Allergic Rhinitis patients (Group 2) between the age group of 18–50, willing to practice yoga for a period of three months and with full compliance were recruited for the study. People with respiratory ailments and other coexistent illness and smoking habits were excluded. Subjects who were taking medication for allergic rhinitis or other respiratory tract infections were not included in the study as it can affect the total Nasal Airway Resistance.

The resistance was measured at day 0, that is before the start of practicing yoga and then after a period the 3 months. Written and informed consent was taken before the procedure. All the healthy volunteers were free from any systemic and nasal diseases and were having no nasal complaint or any history of nasal allergy for last 3 months. None of these subjects were using any medicine affecting systemic or nasal circulation. A proper otorhinolaryngological examination of all participants was done prior to the study. Anthropometric measurements like height and weight of each subject was measured before the test procedure. Height and weight were recorded. There was a compliance record given to the subjects, which was also monitored periodically to ensure that they practice yoga regularly.

The Healthy volunteers and Allergic Rhinitis patients were taught Hatha yogasanas by a trained yoga instructor. The following are the list of specific asanas which were taught.

• Tadasana (mountain pose)

• Ardhachakrasana(Half-Wheel Posture)

• Ardhakatichakrasana (Lateral arc posture)

• Bhujangasana (Cobra Pose)

• Vrksasana (Tree Pose)

• Veerabadrasana(Warrior Pose)

• Gomukasana (Cow Face Pose)

• Ustrasana (Camel Pose)

• Dhanurasana (Bow Pose)

• Surya Namaskara

• Nadi Shodhana Pranayama (Alternate Nostril Breathing Technique)

• Bhastrika Pranayama (The Bellows Breathing)

• Bhramari Pranayama (Humming Bee Breathing Technique)

• Kapalabhati (Hyperventilating Practice)

In this study, we conducted a series of experiments using typical equipment such as rhinomanometry and spirometer to assess objectively the effect of Hatha yogasanas on the airway resistance.

Regular calibration ensures maximum accuracy, so before starting the test every time the instrument was calibrated. The rhinomanometer and spirometer used was manufactured by Piston Kft., Budapest, 1033, Hungary.

The technique of the whole procedure was explained in full detail to all subjects. Series of trial recordings were performed with an intention that they were familiar with the technique and equipment thereby eliminating any anxiety which is a known factor for reducing nasal resistance. Rhinomanometry examination was performed during quiet breathing with close mouth in an upright sitting position and the following parameters were recorded. Equipment used had following features:

1. During spontaneous respiration transnasal pressure differences and nasal air flow were recorded simultaneously.

2. Nasal air flow and pressure curve was displayed on a visual display unit (VDU) which allowed controlling the regularity of patients breathing.

3. Data obtained in the form of printed graph which contained nasal airflow and pressure-flow relation at 150 mm Pa pressure [12].

Nasal resistance was kept static at 150 Pa because at this pressure difference both laminar and turbulent airflow were prevailed and nasal resistance can be assessed with minimal physical effort. Calculations of transnasal resistance were made according to Ohm’s law.

Nasal resistance to airflow was calculated by following equation

$$\text{R}=\mathrm{\Delta }\text{P}/\text{V}$$

R is total nasal airflow resistance in Pa/cm³/s, ∆P is 150 Pa pressure, V is nasal airflow (sum of left and right) during inspiration.Total nasal airflow resistance reflects the resistance of both side of nasal cavity. The advantage of measuring the total nasal airflow resistance is to avoid the effect of nasal cycle over unilateral nasal airflow resistance as the nasal cycle may lead to a change of fourfold in unilateral nasal airflow resistance [26].

Study Design

The study is a non blinded pilot study. 51 healthy volunteers and 51 Allergic rhinitis patients were recruited for the study.

Inclusion Criteria

The healthy volunteers and Allergic rhinitis patients between the age group of 18–50, willing to come to the hospital and practice yoga daily for a period of three months and with full compliance were recruited for the study.

Exclusion Criteria

People with serious respiratory ailments and other coexistent illness and smoking habits were excluded. Subjects who were taking medication for allergic rhinitis or other respiratory tract infections were not included in the study as it can affect the total Nasal Airway Resistance. The study protocol was approved by the Institutional ethics committee at the St.John’s national academy of health sciences. The study site was St.John’s national academy of health sciences, Bangalore, Karnataka, India during March 2013–April 2015. The data analysis was done using a SPSS (Software package for social sciences) version 16.

Result

The Comparison of the Objective analysis parameters pre yoga and post yoga was found to be as follows, Total Nasal Airway Resistance in 51 Healthy volunteers was 0.17 Pa/cm³/s pre yoga and 0.14 Pa/cm³/s post yoga at 150 Pa with P < 0.05*. Pulmonary function test parameters FVC pre yoga was 2.8 and 3.13 post yoga with P < 0.01**, FEV1 was 2.19 pre yoga and 2.36 post yoga, %RSD was 93.11 pre yoga and 94.2 post yoga. The subjective analysis parameters was found to be as follows, the Physical component score of the SF-12 health survey questionnaire was 49.68 pre yoga and 51.99 post yoga with P < 0.05* and Mental component score of the SF-12 health survey questionnaire was 51.04 pre yoga 55.05 post yoga with P < 0.01**, and the SNOT questionnaire score was 6.76 pre yoga and 4.03 post yoga P < 0.001***.The Total Nasal Airway Resistance in 51 Allergic Rhinitis was 0.24 Pa/cm³/s pre yoga and 0.19 Pa/cm³/s post yoga at 150 Pa with P < 0.05. The FVC pre yoga was 2.59 and 2.79 post yoga, FEV1 was 1.73 pre yoga and 2.11 post yoga with P < 0.01**, %RSD was 82 pre yoga and 95.21 post yoga P < 0.001***. The Physical component score of the SF-12 health survey questionnaire was 40.07 pre yoga and 43.2 post yoga with P < 0.05* and Mental component score of the SF-12 health survey questionnaire was 45.6 pre yoga 50.3 post yoga with P < 0.01**, and the SNOT questionnaire score was 14.68 pre yoga and 12.17 post yoga P < 0.001***.

Discussion

Aerodynamics of the nasal cavity is determined by two components one is static and others are variable factors which affect nasal cavity. Static component includes bony and cartilage framework of nasal cavity in comparison to the variable factors which are mainly affected by functional status of nasal mucosa, physical activity, endocrine stimuli, air temperature, humidity, O2 and CO2 pressure in the blood and nasal cycle. Total nasal resistance gives an overall measure of nasal functions and also reflects the degree of nasal obstruction during breathing. Previous study by Ohki et al. in 1991 [26] over nasal airflow resistance showed that there is a difference in the mean value of nasal airflow resistance between Caucasian, Negros and Orientals. This difference was found due to difference in nasal width and ventral and transverse nostril diameter. These differences were more marked when the nasal airflow resistance was calculated in decongested nose. The mean nasal resistance in Caucasians, Negros and Orientals was 0.129, 0.146 and 0.184 Pa/cm³/s respectively [26]. An another study of 85 healthy adults has showed that the mean value of total NAR was 0.24 Pa/cm³/s ranged from 0.12 to 0.52 Pa/cm³/s at a reference pressure of 150 Pa in Malay population [27], while this value was 0.21 Pa/cm³/s at a reference pressure of 150 Pa in German population [28]. A study by Morris et al. in 1992 [29] on healthy adult subject showed that the mean total NAR was around 0.23 Pa/cm³/s with range from 0.15 to 0.39. The NAR was not related to vital capacity and height [29]. In a study by Shailendra Gupta et al. mean total NAR in Chattishgarh population was found to be 0.2144 Pa/cm³/s ranged from 0.14 to 0.37 Pa/cm³/s. It was observed that the maximum NAR in healthy subject recorded was 0.37 Pa/cm³/s. But this can be explained on the basis of anatomical differences among individuals as well as pollution in the experimental city habituate high nasal resistance without producing symptoms.

Pranayama is an intergral part of Hatha yogasanas. As a deep breathing technique, pranayama reduces dead space ventilation and decreases work of breathing. It also refreshes the air throughout the lungs, in contrast with shallow breathing that refreshes the air only at the base of the lungs [30]. Regular practice of pranayama improves cardiovascular and respiratory functions, improves autonomic tone toward the parasympathetic system, decreases the effect of stress and strain on the body and improves physical and mental health [31–33]. Pulmonary function parameters (PFT) provide important clinical information to identify and quantify the defects and abnormalities in the functioning of the respiratory system. A study by Dinesh et al.,after 12 weeks of fast pranayama training FEV₁/FVC, PEFR, and FEF_25–75 were significantly improved (P = 0.02, P < 0.001, and P < 0.001, respectively) compared with the values at baseline. However, other parameters (FVC, FEV₁, and MVV) did not show significant (P > 0.05) change [34]. Sivakumar et al. studied the acute effect of deep breathing (2–10 min) and observed an improvement in the PFT parameters in healthy volunteers [35].

Yadav and Das attributed that improvement in the PFT parameters by yogic practices due to increased respiratory muscle strength, clearing of respiratory secretions and using the diaphragmatic and abdominal muscles for filling the respiratory apparatus more efficiently and completely. Furthermore, the improvement in the PFT parameters may be due to rise in thoracic - pulmonary compliances and broncho dilatation by training in Nadisodhana pranayamas [36]. Stimulation of pulmonary stretch receptors by inflation of the lung reflexely relaxes smooth muscles of larynx and tracheo bronchial tree. Probably, this modulates the airway caliber and reduces airway resistance [37]. Previous investigators demonstrated the effect of pranayama on enhancement of the respiratory muscle efficiency and lung compliance due to reduction in elastic and viscous resistance of lung [38]. Furthermore, pranayama acts as stimulus for release of lung surfactant and prostaglandins into alveolar spaces, which increases the lung compliances. [39].

Significantly higher improvement in PFT parameter (FEF_25–75) in FPG can be hypothesized to the reason that breathing during fast pranayama requires breath coordination at higher rate and hence, higher rate of respiratory muscle activity. This produces strengthening of the respiratory muscles and therefore, improvement in the effort produced by the subjects (Fig. 1).

Fig. 1.

Shows the demographic variables of healthy volunteers

The Tables 1 and 6 shows the anthropometric measurements of the healthy volunteers and allergic rhinitis patients. In the present study the Total nasal airway resistance in 51 Healthy volunteers was 0.17 Pa/cm³/s pre yoga and 0.14 Pa/cm³/s post yoga at 150 Pa as shown in the Table 2, this shows there was significant decrease in the resistance as shown in the Fig. 2, and the significant index was P < 0.05*. As shown in the Table 3 and Fig. 3, Pulmonary function test parameters FVC pre yoga was 2.8 and 3.13 post yoga, this shows there was significant increase in the Forced vital capacity with the significant index P < 0.01**, FEV1 was 2.19 pre yoga and 2.36 post yoga, %RSD was 93.11 pre yoga and 94.2 post yoga, though there was increase in the Forced Expiratory Volume and % Residual standard deviation the change was not significant. The Table 4 and Fig. 4 shows the subjective analysis parameters, the Physical component score of the SF-12 health survey questionnaire was 49.68 pre yoga and 51.99 post yoga, this shows there is improvement in the quality of life with the significant index P < 0.05* and Mental component score of the SF-12 health survey questionnaire was 51.04 pre yoga 55.05 post yoga, this shows improvement in the quality of life with significant index P < 0.01**, and the Table 5 and Fig. 5 shows that the SNOT questionnaire score was 6.76 pre yoga and 4.03 post yoga, this shows there is decrease in the symptoms of the SNOT questionnaire with the significant index P < 0.001*** (Fig. 6). The Table 7 and Fig. 7 shows the Total Nasal Airway Resistance in 51 Allergic Rhinitis and it was 0.24 Pa/cm³/s pre yoga and 0.19 Pa/cm³/s post yoga at 150 Pa, this shows there is significant decrease in the resistance with the significant index P < 0.05. Table 8 and Fig. 8 shows the PFT parameters, the FVC pre yoga was 2.59 and 2.79 post yoga, there was improvement in the Forced vital capacity but the change was not significant, FEV1 was 1.73 pre yoga and 2.11 post yoga, this shows there was significant improvement in the Forced Expiratory volume with the significant index P < 0.01**, %RSD was 82 pre yoga and 95.21 post yoga, this shows that there was significant improvement in the % Residual standard deviation with significant index P < 0.001***. Table 9 and Fig. 9 shows the SF-12 score, The Physical component score of the SF-12 health survey questionnaire was 40.07 pre yoga and 43.2 post yoga with P < 0.05* and Mental component score of the SF-12 health survey questionnaire was 45.6 pre yoga 50.3 post yoga with P < 0.01**, this shows the quality of life had significantly improved and the Table 10 and Fig. 10 shows that the SNOT questionnaire score was 14.68 pre yoga and 12.17 post yoga, there is significant reduction in the SNOT questionnaire with P < 0.001***. The main limitation of the study was the compliance of the participants in doing yoga systematically, such participants were removed and again new participants were recruited only if they agree to practice yoga regularly.

Table 1.

Shows the mean and standard deviation of the age, height, and weight of the healthy volunteers

Demographic variables	Mean	SD
Age (years)	33.1	8.9
Weight (kgs)	66.80	8.0
Height (cms)	161.3	8.4

Table 6.

Shows The Mean and Standard deviation of the Age, Height, and Weight of the Allergic rhinitis patients

Demographic variables	Mean	SD
Age (Years)	35.2	6.1
Weight (Kgs)	69.40	3.1
Height (Cms)	159.11	4.5

Table 2.

Comparison of Total Nasal Airway Resistance at 150 Pa pressure between Pre yoga and Post yoga in Healthy volunteers

Total Nasal Airway Resistances at varied pressures	Pre yoga	Post yoga	P value
Mean resistance at 150 Pa	0.17	0.14	0.02*

* P < 0.05; ** P < 0.01; *** P < 0.001

Fig. 2.

Shows the Mean Resistance at 150 Pa Pressure pre yoga and post yoga in Healthy volunteers

Table 3.

Comparison of PFT parameters between Pre yoga and Post yoga in Healthy volunteers

PFT Parameters	Pre yoga	Post yoga	P value
Mean FVC	2.8	3.13	0.01*
Mean FEV1	2.19	2.36	0.08
Mean  % RSD	93.11	94.2	0.06

* P < 0.05; ** P < 0.01; *** P < 0.001

Fig. 3.

Shows the FVC, FEV1 & % RSD pre yoga and post yoga in Healthy Volunteers

Table 4.

Comparison of Short Form 12 – Health Survey questionnaire scores Pre yoga and Post yoga in Healthy Volunteers

Components of SF-12 Health survey questionnaire	Pre yoga	Post yoga	P value
Mean Physical Component Score(PCS) of SF-12 Healthy survey questionnaire	49.68	51.99	0.05*
Mean Mental Component Score(MCS) of SF-12 Health survey questionnaire	51.04	55.05	0.01**

* P < 0.05; ** P < 0.01; *** P < 0.001

Fig. 4.

Shows the of Short Form 12 – Health Survey questionnaire scores Pre yoga and Post yoga in Healthy Volunteers

Table 5.

Comparison of Sino Nasal Outcome Test (SNOT) Questionnaire scores Pre yoga and Post Yoga in healthy volunteers

SNOT Scores	Pre yoga	Post yoga	P value
Mean SNOT Scores	6.76	4.03	0.001***

* P < 0.05; ** P < 0.01; *** P < 0.001

Fig. 5.

Shows the Sinonasal outcome test questionnaire scores pre yoga and post yoga in Healthy volunteers

Fig. 6.

Shows the demographic variables of allergic rhinitis patients

Table 7.

Comparison of Total Nasal Airway Resistance at 150 Pa pressure between Pre yoga and Post yoga in Allergic Rhinitis Patients

Total nasal airway resistances at varied pressures	Pre yoga	Post yoga	P value
Mean resistance at 150 Pa	0.24	0.19	0.05*

* P < 0.05; ** P < 0.01; *** P < 0.001

Fig. 7.

a Shows the Mean Resistance at 150 Pa Pressure pre yoga and post yoga in Allergic Rhinitis Patients

Table 8.

Comparison of PFT parameters between Pre yoga and Post yoga in Allergic Rhinitis Patients

PFT parameters	Pre yoga	Post yoga	P value
Mean FVC	2.59	2.79	0.1
Mean FEV1	1.73	2.11	0.002**
Mean % RSD	82	95.21	0.001***

* P < 0.05; ** P < 0.01; *** P < 0.001

Fig. 8.

Shows the FVC, FEV1 &  % RSD pre yoga and post yoga in Allergic Rhinitis patients

Table 9.

Comparison of Short Form 12– Health Survey questionnaire scores Pre yoga and Post yoga in Allergic Rhinitis Patients

Components of SF-12 health survey questionnaire	Pre yoga	Post yoga	P value
Mean physical component score(PCS) of SF-12 Healthy survey questionnaire	40.7	43.2	0.03*
Mean mental component score(MCS) of SF-12 Health survey questionnaire	45.6	50.3	0.005**

* P < 0.05; ** P < 0.01; *** P < 0.001

Fig. 9.

Shows the of Short Form 12 – Health Survey questionnaire scores Pre yoga and Post yoga in Allergic Rhinitis patients

Table 10.

Comparison of Sino Nasal Outcome Test (SNOT) Questionnaire scores Pre yoga and Post Yoga in Allergic Rhinitis patients

SNOT Scores	Pre yoga	Post yoga	P value
Mean SNOT Scores	14.68	12.17	0.001***

* P < 0.05; ** P < 0.01; *** P < 0.001

Fig. 10.

Shows the Sinonasal outcome test questionnaire scores pre yoga and post yoga in Allergic Rhinitis patients

Conclusion

The present study shows that there is significant decrease in the total nasal airway resistance in both healthy volunteers and allergic rhinitis patients and the PFT parameters also show significant improvement in both the groups after the regular practice of yoga. The Quality of life of the individuals of both the groups was shown to be better as per the SNOT and SF 12 Questionnaire. There have been no scientific studies concerning the effect of yoga on airway resistance; the present study is the first study to check the intervention of yoga on the nasal airway resistance. The scientific documentation of the benefits of Yoga on the airway resistance can be an eye opener in the management of several diseases of the airways.

Compliance with Ethical Standards

Conflict of interest

Chellaa. R, Dr. Soumya M.S., Dr. Inbaraj. G, Dr. Ravi Nayar, Dr. Poonam. K. Saidha, Vishma Hydie Menezes, Rajeeva, declare that we have do not have any conflicts of interest.

Ethical Approvals

The study was carried out after obtaining permission from the Institutional Ethics Committee in St.John’s National Academy of Health Sciences which follows the 1964 Helsinki declaration and its later amendments.

Informed Consent

Complete information about the study was clearly explained to all the subjects in the study and a proper informed consent was obtained from all the subjects in the study.