Indian J Physiol Pharmacol 1996; 40(4): 318-324

STUDY OF PULMONARY AND AUTONOMIC FUNCTIONS OFASTHMA PATIENTS AFTER YOGA TRAINING

AYESHA AKHTAR KHANAM*, USHA SACHDEVA,RANDEEP GULERIA** AND K. K. DEEPAK

Departments ofPhysiology and **Medicine,All India Institute ofMedical Science,New Delhi - 110029

( Received on May 15, 1996 )

Abstract: "The concept of yoga is helpful for the treatment of Bronchial Asthma",has created a great interest in the medical research field. In order to investigatewhether autonomic ftmctions and pulmonary functions are improved in asthmapatients after short term yoga training, a study was conducted with ninediagnosed bronchial asthma patients. Yoga training was given for seven days ina camp in Adhyatma Sadhna Kendra, New Delhi. The autonomic function teststo measure the parasympathetic reactivity (Deep Breathing test, ValsalvaManouever), Sympathetic reactivity (Hand Grip test, Cold Pressure test), andpulmonary function tests FVC, FEV), PEFR, PIF, BHT and CE were recordedbefore and after yoga training. The resting heart rate after yoga training(P < 0.05) was significantly decreased (89.55 ± 18.46/min to 76.22 ± 16.44/min).The sympathetic reactivity was reduced following yoga training as indicated bysignificant (P < 0.01) reduction in pBP after HGT. There was no change inparasympathetic reactivity. The FVC, FEV!' PEFR did not show any significantchange. The PIF (P < 0.01), BHT (P < 0.01) and CE (P < 0.01) showed significantimprovement. The results closely indicated the reduction in sympathetic reactivityand improvement in the pulmonary ventilation by way of relaxation of voltmtaryinspiratory and expiratory muscles. The "comprehensive yogic life style changeprogramme for patients of Bronchial Asthma" have shown significant benefiteven within a short period.

Key words: yoga as tham a autonomic function test

INTRODUCTION

Electrophysiological, biochemical andpsychological studies on the effect of regularpractice of yoga asana and pranayamas haverevealed physical and mental well being. InBronchial Asthma the airway resistance isincreased due to inflamatory allergic andpsychological factors. Meti and Srinivasan (1)have shown that yoga practice has curative effectin Bronchial Asthma patients. Their studyshowed that Paranayama may alter the airwayreactivity in Asthmatic subjects as indicated by

increased dose of histamine required to providea 20% reduction in forced expiratory volume in1st second. A very short term practice of 7 daysof nonconventional therapy like Kunjal, J alneti,Pranayama and Yoga Asana and Netikriya astherapeutic procedure for the treatment ofBronchial Asthma has already been reported byseveral authors (2). In an extensive study on188 asthma patients for 8 years by Vincent et al(2) have shown significant improvement ingeneral health, symptoms, medicationrequirement, asthma attacks and other

"'Corresponding Author and present address : Department of Physiology, Comilla Medical College, Comilia,Bangladesh

!wlian J Physiol Pharmacol 1996~ 40(4) Effect of Yoga on Asthma 319

respiratory crisis. Yogic practices which are ofmild form are considered useful for positivehealth and advocated for use in treatment andprevention of asthma (3). The classical workconducted by Nagarathna and Nagendra (4) haveshown significant improvement in number ofasthma attacks and scores in asthma patientsundergoing yoga training. Improvement in thepulmonary functions after yoga treatment inasthma patients may be the contributing factor(5, 6, 7). The subjective improvement in all thepatients occurred due to ease in breathingassociated with decreased air way resistance afteryogic treatment (6). Bronchial asthma is afunctional disorder and has a psychosomaticbasis. Autonomic imbalance may contribute topossible increase in the airway reactivity (8).These may be a characteristic increasedparasympathetic activity. A study conducted onasthma patients who underwent yoga trainingrevealed an almost equal distribution of patientshaving sympathetic, normal nd parasymatheticrange of score. Six patients having sympatheticpredominant scores showed a shift to normalrange while one patient changed toparasympathetic side at the end of treatmentperiod (9). The relaxation sessions facilitated bybiofeed back have also shown reduction in airwayresistance (10). There is thus a need to examinethe value of short term yogic intervention ininfluencing pulmonary .functions by altering theautonomic status of asthma patients. The presentinvestigations were undertaken to determine theeffect of continued effect of Kriya, Pranayama,Asanas, and relaxation on Pulmonary FunctionTests and Autonomic Function Tests of Asthmapatients.

METHODS

The study was conducted on nine diagnosedcases of Asthma (6 males and 3 female with agerange of 12-60 yrs) patients having averagedisease duration of 13.55 yrs. These subjects werein remission phase of asthama. The patients were

from AIIMS (New Delhi) OPD receivingtreatment in the Chest Clinic. The diagnosis wasbased on paroxysms of dysponea, wheezing andcough which improved either spontaneously orwith drug therapy. The study was explained tothe patients and their signed informed consentwas taken according to the ethical principles ofIndian Council of Medical Research, New Delhi.All the patients were nonsmoker. They wereroutinely scanned out for cardiac problems,diabetes and rheumatoid arthritis as these canalter the autonomic parameters. The patientswere taken to Yoga Training Camp (AdhyatmaSadhana Kendra, Chattarpur, New Delhi) for oneweek. All the patients served as their owncontrol.

Training in yoga: All the patients receivedsame yoga training. These consisted of differentyoga Asanas, (Padmasana, Tadasana,Utkatasana, Chakrasana, Trikon sana andBhujangasana), Pranayamas (voluntaryregulation of respiration), Nadi Shodhan,Bhramari, Anuloma vilomas, Preksha Dhayanand lectures on the philosophy of yoga. Theasanas and pranayamas practices were scheduledtwice a day morning and evening for one hourin each session, 14 sessions for 7 days. Thepatients started their schedule early in themorning at 4 a. m. All the patients were keptunder same non spicy diet and in the sameenvironmental condition with maximumrelaxation. The patients were asked to continuetheir medicine and were advised to record thechange in drug dosages.

Parameters: The autonomic functions (AFT)and pulmonary function (PFT) were assessedprior to the yoga training and at the end of oneweek of practice. Both the autonomic andpulmonary function tests were non-invasive. Thetests were done 2 hr after meals and they wereinstructed to avoid caffeine beverages atleast twohours before tests. All the autonomic functiontests were done with 2 min interval.

320 Khanam et al

The Autonomic Function Tests: Status ofautonomic reactivity was assessed by using fourautonomic function tests (11). The EKG andstethographic record of respiration were obtainedon two channel Polyrite (Instrument andChemicals Pvt. Ltd., Ambala, India). The EKGin standard Limb lead II was continuouslymonitored through all the tests. The patientswere explained the whole procedure andmonitored, while measurements were beingtaken. Before any test the base linecardiorespiratory parameters (HR, RR and BP)were recorded in respective tests.

Deep Breathing Test (DBT): The patientswere asked to sit quietly on the stool. Then theywere asked to take deep inspiration andexpiration at a rate of six breaths per min (3 secinspiration, 2 sec pause, 3 sec expiration and 2sec pause). The recording of EKG andrespiration was done on the Polyrite. Theparasympathetic reactivity was measured bycalculating E : I (Expiration: Inspiration) ratio.

E I. Maximn R - R interval during Expiration

: ra ti~ __--:---=----=---:----:---:-----"'-----=,..:----,--------,----Minimmn R - R interval during II/~piration

Valsalva maneuver: The Valsalva maneuvercomprises of abrupt transient voluntary elevationof intrathoracic and intra-abdominal pressuresprovoked by straining. Straining is initiated atthe end of normal inspiration (11). StandardValsalva maneuver was carried out by thepatients by expiring forcefully through a mouth

Indian J Physiol Pharmacal 1996; 40(4)

piece attached to a manometer to generatepressure of 40 mm of Hg and maintaining thislevel for 15 sec. The heart rate responses wererecorded on the Polyrite before, during and 30sec after the maneuver. From the records,Valsalva ratio was calculated using the formula.

Longest R - R interval after maneuverValsalva ratio: --"'------------­

Shol1~st R - R interval during man<.'u\,C[

Hang Grip Test (HGT): This is a sympathetictest. The patients were asked to grip thedynamometer with their dominant hand at 30%of their maximum voluntary capacity. The bloodpressure and heart rate changes were taken asthe difference between resting reading andreading before release of hand grip.

Cold Pressure Test (CPT): It is a sympathetictest. The patients were asked to immerse theirright hand in cold water at 100 C upto the wristfor 1 min. The BP and HR were recorded at 1min and 2.5 mjn (13). Changes in HR and BPwere calculated as the difference between theresting value and value obtained just beforetaking out the hand from cold water.

Pulmonary Function Tests: The pulmonaryfunction tests were assessed by using transfertest machine (P.K. Morgan, Pvt. Ltd., ChathamKent, England). The patients were acclimatizedto the laboratory for 10 min. The level of themouth piece was adjusted so that the patientwas comfortable and the neck was not flexed or

TABLE I: Shows sympathetic activity tests of asthma patients pre Hnd post yoga trai.ning.

Tests

HGTBasal PreyDuring PreyBasal PastyDuring pastyCPTBasal preyDuring preyBasal pastyDuring pasty

Prey = Pre yoga training *P<.05Postt = Post yoga training

Sj'stolic BP mm of Hg

118 ± 17.91141.33 ± 27.05116.66 ± 16.15113.66 ± 31.73

120.00 ± 19.44135.11 ± 31.17116.66 ± 18.02128.55 ± 27.21

Diastolic BP mm of Hg

79.55 ± 11.1799.33 ± 20.2777.11 ± 8.5588.77 ± 19.37*

81.33 ± 14.2894.44 ± 26.1678.00 ± 11.18*86.44 ± 15.47

Indi::Ul J Physiol Ph<trm<tco] 1996; 40(4) Effect or Yoga on Asthma 321

TABLE 11: Showing pulmon<try n.mction tests or <t,;thma p<\tients pre and post yoga training.

Para.meter:;

FVCrEV j

P8FHBfITPlFC8

Pre yoga

2.10 ± 0.65 Umin1.51 ± 0.34 Ll1st see5.79 ± 1.20 Llmill

24.88 ± 8.08 Sec3.38 ± 1.68 Llmin

84.17 ± 9.54 em/mi.n

Post yoga

1.73 ± 0.41 Llmin1.45 ± 0.39 Ll1st see

6.5 ± 1.65 Llmin34.88 ± 9.42 See**

5.38 ± 1.88 Llmin**87.7:3 ± 10.a4 cm/min*"'*

"""P <.0.1l1**"P <.0.001

extended too much. Patients were then subjectedto pulmonary function tests including forced vitalcapacity (FVC), forced expiratory volume in 1stsecond (FEV 1) peak expiratory flow rate (PEFR),P ak inspiratory flow rate (PIF), Breath holdingtime (BRT) and chest expansion (CE). The PEFRwas measured by the Pink City Flow Meter andCE was measured by the measuring tape.

For analysis the students paired 't' test wasused to determine the differences between visitI and visit II with P < 0.05 being the level ofsignificance.

RESULTS

visit I was 89.55 ± 18.46/min, and in visit II itdecreased to 76.22 ± 16.44/min. The slowing ofRR was statistically significant (P < 0.05l. Therewas no significant differences in baseline restingrespiration of patients in visit I and visit II(21. 77 ± 3.38 and 22.66 ± 4.0/min respectivelyj.The baseline systolic and diastolic BP was alsonot changed after yoga training (Fig. 1).

Effect on parasympathetic reactivity: The E:Iratio was similar in both the visits. The VRvalues of the patients in visit I and visit II were

140 .....--------------------,. 140

In this study two different parameters werestudied namely autonomic and pulmonaryparameters. The results of the parameters aregiven separately in Table I and II. All the nineasthma patients underwent autonomic andpulmonary function tests before and after yogatraining for one week. During 1st visit sevenpatients were on bronchodilator (in the form ofinhaler and tablets) and two were on medicines.During training only two were taking inhalers(one patient for 3 times a day for one day, whowas otherwise taking atleast 8 puffs in a dayregularly and one patient for only once in a day,who used to take thrice in a day previously).Rest of the patients were without anymedication. They were feeling subjectively betterafter completing camp during visit II.

per minute

RR HR• preintervenlion

mm of Hg

SBP DBPWiriJ postintervention

120

80

60

4U

20

Autonomic parameters :

Baseline cardia-respiratory data: The meanbaseline resting heart rate (BRR) of patients in

Fig. 1 : Bar diagrilm showi.ng bilseli.ne Respiratory rate(IlRi,Heilrt rilte(HR), systolic i'lnd diastolic blondpressure(SBP, OBP) pre yoga and post .vogilintervention respectively.

322 Khanam et a1 Indian J Physiol Pharmacol 1996; 40(4)

similar and were also not altered after yogatraining. Yoga training significantly reduced theHR response after HGT (P < 0.01) (Fig. 2).

BEATS/MIN

100 1

BEFORE AFTER

Effect on sympathetic reactivity: Yogatraining significantly reduced the hypertensiveeffect of HGT as indicated by the DBPreduction after HGT in visit II (P < 0.05).Response in visit I and visit II before andafter CPT, did not show any significant change(Table I).

Pulmonary parameters: The mean ±SD forFVC, FEV!' PEFR, PIF, BHT and CE before andafter yoga training are given in Table II. Invisit II the patients showed significantimprovement in three of the pulmonary functiontests in peak inspiratory flow rate (PIF) (from3.38 ± 1.68 to 5.38 ± 1.88 L/min, P < 0.01),breath holding time (BHT), (24.88 ± 8.06 sec to31.88 ::t 9.42 sec, P < 0.01) and CE (84.17 ± 9.54cm to 87.73 ± 10.34 em, P < 0.001). There wasno significant changes in FVC, FEV1 and PEFRin comparing the values between visit I andvisit II (Table II) (Fig. 3 and 4) .

• Preintemntion ~ Posllnlmention

Fig. 2: Bar diagram showing heart rate after Hand Grip testpre yoga and post yoga respectively.

LlMIN

10

PRE & POST TRAINING BHT AND CESECS Cms

100,..----------------------,100

*

4

PEFR

• Preintervenlion

PIF

Postintervention

80

60

40 .

20U .-

DHT

.PRE .POST

CE

80

60

. 40

20

Fig. 3: Bar diagram showing peak expiratory /low rate andpeak inspiratory /low rate pre yoga and post yogarespectively.

Fig. 4 : Bar diagram showing breath holding time andchest expansion pre yoga and post yogarespectively.

Indian .J Physiol Pharmacol 1996; 40(4) Effect of Yoga on Asthma :323

DISCUSSION

We have found almost normal parasympa­thetic and higher sympathetic functions inasthma patients. The elevated sympatheticfunction in asthma patients were similar to thatreported earlier. The link between autonomicand pulmonary function in asthma patients afteryoga training have shown a strong association(14). Patients having predominant sympatheticscores showed a shift to normal range and 7 ofthem stopped medicine completely at the end oftreatment with profound alevation of symptomsand feeling of well being. Gharote et al (9) madesimilar observations in asthama patients. In ourstudy, seven out of nine patients were onmedicine at the beginning of yoga camp and onlytwo had taken the inhaler puffs which was lesserin number than their routine. The observedsignificant reduction in resting HR after yogictraining is most probably due to decreasedsympathetic activity. We measured the HR from10 second EKG strip and respiratory influenceswere eliminated. As E:I and Valsalva ratioshowed no changes between visits, it indicatesthat there is no change in parasympatheticreactivity in comparison with sympathetic whichis decreased. Although vagal parasympatheticpathways are predominant for HR andsympathetic pathways plays a major part in BP(12).

The measure of sympathetic function viasustained hand grip have shown significantlowering of diastolic BP response in visit II(Table 1).

However, in cold pressure test, thesympathetic reactivity marker have shown nosignificant change in BP, but reduction in HRresponse. These observations point towardsreduced sympathetic activity and responses aresimilar to 'Relaxation Response' (0). It isevident from present investigation that yogawhen practised together with meditationproduced maximum effects on sympatheticautonomic activities (0).

The ventilatory parameter such as FVC andFEV1 were not altered although earlier workershave shown significant improvement in thesefunctions (2, 5, 15). The PEFR did show a smallincrease in visit II (5.79 ± 1.20 Llmin,6.5 ± 1.65 Umin). Similar to the finding of otherworkers (4, 10). One possible explanation couldbe that the structural damage of lung in thesepatients due to long standing asthma did notallow functional ventilatory improvement. Onexamining the individual data all the patientsdid show an increase in PEFR, it could be dueto high intra-individual variations that theaverage value was not significant. Thus a largersample size will be helpful in confirming ourfindings. The breath holding time, peak inspi­ratory flow rate and chest expansion showedsignificant increase after yoga training. Yogapractice is non-vigorous, yet it helped to improvethe physical endurance of patients (16).

Abundant objective data now exist indicatingthat psychological factors can interact with theasthmatic diathesis to worsen or improve thecourse of the disease. The mechanisms of theseinteraction are not well understood. Thepsychosomatic imbalance in many patients withasthma play some role in modifying the airwayresistance (6) associated with emotionaldisturbances and accompanied by generalisedand localised muscle tension, including that ofthe voluntary respiratory musculature. Thisincreased muscle tension may be precipitatingconcomitant factors that perhaps aggravate theasthmatic syndrome. The relaxation of skeletalmuscle resulted in increased chest expansion,breath holding time and peak inspiratory flowrate, which lead to improvement and subjectivewell being in all the subjects. The above trainingof yoga is expected to give delayed effects ratherthan immediate effects on body functions as theyare supposed to work on nervous system andthe psychological aspect of the patients asreported by others (5). From our results, it isevident that yoga asanas and pranayamas havea vital role to play in the immediate management

324 Khanam et al Indian J Physiol Pharmacol 19%; 40(4)

of bronchial asthma. There might bebronchodilatation by correcting their abnormalbreathing patterns and reducing the muscle toneof inspiratory and expiratory muscles. Due toimproved breathing pattern respiratorybronchioles may be widened and perfusion of alarge number of alveoli can be carried outefficiently. Yoga alongwith Dhyana appears toresult in somatic musculature relaxation finallyresulting in reduction in airway resistance thusrelieving the patients of asthama by giving themsubjective well being. Further deep andcontrolled breathing desensitization of thesensory nerve endings may occur and this inturnmight have helped to reduce the allergiccondition to the environment.

The "Comprehensive yogic life style changeprogramme for patients of bronchial Asthma"have shown significant benefit even within a

very short period. We are hopeful about the longterm effectiveness of the programme incontrolling as well as curing the disease.

ACKNOWLEDGEMENTS

We thank Mr. Mohinder Singh and ShriRajind er Kumar for technical assistance, Dr.Dwevedi for statistical analysis, V. Ramesh forcompiling the data and Mrs. Renu Katyal fortyping. The authors are grateful to NavitaKaushal and Dr. B.H. Paudel for their help inlaboratory. Sincere thanks to patients and staffmembers of "Adhyatma Sadhna Kendra" forextending the cooperation for this study. Thanksare also due to WHO for providing financialsupport. Dr. Ayesha Akhtar Khanam was aWHO Fellow in the Department of PhysiologyAIIMS from Comilla Medical College, Comilla,Bangladesh.

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