Effect of Yoga on Pulmonary Functional Measures Among Adult Asthmatics: A Randomized Controlled Trial

Introduction

Apart from the regular education, yoga seems to be a positive predictor of physical and mental health among patients with chronic illnesses. Research suggests that social support, education and yoga on control measures by the healthcare professionals is advantageous for promoting their quality of life. 

Gao et al (2011) investigated the prevalence of asthma in China’s Qinghai Province in 27,851 adults between 2006 and 2007. The prevalence of asthma in rural, urban, half-farming and half-herding areas, and in pastoral areas was 0.64%, 0.27%, 0.15% and 0.04% respectively. The highest incidence was reported in rural areas and lowest in the pastoral areas. The findings revealed that overall prevalence was 0.38%. The prevalence of asthma in higher altitudes was lower than that in the lower altitudes, and was lower in herdsmen as compared to other occupational populations.

Review of the Literature

Shruti Agnihotri, Surya Kant, Mishra, Prashant Mani Tripathi (2015) explored the possible benefits of yoga in asthma patients through the systematic analysis of six randomized controlled trials. The study findings revealed that yoga is one of the methods that can help to increase muscular efficiency and reduce perceived exertion and has profound effect on the autonomic nervous system, improve lung function and breath holding time. 

Karmur et al (2015) conducted the prospective study to find effects of 10 weeks of yoga practice on pulmonary function tests among 40 subjects aged between 20 to 65 years. The results revealed that respiratory rate decreased, while breath holding time and maximum ventilator volume increased in the subjects. The study concluded that yoga practice could be advocated to improve respiratory efficiency for healthy individuals as well as an alternative therapy or as an adjunct to conventional therapy in individuals with respiratory diseases.

Biju, Geetha, Sodhakumari (2012) investigated the physiological parameters, pulmonary function and severity among 70 asthma patients who were on beta 2 agonist inhalers and yoga therapy for three months. The findings revealed that yogic practices resulted in significant improvement in pulmonary function, decrease in respiratory rate, decrease in pulse rate and body weight which was not statistically significant. Decrease in frequency of asthma attacks and decrease in frequency of use of inhalers was also reported. All the pulmonary functions improved in the yoga group, except for forced expiratory volume in the first second (FEV1 ). All the parameters showed statistically significant difference between the case and control groups at the onset of study. Peak expiratory flow rate (PEFR) showed significant difference between the two groups.

Singh et al (2012) conducted a randomized controlled study including 60 patients that revealed that the lung function improved significantly in the patients of the yoga group after two months of yoga practice from the baseline. Hence, the study concluded that pranayama and yoga breathing could be used to increase respiratory stamina, relax the chest muscles, expand the lungs, raise energy levels, and calm the body.

Sodhi C, Singh S, Dandona PK (2009) studied the effect of yoga training on pulmonary functions in patients with bronchial asthma. One hundred twenty patients with asthma were randomized into two groups i.e Group A (yoga training group) and Group B (control group). Each group included sixty patients. Pulmonary function tests were performed on all the patients at baseline, after four weeks and then after eight weeks. Majority of the subjects in the two groups had mild disease (34 patients in Group A and 32 in Group B). Group A subjects showed a statistically significant increasing trend (p < 0.01) in % predicting peak expiratory flow rate (PEFR), forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), forced mid expiratory flow in 0.25- 0.75 seconds (FEF25-75) and FEV1/FVC% ratio at four weeks and eight weeks as compared to Group B. Thus, it was concluded that yoga breathing exercises used adjunctively with standard pharmacological treatment significantly improved pulmonary function in patients with bronchial asthma.

Sabina et al (2005) conducted a study among 62 patients with asthma and found that pranayama reduces stress, a common asthma trigger. It was observed that breathing exercises emphasized in yoga have the potential to improve lung function and quality of life.

Karmur et al (2015) conducted the prospective study to find effects of 10 weeks yoga practice on pulmonary function tests among 40 subjects aged between 20 to 65 years. The results revealed that respiratory rate decreased, while breath holding time and maximum ventilator volume increased in the subjects. The study concluded that yoga practice could be advocated to improve respiratory efficiency for healthy individuals as well as an alternative therapy or as adjunct to conventional therapy in respiratory diseases.

Biju, Geetha, Sodhakumari (2012) investigated the physiological parameters and pulmonary functions and severity among 70 asthma patients who were on beta 2 agonist inhalers and yoga therapy for three months. The findings revealed that yogic practices resulted in significant improvement in pulmonary functions; decrease in respiratory rate; decrease in pulse rate and body weight which was not statistically significant; decrease in frequency of asthma attacks and decrease in frequency of use of inhalers. All the pulmonary functions were improved in the yoga group, except for FEV1 . All the parameters showed statistically significant difference between the case and control groups at the onset of study. PEFR showed significant difference between the two groups.

Methodology

The randomized controlled trial was used as the research design and patients with bronchial asthma who met the Global Initiatives of Asthma (GINA) criteria and those in the partially controlled and uncontrolled levels of asthma were selected as the sample. The investigator demonstrated the intervention, yoga namely Nadisudhi paranayama, Bhastrika pranayama, Gomukhasana, Ardha chandrasana, Tadasana, Bhujangasana, Nindra pada asana and Savasana to the patients who attended Chest and T.B OPD, Sri Ramachandra Hospital for the period of six months using block randomization. PFT was done to determine the lung status after intervention. The patients were asked to maintain symptom dairy and the yoga performance dairy at home to check the compliance status. 

Data Collection

The sample size of 125 in each arm was obtained by calculation based on the power analysis. The investigator allocated the samples to each group based on the random allocation software version 2. The pre-assessment on asthma control questionnaire was carried out. Following this, on day one, five yoga techniques were taught and patients were asked to return demonstrate them. On day three, another three techniques were taught and the patients were asked to perform them at home and maintain the diary of practice. The performance of the practices were assessed on day 30, 60 and 90. Nonparametric test using R software of 3.2.3 version was used to do the data analysis. Descriptive (Mean and SD) and Inferential statistics (Mann Whitney and Wilcoxon signed rank test) were used. 

Data Analysis

Table 1 describes the frequency and percentage distribution of demographic variables of asthma patients. Majority of them, 28 (22.4%) in study group and 33 (26.4%) in the control group were in the age group of 31-40 years. With respect to the gender, 70 (56%) in study group and 69 (55.2%) in the control group were males.

About education, 65 (52 %) and 57 (45.6%) had primary level of education in the study and control groups respectively. Ninety-eight (78.4 %) in the study group and 96 (76.4%) in the control group were married.

Regarding occupation, 64 (50.4%) in the study group and 65 (52%) in the control group were in the category of employed, 58 (46.4%) and 53 (42.4%) had an income of below Rs.3001-6000 in the study group and control groups respectively. Seventy-nine (63.2%) in the study group and 76 (60.8%) in the control group were from nuclear families. Most of the subjects, 67 (53.6%) in the study group and 64 (51.2) hailed from urban areas. Family history of asthma was reported by 79 (63.2%) and 83 (66.4%) in the study and control groups respectively. Homogeneity was maintained in the distribution of socio demographic variables in both the groups.

Table 2 depicts that on the posttest I, 80 % (96) of the patients with asthma and in the posttest II, 82% (98) of the patients in the study group had satisfactory practice.

Results from table 3 showed that Forced vital capacity (FVC- liter), Forced expiratory volume in the first second (FEV₁ ), ratio of FEV₁ / FVC and Peak expiratory flow rate (PEF) of both the study and control groups. It can be observed from the table that all the data of control group such as FVC, FEV₁ , FVC/FEV₁ , PEFR did not change (p<0.05). The study group showed a statistically significant increasing trend in FVC (Liter) over time, from baseline to at 6 months, while the control group subjects showed variable change in FVC (Liter) with an overall decrease which was not statistically significant. 

Discussion

Asthma is associated with increase in airway resistance, decrease in forced respiration volumes and flow rates, hyperinflation of the lungs and increased work of breathing (Peter J. Barnes, 2008). Apart from the pharmacological modes of asthma management, complementary and alternative medicine (CAM) that includes the ancient practice of yoga is emerging as an adjunct therapy for asthma (Wong ML and Hong CY et al, 2009).

The present study revealed that there was an improvement in the levels of asthma control. During Pretest, 27 (22%) in the study group and 21 (17%) in control group were in partially controlled level of asthma control; 98 (78%) in the study group and 104 (83%) in the control group were in uncontrolled level of asthma control. In the Posttest III, 30 (25%) in the study group were in the controlled level of asthma control, 54 (45%) in the study group, 58 (47%) in the control group were in partially controlled level of asthma control and 36 (30%) in the study group, 65 (53%) in the control group were in uncontrolled level of asthma control. These findings indicate that the integrated approach had improved their level of asthma control, which was statistically proven.

Effective asthma management in terms of asthma selfmanagement education is of utmost importance in achieving control which includes inhaler technique assessment, written asthma plans, self-monitoring of symptoms or airflow, and regular medical review (GINA, 2011; Guarnaccia 2007; O’Byrne 2006). Hence, the investigator educated the patients on disease condition and instructed to self-monitor using peak flow meter at home. 

Pulmonary functional measures

Results of table 3 showed that forced vital capacity (FVC- liter) increased from 2.58 during pretest to 3.42 in the posttest III in the study group, whereas in the control group, it remained the same from 2.48 to 2.58 in the posttest III. Forced expiratory volume in the first second (FEV₁ ) increased from 2.02 in pretest to 2.22 in the posttest III in the study group, whereas in the control group, it remained the same from 2.01 in pretest to 2.13 in the posttest III. The ratio of FEV₁ / FVC had improved from 72.34 in pretest to 78.36 in posttest III in the study group, but in the control group, it was 72.04 to 70.83 in the posttest III. Peak expiratory flow rate (PEF) had improvement from 5.94 in the pretest to 6.16 in the posttest III in study group, whereas in the control group it remained the same from 5.12 to 5.04 in the posttest III. It can be observed from the table that all data of the control group such as FVC, FEV₁ , FVC/FEV₁ , PEFR did not change. After six months of yoga training, Posttest III, in comparison with control group, all indicators of the study group were significantly improved with the level of p<0.05 to 0.001 respectively.

The study group showed a statistically significant increasing trend in FVC (Liter) over time, from baseline to at 6 months, while the control group subjects showed variable change in FVC (Liter) with an overall decrease, which was statistically not significant. The findings of the present study are supported by Nathan and colleagues (2006), who compared the maximal PEF measurement at first hospital visit with the six-month follow-up measurement. Another study findings by Candy sodhi (2008) determined the role of yoga breathing exercises as an adjunct treatment for bronchial asthma. One hundred twenty patients with asthma were randomized into two groups i.e Group A (yoga training group) and Group B (control group). Each group included sixty patients. Pulmonary function tests were performed in all the patients at baseline, after four weeks and after eight weeks. Majority of the subjects in the two groups had mild disease (34 patients in Group A and 32 in Group B). Group A subjects showed a statistically significant increasing trend (P<0.01) in % predicted peak expiratory flow rate (PEFR), forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), forced mid expiratory flow in 0.25–0.75 seconds (FEF25-75) and FEV₁/FVC% ratio at four weeks and eight weeks as compared to Group B. Thus, yoga breathing exercises used adjunctively with standard pharmacological treatment significantly improved pulmonary functions in patients with bronchial asthma. These findings are substantiated by Agarwal S (2013) who assessed the effects of pranayama yoga practice on lung function in patients with bronchial diseases. After three months of yoga practice, breath indicators such as FVC, FEV₁, FEV₁/FVC, PEFR of intervention group significantly improved with p value < .01 to .001 in comparison with the previous three months of the control group. Practicing pranayama yoga was beneficial to patients with bronchial asthma.

Ramprabhu et al (2009) demonstrated the significant changes in FEV₁ and PEFR in the yoga group after eight weeks of study period from the baseline. This study supported the efficacy of yoga in the management of bronchial asthma.

Conclusion

Yoga is one of the complementary medicine which has a great impact in decreasing the asthma symptoms and reduces medication use and leads to improvement in the quality of life. The current study is supported by the findings of previously conducted experiments that yoga may be an effective tool in the management of asthma and can be practiced as an adjuvant therapy to standard medical therapy for better outcomes.

The findings of the present study were consistent with the literature and supported by the studies conducted around the world. Based on the method of selection, sample size and support from many studies conducted throughout the world, the findings could be generalized to the patients with bronchial asthma.