Study of Pulmonary Function by Spirometry in Asymptomatic Adult Smokers. Mitesh Thakkar 1, Jaishree Ghanekar 2,Prakash Kyada 3 & Asees Paul Singh 3

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1 International Journal of Current Medical And Applied Sciences, 2016, July, 11(2), ORIGINAL RESEARCH ARTICLE Study of Pulmonary Function by Spirometry in Asymptomatic Adult Smokers. Mitesh Thakkar 1, Jaishree Ghanekar 2,Prakash Kyada 3 & Asees Paul Singh 3 1 Associate Professor, 2 Professor and HOD, 3 Senior Resident, Department of Medicine, MGM s Medical College and Hospital, Kamothe, Navi Mumbai, [MS], India Abstract: Spirometry- an easy tool to analyse pulmonary functions in asymptomatic smokers. Smoking, especially cigarette smoking, is one of the many causes that lead to preventable deaths all over the world. In India smoking is a common habit. Cigarette smoking has extensive effects on respiratory function and is clearly implicated in the etiology of a number of respiratory diseases, particularly chronic bronchitis, emphysema, and bronchial carcinoma. Aims: To analyze the effect of smoking on spirometric values in asymptomatic adult smokers. Methods: This is a cohort study conducted at MGM hospital Kamothe. Thirty asymptomatic smokers and 30 control fulfilling inclusion criteria were selected for study. Both groups (study and control) were subjected to Spirometry. Results: All the subjects in our study were male, 56.6% had smoking history of more than 4 pack years with the mean duration of 5.37 pack years. 73.3% (22) smokers had FEV1 below 80% % ( 20) smokers had FVC below 80%. 60 %( 18) smokers had FEV1/FVC ratio < 75%.In our study we also came to the conclusion that among all smokers 70% smokers had obstructive changes, 20% showed restrictive changes and rest 10% smokers had absolute normal PFT. Conclusion: Spirometry should be performed in all smokers to rule out reduction in pulmonary function at an early stage and cessation of smoking should be encouraged by effective counseling and behavioral therapy. Key Words: Spirometry, cigarette smoking, obstructive lung disease. Introduction: Smoking, especially cigarette smoking, is one of the many causes that leads to preventable deaths all over the world [1]. Cigarettes kill an estimated 5 million people annually worldwide[2]. The World Health Organization reported that tobacco smoking killed 100 million people worldwide in the 20th century and warned that it could kill one billion people around the world in the 21st century [3]. By the early 2030, tobacco related death would increase to about 10 million a year [4]. Tobacco smoking rates have decreased in industrialized countries since 1975, but there has been a corresponding 50% increase in smoking rates in lowincome countries [5]. Cigarette smoking has extensive effects on respiratory function and is clearly implicated in the etiology of a number of respiratory diseases, particularly chronic bronchitis, emphysema, and bronchial carcinoma. Compared with non-smokers, death from lung cancer is 8-25 times more common among cigarette smokers [6]. Spirometry is a useful, easily available tool to evaluate functions of lung. It also facilitates early detection of abnormality in otherwise asymptomatic individuals, who had been smoking for 2 years or more. Address for correspondence: Dr. Asees Paul Singh Senior Resident, Department of Medicine, MGM s Medical College & Hospital, Kamothe, Navi Mumbai [MS], India. dr.aseespaul@gmail.com How to cite this article: Mitesh Thakkar, Jaishree Ghanekar,Prakash Kyada, Asees Paul Singh: Study of Pulmonary Function by Spirometry in Asymptomatic Adult Smokers. International Journal of current Medical and Applied sciences; 2016, 11(2), Access this Article Online Quick Response Code Website: Subject: Medical Sciences IJCMAAS,E-ISSN: ,P-ISSN: Page 76

2 Mitesh Thakkar, Jaishree Ghanekar,Prakash Kyada & Asees Paul Singh. Material and Methods: A cohort study was carried out at MGM Medical College and Hospital, Kamothe, Navi Mumbai, Maharashtra, India, over a period of two years after receiving approval from the Institutional Ethics Review Committee (IERC). Thirty control and 30 asymptomatic smokers fulfilling inclusion criteria were selected for study. Both groups (study and control) were subjected to spirometry. The Inclusion criteria included asymptomatic male population between years of age, who smokes more than 10 cigarettes /4 bidis per day continuously at least for more than 2 years. The exclusion criteria included known case of pulmonary condition such as Asthma, COPD etc. cardiac condition such as MI, CCF etc. Those who smoke less than 10 cigarettes per day, recent eye surgeries, uncooperative subjects. Fracture ribs or any thoracic cage deformities. Population whose age is more than 50 years and female population. Smokers were divided in 3 groups according to pack years as per WHO 1998 guidelines. Mild smokers: smoking pack year s 1-3. Moderate smokers: smoking pack years 4-6. Heavy smokers: smoking pack years Statistical analysis of our study was done using Pearson s chi-square test and appropriate Non Parametric statistical tests. Significance is assessed at 5 % level of significance. Student t-test (independent, two tailed) has been used to find out the significance of study parameters on a continuous scale between two groups. Chi square test is used to find out the significance of study parameters on a categorical scale between two groups. Results: In present study maximum number of study and control group were in age group of years (60%). The distribution of smokers as per pack year is shown in table 1. As observed in table there were 43.3% of persons with pack years of 7-10 while mild and moderate smokers were observed in 23.3% and 33.3% of persons respectively. Table 1: Distribution of Smokers as Per Pack Year Pack Year Number Of Cases Percentage 1-3 (mild) (moderate) (severe) Total In present study maximum number of study and control group were in age group of years (60%). The distribution of smokers as per pack year is shown in table 1. As observed in table there were 43.3% of persons with pack years of 7-10 while mild and moderate smokers were observed in 23.3% and 33.3% of persons respectively. Graph 1: Distribution of FEV1 among Smokers The distribution of FEV1 among smokers is shown in graph 1. In present study, 73.3 %( 22) smokers had FEV1 below 80% rest 26.7 %( 8) individual had normal FEV1 values, while only 23.3 %(7) of non-smokers had FEV1 < 80%. Table 2: Distribution of Data by FVC of Smokers: FVC Number of Percentage Cases TOTAL Logic 2016, IJCMAAS, E-ISSN: ,P-ISSN:

3 The distribution of data by FVC of smokers is shown in table 2. In present study, 66.7 %( 20) smokers had FVC below 80% rest 33.3 %( 10) individual had normal FVC values, where as 83.4 %(25) individuals among nonsmokers had FVC above 80% which is normal. Percentage Percentage of smokers Peak Expiratory Flow Rate Graph 2 : Distribution of Data by PEFR of Smokers PEFR values showed significant reduction (below 80%) in 70% of smokers, while values were above 80% in 73% of non smokers (graph 2). Graph 3: Distribution of Data by FEV1/FVC of Smoker Considering FEV1/FVC ratio of >75% as normal, our study found that 60 %( 18) smokers had FEV1/FVC ratio < 75% and 40 %( 12) smokers had FEV1/FVC ratio >75%, while all non smokers had FEV1/FVC value above 75%. (graph 3). Graph 4: Comparison of Actual Mean Value and Predicted Mean Value of FEV1/FVC. International Journal of Current Medical And Applied Sciences [IJCMAAS], Volume: 11, Issue: : 2. Page 78

4 Mitesh Thakkar, Jaishree Ghanekar,Prakash Kyada & Asees Paul Singh. It was observed in our study that actual mean value of FEV1/FVC was significantly lower than predicted value in smoker group and its difference increased with increase in degree of smoking (graph 4). Table 3: Comparison of Mean and Standard Deviation of Smokers and Nonsmokers. Smokers Non-Smokers Variables N MEAN S.D MEAN S.D Age Smoking Packs FEV FEF 25% FEF 50% FVC PEFR FEV1/FVC The comparison of mean and standard deviation of variables in smokers and non smoker is shown in table 3. As can be observed,although mean age of both age groups had no significant difference, all spirometric values were significantly reduced in smokers as compare to non-smokers. Table 4: Paired T-Test for Comparison of Variables between Smokers and Non-Smokers Variables T- value P value Result FEV1 Smokers-Non Smokers * Highly Significant FEV25% Smokers-Non Smokers * Highly Significant FEV50% Smokers-Non Smokers * Highly Significant FVC Smokers-Non Smokers * Highly Significant PEFR Smokers-Non Smokers * Highly Significant FEV1/FVC Smoker-Non Smokers * Highly Significant In table 4 we compared all the spirometric values of both smokers and non smokers which showed statistical significant reduction in values among smokers (p values <0.05). The T test shows statistical difference between groups. Discussion: Cigarette smoke contains many toxic compounds that are delivered into the bloodstream by absorption through the alveoli in the lung [6]. The inhaled irritants initiate an inflammatory cascade. This inflammatory process leads to tissue damage, enlarged mucous glands and a range of systemic effects. The chronic inflammation leads to various structural changes in the lungs and perpetuate airflow limitation [7,8]. Spirometry is one of the most commonly ordered lung function test. It gives three important measures FEV1, FVC, FEV1/FVC ratio. FVC is reduced in both obstructive and restrictive disorders, but alone does not differentiate between two. Obstructive disorders results in a marked decrease in both FVC and FEV1/FVC ratio, whereas restrictive disorders results in a loss of FVC without loss in FEV1/FVC [9,10]. Smoking leads to rapid decline in pulmonary function specially those indicating diameter of airway, such as forced expiratory flow in one second (FEV1). In people who have smoked only a few years, maximum expiratory flow volume curves demonstrate decrease in flow rates at small lung volumes (small airway obstruction) [11]. The studies conducted in past showed similar results [12,13,14,15,16]. All these studies showed that actual value of spirometric parameters are significantly lower in all smokers group than non-smokers (control), with obstructive pulmonary impairment being commonest. Conclusion: The tobacco smoking in any form has significantly deleterious effects on the pulmonary functions. Spirometry is one of the non-invasive types of pulmonary function test that provide measurable feedback about the function of the lungs. It is a cost effective and easily available investigation for screening and detection of early changes in asymptomatic smokers, since symptoms due to smoking may appear late. Thus we conclude that spirometry should be performed in all smokers to rule out reduction in lung volumes at an early stage and cessation of smoking should be encouraged by effective counseling and behavioral therapy. References: 1. Méndez D, et al. The potential impact of smoking control policies on future global smoking trends.tobacco Control. 2013;22: Bulletin of the WHO, International Journal of Public Health, June 2006, 2006 ; 84(6) : WHO Report: Tobacco Could Kill One Billion by 2100, Science Daily; Aug 2008; 24: Yach D. Partnering for better lung health: Improving tobacco and tuberculosis control. Int J Tuberc Lung Dis 2000; 4:

5 5. Yu JJ, Shopland DR. Cigarette smoking behaviour and consumption characteristics for the Asia-Pacific region. World Smoking Health 198.9; 14: Crofton and Douglas s Respiratory Diseases 1, 5th edition, Smoking, 10: Barnes PJ, et al. Immunology of asthma and chronic obstructive pulmonary disease. Nat RevImmunol 2008 ; 8: Danahay H, et al. Epithelial mucus-hypersecretion and respiratory disease. Curr Drug Targets Inflamm Allergy 2005;4: P. Meek, et al. ATS/ERS Standards for the Diagnosis and Management of Patients with COPD, Patient Section Am J Respir Crit Care Med, 2005;172, American Thoracic Society Patient Information series, Am J RespirCrit Care 2007; Med, 176, P5-P European Respiratory Society: Standardized lung function testing, Eur. Respir. J. 1993;6: Mishra R, et al. To study the correlation between ciliary function test and pulmonary Function test among adult male smokers and nonsmokers, November 2011;12, Boskabady M.H, et al. Pulmonary function tests and respiratory symptoms among smokers in the city of mashhad (north east of Iran) Rev Port Pneumol. 2011;17: Karia R, et al. Comparative study of spirometric parameters between active tobacco smokers and tobacco non-smokers, IOSR Journal of Pharmacy Mar.- Apr. 2012; 2 (2): Bano R, et al. Study of Pulmonary Function Tests among smokers and non-smokers in a rural area. Indian J PhysiolPharmacol Jan-Mar; 55(1): Geijer RM, et al. Prevalence of undetected persistent airflow obstruction in male smokers years old. FamPract. 2005; 22: List of Abbreviations: COPD-Chronic Obstructive Pulmonary Disease CCF- Congestive Cardiac Failure FEV1-Forced Expiratory Volume in 1 st second FVC- Forced Vital Capacity MI- Myocardial Infarction PFT- Pulmonary Function Test PEFR-Peak Expiratory Flow Rate WHO-World Health Organisation Conflict of interest: None declared No source of funding. International Journal of Current Medical And Applied Sciences [IJCMAAS], Volume: 11, Issue: 2. Page 80