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 Table of Contents  
Year : 2020  |  Volume : 4  |  Issue : 3  |  Page : 209-213

Is early diagnosis of chronic obstructive airway disease using spirometry in asymptomatic smokers an effect tool for smoking cessation in the Indian population? A study from Central India

1 Anaesthesiologist, Command Hospital, Bengaluru, Karnataka, India
2 Associate Proffessor Medicine and Oncologist, Command Hospital, Bengaluru, Karnataka, India
3 Professor in Biochemistry, Dr VRK Medical College, Hyderabad, Telangana, India
4 Community Medical Specialist, Pune, Maharashtra, India
5 Physician, Airforce Hospital, Coimbatore, Tamil Nadu, India

Date of Submission24-Apr-2020
Date of Acceptance02-May-2020
Date of Web Publication12-Sep-2020

Correspondence Address:
Dr. Rahul Sud
Department of Medicine and Oncology, RTC, Command Hospital Airforce, Bengaluru - 560 007, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/bbrj.bbrj_62_20

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Background: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality in smokers worldwide. A chronic smoker remains asymptomatic for a long time with underlying deteriorating lung function which manifests in later life as COPD. Although there is no screening for the disease, a spirometric evaluation of chronic smokers to detect the early asymptomatic disease and counseling for smoking cessation may slow down further progression of disease. India has a large population of smokers including a sizable number in the defense forces who need to be fighting fit at all times. The data with this regard from Indian scenario are scanty. The present study was carried out with an aim to detect early COPD in chronic smokers and further counsel these individuals to abstain from smoking. This cross-sectional study was done in Air Force Hospital Gorakhpur, India, from August 2014, and 2974 individuals were evaluated and followed. Methods: The individuals were standardized on the basis of personal history including age, number of cigarettes smoking per day, and duration of smoking. The diagnosis of COPD in such individuals was based on the spirometric evaluation which included forced expiratory volume in one sec (FEV1), forced vital capacity (FVC), and FEV1/FVC which were measured at rest and postbronchodilators. The individuals were diagnosed as COPD as per GOLD criteria (Gr C) and nonCOPD (Gr N). Both groups were followed up for 1 year with motivational counseling to stop smoking and spirometry repeated in those who quit smoking completely or partially. Results: COPD was observed in 187 (18.7%) asymptomatic smokers and among these 1.8% having severe COPD. 26% of these patients completely abstained from smoking after diagnosis and counseling and these patients had the least drop in FEV1 after 1 year as compared to partial and nonquitters of smoking. Conclusion: Spirometer for early diagnosis of COPD in asymptomatic nonsmoker is an effective tool. The detection of COPD early paves a way for effective counseling in pursuit for smoking cessation in young adults.

Keywords: Chronic obstructive pulmonary disease, counseling, pack years, spirometer

How to cite this article:
Patra A K, Sud R, Patra I, Patel B B, Boro D K. Is early diagnosis of chronic obstructive airway disease using spirometry in asymptomatic smokers an effect tool for smoking cessation in the Indian population? A study from Central India. Biomed Biotechnol Res J 2020;4:209-13

How to cite this URL:
Patra A K, Sud R, Patra I, Patel B B, Boro D K. Is early diagnosis of chronic obstructive airway disease using spirometry in asymptomatic smokers an effect tool for smoking cessation in the Indian population? A study from Central India. Biomed Biotechnol Res J [serial online] 2020 [cited 2022 Jan 24];4:209-13. Available from: https://www.bmbtrj.org/text.asp?2020/4/3/209/294860

  Introduction Top

Chronic obstructive pulmonary disease (COPD) is a life-threatening lung disease characterized by an irreversible airflow limitation and destruction of the lung parenchyma. The primary cause of COPD is cigarette smoking though it is multifactorial.[1] Intermittent exacerbations and comorbidities contribute to the overall severity and mortality of the disease.

COPD is often underdiagnosed. Spirometer is the most common tool used for its diagnosis. It is a safe, reliable, noninvasive, simple, and nonexpensive method for detecting airflow limitations even in the early stages.

Cigarette smoking is the most common risk for the development of COPD and 20%–30% of all smokers may develop this condition. Early COPD may be asymptomatic; however, it may progress silently as smoking continues. Symptoms such as dyspnea, excessive sputum production, and chronic cough may occur late in the disease. Once established, the disease progresses to become chronic and irreversible.[2] Persistent smokers may consider themselves symptom-free and healthy, though they may have moderate or even severe COPD. In addition, young adult smokers may not complain of symptoms related to smoking. The middle-aged smokers in the armed forces are liable to develop COPD later in life during their active service or once they retire due to their smoking habits. No data or study on the occurrence of COPD in such vulnerable population is available till date. This study was carried out with the aim to evaluate the prevalence of early COPD in a secondary care hospital by the detection of airflow limitation by spirometry in asymptomatic smokers among defense personnel and dependents between the age group of 40 and 55 years. The objective of the study was to assess the occurrence of early COPD in asymptomatic smokers between the age group of 40 and 55 years with at least 10 pack years of smoking.

  Methods Top

Hospital Ethical committee consists of Head of the hospital, Independent councilor and an administrative office. The ethical clearance was taken prior to study and as there was no intervention or invasive procedure and as per international guidelines. A cross-sectional observational study was started in Air Force Hospital Gorakhpur, which is a secondary care hospital catering to a large population of serving personnel's and their dependents in central and eastern India in August 2014 after obtaining local hospital ethical committee clearance. Defense personnel and their dependents visiting outpatient department services of hospital as patients or as attendants to patients were considered as the subjects to the study. All such subjects who report within the study period of 2 years were assessed. We included only asymptomatic subjects of 40–55 years age group with at least 10 pack-year smoking. Subjects with chronic lung disease, bronchial asthma, pneumonia, bronchiectasis, malignancy, or viral infection during last 2 months were excluded from the study; subjects using tobacco in any form other than cigarette smoking were also not considered. During the study, individuals who had a positive reversibility test after spirometry or showed poor compliance were excluded. Written informed consent was obtained from each subject ensuring their willingness to undergo the study.

All the subjects provided a standardized personal history including age, number of cigarettes smoking per day, and duration of smoking. Height and weight of every individual was measured and body mass index (BMI) was derived. Cigarette smoking habits were recorded as pack-years. The number of cigarette pack-years was calculated as the product of the period of tobacco use (in years) and the average number of pack of cigarettes (20 cigarettes were considered equivalent to one pack) smoked per day. The diagnosis of chronic obstructive airway disease in such individuals was based on the spirometric evaluation. Spirometric parameters such as forced expiratory volume in one sec (FEV1), forced vital capacity (FVC), and FEV1/FVC were measured at rest using respirometer incentive breathing exerciser, Mr. Romsons Medicons, E-20. All the tests were performed as per the standard protocol.[3] The procedure was explained and demonstrated to every individual. He was made to sit in correct posture with head slightly elevated. A nose clip was attached and mouthpiece of the spirometer was placed in position. Instruction was given to make tight seal of lips around the mouth-piece. The individual was then allowed to inhale completely and rapidly with a pause of <1 sec at total lung capacity; this was followed by maximal exhalation until no more air can be expelled while still maintaining the upright posture. Such maneuver was repeated thrice to obtain the best record of the test. After the base line recording, reversibility test was performed. Salbutamol Metered dose Inhaler (MDI) without a spacer was used to administer the only bronchodilator for the test. After a gentle and complete expiration, two puffs of salbutamol (100 mcg) were administered and the individual was instructed to hold breath for 5–10 s before exhalation. Such procedure was performed four times at 30 s interval to administer a total of 400 mcg Salbutamol. The postbronchodilator spirometry recordings were obtained after 10 min but within 15 min in a similar fashion. Bronchodilator response was assessed by comparing the pre-and postbronchodilator FEV1 (△FEV1). The FEV1 increase by 12% from the baseline value was accepted as positive bronchodilator response. MDI salbutamol 400 mcg was the only bronchodilator considered for the study. Individuals with positive bronchodilator reversibility were regarded as bronchial asthma patients and were excluded from the study.

The postbronchodilator values of FEV1 and FVC of the remaining individuals were assessed to diagnose COPD as per the GOLD criteria. Individuals with FEV1/FVC <70% after bronchodilator were considered of having COPD (Gr C) and individuals with FEV1/FVC >70% were considered nonCOPD (Gr N).

An individualized smoking counseling by the motivational interviewing technique to quit smoking and education regarding the association of COPD and smoking was given to all personnel in the study. Follow-up was done after 1 year of initial assessment. At the follow-up visit, the smoking status was assessed and individuals were classified as completely reformed, partially reformed, or unreformed smoker on the basis of smoking habit. Statement of the individual regarding his smoking habit was considered final for this study. The completely reformed group included the subjects who stopped smoking and maintain a constant abstinence throughout the study period. The unreformed group included patients who had not changed his smoking habits. The rest who had curtailed but could not stop smoking completely were included in the partially reformed group. Subjects who did not report follow-up visits were marked as “loss to follow-up.” Similar spirometric analysis was repeated during this visit and any change in the pulmonary function was assessed by spirometric FEV1 values. Repeat counseling was done for partially reformed and unreformed smokers to quit smoking.

Statistical method

Statistical analysis was done through SPSS (Statistical Package for the Social Sciences for Windows, SPSS, Inc., Chicago, IL, USA) 20.0. Results were expressed as mean ± standard deviation (SD); P < 0.05 was accepted as significant for analysis. Statistical tests such as mean, SD, Independent t-tests were used as per the requirement of the study design.

  Results Top

We evaluated 2974 subjects who satisfied the inclusion criteria; 790 subjects were excluded from the study as they have previously diagnosed lung diseases; 1105 subjects have habits of other forms of tobacco use and 54 patients were excluded as they were found to have a positive bronchodilator-reversibility test. Another 25 patients were excluded as they could not perform the spirometry properly and showed poor compliance. The general characteristics of the individuals accepted for the study is summarized in [Table 1].
Table 1: General characteristics of study population

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We found COPD in 187 (18.7%) asymptomatic smokers, among which stage I, stage II, stage III, and stage IV disease were found in 72, 69, 28, and 18 individuals, respectively [Figure 1]. This group had a statistically significant difference (P < 0.05) to the group of individuals not having the disease with respect to age, weight, BMI, duration of smoking, FEV1, FVC, and FEV1/FVC [Table 2].
Figure 1: Frequency of chronic obstructive pulmonary disease patients

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Table 2: Comparison of variables between Group C and Group N

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After smoking cessation counseling, 26% of individuals were categorized as complete reformed whereas 16% remained unreformed. Almost 52% of people curtailed their smoking habit, but could not stop smoking completely and 6% people did not report the follow-up visit [Figure 2].
Figure 2: Comparison of forced expiratory volume in one sec before and after counseling

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The complete reformed, partial reformed, and unreformed cases had a decline in FEV1 values of 15 ml, 50 ml, and 55 ml, respectively.

  Discussion Top

COPD is a disease of airflow limitations due to an abnormal inflammatory response in the lungs to noxious particles. It is a progressive disease and once the disease process starts it is not fully reversible. The prevalence of the disease is increasing in both the sexes worldwide and it is presumed to be the third leading cause of death.[4] Morbidity due to COPD causes a significant cost to health delivery system. The dependent population of our hospital is mostly armed force personnel and their families. Any occurrence of such chronic disease definitely puts a serious social and economic impact on the country. Thus, a study was planned in this zone of the country with the aim to bring out sensitization against smoking.

The prevalence of COPD in general population is 7.6% as per various studies. The majority of studies included subjects of age group 40–64 years. The prevalence was more in age group >65 and less in age group <40 years. The prevalence varies with different studies due to different criteria used to define the disease. Also, it was found to vary with geographic location; the South-East Asia has the highest prevalence rate (12.5%). The concurrent incidence of tuberculosis in this part of the world has been attributed to this high rate.[5] Smoking independently affects airflow limitation and 20% of all smokers are known to develop clinically significant COPD. This was correlating the prevalence rate, i.e., 18.7% in our study population. But, we screened the asymptomatic smokers of 40–55 years age group only. Though most of them are in Stage I and II, 2.8% were found to have Stage III (FEV1 30%–50%) and 1.8% were having Stage IV (FEV1 <30%) disease [Figure 2].

There are various methods described in literature to diagnose COPD in its early stages. Most of them are in the form of questionnaires. But, none of the questionnaire is validated. Also, to diagnose COPD, the ideal method should correlate airflow limitation objectively. The internationally used GOLD classification for the definition of COPD states that the value of postbronchodilator FEV1/FVC should be <70%. FEV1/FVC fixed ratio <70% is 97.9% sensitive, 91.2% specific with 72% positive predictive value, and 99.2% negative predictive value in diagnosing COPD and thus most widely used method.[5] Also, it can be easily used, safe, and noninvasive. We used FEV1/FVC <70% to diagnose COPD and postbronchodilator FEV1 values to know the severity of airflow limitation in our study.

Cigarette smoking is the main risk factor of COPD. Cigarette smoke contains over 4000 chemical compounds, and large amounts of those are highly reactive free radicals and oxidants. It has been estimated that COPD can develop in an individual with an over 20 pack-year smoking history; however, early obstruction may even be seen in 10 pack years.[1] Thus, we considered 10 pack-year smoking as the inclusion criteria for this study. The findings of this study also corroborated the findings of other literature as it revealed the Gr C has an average smoking of 12 pack-years. We also found a statistically significant difference between the Gr C and Gr N with respect to duration of smoking though the groups did not differ in number of cigarettes smoked per day or number of pack-years [Table 2].

Age of the individual is another significant factor affecting the occurrence of COPD. After 25 years, there is a natural decline in FEV1 values by 20–40 ml every years which may be aggravated in smoking.[4] We found a statistically significant difference (P < 0.05) in age among the groups though the values were not clinically significant. In the recent studies, there is an association observed between obesity (BMI > 30Kg/m2) and COPD; this association is attributed to the altered metabolic functions, immunomodulation, oxidative stress, and insulin resistance in obese patients and increased use of steroids in COPD patients causing weight gain. In our study, we found a statistically significant difference in the groups when weight and BMI were compared [Table 2].

Once the disease starts, the airflow limitation gradually decreases the rate of which depends on the exposure of the causative agent. So, patients may be asymptomatic in initial stages but gradually may develop clinical and spirometric findings of airflow limitation. In this study, the asymptomatic smokers who have already developed COPD had a significant low value of FEV1, FVC, and FEV1/FVC reflecting the compromised pulmonary function in this group.

Males are affected twice more commonly than females though both are equally susceptible. But, with increase in smoking in women and exposure of nonsmoking women to biomass combustible products, the difference is narrowing.[5] In our study, all the patients were male as the prevalence of female smoker in this society is probably very low and thus they did not satisfy the inclusion criteria for the study.

Smoking cessation is the most recommended and the only measure to arrest the progression of the disease.[6] In this study, we carried out only a single smoking cessation counseling session for these asymptomatic smokers and found 26% complete reformed cases. The percentage of sustained quitters was better in studies where intensive smoking cessation programs were conducted with intermittent meetings with the counselor to reinforce the behavioral change.[7] Also, when patients were followed after 1 year of smoking cessation, it was found that though no impact was seen on change of FEV1, it certainly altered the airway inflammatory process in asymptomatic smokers.[8] So, the early detection of new COPD cases in the reversible state and the motivation of the patient to give up smoking are of major importance in the prevention of COPD progression to greater severity. We encountered that 6% of the patients were lost to follow-up [Figure 2]. These may be due to the denial[9] to accept regarding the disease. The authors feel intermittent counseling could have decreased the percentage of partial or unreformed cases as well as the cases lost to follow-up.

Long-term impact of smoking cessation has been examined in many studies. Though there is age-related FEV1 decline by 20 ml/year, in smokers, it may be 50–60 ml/year. In sustained quitters for 11 years, it was found to be only 35 ml/year.[7] In our study, after 1 year, the complete reformed cases were found to have a FEV1 lessened by only 15 ml, but partial reformed and unreformed cases were found to have 50 ml and 55 ml less FEV1, respectively, than their baseline values [Figure 3]. The study had few limitations as only males were included in the study as smoking in females is rarely encountered in this population; also, the age group considered was very narrow making the comparable groups almost similar clinically in many factors. The authors also feel there should be some objective parameters to judge smoking cessation which was not considered. However, the study recommends smoking cessation programs should be carried out frequently including motivational lectures and videos showing effects of smoking and benefits of abstinence. Also, if spirometry can be included in the battery of tests during routine annual medical examination for serving armed force personnel with smoking history of more than 10 pack-years, early detection may check the disease progression in these individuals.
Figure 3: Smoking status at followup

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  Conclusion Top

COPD is a disease, once established is irreversible and progressive. Thus, detection of the disease in its early stage before developing symptoms is crucial in preventing the progress of the disease. Moreover, if an individual is aware of the imminent threat of COPD, he is more likely to be encouraged to quit smoking. We found that 18.7% population smoking already developed COPD at presentation and were totally unaware as they were asymptomatic; also, 1.8% had severe disease. Many of them agreed to give up smoking to prevent further worsening of lung function after counseling complete abstinence of smoking was followed only by 26% of patients after counseling and all of these patients were well educated and complied with the instruction given. They were found to have the least decrease in FEV1 in the follow-up visit. Thus detection of early airway limitation may offer an advantage in imposing disease control measures. The patients from the rural areas of India who had not received any or incomplete formal education showed poor compliance in abstaining from smoking. All the serving soldiers who were detected to have early COPD gave up smoking, while the rest were educated to quit also. Similar pattern of detection needs to be implemented at other military center and should recommend at other hospitals for early detection of COPD, thereby promoting smoking cessation.

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Conflicts of interest

There are no conflicts of interest.

  References Top

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Bednarek M, Maciejewski J, Wozniak M, Kuca P, Zielinski J. Prevalence, severity and underdiagnosis of COPD in the primary care setting. Thorax 2008;63:402-7.  Back to cited text no. 2
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Willemse BW, Postma DS, Timens W, ten Hacken NH. The impact of smoking cessation on respiratory symptoms, lung function, airway hyperresponsiveness and inflammation. Eur Respir J 2004;23:464-76.  Back to cited text no. 6
Scanlon PD, Connett JE, Waller LA, Altose MD, Bailey WC, Sonia Buist A, et al. Smoking cessation and lung function in mild-to-moderate chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2000;161:381-90.  Back to cited text no. 7
Willemse BW, ten Hacken NH, Rutgers B, Lesman-Leegte IG, Postma DS, Timens W. Effect of 1-year smoking cessation on airway inflammation in COPD and asymptomatic smokers. Eur Respir J 2005;26:835-45.  Back to cited text no. 8
Pinnock H, Sohanpal R. Chronic obstructive pulmonary disease: Chronic Obstr Pulm Dis (Miami2016;3:605-9.  Back to cited text no. 9


  [Figure 1], [Figure 2], [Figure 3]

  [Table 1], [Table 2]


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