|Year : 2014 | Volume
| Issue : 1 | Page : 48-51
An Indian study of computerized pulmonary function tests in sedentary versus physically active individuals
Amrith Pakkala1, CP Ganashree2, T Raghavendra3
1 Department of Physiology, PES Institute of Medical Sciences and Research, Kuppam, Andhra Pradesh, India
2 Department of Physiology, Basaveshwara Medical College, Chitradurga, Karnataka, India
3 Department of Anesthesiology, Basaveshwara Medical College, Chitradurga, Karnataka, India
|Date of Web Publication||29-Apr-2014|
40, SM Road, T.Dasarahalli, Bangalore 560 057
Background: Sedentary life-style is a modern day reality. Various physiological parameters are likely to be affected due to physical inactivity. Pulmonary function tests are likely to be compromised to varying degrees in these individuals. It is thus important to study the pattern of ventilatory studies in these subjects as compared with a physically active group. This study was conducted to compare these two groups of people in order to find out the importance of physical activity in the pulmonary function. Materials and Methods: A total of 30 male subjects between 45 and 60 years of age with a desk job and no regular exercise habit free from diabetes and hypertension, non-smokers were selected as study subjects and a similar number of male subjects otherwise comparable anthropometrically with a physically active life-style like a morning walk for at least 1 h as controls were randomly selected. Flow-volume loop, forced expiratory volume in the first second (FEV 1 ), forced vital capacity (FVC) and FEV 1 / FVC were recorded using the computerized spirometer. Results: FEV 1 , FVC and FEV 1 / FVC ratio measured in sedentary subjects were significantly reduced (P < 0.05) when compared with physically active individuals. Conclusion: The incidence of restrictive tendency is more in the sedentary as compared to controls. As changes in respiratory mechanics due to inactivity are almost completely reversible, early intervention in such patients will ensure lesser chance of complications later in life. With the advent of computerized spirometry analysis of flow-volume loops is indeed of great help to the early prediction of respiratory morbidity.
ملخص : خلفية البحث: إن نمط الحياة الهادئ الذى يتطلب كثرة الجلوس أصبح واقعا في الوقت المعاصر ومن الممكن أن تتأثر نواحي فيسيولوجية عديدة بسبب نقص النشاط البدني بما فى ذلك وظائف الرئة وبدرجات متفاوتة، وعليه من الضروري اجراء اختبارات الجهاز التنفسى في هؤلاء الأشخاص مقارنة بالأشخاص النشطاء بدنيا. وتهدف هذه الدراسة الى مقارنة هاتين المجموعتين للكشف عن أهمية النشاط البدني في وظائف الرئة.
المواد والطرق : تم اختيار 30 فردا ذكور أعمارهم بين 45 و 60 سنة يعملون فى وظائف مكتبية ولا يمارسون تمارين منتظمة ولا يعانون من مرض الضغط أو السكر ولا يدخنون. كما تم اختيار مجموعة مشابهة جسمياً من ذكور لديهم نمط حياة مختلف يمارسون نشاط بدني مثل المشي الصباحي لمدة ساعة على الأقل. تم قياس مؤشرات خصائص الجهاز التنفسى الاتية باستعمال جهار كشف خصائص الجهاز التنفسى المحوسب: Flow-volume loop, FEV1, FEV1/FVC ratio
النتائج: لقد لوحظ تدنى كل الؤشرات (FEV1, FEV1/FVC ratio) فى الافراد الذين لا يمارسون تمارين منتظمة بالمقارنة للافراد الذين يمارسون النشاط البدنى.
الخلاصة: بما ان التغييرات التى سجلت فى الافراد لا يمارسون تمارين منتظمة يمكن تلافيها ينبغى عليهم الانخراط فى تمارين رياضية لحمايتهم من العديد من الامراض التى قد تصيبهم فى المستقبل.
ولعل توفر أجهزة كشف خصائص الجهاز التنفسى المحوسب تساعد فى الكشف عن الافراد قليلى الحركة والمهددون بمضاعفات صحية فى المستقبل.
Keywords: Forced expiratory volume in the first second, forced expiratory volume in the first second/forced vital capacity, forced vital capacity, pulmonary function tests, respiratory morbidity, sedentary
|How to cite this article:|
Pakkala A, Ganashree C P, Raghavendra T. An Indian study of computerized pulmonary function tests in sedentary versus physically active individuals. Saudi J Sports Med 2014;14:48-51
|How to cite this URL:|
Pakkala A, Ganashree C P, Raghavendra T. An Indian study of computerized pulmonary function tests in sedentary versus physically active individuals. Saudi J Sports Med [serial online] 2014 [cited 2019 Jul 23];14:48-51. Available from: http://www.sjosm.org/text.asp?2014/14/1/48/131626
| Introduction|| |
Sedentary life-style is a modern day reality. Physical activity is important for various physiological functions. Various physiological parameters are likely to be affected due to physical inactivity. Pulmonary function tests (PFT) are likely to be compromised to varying degrees in these individuals. Adaptability of the healthy pulmonary system in delivering oxygen to meet the demands of various degrees of physical activity has not been adequately studied. This is important in view of the relatively larger reserve capacity of the respiratory system physiologically. This could delay the onset of clinically detectable symptoms of respiratory disease. Racial factors may also affect various ventilator parameters.
It is thus important to study the pattern of ventilatory studies in these subjects as compared with a physically active group. This study was conducted to compare these two groups of people in order to find out the importance of physical activity in pulmonary function.
| Materials and Methods|| |
A total of 30 male subjects between 45 and 60 years of age with a desk job and no regular exercise habit free from diabetes and hypertension, non-smokers were selected as study subjects and a similar number of male subjects otherwise comparable anthropometrically with a physically active life-style like a morning walk for at least 1 h as controls were randomly selected. Flow-volume loop, forced expiratory volume in the first second (FEV 1 ), forced vital capacity (FVC) and FEV 1 / FVC were recorded using the computerized spirometer.
- Following were the inclusion criteria:
- Age group 45-60 years,
- Blood pressure and blood glucose levels within normal range.
- The exclusion criteria were:
- Patients who were known cases of restrictive disease and/or taking treatment for the same
- Patients with chronic systemic illness such as diabetes, hypertension and coronary heart disease
- Those who were underweight (body mass index [BMI] <18 kg/m 2 ) or overweight (BMI >25 kg/m 2 ).
Their BMI was calculated using Quetelet's formula: 
The testing was carried out between 11 a.m. and 1 p.m. in a well-ventilated room. All the subjects were initially familiarized with the instrument used for testing - computerized spirometer. The procedure was explained clearly and sufficient demonstration given. Patient was comfortably seated and was asked to expire air as forcefully and as rapidly as possible, into the mouthpiece of the computerized spirometer, followed by a deep inspiration. Flow-volume loop, FEV 1, FVC, and FEV 1 / FVC were recorded. Each patient repeated the test thrice with a minimum gap of 3 min between any two efforts. The best of the three readings was considered for analysis.
Normal values of FVC and FEV 1 indicated normal PFT. Low values indicated the presence of disease (obstruction/restriction). When the measured value of FEV 1 / FVC was 90% or more of the predicted value, in the presence of low FEV 1 and/or low FVC, it indicated the presence of restriction. 
Thus, they were classified into two groups as follows:
- Control group: Normal weight patients (BMI 18-22.9 kg/m 2 )
- Study group: Obese patients (BMI >25 kg/m 2 ).
Unpaired Student t-test was used to determine significance, P < 0.05 is considered as significant.
| Results|| |
[Table 1] and [Table 2] show that the measured FEV 1 and FVC values in the study group were significantly lower when compared with the controls. Percentage of predicted value of FEV 1 and FVC showed a similar pattern. The measured value of FEV 1 / FVC per se and as a percentage of predicted value is significantly reduced in the sedentary as compared with controls shown in [Table 3].
|Table 1: Comparison of FEV1 values ‑ measured and as percentage of predicted|
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|Table 3: Comparison of FEV1/FVC values: Predicted, measured and as percentage of predicted ‑ among all three groups|
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| Discussion|| |
Sedentary life-style is associated with many co-morbid conditions such as diabetes, systemic arterial hypertension, dyslipidemia, coronary artery disease, sleep apnea, stroke, gallbladder disease and cancers of the breast and colon. 
Adipocyte is no longer considered as a depot for fat storage alone. Studies have proved that it to be an endocrine cell releasing many chemical mediators like leptin (an energy balance regulating hormone), cytokinins such as tumor necrosis factor-alpha and interleukin-6, complement factors such as factor-D, prothrombotic factors such as plasminogen activator inhibitor-1 and angiotensinogen, which is a component of the blood pressure regulating system. Such mediators are involved in lipid homeostasis, insulin sensitivity, blood pressure control, coagulation, vascular health and contribute to obesity-related pathologies. 
Indians are genetically susceptible to weight accumulation, especially around the waist. In males, abdominal obesity is more common. In such cases, excess adipose tissue is present in the anterior chest wall, anterior abdominal wall and around visceral organs. This results in the chest wall being less compliant and lowered respiratory muscle endurance causing airway resistance and work of breathing to increase correspondingly. , Diaphragmatic movement is hindered resulting in diminished basal lung expansion during inspiration and ventilation-perfusion abnormalities with arterial hypoxemia due to closure of peripheral lung units. 
Vital capacity (VC) and Total lung capacity (TLC) are decreased in obesity. It is not certain as to the factors causing this reduction, but there are few hypotheses - the increased abdominal volume may lead to decreased descent of the diaphragm during inspiration and consequently the thoracic expansion reduces. Abdominal elasticity increases along with an expansion of the ring of insertion of the diaphragm to the lower rib cage. , Intrathoracic fat is more in obese individuals, which compete with the lungs for space within the intrathoracic cavity. This mechanism would be analogous to that proposed for the restrictive pattern associated with chronic heart failure, which is much improved after cardiac transplantation. 
Reduced TLC was formerly thought to occur only in massively obese subjects, but has now been found in some subjects with less severe obesity also. Prospective studies have revealed that weight gain is associated with the loss of pulmonary function while weight loss is associated with the increase in VC. ,
A reduced FVC on spirometry in the absence of a reduced FEV 1 -to-FVC ratio suggests a restrictive ventilatory problem. Measuring the TLC and residual volume (RV) can confirm the restriction suggested by spirometry. Restrictive lung diseases exhibit reduced TLC percentage with relative preservation of the RV/TLC percentage in fibrosis, a reduced inspiratory capacity and expiratory reserve volume (ERV) in neuromuscular disease and severe reduction of the ERV in extreme obesity. 
Because this class of patients notoriously have a decreased functional residual capacity, they will desaturate quickly;  this will be seen prior to intubation (period of apnea) and after extubation, if oxygen isn't maintained.
While no single test can effectively predict intra-operative and post-operative morbidity and mortality from pulmonary complications, the FEV 1 obtained from good quality spirometry is a useful tool. When the FEV 1 is greater than 2 L or 50% of predicted value, major complications are rare. Operative risk is heavily dependent on the surgical site, with chest surgery having the highest risk for post-operative complications, followed by upper and lower abdominal sites. Among the most important modifiable patient-related factors associated with increased operative risk for pulmonary complications is obesity.  The deleterious effect of weight gain is, to a large extent, reversible. Improvement in pulmonary mechanics is the great advantage gained by obese patients upon losing weight. 
| Conclusion|| |
The incidence of restrictive tendency is more in the sedentary as compared with controls. As the changes in respiratory mechanics due to sedentariness are almost completely reversible, early intervention in such patients will ensure lesser chance of complications later in life. The risks in artificial ventilation are better assessed by analyzing the PFTs in totality. With the advent of computerized spirometry analysis of flow-volume loops is indeed of great help to the sedentary.
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[Table 1], [Table 2], [Table 3]