The study of pulmonary functions tests and fat distribution in overweight and obese adult males.
Overweight and obesity represent a rapidly growing threat to the health of populations in an increasing number of countries. Indeed, they are now so common that they are replacing more traditional problems such as undernutrition and infectious diseases as the most significant causes of ill health. Obesity comorbidities include coronary heart disease, hypertension and stroke, certain types of cancer, non-insulin-dependent diabetes mellitus, gallbladder disease, dyslipidemia, osteoarthritis and gout, and pulmonary diseases including sleep apnea. 
Nowadays, the standards of living continue to rise, weight gain and obesity are a growing global threat to health. In 2016, >1.9 billion adults, 18 years and older, were overweight. Of these, over 650 million were obese, 39% of adults aged 18 years and over were overweight in 2016, and 13% were obese. 
Studies have shown that obesity, especially abdominal obesity negatively, affects pulmonary functions. Increasing body mass index (BMI) is typically associated with a reduction in forced expiratory volume in one second (FEV1), forced vital capacity (FVC), total lung capacity, functional residual capacity, and expiratory reserve volume. With severe obesity, diaphragmatic movements are restricted and thoracic compliance is reduced.  Reduction in the body weight by lifestyle modification and exercise can improve the pulmonary functions.
Aims and Objectives
The objectives of this study were as follows:
1. To compare the pulmonary function tests in non-obese, overweight, and obese individuals.
2. To find out the correlation of BMI with severity of pulmonary dysfunctions among obese individuals.
3. To create awareness in the society that reducing the body weight can improve the pulmonary functions and prevent the occurrence of other health consequences due to obesity.
MATERIALS AND METHODS
The present study was conducted in the Physiology Department, SBKS Medical College, Pipariya, Vadodara, during the period from December 2009 to September 2011. A total of 90 adult males, 30 obese, 30 overweight, and 30 non-obese, in the age group of 18-45 years, were selected for the study.
All the subjects have given written and informed consent for participating in the study. Ethical approval regarding the study was given by Sumandeep Vidyapeeth Ethical Committee, Pipariya, district Vadodara.
All the subjects were undergone detailed clinical history and systemic examination. The subjects having chronic lung diseases, cardiac disease, doing regular exercise or yoga, current or history of smoking, and seasonal allergic lung disease were excluded from our study. All the respiratory parameters were taken in sitting position.
The BMI was calculated by the standard formula of weight and height of all the subjects and accordingly considered as overweight (25 kg/[m.sup.2]) and obese (30 kg/[m.sup.2]). Waist circumference (WC) was measured using tailor's measuring tape and WC >90 cm was defined as abdominal obesity.  Similarly, hip circumference was measured and waist-hip ratio was calculated (>0.9 is called obese).
The respiratory parameters including FEV1%, FVC%, FEV1/FVC%, maximal voluntary ventilation (MVV), and peak expiratory flow rate (PEFR) were measured using SPIROLAB II (MIR) software. All the parameters were repeated thrice to get the best results. Statistical analysis of all the collected data was done using GraphPad Instat software and one-way ANOVA test, and Pearson correlation coefficient was applied.
The anthropometric variables observed from the study of pulmonary function tests in 30 overweight, 30 obese, and 30 non-obese adult males were shown in Table 1. In the study, weight, BMI, WC, and waist-hip ratio were found statistically significant in non-obese, overweight, and obese groups. The mean BMI of non-obese, overweight, and obese groups was 22.64 [+ or -] 1.79, 26.09 [+ or -] 2.12, and 29.84 [+ or -] 2.49, respectively. The mean WC in non-obese, overweight, and obese groups was 94 [+ or -] 1.35, 98 [+ or -] 3.76, and 104 [+ or -] 4.54, respectively. The mean waist-hip ratio in non-obese, overweight, and obese groups was 0.965 [+ or -] 0.13, 0.966 [+ or -] 0.18, and 0.969 [+ or -] 0.020, respectively.
Table 2 shows observed respiratory parameters in non-obese, overweight, and obese adult males between 18 and 45 years age group. In our study, respiratory parameters such as FVC%, MVV, and PEFR values were reduced significantly in overweight and obese groups. However, FEV1% and FEV1/FVC% ratio were increased significantly in overweight and obese groups.
Table 3 shows that in obese group showed significant negative correlation of BMI with FVC (r = -0.2563), FEV1 (r = -0.3659), and PEFR (r = -0.4526). However, FEV1/FVC% ratio showed positive correlation with BMI values in obese groups.
The present study was aimed to evaluate the lung functions in non-obese, overweight, and obese individuals. The results shown that there is reduction in FVC%, PEFR, and MVV values and FEV1% and FEV1/FVC% ratio are increased in overweight and obese individuals as compared to non-obese individuals who are consistent with restrictive lung disease. The reason for this may be due to restriction in diaphragmatic movements and reduction in thoracic compliance due to excessive abdominal fat deposition.
Devershetty et al.  concluded that there are no significant differences in FEV1, FVC, and FEF 25-75% between the obese and non-obese adult females. However, there was a significant difference in FVC/FEV1 ratio and PEFR between the two groups similar to our study.
Malini et al.  found that MVV is reduced significantly in obese adult females as compared to non-obese females which coincides with our study.
Mahajan et al.  concluded in adult males that the values of FEV1, FVC, and MVV were significantly reduced in obese males similar to our study, but FEV1/FVC ratio, PEFR, and FEF 25-75% show insignificant changes.
Collins et al.  found that comparing pulmonary function tests between patients with a waist-hip ratio (WHR) <0.950 (lower body fat distribution) and subjects with a WHR of 0.950 or greater (upper body fat distribution) revealed that FVC, [FEV.sub.1], and TLC were significantly lower in the patients with upper body fat distribution. Our study was limited to subjects with lower body fat distribution only.
The present study shows that increase in abdominal obesity may affect pulmonary functions. Decrease in WC by weight reduction through lifestyle modification and regular exercise may improve the respiratory functions. The present study was limited to small group of adult males with 18-45 years age group. However, large sample size including subjects of all age groups and both sexes is required to strengthen the study results.
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Divyesh S Vadasmiya, Hitesh V Patel
Department of Physiology, GMERS Medical College, Gandhinagar, Gujarat, India
Correspondence to: Divyesh S Vadasmiya, E-mail: firstname.lastname@example.org
Received: September 18, 2018, Accepted: November 03, 2018
Source of Support: Nil, Conflict of Interest: None declared.
Table 1: Anthropometric variables in comparison between non-obese, overweight, and obese group Parameters Non-obese Overweight Mean[+ or -]SD Mean[+ or -]SD Age (years) 30.26[+ or -]7.95 29.33[+ or -]6.56 Weight (kg) 64.30[+ or -]6.14 70.18[+ or -]5.85 Height (m) 1.68[+ or -]0.037 1.64[+ or -]0.027 BMI (kg/[m.sup.2]) 22.64[+ or -]1.79 26.09[+ or -]2.12 WC (cm) 94[+ or -]1.35 98[+ or -]3.76 WHR 0.965[+ or -]0.13 0.966[+ or -]0.18 Parameters Obese P value Mean[+ or -]SD Age (years) 31.88[+ or -]7.71 NS Weight (kg) 77.16[+ or -]6.53 <0.001 Height (m) 1.61[+ or -]0.039 NS BMI (kg/[m.sup.2]) 29.84[+ or -]2.49 <0.001 WC (cm) 104[+ or -]4.54 <0.001 WHR 0.969[+ or -]0.020 <0.001 BMI: Body mass index, WC: Waist circumference, WHR: Waist-hip ratio Table 2: Comparison of respiratory parameters in non-obese, overweight, and obese group Parameters Non-obese Overweight Obese Mean[+ or -]SD Mean[+ or -]SD Mean[+ or -]SD FEV1% 82.24[+ or -]3.66 84.56[+ or -]4.80 88.16[+ or -]5.37 FVC% 96.32[+ or -]2.86 80.34[+ or -]3.86 72.44[+ or -]4.35 FEV1/FVC% 85.36[+ or -]4.86 105.25[+ or -]6.54 122.7[+ or -]5.38 MVV L/min 131.4[+ or -]22.64 120.45[+ or -]2.87 112.7[+ or -]12.65 PEFR L/sec 9.66[+ or -]2.12 7.24[+ or -]3.56 4.55[+ or -]4.26 Parameters P value FEV1% <0.001 FVC% <0.001 FEV1/FVC% <0.001 MVV L/min <0.001 PEFR L/sec <0.001 FEV1%: Forced expiratory volume in one second, FVC: Forced vital capacity, MVV: Maximal voluntary ventilation, PEFR: Peak expiratory flow rate Table 3: Correlation coefficient of respiratory parameters with BMI in obese adult males Parameters FEV1% FVC% FEV1/FVC% PEFR BMI -0.2563 -0.3659 0.001569 -0.4526 P value 0.0765 0.5261 0.7545 0.0105 FEV1%: Forced expiratory volume in one second, FVC: Forced vital capacity, PEFR: Peak expiratory flow rate, BMI: Body mass index
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|Title Annotation:||RESEARCH ARTICLE|
|Author:||Vadasmiya, Divyesh S.; Patel, Hitesh V.|
|Publication:||National Journal of Physiology, Pharmacy and Pharmacology|
|Date:||Jan 1, 2019|
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