Journal of Clinical and Diagnostic Research. 2018 Aug, Vol-12(8): CC24-CC27 24 24 DOI: 10.7860/JCDR/2018/36228.12002 Original Article Physiology Section Effect of Obesity on Pulmonary Functions among the Adolescent Students of a Private University in Malaysia INTRODUCTION The lifestyle of the Malaysian students has changed in the past decades. Nowadays, many of them have adopted unhealthy habits, like lack of exercise, intake of fast food, which may impair their health [1]. Prevalence of obesity and overweight is increasing in adults and children in both developed and developing countries [2,3]. Obesity is a risk factor for many conditions including respiratory disorders such as asthma, increased airway resistance and atopy [4,5]. Therefore, increasing numbers of obese adolescents with respiratory disorders are referred for lung function testing. Based on the excess body fat distribution, obesity can be categorized as central pattern and peripheral pattern. Body Mass Index (BMI) is a measure of relative adipocity, whereas WC and WHR are considered as measure of central obesity. Central adiposity may be associated with a modest impairment of lung volumes such as FVC, FEV1 and TLC in normal and mildly obese men [6]. Studies have shown that both obesity itself and pattern of body fat distribution have independent effect on ventilatory functions [7]. Most of the previous studies on pulmonary function impairment in relation to obesity have used BMI as obesity indicator [8,9]. However, the abdominal obesity markers such as WC and WHR are better predictor of pulmonary function than BMI [10]. Studies investigating pulmonary functions in relation to obesity among adolescents in Malaysia are few. Hence, the present study was aimed to evaluate the effect of obesity on pulmonary functions, and also to identify the association between WC, HC, BMI and WHR with pulmonary functions among adolescent students of a private university in Malaysia. MATERIALS AND METHODS This cross-sectional comparative study was conducted in the Human Physiology Laboratory of a Private University (MSU), Malaysia. Necessary ethical approval has been taken from the university ethical committee (registration No-MSU-HE 124). A total of 100 (50 obese and 50 non obese) non-smoking adolescent students of both sexes aged between 16 to 19 years were randomly selected for the study. Written consent was obtained from each participant. The study was conducted during the period from June to December 2017. BMI of each subject was calculated as per the following formula: BMI=weight (kilograms)/height 2 (meter 2 ). Subjects having BMI greater than the 95 th percentile for age were classified as obese [11]. A total of 50 such obese boys were identified. An identical number of age-matched non-obese with BMI=18.50- 24.99 kg/m 2 were taken as controls. Subject with symptoms of illness like fever, cough, abdominal pain, any history of pulmonary diseases, anxious, apprehensive, and uncooperative ones were excluded from the study. All subjects were explained about the procedures to be undertaken. The following measurements/tests were performed. Anthropometric Measurements The body weight of the studied participants were measured by using balanced beam scale to an accuracy of ±0.1 kg with the subject wearing minimum clothing while body height was measured with the measuring rod attached to the balanced beam with an accuracy of ±0.50 cm. Waist circumference was ANIRUDDHA BHATTACHARJEE 1 , TABARAK MALIK 2 , AYE AYE MYAT 3 , RAJEEV SHARMA 4 , VT SHAKUNTHALA 5 Keywords: Body mass index, Hip circumference, Pulmonary function test, Waist circumference, Waist hip ratio ABSTRACT Introduction: Obesity is a risk factor for many conditions including respiratory disorders. However, studies investigating pulmonary functions in obese adolescents from Malaysia are few in number. Aim: To investigate the effect of obesity on pulmonary function variables in the adolescent obese students of a private university in Malaysia. Materials and Methods: A Cross-sectional comparative study was conducted in a total of 100 (50 obese and 50 non obese control) adolescent students of both sexes aged 16- 19 years. Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV 1 ), FEV 1 as a percentage of FVC (FEV 1 / FVC%), maximum mid expiratory flow rate (FEF 25-75% ) and peak expiratory flow rate (PEFR) were measured using a computerized spirometer (Spirobank II MIR via Del Maggiolino125, 00155 Roma, Italy). Body weight, height, Waist Circumference (WC) and Hip Circumference (HC) were measured. Student’s t-test and Pearson’s product moment correlation (r) were used to interpret the data. The p-values less than 0.05 were considered as statistically significant. Results: There was no significant difference in mean pulmonary function parameters between obese and non-obese control group. However, five obese subjects had mild restriction, whereas no obstructive impairment was detected in any subject of the obese and control groups. In obese group, BMI, WC, HC and Waist Hip Ratio (WHR) had negative significant (p<0.01) correlation with FEV1/FVC%, whereas FVC and FEV1 had positive significant (p<0.05) correlation with WC and HC. However, in normal weight control group, FVC and FEV 1 had positive significant association with WC and WHR, whereas, rest of the dynamic pulmonary measurements had no significant correlation with measured anthropometric obesity indices. Conclusion: Our study did not find any significant effect of obesity/overweight on dynamic lung volumes among adolescent students. Significant negative correlation between BMI, WC, HC and WHR with FEV 1 /FVC% suggests that obesity decreases FEV 1 / FVC% and obese are more prone to obstructive lung diseases.