Effect of Body Fat Distribution on Pulmonary Functions in Young Healthy Obese Students 1* 1 1

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1 JKIMSU, Vol. 4, No. 4, Ot-De 05 ISSN 3-46 ORIGINAL ARTICLE Effet of Body Fat Distribution on Pulmonary Funtions in Young Healthy Obese Students * Sowmya Timmanna Koraddi, Shrilaxmi Bagali, Manjunatha Aithala Department of Physiology, Shri B.M.Patil Medial College Hospital and Researh Centre, BLDE University, Vijayapur-58603, Karnataka, India Abstrat: Bakground: Obesity is defined as abnormal or exessive fat aumulation that may impair health. WHO defines obesity as Body Mass Index (BMI) 30 Kg/m. Obesity is beoming more prevalent in the world and has effets on different body systems. Main is the impat on respiratory funtion. Aim & Objetives: We have aimed to study the gender differene in obesity indued hanges on pulmonary funtions and determine adiposity marker whih best predits the pulmonary funtion in young adult obese individuals and age-mathed non-obese young adult subjets. Materials and Methods: A ross setional study was onduted on obese (BMI 30 kg/m ) male (n=3) and female (n=8) students aged 8-5 years and ompared with age mathed non-obese (BMI Kg/m ) male (n=3) and female subjets (n=7) as ontrols. Weight(kg), Height(m), Body - Mass Index(BMI, kgm ), Waist Cirumferene(WC, m), Waist to Hip Ratio(WHR),Waist to Height Ratio (WHtR), Fored Vital Capaity (FVC, L), Fored Expiratory Volume in first seond (FEV, L/min), FEV %, FEF 5-75% (L/se), Peak Expiratory Flow Rate (PEFR, L/min) and Maximum Expiratory Pressure (MEP, mm Hg) were reorded. Results: Systoli Blood Pressure, Diastoli Blood Pressure, Pulse Rate and Respiratory Rate were signifiantly higher in obese students when ompared to their respetive ontrols. We observed highly signifiant redution in PEFR (p<0.00) and MEP (p<0.00) in both obese male and female groups ompared to ontrols. FEV % was signifiantly lower in obese female students. Linear regression analysis revealed that BMI, WHR and WC were signifiant preditors of PEFR. BMI was only the signifiant preditor of MEP. WHtR and WHR were best preditors of FVC, FEF5-75% and FEV. Conlusion: Obesity and pattern of fat distribution have independent effet on pulmonary funtion. Keywords: Pulmonary Funtions, Obesity, Fat distribution Introdution: Obesity is one of the most frequently found health risks and its prevalene appears to be inreased all over the world beause of physial inativity and westernized diet [].Weight and Body Mass Index (BMI) as measures of overall adiposity are used as preditors of pulmonary funtion in many epidemiologi studies. These measures are widely aepted as determinants of pulmonary funtion. Abdominal adiposity may influene pulmonary funtion through a mehanism that is distint from that of overall adiposity. Trunal obesity redues hest wall ompliane, respiratory musle funtion and peripheral airway size [, 3]. In obese adults, the most frequently reported abnormalities are redutions in lung volumes and expiratory flow rates [4].Pulmonary funtion tests permit aurate assessment of the funtional state of the respiratory system and allow quantifiation of the severity of disease, thereby enabling early detetion, assessment of the natural history and response to therapy. The pattern of pulmonary funtion is found to worsen with the degree of obesity moving from a restritive pattern in mild Journal of Krishna Institute of Medial Sienes University 8

2 JKIMSU, Vol. 4, No. 4, Ot-De 05 to moderate obesity with both Fored Expiratory Volume in first seond (FEV, L/min) and Fored Vital Capaity (FVC, L), redued and FEV/FVC ratio being normal to an obstrutive pattern in severe and morbid obesity with signifiant derease in FEV as against FVC andfev/fvc ratio being dereased [5, 6]. A study was onduted in general population of Amritsar on 00 obese and 00 non obese male individuals, showed dereased FVC and FEV in obese as ompared to non obese individuals [7]. In previous studies, they reported that only redution in pulmonary funtion parameters in obese subjets, but whih adiposity marker best predits pulmonary funtion is not properly onveyed [5-9]. Hene, the aim of the study was to evaluate the effet of obesity on pulmonary funtions and to determine adiposity marker whih best predits the pulmonary funtion in obese subjets of South Indian aged 8-5 years. Materials and Methods: The present omparative study was onduted on obese male students (n=3, BMI 30kg/m ) aged 8-5 years and ompared with age mathed non o b e s e m a l e o n t r o l s ( n = 3, B M I kg/m ). Similarly, obese female students (n=8, BMI >30kg/m ) aged 8-5 years and ompared with age mathed non obese female ontrols (n=7, BMI kg/m ) of KCP Siene ollege, Vijayapur. Duration of study was from Deember 03 to May 04. Institutional ethis learane was obtained. Subjets with history of asthma, diabetes mellitus, hypertension, other ardiovasular diseases, endorine disease or surgery, on hroni mediation, smokers, aloholis, with notieable weight gain or weight loss over the preeding 3 months were exluded from study. Blood pressure was measured by merury sphygmomanometer in lying down posture omfortably on bed after 0 minutes of rest. An average of 3 blood pressure readings has been taken.height (entimeters, m) a n d We i g h t ( K i l o g r a m s, k g ), Wa i s t Cirumferene (WC, m) and Hip Cirumferene (HC, m) were reorded. BMI (kg/m ), Waist to Hip irumferene and Waist to Height ratio of both study and ontrol groups were alulated. Pulse Rate (beats per minute, bpm), Respiratory Rate (yles per minute, pm), Systoli Blood Pressure (SBP, mmhg) and Diastoli Blood Pressure (DBP, mmhg) were also reorded. The subjets were informed regarding the proedure. Demonstration was given by investigator in regard of reording of various pulmonary funtion tests by using Spiropa (MEDICAID) systems Ltl, India. The readings were taken in a omfortable upright sitting position in eah individual. Fored Vital Capaity (FVC, L), Fored Expiratory Volume in first seond (FEV, L/min) determine large airway lung funtions, FEV %, Fored Expiratory Flow at 5%-75% of Fored Vital Capaity (FEF L/se) determines 5-75%, small airway funtion of lungs. Peak Expiratory Flow Rate (PEFR, L/min) and Maximum Expiratory Pressure (MEP, mm Hg) were reorded [0]. Statistial Analysis: It is done by using SPSS software 6 version. All observations were expressed as mean ± SD (Standard Deviation). Signifiane of differene between the study and ontrol groups was determined using student's unpaired t test. Correlation between adiposity markers (BMI, WC, WHR, WHtR) and pulmonary funtions was done using Pearson's orrelation. Step Wise Linear Regression analysis was done to find the Journal of Krishna Institute of Medial Sienes University 9

3 JKIMSU, Vol. 4, No. 4, Ot-De 05 assoiation with adiposity markers that ould best predit pulmonary funtions. Results: Anthropometri and Physiologial Parameters: Table shows anthropometri parameters suh as age, weight, height, BMI, WC, HC, WHR, WHtR, Pulse rate, Respiratory rate, Systoli and Diastoli blood pressure of male and female study groups ompared with their respetive ontrols and were expressed in Mean ± SD. The non-obese and obese male and female groups had similar age and height. There was a signifiant inrease in weight, BMI, WC, WHR, WHtR, Pulse rate, Respiratory rate, and Systoli and Diastoli blood pressure in obese males and females groups ompared to their respetive ontrol groups. Table : Anthropometri and Physiologial Parameters Females Males Parameters Control Study Group p Control Study Group p value Group (N=7) value Group (n=3) (N=8) (n=3) Age (Years) 0.7 ± ± ± ± Height (m) ± ± ± ± Weight (kg) ± ± * ± ± * BMI (kg/ m ).0± ± * 0.97 ± ±.6 WC(m) 84.± ± * 8.8± ± * 0.000* HC(m) 08.05±9.50.5± ± ± WC/HC 0.77± ± * 0.78 ± ± * WC/Ht 0.5 ± ± * 0.49 ± ± * Pulse Rate (bpm) Respiratory Rate (pm) 7.66 ± ± * 74.6± ± * 3.38 ± ± * 3.96 ± ± * SBP (mmhg) 4.88 ± ± * 5.06 ± ± * DBP (mmhg) 74. ± ± * ± ± * Data are presented as mean ± SD. BMI- Body Mass Index, SBP- Systoli Blood Pressure, DBP-Diastoli Blood Pressure, bpm- beats per minute, pm-yles per minute. *indiates level of signifiane, p<0.0 Journal of Krishna Institute of Medial Sienes University 0

4 JKIMSU, Vol. 4, No. 4, Ot-De 05 Respiratory Parameters: Table shows redution in FVC, FEV, FEV%, FEF 5-75%, PEFR, MEP in obese males and females ompared to ontrol. FEV% (p<0.05) was signifiantly redued in female study group ompared to ontrols. PEFR (p< 0.00) and MEP (p<0.00) were signifiantly redued in both female and male study groups ompared to their respetive ontrol groups. Table : Pulmonary Funtion Parameters Data are presented as mean ± SD.*Indiates the level of signifiane (p 0.05) Bivariate Analysis: Table 3 shows orrelation of adiposity markers (BMI, WC, WHR, WHtR) with pulmonary funtions. In present study, showed Fored Vital Capaity (FVC) and Fored Expiratory Volume in first seond (FEV ) were negatively orrelated with adiposity markers and among them WC {FVC (r = -0.53, p< 0.0), FEV (r = -0.36, p <0.05)}, WHtR {FVC(r = , p< 0.00), FEV (r = -0.39, p < 0.0)} were statistially signifiant. Present study showed signifiant negative orrelation of Fored Expiratory Flow at 5%-75% of Fored Vital Capaity (FEF ), 5-75% Peak Expiratory Flow Rate (PEFR) and Maximum Expiratory Pressure (MEP) with all adiposity markers. Journal of Krishna Institute of Medial Sienes University

5 JKIMSU, Vol. 4, No. 4, Ot-De 05 Table 3: Bivariate Analysis of Adiposity Markers with Pulmonary Funtions Stepwise Linear Regression Analysis: Table 4 shows stepwise linear regression analysis. BMI, WC, WHR and WHtR were independent variables and FVC, FEV, FEF5-75%, PEFR, MEP were dependent variables. Among adiposity markers, WHR {FVC (β= 0.370, p= 0.005), FEV (β= , p< 0.00), FEF 5-75% (β= -0.39, p= 0.0)}and WHtR {FVC (β= -0.68, p< 0.0), r is orrelation, * indiates level of signifiane(p< 0.05) Table 4: Stepwise Linear Regression Analysis FEV (β= p= 0.006), FEF 5-75% (β= -0.58, p= 0.00)} were signifiant preditors of FVC, FEV, FEF 5-75%. BMI (β = , p = 0.007), WC (β = -0.63, p = 0.035) and WHR (β = -0.43, p = 0.006), were signifiant preditors of PEFR and BMI (β = -0.66, p <0.00) was only the signifiant preditor of MEP. Dependent variables- FVC, FEV,FEF5-75%, PEFR, MEP and independent variables- BMI, WC, WHR, WHtR. *Indiates the level of signifiane (p 0.0) Journal of Krishna Institute of Medial Sienes University

6 JKIMSU, Vol. 4, No. 4, Ot-De 05 Disussion: Lung funtions are signifiantly related to power of abdominal musles and upper body fat perentage. In literature, it was stated that lung funtions are under the influene of musularity and fat distribution rather than body weight. BMI determines overall adiposity where as WC and WHR determine abdominal adiposity [8]. Obesity might impair pulmonary funtion via several mehanisms. The inreased adiposity around ribs, diaphragm and abdomen leading to limited movement of ribs, dereased total thorai and pulmonary volume auses redution in hest wall ompliane and preventing full exursion of the diaphragm. There are also effets of obesity on upper airway tone [9, 0]. Resistane as well as mehanial load will be inreased whih in turn inreases the work of breathing. Obese individuals have an inreased demand for ventilation and respiratory musle ineffiieny, dereased funtional residual apaity and expiratory reserve volume and losure of peripheral lung units. It adversely affets hest wall mehanis and auses a derease in total respiratory ompliane due to deposition of subutaneous adipose tissue [6]. In present study WC, WHtR were signifiantly negatively orrelated with FVC and FEV. Linear regression analysis showed WHtR, WHR were signifiant preditors for FVC and FEV. In a study onduted by Helala et al, they observed signifiant negative orrelation between WC and FVC in obese group. With average m inrease in WC was assoiated with 0ml redution in FVC. WC was signifiantly negatively assoiated with FEV in obese group. With inrease in m of WC was assoiated with 3ml redution in FEV []. Robert et al onluded that obese men showed more impairment of FVC with weight gain than obese women, estimated redution of FVC was 7ml/kg weight gain for men and 0ml/ kg for women []. BMI is negatively orrelated with FEV but not signifiant, suggesting restritive pattern and might be due to inlusion of young aged adults and less number of subjets and this finding is orroborated with the study of Behera et al [0]. Helela et al study showed similar finding but was signifiant in obese group. A redution in absolute value of FEV indiates airway narrowing. Hene, FVC and FEV are more affeted by abdominal adiposity in the present study. We have observed signifiant redution in FEV % only in obese females ompared to ontrols and BMI, WC, WHR, WHtR showed nonsignifiant negative orrelation with FEV Abdominal %. adiposity may influene FEV but in present % study did not get signifiant preditor of it, may due to inlusion of less number of subjets. Similar findings were observed by Chen et al [], Canoy et al showed nonsignifiant negative orrelation of WC with FEV [4]. % We observed signifiant negative orrelation of Journal of Krishna Institute of Medial Sienes University 3

7 JKIMSU, Vol. 4, No. 4, Ot-De 05 adiposity markers with Fored Expiratory Flow at 5%-75% of Fored Vital Capaity (FEF 5-75%, L/se) and findings were similar to Helala et al study. On stepwise linear regression analysis we found that WHR, WHtR were signifiant preditors of FEF 5-75%. Similar results by JE Park et al showed WHR inreased by 0.0 leads to redution of FEF FEF 5-75% 5-75% by 88. ml [5]. Therefore is more affeted by abdominal adiposity. In our study PEFR is negatively orrelated with adiposity markers. Shenoy et al, Mahajan et al, Sonu Ajmani [7, 6-9] observed similar findings. Viger et al showed strong negative orrelation between BMI and PEFR. Stepwise linear regression analysis showed BMI, WHR and WC were signifiant preditors of PEFR. Our finding was similar to Saxena et al who reported PEFR was negatively assoiated with adiposity markers and on multivariate analysis, WHR found to be most signifiant parameter that showed signifiant negative assoiation with PEFR. Hene PEFR is affeted by both overall and abdominal adiposity. Lower values of PEFR ould be linked to mehanial effet of obesity on diaphragm and also beause of fat deposition between the musles and ribs that an lead to inrease in metaboli demands and work of breathing [0-5]. In our study, MEP was signifiantly redued in both female and male study groups ompared to their respetive ontrol groups and signifiant negative orrelation with adiposity markers. BMI was only the signifiant preditor of MEP in present study. Choudary et al in their study found that MEP was found to be positively orrelated in both sexes [6]. Our findings indiate the onsequene of inreased abdominal obesity on pulmonary funtions. Limitation of the study : The sample size was small and the dietary habits of the individuals under study were not evaluated. Conlusion : The study onludes that all the respiratory parameters were signifiantly redued equally in both males and female obese subjets ompared to their respetive non-obese subjets. FVC, FEV and FEF 5-75% are best predited by WHR, WHtR. BMI, WC and WHtR are best preditors of PEFR. MEP is best predited by BMI. Obesity and pattern of fat distribution have independent effet on pulmonary funtion. Aknowledgement : We thank the student volunteers of KCP Siene College, Vijayapur for partiipating in our study. Journal of Krishna Institute of Medial Sienes University 4

8 JKIMSU, Vol. 4, No. 4, Ot-De 05 Referenes. World Health Organization (WHO). Obesity: preventing and managing the global epidemi.who Tehnial Report Series No.894, Geneva: WHO, 000. Chen Y, Rennie D, Cormier Y, Dosman J. Waist irumferene is assoiated with pulmonary funtion in normal weight, overweight and obese subjets. Am J Clin Nutr 007;85: Ceylan E, Comleki A, Akkolu C, Itil O, Ergor G. The effet of body fat distribution on pulmonary tests in overweight and obese. South Med J 009; 0(): Raison J, Cassuto D, Orvoen-Frija E. Disturbanes in respiratory funtion in obese subjets. In: Ailhaud G, editor Obesity in Europe 9 Proeedings of the 3rd Congress on Obesity. London. John Libbey and Company Limited 00: Sahebjami H and Gartside PS. Pulmonary Funtion in Obese Subjets with a Normal FEV/FVC Ratio. Chest 996;0: Koenig SM. Pulmonary ompliations of obesity: a review. Am J Med Si 00; 3: Mahajan S, Arora AK, Gupta P. Obesity and spirometri ventilatory status in adult male population of Amritsar. National Journal of Physiology, Pharmay and Pharmaology 0; : Saxena Y, Purwar B, Upmanyu R. Adiposity: Determinant of Peak Expiratory Flow Rate in Young Indian Adult Males. The Indian Journal of Chest Diseases and Allied Sienes 0; 53: Kumar Durgesh et al. Spirometri evaluation of lung funtions in obese and non obese subjets. Journal of Advane Researhes in Biologial Sienes Behera AA, Behera BB, Dash S, Mishra S. Effet of body mass index on gender differene in lung funtions in Indian population. International Journal of Clinial and Experimental Physiology 04; :9-3.. Monada J, Jose: Body Fat Predits Fored Vital Capaity in College Males. European Journal of Sport Siene 003; 3:-. Helala L, Wagih K, Ablelmonem: Study of relation between body mass index, waist irumferene and spirometry in COPD patients. Egyptian Journal of Chest Disease of Tuberulosis 04; 63: Robert A, Wise, Enright P L, Connet E J, Niolas R: effet of weight gain on pulmonary funtion after smoking essation in lung health study. Am J Respir Crit Care Med 998; 57: HU Y-H, Reilly KH, Liang Y-J, Xi B, Liu J-T, Xu D-J, Yan Y-K, Xie B, Li X-Y. Inrease in Body Mass Index, Waist Cirumferene and Waist-to-height Ratio is Assoiated with High Blood Pressure in Children and Adolesents in China. The Journal of International Medial Researh 0; 39: Park JE, Chung JH, Lee KH, Shin KC. The Effet of Body Composition on Pulmonary Funtion. Tuber Respir Dis 0; 7: Pal GK. Textbook of pratial Physiology. Universities press, Hyderabad. 00;3: Kaur J, Singh M, Batra AP, Garg R, Kaur M, Punia N. Blood pressure and obesity variation among population of Amritsar distrit. International Journal of Basi and Applied Medial Sienes 03; 3:3-8. Shenoy J, Shivakumar J, Deepti SK, Mirajkar A, Journal of Krishna Institute of Medial Sienes University 5

9 JKIMSU, Vol. 4, No. 4, Ot-De 05 Muniyappanavar NS, Pai GP.Status of Pulmonary funtion in Indian young overweight male individuals. Researh Journal of Pharmaeutial, Biologial and Chemial Sienes 0; 4: Mahajan S, Arora AK, Gupta P Correlation of Obesity and Spirometri Ventilatory Status of adult female population of north India. Advane Laboratory Mediine International.0; : Saxena Y, Sexena V, Divedi J, Sharma K R. Evaluation of dynami funtion tests in normal obese individuals. Indian J Physiol Pharmaol 008; 5: Sindhu CS. Obesity Assessment Based on BMI in the Young Adults of Haryana- a state of India. Researh Journal of Reent Sienes 03; : Costa D, Barbalho CM, Miguel Soares PG, Forti MP, Coutinho Azevedo LM.The impat of obesity on pulmonary funtion in adult women. Clinis 008; 3. Chatterjee P, Das P. Changes in Lung Funtion status of Adult Female over last one deade:a Cross-Setional study in Kolkata, India. International Researh Journal of Environment Sienes 03;: Bishwalata R, Singh BA, Singh A, Devi LU, Singh BK. Overweight and obesity among shoolhildren in Manipur, India. The National Medial Journal of India 00; 3: Sarwari KM, Ali I, Jaleeli K A, Shanmukhappa NJ. Assessment of pulmonary funtion tests in young obese males and females in the age group of 8-5 years. International Journal of Basi and Applied Medial Siene 0; : Choudhuri D, Choudhuri S. Effet of gender and body mass index on pulmonary funtion tests in adolsents of tribal population of north eastern state of India. Ind J Phy Phar 04; 58: :79-4. *Author for Correspondene: Sowmya Koraddi, Department of Physiology, BLDE University's Shri B.M.Patil Medial College Hospital and Researh Centre, Vijayapur Karnataka, India sowmya_88@yahoo.o.in Cell: Journal of Krishna Institute of Medial Sienes University 6