obesity is an isolated risk factor for cardiovascular disease ; it can lead to cardiac hypertrophy followed by dilated cardiomyopathy , predisposing to fatal arrhythmias . 

1 
  obesity also causes organ - specific changes , which are due to a direct mechanical effect of the adipose tissue or occur systemically through humoral mediators and metabolic adjustments that change heart hemodynamics and geometry , as well as possibly lung function . 
 1 
 3 
  a recent epidemiological study 
 4 
  found a relationship between lung function and left ventricular mass ( lvm ) , although the relationship differed between genders .
functional effects of obesity that are associated with being male or female are common in pulmonary function testing , since fat concentrated in the chest ( android obesity ) could lead to deeper changes in lung function than could fat concentrated in the hips ( gynecoid obesity ) . in contrast , another study , which had a case - control design and involved children with and without metabolic syndrome , found no relationship between lung function and lvm . 

5 
  recent evidence suggests that inflammatory mediators act independently of confounding variables on cardiac remodeling in obese individuals , 
 2 
 6 
  as well as on lung function , 
 7 
 8 
  primarily at the level of the small airways .
in contrast , there is evidence of purely mechanical cardiopulmonary effects , with no effect of inflammatory mediators , 
 9 
 10 
  or an interaction of mechanical and inflammatory factors in cases of lung function and asthma associated with obesity . 
 11 
  therefore , the primary objective of this exploratory study was to look for correlations between lung function and cardiac dimension variables , in order to test the hypothesis that regardless of being a purely mechanical or gender - related factor , the relative size of the small airways ( dysanapsis ) , as measured indirectly by the ratio of fef25 - 75% to fvc ( fef25 - 75/fvc , % ) , is correlated with left ventricular hypertrophy ( remodeling ) , since the small airways are especially susceptible to mechanical - inflammatory interactions and bronchial hyperreactivity .
similarly , we aimed to determine the degree of association between lung function and ventricular mass in the study population , with the goal of guiding future studies related to common mechanisms of cardiac and pulmonary impairment in morbid obesity .
to the best of our knowledge , based on our review of currently available databases ( bireme , scielo , pubmed , cochrane library , and google academic ) , this is the first study to investigate this relationship in morbidly obese individuals .
we planned this study based on secondary data obtained from a bariatric surgery outpatient clinic , which is a state referral center for this type of surgery . in this retrospective study
, we reviewed the medical records of all obese individuals who were candidates for bariatric surgery between january of 2006 and december of 2010 , with the total number of individuals being 192 .
individuals underwent a standardized clinical assessment , which was based on an instrument designated " clinical assessment form for obese patients " ( a protocol at the department of bariatric surgery ) , in which detailed information was obtained on anthropometric parameters , degree of obesity , comorbidities , and pressure levels , among other clinical data and relevant tests , assessed by physicians , nutritionists , and nurses working in that department .
the aim of the medical record review was to systematically collect the following clinical data on and test results for morbidly obese individuals ( bmi  40 kg / m 
 12 
 : ( i ) anthropometry ; ( ii ) simple spirometry ; ( iii ) m - mode echocardiography ; ( iv ) reporting of bronchial asthma ( diagnosis and/or treatment ) ; ( v ) reporting of current or former smoking ; and ( vi ) reporting ( diagnosis and/or treatment ) of systemic arterial hypertension ( sah ) .
current or former smoking refers to a longer than 1-year history of smoking , regardless of the number of pack - years .
sah was defined as a current drug treatment for sah or at least two arterial blood pressure measurements  140/90 mmhg .
data on the forms , as well as test results , were only accepted if they had been properly recorded within 1 year before surgery .
only 45 patients met all of the above inclusion criteria , of whom 3 were excluded because of an echocardiographic report of acoustic window impairment caused by obesity and 3 were excluded because they did not meet the spirometry quality criteria .
the main reasons for exclusion of the remaining cases were not being diagnosed with morbid obesity ( 136 individuals ) and being a morbidly obese patient with no spirometric data ( 4 individuals ) , no echocardiographic data ( 5 individuals ) , or neither ( 2 individuals ) .
anthropometric data were obtained by using a stadiometer and a scale for obese individuals , and bmi was calculated by the formula weight / height ( in kg / m .
waist circumference values were not collected , since such values were lacking in many cases .
the study was approved by the human research ethics committee of the federal university of mato grosso do sul and was in compliance with the declaration of helsinki .
spirometry with forced expiratory maneuver was performed in the pulmonary function section of the department of pulmonology of the university .
all tests met the acceptability criteria established in the brazilian guidelines for pulmonary function testing , 
 13 
  and values were corrected to body temperature , pressure saturated .
, rio de janeiro , brazil ) , with individuals in a sitting position and wearing a nose clip .
the equipment was always calibrated in the morning , in accordance with the manufacturer instructions , and the tests were always conducted by one of two trained spirometry technicians belonging to the department of pulmonology .
at least three acceptable maneuvers were always performed , and instantaneous flow was expressed as that obtained from the one maneuver with the highest sum of fvc ( in l ) and fev1 ( in l / min ) .
, 
 14 
  and the mean  sd of the study population was recorded .
echocardiography was performed by two cardiologists , who used a nemio 17 - 2005 echocardiograph ( toshiba , tokyo , japan ) .
those two cardiologists , one of whom is one of the present authors , work specifically in the echocardiography section of the hospital . for the purposes of this study , only data acquired in m - mode were collected ; left ventricle end - diastolic volume ( lvdv ) and lv end - systolic volume ( lvsv ) were indirectly measured using the teicholz formula , and lvm was calculated using the formula by devereux et al . 

15 
  the measurements were obtained from parasternal lv cross - sections at the level of the papillary muscles .
left atrial ( la ) dimensions , lv end - diastolic diameter ( lvdd ) , and lv end - systolic diameter ( lvsd ) were also measured .
we used as criteria for lvm indexation both height to the power of 1.7 ( lvm / m , which is a criterion recommended for obese individuals , and height squared ( lvm / m . relative lv posterior wall thickness ( rlvpwt ) was obtained by dividing lv posterior wall thickness ( lvpwt ) by lvdd .
our sample size calculation ( pass software , version 11 ; ncss llc , kaysville , ut , usa ) showed that 40 individuals would be enough to provide a power of 80% for a significant correlation coefficient of 0.40 at  = 0.05 ( fef25 - 75/fvc , % vs. lvm / lvpwt / rlvpwt ) . for multiple linear regression analysis ( based on lvm ) , 40 individuals would be necessary to provide a power of 98% and an r= 0.37 , in a model with four independent variables ( weight , fev1 , fvc , and fef25 - 75/fvc , % ) . the categorical variables reporting of smoking , reporting of asthma , and reporting of sah were also computed , and gender and reporting of sah were coded as a binary variable for purposes of statistical adjustment . correlations between various spirometric and echocardiographic variables were assessed by pearson 's correlation test . only lvm and lvpwt required log transformation to fit a normal distribution .
the relationship between reporting of asthma ( diagnosis and/or treatment ) or current / former smoking and fef25 - 75/fvc , % , below or above the lower limit of the normal range , was assessed by fischer 's exact test .
the relationship between fef25 - 75/fvc , % and lvpwt / rlvpwt was tested by partial correlation analysis , adjusted for weight , gender , and sah , which are traditionally the most important determinants of lv hypertrophy in obesity . in order to determine which variable would be the best predictor of lvm ( dependent variable ) , we tested a stepwise multivariate linear regression model , in which the independent variables were only the variables showing a significant correlation ( p < 0.05 ) with lvm , whether indexed or not . for all calculations and graphs , we used the ibm spss statistics software package , version 20.0 ( ibm corp . ,
of the 45 patients for whom all data were originally available for inclusion , 6 were excluded because of reported failures in m - mode echocardiography or in pulmonary function testing , which did not meet quality criteria .
the anthropometric and demographic data of the 39 patients included in the study are shown in table 1 .
females predominated in the study ( 74.3% ) , the mean age of the participants was 35.5  7.7 years , and 8 participants were considered super - obese ( bmi > 55 kg / m .
sah ( diagnosis and/or treatment ) was reported to be present in 21 individuals ( 54% ) . only 1 individual reported both asthma and smoking .
the mean values of la diameter , lvm , and lvm / m were increased relative to normal mean values for the brazilian population . 

16 
 
 table 1.characteristics of the individuals included in the study ( n = 39).a 
 characteristic 

 result 
 age , years35.5  7.7height , cm163.1  9.1weight , kg131.4  25.9bmi , kg / m249.2  7.6bs , m22.3  0.3gender ( m / f ) , n / n10/29asthma ( y / n ) , n / n7/32smoking ( y / n ) , n / n6/33sah ( y / n ) , n / n21/18bs : body surface ; m : male ; f : female ; y : yes ; n : no ; and sah : systemic arterial hypertension .
bs : body surface ; m : male ; f : female ; y : yes ; n : no ; and sah : systemic arterial hypertension .
parameter 

 result 
 spirometry 
 fev1 , l2.8  0.6fev1 , % predicted87.9  11.8fvc , l3.4  0.8fvc , % predicted88.4  11.7fev1/fvc , % 83.1  6.4fef25 - 75/fvc , % 99.5  30.2echocardiography 
 la , mm36.2  4.1st , mm11.6  4.4lvpwt , mm10.7  2.3rlvpwt0.2  0.1lvdd , mm48.2  4.1lvsd , mm29.6  3.7lvdv , ml108.9  21.7lvsv , ml34.9  11.2lvm , g248.3  84.9lvm , g / m 
 106.7  30.4lvm , g / m 
 92.1  26.1la : left atrium ; st : septal thickness ; lvpwt : left ventricular posterior wall thickness ; rlvpwt : relative left ventricular posterior wall thickness ; lvdd : left ventricular end - diastolic diameter ; lvsd : left ventricular end - systolic diameter ; lvdv : left ventricular end - diastolic volume ; lvsv : left ventricular end - systolic volume ; and lvm : left ventricular mass . 
 
la : left atrium ; st : septal thickness ; lvpwt : left ventricular posterior wall thickness ; rlvpwt : relative left ventricular posterior wall thickness ; lvdd : left ventricular end - diastolic diameter ; lvsd : left ventricular end - systolic diameter ; lvdv : left ventricular end - diastolic volume ; lvsv : left ventricular end - systolic volume ; and lvm : left ventricular mass .
chief among the significant correlations is the weak direct relationship between bmi and the variables lvdd(r = 0.359 ; p < 0.05 ) , lvsd ( r = 0.387 ; p < 0.05 ) , lvdv ( r = 0.387 ; p < 0.05 ) , and lvsv ( r = 0.425 ; p < 0.01 ) . a moderate inverse correlation was found between fef25 - 75/fvc , % and the variables of lv remodeling ( table 3 ) in the univariate analysis , and this correlation remained statistically significant for lvpwt ( r = 0.355 ; p < 0.05 ) and rlvpwt ( r = 0.349 ; p < 0.05 ) even after adjustment for weight , gender , and sah ( figures 1a and 1b , respectively ) .
the correlation between indexed lvm ( in g / m and fef25 - 75/fvc , % was borderline for statistical significance ( p = 0.05 ; figure 1c ) . interestingly , fef25 - 75/fvc , % did not correlate with the variables of lv internal diameter or lv volume .
fischer 's exact test showed no statistically significant association between fef25 - 75/fvc , % , below or above the lower limit of the normal range , and reporting of asthma or smoking ( p > 0.05 for both ) . 

table 3.univariate correlations of anthropometric and spirometric variables with transthoracic echocardiography variables ( m - mode ) in the sample as a whole ( n = 39 ) . 

parameter 

 lv hypertrophy 

 lv diameter / volume 

 lvm , g 

 lvm , g / m 

 lvm , g / m 

 st , mm 

 lvpwt , mm 

 rlvpwt 

 la , mm 

 lvedd , mm 

 lvesd , mm 

 lvedv , ml 

 lvesv , ml 
 anthropometry 










 bmi , kg / m 
 0.1750.1920.2270.0780.0920.0460.0690.359 * 0.387 * 0.387 * 0.425 
 weight , kg0.476 
 0.2930.3120.1600.360 * 0.1690.380 * 0.447 
 0.476 
 0.455 
 0.556 
 spirometry 










 fev1 , l0.590 
 0.388 * 0.401 * 0.1620.389 * 0.2120.473 
 0.406 
 0.388 * 0.386 *
0.346 * 0.380 * 0.1640.429 
 0.2640.513 
 0.365 * 0.3150.366 * 0.418 
 fvc , % predicted0.0870.1590.2560.0710.0170.0610.0190.1330.0480.1940.038fev1/fvc , % 0.0030.0770.0400.0020.1140.1450.0820.1180.1970.0470.167fef25 - 75/fvc , % 0.397*0.2750.3180.0540.453 
 0.404 
 0.1680.0090.0410.0570.020lv : left ventricular ; lvm : lv mass ; st : septal thickness ; lvpwt : lv posterior wall thickness ; rlvpwt : relative lv posterior wall thickness ; la : left atrium ; lvdd : lv end - diastolic diameter ; lvsd : lv end - systolic diameter ; lvdv : lv end - diastolic volume ; and lvsv : lv end - systolic volume . * p < 0.05 ; p = 0.05 ; p < 0.01 . 
 
lv : left ventricular ; lvm : lv mass ; st : septal thickness ; lvpwt : lv posterior wall thickness ; rlvpwt : relative lv posterior wall thickness ; la : left atrium ; lvdd : lv end - diastolic diameter ; lvsd : lv end - systolic diameter ; lvdv : lv end - diastolic volume ; and lvsv : lv end - systolic volume . *
p < 0.05 ; p = 0.05 ; p < 0.01 . 
 figure 1.correlation of fef25 - 75/fvc , % , adjusted for the variables weight , gender , and systemic arterial hypertension , with left ventricular posterior wall thickness , in a ; with relative left ventricular posterior wall thickness , in b ; and with left ventricular mass adjusted for body size in obese individuals , in c. 
  stepwise multiple linear regression analysis ( table 4 ) showed that the variation in lvm among morbidly obese individuals is better predicted by fvc ( in l ) , which explained 36.9% ( p
< 0.0001 ) of the variation in lvm in the study population . the best predictor of lvm indexed to height squared and lvm indexed to height to the power of 1.7 was fev1 ( in l / min
; p < 0.05 for both ; table 4 ) . 
 table 4.stepwise multiple linear regression for the dependent variable left ventricular mass ( in grams or indexed to body surface area ; n = 39 ) . 

dependent variable 

 predictor variable 

 beta 

 95% ci 

 adjusted r 

 p 
 lvm , gfvc , l0.600.43 - 1.130.369 < 0.001lvm , g / m 
 fev1 , l / min0.380.29 - 2.80.126 < 0.05lvm , g / m 
 fev1 , l / min0.400.2 - 1.30.161 < 0.05lvm : left ventricular mass . 
 
this retrospective study shows there is an independent association between the relative size of the small airways ( fef25 - 75/fvc,% ) and echocardiographic parameters of ventricular hypertrophy in morbidly obese individuals .
in addition , fvc ( in l ) and fev1 ( in l / min ) were found to be important predictors of lvm in grams or indexed to body surface area .
both lvm and lv internal diameters are increased in obesity , regardless of sah . 

17 
  in our study , we found no relationship of bmi with lvm in grams or indexed to body surface area or with lvpwt , but we found a relationship of bmi with lv internal diameters and lv volumes , which is consistent with the literature . 

2 
 17 
  this positive association is likely to be due to increased preload and increased cardiac output , causing ventricular dilatation , which could later progress to lv remodeling . 

18 
  the literature shows inconsistent associations between bmi and spirometric results , with some studies showing an association 
 19 
  and others not showing any . 

20 
  this is probably due to differences in gender ratio among studies , since the android type of obesity favors the correlation between bmi and lung function , unlike the gynecoid phenotype , which does not produce excessive accumulation of fat mass in the chest . in our study , females predominated ( 74% ) , which partly explains the lack of correlation between any spirometric variable and bmi .
the relationships of fvc , fev1 , and fef25 - 75% with lvm and lvpwt have been studied in ( non - obese ) elderly individuals with cardiovascular disease , and the results differ among studies in regard to the direction of the correlation , with correlations being positive 
 21 
  or negative , 
 22 
  which more strongly reflects loss of lung function associated with advanced age and with the effects of sah and pulmonary hypertension , as well as with the pulmonary restrictive effects of cardiomegaly . one study 
 4 
  showed an inverse relationship between lvm and fvc in nonsmoking females and a direct relationship between lvm and fvc in nonsmoking males under 60 years of age .
the fact that most of our sample consists of females ( 74% ) suggests that , in morbidly obese individuals , the direction of the correlation may be different for some lung function variables .
fef25 - 75/fvc , % is a measure that corrects to some extent for the large variability found in fef25 - 75% alone and reflects changes predominantly in the small airways , being adjusted for lung size on the basis of fvc . 

17 
  the correlations of fef25 - 75/fvc , % with lvm indexed to body surface area ( in g / m and with lvpwt / rlvpwt , correlations that remained after adjustment for weight , gender , and sah , possibly reflect the direct mechanical effects of obesity , but may also suggest that there are other independent ( inflammatory or lipotoxic ) mechanisms . since research on the subject is scarce , there is limited evidence that the small airways are independently affected by obesity , as has been reported in nonsmoking males . 

23 
  the hypotheses raised in that study 
 23 
  include an increase in blood volume in obese individuals , causing bronchial vessel congestion ; the presence of increased levels of very - low - molecular - weight lipoproteins , which could trigger the release of histamine ; and altered lipoprotein metabolism in obesity , which could elicit and amplify these effects .
recent data in the literature also indicate that obesity is characterized by hyperresponsiveness to methacholine , predominantly in the small airways , 
 24 
  and that this hyperresponsiveness correlates better with fef25 - 75/fvc , % . 

25 
  on this point , a recent study suggests that groups of obese individuals with hyperresponsiveness are associated with greater lvm . 

26 
  small airway hyperresponsiveness in obese individuals also could be partially explained by dysanapsis ( which is assessed indirectly by fef25 - 75/fvc , % ) , a term coined by green et al . 

27 
  to explain the large interindividual variability in airway size , regardless of lung parenchyma size
. an important predictor of lvm , bmi correlated directly with cardiac size and mass in several studies , although lean body mass remains a better predictor of lvm . 

2 
 28 
 29 
  this retrospective study found no correlations between bmi and lvm ( in grams or indexed to body surface area ) , which is in agreement with another study , 
 30 
  and this is possibly due to differences in obesity phenotypes , prevalence of sah , and number of individuals studied .
of note in our study is the fact that fvc ( in l ) was the best predictor of variation in lvm ( in g ) , explaining 37% of this variation in the study population , which suggests that reduced lung volume may be an important variable in establishing a predictive model for lvm in obese individuals in future studies . in turn
is the fact that our sample was small , consisting of candidates for bariatric surgery , was limited by the criterion of including only morbidly obese and super - obese individuals , and was based on criteria that were unclear in the medical charts , such as the diagnosis of asthma or sah .
in addition , data on diabetes were not collected , although the relationship between diabetes and lvm is inconsistent in the literature .
other important limitations were the limited acoustic window in the analysis of m - mode echocardiographic variables in obese individuals and the lack of a specific , standardized protocol for m - mode echocardiography , since we did not obtain data on inter - rater agreement for the two echocardiographers . in this regard , because this was a retrospective study , we sought not to use echocardiographic data for which accuracy is significantly decreased by the effects of obesity on the acoustic window , such as ejection fraction and doppler echocardiography data .
we therefore conclude that the small airways in morbidly obese individuals have a correlation with cardiac hypertrophy , regardless of usual anthropometric variables , gender , or sah .
this study reveals that factors other than mechanical and/or hemodynamic limitations imposed by increased body mass may be important in the joint changes seen in the small airways and in cardiac hypertrophy . in addition
, further studies are needed to examine the impact that lung function parameters have on predictive equations for lvm in obese individuals .
  verificar a existncia de correlaes entre variveis de funo pulmonar e de dimenses cardacas em obesos mrbidos , buscando testar a hiptese de que o tamanho relativo das pequenas vias areas correlaciona - se com hipertrofia cardaca esquerda de forma independente .
  estudo retrospectivo de 192 pronturios mdicos que continham um protocolo clnico de candidatos  cirurgia baritrica entre janeiro de 2006 a dezembro de 2010 .
  dos 192 pacientes avaliados , 39 ( 29 mulheres ) preencheram os critrios de incluso .
a mdia do imc foi de 49,2  7,6 kg / m , e a mdia de idade foi de 35,5  7,7 anos .
as correlaes da fef25 - 75/cvf , % com a espessura da parede posterior do ventrculo esquerdo e a espessura relativa da parede posterior do ventrculo esquerdo se mantiveram estatisticamente significativas aps ajuste para peso , sexo e histria de hipertenso arterial sistmica ( r = 0,355 e r = 0,349 , respectivamente ) .
aps anlise de regresso linear multivariada stepwise , a cvf e o vef1 foram os principais determinantes da massa ventricular esquerda ( em gramas ou indexada para rea de superfcie corporal ) .
  uma reduo no tamanho relativo das pequenas vias areas parece apresentar uma correlao independente com hipertrofia cardaca relacionada  obesidade , independente de fatores que afetam a mecnica respiratria ( imc e peso ) , sexo ou histria de hipertenso arterial sistmica .
o vef1 e a cvf , por outro lado , podem ser importantes determinantes preditivos da massa ventricular esquerda em obesos mrbidos .
a obesidade  um fator de risco isolado para as doenas cardiovasculares , podendo levar a hipertrofia cardaca seguida de miocardiopatia dilatada , predispondo a arritmias fatais.a obesidade tambm provoca alteraes rgo - especficas , causadas por efeito mecnico direto do tecido adiposo , ou , sistemicamente , atravs de mediadores humorais e ajustes metablicos que alteram a hemodinmica e a geometria cardaca , assim como , possivelmente , a funo pulmonar . 
 1 
 3 
  um estudo epidemiolgico recente 
 4 
  encontrou uma relao entre funo pulmonar e massa ventricular esquerda ( mve ) , ainda que diferente entre os sexos .
efeitos funcionais da obesidade associados ao sexo masculino ou feminino so comuns no estudo da funo pulmonar , pois uma obesidade concentrada no trax ( obesidade androide ) poderia levar a alteraes mais profundas na funo pulmonar do que um tipo de obesidade mais acentuada no quadril ( obesidade ginecoide ) .
outro estudo , ao contrrio , com desenho caso - controle em crianas com e sem sndrome metablica , no encontrou relao entre funo pulmonar e mve . 

5 
  evidncias recentes sugerem a ao de mediadores inflamatrios de forma independente de variveis de confuso no remodelamento cardaco em obesos , e tambm de forma independente sobre a funo pulmonar , principalmente ao nvel das pequenas vias areas .
ao contrrio , existem evidncias de efeitos puramente mecnicos cardiopulmonares , sem efeito de mediadores inflamatrios , ou uma interao de fatores mecnicos e inflamatrios no caso de funo pulmonar e asma associada  obesidade . 
 11 
  assim , o objetivo principal
do presente estudo exploratrio foi verificar a existncia de correlaes entre variveis de funo pulmonar e de dimenses cardacas , buscando testar a hiptese de que o tamanho relativo das pequenas vias areas ( dysanapsis ) , mensurado indiretamente pela razo do fef25 - 75% com a cvf ( fef25 75/cvf , % ) , correlaciona - se com hipertrofia cardaca esquerda ( remodelamento ) independente de ser um fator meramente mecnico ou de sexo , pois as pequenas vias areas so especialmente susceptveis a interaes mecnico - inflamatrias e  hiper - reatividade brnquica .
no mesmo sentido , objetivamos conhecer o grau de associao entre funo pulmonar e massa ventricular na populao estudada , orientando futuros estudos relacionados aos mecanismos comuns de comprometimento cardaco e pulmonar na obesidade mrbida .
at o melhor que pudemos averiguar nas bases de dados atualmente  disposio ( bireme , scielo , pubmed , cochrane library e google acadmico ) , este  o primeiro estudo a investigar essa relao em obesos mrbidos .
planejamos o presente estudo com base em dados secundrios de um ambulatrio de cirurgia baritrica , referncia estadual para esse tipo de cirurgia .
no presente estudo retrospectivo , foram revisados os pronturios de todos os indivduos obesos candidatos  cirurgia baritrica entre janeiro de 2006 e dezembro de 2010 , totalizando 192 indivduos .
os indivduos se submetiam a uma avaliao clnica padronizada , baseada em um instrumento denominado " ficha clnica de avaliao de obesos " ( protocolo do servio de cirurgia baritrica ) , no qual eram detalhados parmetros antropomtricos , grau de obesidade , comorbidades e nveis pressricos , entre outros dados clnicos e exames relevantes , avaliados por mdicos , nutricionistas e enfermeiras dedicados ao servio . a reviso dos pronturios visou coletar os seguintes dados clnicos e de exames , de maneira sistemtica , em indivduos com obesidade mrbida ( imc  40 kg / m 
 12 
 : ( i ) antropometria ; ( ii ) espirometria simples ; ( iii ) ecocardiografia modo m ;
( iv ) relato de asma brnquica ( diagnstico e / ou tratamento ) ; ( v ) relato de tabagismo atual ou passado ; e ( vi ) relato ( diagnstico e / ou tratamento ) de hipertenso arterial sistmica ( has ) . a asma foi definida como o relato de diagnstico mdico atual ou prvio .
o tabagismo atual ou prvio refere - se  histria de tabagismo por mais de um ano , independente de carga tabgica . a has foi definida como o tratamento atual medicamentoso para has ou como pelo menos duas medidas de presso arterial  140/90 mmhg .
os dados da ficha e os resultados dos exames s eram aceitos se estivessem dentro do prazo de at um ano antes da cirurgia e estivessem adequadamente preenchidos .
somente 45 pacientes preencheram todos os critrios de incluso citados acima , sendo que foram excludos 3 casos com laudo ecocardiogrfico declarando janela acstica prejudicada pela obesidade e 3 casos que no preencheram os critrios adequados de qualidade para a espirometria .
as principais causas de excluso dos demais casos foram no ser diagnosticado com obesidade mrbida ( em 136 indivduos ) , assim como no haver dados sobre espirometria ( em 4 ) , ecocardiograma ( em 5 ) ou dos dois exames ( em 2 ) em pacientes com obesidade mrbida .
os dados antropomtricos foram coletados em estadimetro e balana apropriada para obesos , sendo que o imc foi obtido pela equao peso / altura ( em kg / m . os valores de circunferncia abdominal no foram coletados , pois estavam ausentes em muitos casos . o estudo foi aprovado pelo comit de tica em pesquisa em seres humanos da universidade federal de mato grosso do sul , estando de acordo com a declarao de helsinki . a espirometria com manobra expiratria forada foi realizada no setor de funo pulmonar da disciplina de pneumologia da universidade .
todos os testes preencheram os critrios de aceitabilidade das diretrizes brasileiras de funo pulmonare tiveram os valores corrigidos para body temperature , pressure saturated .
os exames foram realizados em um espirmetro vitatrace vt 130 ( pr mdico ltda . ,
rio de janeiro , brasil ) , com os indivduos em posio sentada e utilizando um clip nasal , e o equipamento foi calibrado sempre pela manh , conforme as instrues do fabricante , e realizados sempre por uma de duas tcnicas treinadas em espirometria pertencentes ao servio de pneumologia .
eram sempre realizadas pelo menos trs manobras aceitveis , e o resultado de fluxos instantneos foi expresso como aquele obtido do exame com a maior soma da cvf ( em l ) e vef1 ( em l / min ) .
os valores de referncia para a populao brasileira foram aqueles de pereira et al.,sendo registrado o valor mdio  dp da populao estudada . o ecocardiograma foi realizado com ecocardigrafo nemio 17 - 2005 ( toshiba , tquio , japo ) por dois mdicos cardiologistas com rea de atuao especfica do setor de ecocardiografia do hospital , incluindo um dos autores .
para a finalidade do presente estudo , foram coletados somente os dados obtidos pelo modo unidimensional ( modo m ) , sendo que tanto o volume diastlico final do ventrculo esquerdo ( vdve ) como o volume sistlico final do ve ( vsve ) foram medidos indiretamente pela frmula de teicholz , e a mve foi calculada usando a frmula de devereux et al . 

15 
  as mensuraes foram obtidas por cortes paraesternais transversais do ve ao nvel dos msculos papilares .
tambm foram mensuradas as dimenses de trio esquerdo ( ae ) , dimetro diastlico final de ve ( ddve ) e dimetro sistlico final de ve ( dsve ) .
usamos como critrios para a indexao do valor da mve tanto a altura elevada  potncia de 1,7 ( mve / m , um critrio recomendado para obesos , como a indexao da mve ao quadrado da altura ( mve / m .
a espessura relativa da parede posterior do ve ( erppve ) foi obtida pela diviso da espessura da parede posterior do ve ( eppve ) pelo ddve .
utilizando um clculo amostral no programa pass , verso 11 ( ncss llc , kaysville , ut , eua ) , demonstramos que 40 indivduos seriam suficientes para fornecem um poder de 80% para um coeficiente de correlao significativo de 0,40 a um nvel a = 0,05 ( fef25 - 75/cvf , % vs. mve / eppve / erppve ) .
para a anlise de regresso linear mltipla ( com base na mve ) , seriam necessrios 40 indivduos para um poder de 98% e um r= 0,37 , assumindo quatro variveis independentes no modelo ( peso , vef1 , cvf e fef25 - 75/cvf , % ) .
as variveis categricas de relato de tabagismo , asma e has tambm foram computadas , sendo que sexo e relato de has foram codificados como uma varivel binria para efeitos de ajuste estatstico .
foram realizados clculos de correlaes entre diversas variveis de espirometria simples e ecocardiogrficas pelo teste de correlao de pearson .
somente as variveis mve e eppve precisaram ser transformadas em log para assumir distribuio normal .
a relao entre diagnstico e / ou tratamento relatado para asma ou tabagismo atual / passado e fef25 - 75/cvf , % , abaixo ou acima do limite inferior da normalidade , foi calculada pelo teste exato de fischer .
a relao entre fef25 - 75/cvf , % e eppve / erppve foi testada por correlao parcial , ajustada para peso , sexo e has , que so tradicionalmente os determinantes mais importantes da hipertrofia de ve na obesidade .
para testar qual varivel seria a melhor preditora da mve ( varivel dependente ) , testamos um modelo de regresso linear multivariada stepwise , tendo como variveis independentes somente as variveis cuja correlao foi significativa ( p < 0,05 ) em associao com a mve , indexada ou no .
para todos os clculos e grficos utilizamos o programa estatstico ibm spss statistics , verso 20.0 ( ibm corp . , armonk , ny , eua ) .
dos 45 pacientes originais que continham todos os dados para incluso , 6 foram excludos porque apresentavam falhas relatadas no ecocardiograma modo m ou no teste de funo pulmonar , sem preencher critrios de qualidade .
os dados antropomtricos e demogrficos dos 39 pacientes includos no estudo so mostrados na tabela 1 . o sexo feminino foi predominante no estudo ( 74,3% ) , e a mdia de idade dos participantes foi de 35,5  7,7 anos , sendo 8 considerados superobesos ( imc > 55 kg / m .
asma e tabagismo em algum momento na vida foram relatados por 7 e 6 indivduos , respectivamente . o relato de has ( diagnstico e / ou tratamento ) estava presente em 21 indivduos ( 54% ) .
os valores mdios de dimetro de ae , mve e mve / m estavam aumentados em relao a valores mdios normais para a populao brasileira . 
 16 
 
 tabela 1.caractersticas dos indivduos includos no estudo ( n = 39).a 
 caractersticas 

 resultados 
 idade , anos35,5  7,7altura ,
cm163,1  9,1peso , kg131,4  25,9imc , kg / m249,2  7,6sc , m22,3  0,3sexo ( m / f ) , n / n10/29asma ( s / n ) , n / n7/32tabagismo ( s / n ) , n / n6/33has ( s / n ) , n / n21/18sc : superfcie corporal ; m : masculino ; f : feminino ; s : sim ; n : no ; e has : hipertenso arterial sistmica.avalores expressos em mdia  dp , exceto onde indicado . 
 
sc : superfcie corporal ; m : masculino ; f : feminino ; s : sim ; n : no ; e has : hipertenso arterial sistmica.avalores expressos em mdia  dp , exceto onde indicado . 

parmetros 

 resultados 
 espiromtricos 
 vef1 , l2,8  0,6vef1 , % previsto87,9  11,8cvf , l3,4  0,8cvf , % previsto88,4  11,7vef1/cvf , % 83,1  6,4fef25 - 75/cvf , % 99,5  30,2ecocardiogrficos 
 ae , mm36,2  4,1es , mm11,6  4,4eppve , mm10,7  2,3erppve0,2  0,1ddve , mm48,2  4,1dsve , mm29,6  3,7vdve , ml108,9  21,7vsve , ml34,9  11,2mve , g248,3  84,9mve , g / m 
 106,7  30,4mve , g / m 
 92,1  26,1ae : trio esquerdo ; es : espessura do septo ; eppve : espessura da parede posterior do ventrculo esquerdo ; erppve : espessura relativa da parede posterior do ventrculo esquerdo ; ddve : dimetro diastlico final do ventrculo esquerdo ; dsve : dimetro sistlico final do ventrculo esquerdo ; vdve : volume diastlico final do ventrculo esquerdo ; vsve : volume sistlico final do ventrculo esquerdo ; e mve : massa ventricular esquerda . 
 
ae : trio esquerdo ; es : espessura do septo ; eppve : espessura da parede posterior do ventrculo esquerdo ; erppve : espessura relativa da parede posterior do ventrculo esquerdo ; ddve : dimetro diastlico final do ventrculo esquerdo ; dsve : dimetro sistlico final do ventrculo esquerdo ; vdve : volume diastlico final do ventrculo esquerdo ; vsve : volume sistlico final do ventrculo esquerdo ; e mve : massa ventricular esquerda . as
entre as correlaes significativas , destacamos a relao direta e fraca entre o imc e as variveis ddve ( r = 0,359 ; p < 0,05 ) , dsve ( r = 0,387 ; p < 0,05 ) , vdve ( r = 0,387 ; p < 0,05 ) e vsve ( r = 0,425 ; p < 0,01 ) . a fef25 - 75/cvf , % apresentou correlao inversa e moderada com as variveis de remodelamento de ve ( tabela 3 ) na anlise univariada , mantendo a significncia estatstica mesmo aps ajuste para peso , sexo e has , para eppve ( r = 0,355 ; p < 0,05 ) e erppve ( r = 0,349 ; p < 0,05 ; figuras 1a e 1b , respectivamente ) .
a correlao entre mve indexada ( em g / m e fef25 - 75/cvf , % foi limtrofe para significncia estatstica ( p = 0,05 ; figura 1c )
. de modo interessante , a fef25 - 75/cvf , % no se correlacionou com as variveis de dimetro interno e de volume de ve .
o fef25 - 75% no apresentou correlao com qualquer varivel ecocardiogrfica . o teste exato de fischer no mostrou associao estatisticamente significativa entre o valor de fef25 - 75/cvf , % abaixo ou acima do limite inferior de normalidade e relato de asma ou tabagismo ( p > 0,05 para ambos ) . 

tabela 3.correlaes univariadas das variveis antropomtricas e espiromtricas com as variveis de ecocardiografia transtorcica ( modo m ) na amostra total ( n = 39 ) . 

parmetros 

 hipertrofia de ve 

 dimetro / volume de ve 

 mve , g 

 mve , g / m 

 mve , g / m 

 es , mm 

 eppve , mm 

 erppve 

 ae , mm 

 ddve , mm 

 dsve , mm 

 vdve , ml 

 vsve , ml 
 antropomtricos 










 imc , kg / m 
 0,1750,1920,2270,0780,0920,0460,0690,359 * 0,387 * 0,387 * 0,425 
 peso , kg0,476 
 0,2930,3120,1600,360 * 0,1690,380 * 0,447 
 0,476 
 0,455 
 0,556 
 espiromtricos 










 vef1 , l0,590 
 0,388 * 0,401 * 0,1620,389 * 0,2120,473 
 0,406 
 0,388 * 0,386 * 0,488 
 vef1 , % previsto0,1470,2320,1540,1100,0290,1020,0150,2170,1960,2380,162cvf , l0,584 
 0,346 * 0,380 * 0,1640,429 
 0,2640,513 
 0,365 *
0,3150,366 * 0,418 
 cvf , % previsto0,0870,1590,2560,0710,0170,0610,0190,1330,0480,1940,038vef1/cvf , % 0,0030,0770,0400,0020,1140,1450,0820,1180,1970,0470,167fef25 - 75/cvf , % 0,397*0,2750,3180,0540,453 
 0,404 
 0,1680,0090,0410,0570,020ve : ventrculo esquerdo ; mve : massa ventricular esquerda ; es : espessura do septo ; eppve : espessura da parede posterior do ve ;
erppve : espessura relativa da parede posterior do ve ; ae : trio esquerdo ; ddve : dimetro diastlico final de ve ; dsve : dimetro sistlico final de ve ; vdve : volume diastlico final de ve ; e vsve : volume sistlico final de ve . *
ve : ventrculo esquerdo ; mve : massa ventricular esquerda ; es : espessura do septo ; eppve : espessura
da parede posterior do ve ; erppve : espessura relativa da parede posterior do ve ; ae : trio esquerdo ; ddve : dimetro diastlico final de ve ; dsve : dimetro sistlico final de ve ; vdve : volume diastlico final de ve ; e vsve : volume sistlico final de ve . *
figura 1.correlao de fef25 - 75/cvf , % , ajustada para as variveis peso , sexo e hipertenso arterial sistmica , com a espessura da parede posterior do ventrculo esquerdo , em a ; com a espessura relativa da parede posterior do ventrculo esquerdo , em b ; e com a massa ventricular esquerda ajustada para o tamanho corporal em obesos , em c. 
  o modelo de regresso linear mltipla stepwise estudado ( tabela 4 ) mostrou que a variao na mve entre obesos mrbidos  mais bem prevista pela cvf ( em
l ) , que explicou 36,9% ( p < 0,0001 ) de sua variao na populao estudada . a mve indexada para altura ao quadrado e a mve indexada para a potncia de 1,7 tiveram no vef1 ( em l / min ) o melhor preditor ( p < 0,05 para ambos ; tabela 4 ) . 

tabela 4.regresso linear mltipla stepwise para a varivel dependente massa do ventrculo esquerdo ( em gramas ou indexada para rea de superfcie corporal ; n = 39 ) . 

varivel dependente 

 varivel preditora 

 beta 

 ic95% 

 r ajustado 

 p 
 mve , gcvf , l0,600,43 - 1,130,369 < 0,001mve , g / m 
 vef1 , l / min0,380,29 - 2,80,126 < 0,05mve , g / m 
 vef1 , l / min0,400,2 - 1,30,161 < 0,05mve : massa ventricular esquerda . 
 
o presente estudo retrospectivo mostra uma associao independente entre o tamanho relativo das pequenas vias areas ( fef25 - 75/cvf , % ) e parmetros ecocardiogrficos de hipertrofia ventricular em obesos mrbidos .
l ) e o vef1 ( em l / min ) se mostraram importantes preditores da mve em gramas ou indexada para rea de superfcie corporal .
a mve e os dimetros internos de ve esto aumentados na obesidade , independentemente de has . 

17 
  nosso estudo no mostrou relaes do imc com a mve em gramas ou indexada para rea de superfcie corporal nem com a eppve , mas mostrou uma relao do imc com
os dimetros internos e os volumes de ve , concordante com a literatura , sendo provvel que essa associao positiva ocorra por conta do aumento da pr - carga e do dbito cardaco , causando dilatao ventricular , que posteriormente poderia evoluir para o remodelamento do ve
. 
 18 
  o imc e resultados espiromtricos mostram associaes inconsistentes na literatura , ora mostrando associao , 
 19 
  ora no demonstrando associao , 
 20 
  e isso ocorre provavelmente pelas diferenas na proporo entre sexos nos estudos , pois a obesidade do tipo androide favorece a correlao entre imc e a funo pulmonar , ao contrrio do fentipo ginecoide , que no acumula excessiva massa gordurosa no trax .
nosso estudo apresentou uma predominncia do sexo feminino ( 74% ) , o que explica em parte a ausncia de correlao entre qualquer varivel de espirometria e o imc . as relaes entre cvf , vef1 e fef25 - 75% com mve
e eppve foram estudadas em cardiopatas idosos ( no obesos ) e so discordantes , em estudos realizados , no sentido da direo da correlao , sendo positivas 
 21 
  ou negativas , 
 22 
  o que reflete muito mais uma perda da funo pulmonar associada  idade avanada e aos efeitos de has e de hipertenso pulmonar , assim como aos efeitos restritivos pulmonares da cardiomegalia . um estudo 
 4 
  mostrou uma relao inversa entre mve e cvf em mulheres no fumantes
e uma relao direta para as mesmas variveis em homens com menos de 60 anos e no fumantes .
considerando que a maioria de nossa amostra  de mulheres ( 74% ) , isso sugere que , em obesos mrbidos , algumas variveis de funo pulmonar podem ter direo da correlao diferente . a fef25 - 75/cvf , %  uma medida que corrige parcialmente a grande variabilidade encontrada no fef25 - 75% isolado e reflete alteraes predominantemente de pequenas vias areas , ajustada ao tamanho pulmonar relativo  cvf . 
 17 
  as correlaes da fef25 - 75/cvf , % com a mve indexada para rea de superfcie corporal ( em g / m e com eppve / erppve , mantidas aps ajuste para peso , sexo e has , possivelmente refletem efeitos mecnicos diretos da obesidade , mas tambm podem sugerir que existam outros mecanismos independentes ( inflamatrios ou lipotxicos ) .  
por ser pouco estudado , h limitadas evidncias de que as pequenas vias areas so independentemente afetadas pela obesidade , como relatado em homens no tabagistas.as hipteses levantadas naquele estudo 
 23 
  passam pelo aumento da volemia em obesos , causando congesto dos vasos brnquicos , pela a presena de lipoprotenas de muito baixo peso em nveis aumentados , o que poderia deflagrar liberao de histamina , e pelo metabolismo alterado lipoproteico na obesidade , que poderia instigar e amplificar esses efeitos . dados recentes da literatura indicam tambm que a obesidade  caracterizada por hiper - responsividade  metacolina , predominantemente nas pequenas vias areas , sendo essa melhor correlacionada com a fef25 - 75/cvf , % .sobre esse aspecto , um estudo recente sugere que grupos de obesos com hiper - responsividade esto associados a maior mve.a hiper - responsividade das pequenas vias areas em obesos poderia ser parcialmente explicada tambm pela dysanapsis ( avaliada indiretamente pela fef25 - 75/cvf , % ) , termo cunhado por green et al.para explicar a grande variabilidade interindividual no tamanho das vias areas , independente do tamanho do parnquima pulmonar .
importante fator preditor da mve , o imc correlacionou - se , em vrios estudos , diretamente com o tamanho e a massa cardaca , embora a massa magra ainda seja uma melhor preditora da mve.o presente estudo retrospectivo no mostrou correlaes entre imc e mve ( em gramas ou indexada para rea de superfcie corporal ) , corroborando outro estudo , e isso possivelmente ocorra devido a diferenas de fentipos de obesidade , prevalncia de has e nmero de indivduos estudados .   a destacar em nosso estudo foi o fato de que a cvf ( em
( em g ) , explicando 37% da variao da mesma na populao estudada , sugerindo que a reduo dos volumes pulmonares pode ser uma varivel importante para futuros estudos no estabelecimento de um modelo preditor de mve em obesos .
a mve , por sua vez , se correlaciona com a morbidade e a mortalidade cardiovasculares .
entre os fatores limitantes de nosso estudo est o fato de que nossa amostra foi pequena , composta por pacientes candidatos  cirurgia baritrica , limitada pelo critrio de incluir somente obesos mrbidos e superobesos e baseada em critrios no bem estabelecidos nos pronturios , como o diagnstico de asma ou has .
alm disso , dados referentes a diabetes no foram coletados , embora sua relao com mve seja inconsistente na literatura .
outras limitaes importantes foram a janela acstica limitada na anlise das variveis do ecocardiograma no modo m em obesos e a falta de um protocolo especfico e padronizado na realizao do mesmo , pois no obtivemos dados de concordncia interexaminadores para os dois ecocardiografistas .
nesse pormenor , por se tratar de estudo retrospectivo , buscamos no utilizar dados ecocardiogrficos que perdem acurcia mais intensamente pelos efeitos da obesidade sobre a janela acstica , como a frao de ejeo e dados de ecodopplercardiograma .
conclumos , portanto , que as pequenas vias areas em obesos mrbidos tm uma correlao com a hipertrofia cardaca , independente das variveis antropomtricas usuais , sexo e has .
o presente estudo revela que outros fatores , alm de fatores mecnicos e / ou hemodinmicos impostos pela massa corporal aumentada , podem ser importantes nas alteraes conjuntas de pequenas vias areas e hipertrofia cardaca .
alm disso , outros estudos so necessrios para verificar qual o impacto dos parmetros de funo pulmonar nas equaes preditivas de mve em obesos .
 objective : to look for correlations between lung function and cardiac dimension variables in morbidly obese patients , in order to test the hypothesis that the relative size of the small airways is independently correlated with left ventricular hypertrophy . 
 methods : this was a retrospective study involving 192 medical records containing a clinical protocol employed in candidates for bariatric surgery between january of 2006 and december of 2010 . 
 results : of the 192 patients evaluated , 39 ( 10 males and 29 females ) met the inclusion criteria . 
 the mean bmi of the patients was 49.2  7.6 kg / m2 , and the mean age was 35.5  7.7 years . 
 the fef25 - 75/fvc , % correlated significantly with left ventricular posterior wall thickness and relative left ventricular posterior wall thickness , those correlations remaining statistically significant ( r = 0.355 and r = 0.349 , respectively ) after adjustment for weight , gender , and history of systemic arterial hypertension . 
 stepwise multivariate linear regression analysis showed that fvc and fev1 were the major determinants of left ventricular mass ( in grams or indexed to body surface area ) . 
 conclusions : a reduction in the relative size of the small airways appears to be independently correlated with obesity - related cardiac hypertrophy , regardless of factors affecting respiratory mechanics ( bmi and weight ) , gender , or history of systemic arterial hypertension 
 . however , fev1 and fvc might be important predictors of left ventricular mass in morbidly obese individuals . 