Influence of body mass index on the response to asthma controller agents Maternal vitamin D intake during pregnancy and early childhood wheezing. Impact of low birth weight on early childhood asthma in the United States. Epidemiology of gastroesophageal reflux disease: a general population-based study in Xi'an of Northwest China. Tracking of lung function parameters and the longitudinal relationship with lifestyle. Tumor necrosis factor increases serum leptin levels in humans. Consumption of fish, butter and margarine during pregnancy and development of allergic sensitizations in the offspring: role of maternal atopy. Low physical fitness in childhood is associated with the development of asthma in young adulthood: the Odense schoolchild study. Trend in Obesity Prevalence in European Adult Cohort Populations during Follow-up since 1996 and Their Predictions to 2015 Cluster analysis and clinical asthma phenotypes. Immediate and long term effects of weight reduction in obese people with asthma: randomised controlled study Physical inactivity is associated with lower forced expiratory volume in 1 second : European Prospective Investigation into Cancer-Norfolk Prospective Population Study. A comparison of obese and nonobese people with asthma: exploring an asthma-obesity interaction. Body mass index and phenotype in subjects with mild-to-moderate persistent asthma. Onset and remission of allergic rhinitis and asthma and the relationship with atopic sensitization and smoking. Menopause, postmenopausal estrogen preparations, and the risk of adult-onset asthma. A prospective cohort study. A 5-year follow-up study of 3 polymorphisms in the human glucocorticoid receptor gene in relation to obesity, hypertension, and diabetes. Linkage analysis of markers on chromosome 11q13 with asthma and atopy in a United Kingdom population. Increased risk of concurrent asthma among patients with gastroesophageal reflux disease: a nationwide population-based study. Asthma and Insulin Resistance in Morbidly Obese Children and Adolescents Beta(2)-adrenoceptor polymorphism and body mass index are associated with adult-onset asthma in sedentary but not active women. Body-mass index as a predictor of incident asthma in a prospective cohort of children. Overdiagnosis of asthma in obese and nonobese adults Birth characteristics and asthma symptoms in young adults: results from a population-based cohort study in Norway. Prospective study of body mass index, weight change, and risk of adult-onset asthma in women. Effects of obesity and bariatric surgery on airway hyperresponsiveness, asthma control, and inflammation. Factors associated to lifestyle and risk of adult onset asthma. Asthma is associated with weight gain in females but not males, independent of physical activity. Airway hyperresponsiveness in asthma: a problem of limited smooth muscle relaxation with inspiration. Linkage exclusion analysis of two candidate regions on chromosomes 7 and 11: leptin and UCP2/UCP3 are not QTLs for obesity in US Caucasians. Impact of airway lability, atopy, and tobacco smoking on the development of asthma-like symptoms in asymptomatic teenagers. Snoring and atopic disease: a strong association. Premenstrual asthma: the effect of estrogen on symptoms, pulmonary function, and beta 2-receptors. The Effects of Body Mass on Lung Volumes, Respiratory Mechanics, and Gas Exchange During General Anesthesia
The incidence of asthma has been positively associated with obesity . Asthma comprises diverse “ phenotypes ” reflecting heterogeneity in a number of characteristics , including response to therapy . The present authors examined whether body mass index ( BMI ) influenced the response to placebo , as well as to two asthma controller medications . A post hoc analysis was performed , pooling data from four double-blind , placebo-controlled studies r and omising 3,073 moderate asthmatic adults to montelukast ( n = 1,439 ) , beclomethasone ( n = 894 ) or placebo ( n = 740 ) . The primary end point was asthma control days ; other end points were forced expiratory volume in one second , β-agonist use and nocturnal awakening . Analyses were conducted using BMI classification into normal ( < 25.0 kg·m−2 ; 52 % of patients ) , overweight ( 25–29.9 kg·m−2 ; 32 % ) and obese ( ≥30.0 kg·m−2 ; 16 % ) categories , as well as BMI as a continuous variable . The treatment groups were balanced for BMI , demographic characteristics and parameters of asthma control .  The placebo response for all end points was generally lower with increasing BMI . Similarly , the response to the inhaled corticosteroid decreased , whereas the response to the leukotriene antagonist remained stable . In conclusion , post hoc data from the present study suggested that body mass index may influence the natural history of asthma control ( as reflected by response to placebo ) and may differentially influence response to the two active agents , warranting explicit testing in future prospect i ve studies BACKGROUND Maternal intake of vitamin D in pregnancy is a potentially modifiable but understudied risk factor for the development of asthma in children . OBJECTIVE We investigated whether maternal vitamin D intake in pregnancy is associated with decreased risks of  wheezing symptoms in young children . DESIGN Subjects were from a birth cohort recruited in utero with the primary objective of identifying associations between maternal diet during pregnancy and asthma and allergies in children . A r and om sample of 2000 healthy pregnant women was recruited while attending antenatal clinics at the Aberdeen Maternity Hospital , Scotl and , at approximately 12 wk gestation . Maternal vitamin D intake was ascertained from a food-frequency question naire completed at 32 wk of gestation . The main outcome measures were wheezing symptoms , spirometry , bronchodilator response , atopic sensitization , and exhaled nitric oxide at 5 y. RESULTS Respiratory details through 5 y and maternal food-frequency- question naire data were available for 1212 children . In models adjusted for potential confounders , including the children 's vitamin D intake , a comparison of the highest and lowest quintiles of maternal total vitamin D intake conferred lower risks for ever wheeze [ odds ratio ( OR ) : 0.48 ; 95 % CI : 0.25 , 0.91 ] , wheeze in the previous year ( OR : 0.35 ; 95 % CI : 0.15 , 0.83 ) , and persistent wheeze ( OR : 0.33 ; 95 % CI : 0.11 , 0.98 ) in 5-y-old children . In addition , lower maternal total vitamin D intakes in pregnancy were also associated with decreased bronchodilator response ( P = 0.04 ) . No associations were observed between maternal  vitamin D intakes and spirometry or exhaled nitric oxide concentrations . CONCLUSION Increasing maternal vitamin D intakes during pregnancy may decrease the risk of wheeze symptoms in early childhood OBJECTIVE To estimate the independent contribution of birth weight to asthma prevalence among children younger than 4 years in the United States and to compare the magnitude of its effect on asthma between African American and white children . DESIGN Cross-sectional analysis using the 1988 National Maternal-Infant Health Survey and 1991 Longitudinal Follow-up Survey . SETTING United States . PATIENTS Eight thous and seventy-one subjects , selected from a r and omized , systematic population -based sample and weighted to be nationally representative , who completed both initial and longitudinal follow-up surveys and reported information on asthma diagnosis . MAIN OUTCOME MEASURES Birth weight and other sociodemographic factors linked to birth outcome were analyzed for independent association with physician-diagnosed asthma by age 3 years . RESULTS The prevalence of asthma varied by birth weight category : 6.7 % in children 2500 g or more at birth , 10.9 % in children 1500 to 2499 g at birth , and 21.9 % in children less than 1500 g at birth ( very low birth weight [ VLBW ] ) ( P<.001 ) . Some of the characteristics shown to be independently associated with asthma included : VLBW ( odds ratio [ OR ] , 2.9 ; 95 % confidence interval [ CI ] , 2.3 - 3.6 ) , moderately low birth weight ( OR , 1.4 ; 95 % CI , 1.1 - 1.8 ) , and African American race ( OR , 1.9 ; 95 % CI , 1.6 - 2.4 ) . In stratified analyses , the independent association between VLBW and asthma in white and African American population s was : OR(white ) , 3.1 ( 95 % CI , 2.2 - 4.3 ) and OR(African American ) , 2.5 ( 95 % CI , 2.0 - 3.3 ) . The prevalence of VLBW , however , was tripled in African American compared with white children ( 1.8 % vs 0.6 % ) . CONCLUSIONS These data confirm findings of other studies that identify a strong independent association between low birth weight and asthma . For this 1988 national birth cohort , an estimated 4000 excess asthma cases were attributable to birth weight less than 2500 g. Although the strength of the independent association between VLBW and asthma was smaller in the African American population , the substantially increased prevalence of VLBW in this community may contribute to the disproportionately increased prevalence of asthma among African American children AIM Gastroesophageal reflux disease ( GERD ) is a common disorder in the Western population , but detailed population -based data in China are limited . The aim of this study was to underst and the epidemiology of symptomatic gastroesophageal reflux ( SGER ) in adults of Xi'an , a northwestern city of China , and to explore the potential risk factors of GERD . METHODS Symptoms suggestive of GERD , functional dyspepsia ( FD ) , irritable bowel syndrome ( IBS ) , upper respiratory diseases and some potential risk factors were investigated in a face-to-face manner in a region-stratified r and om sample s of 2789 residents aged 18 - 70 years in Xi'an by using a st and ardized  question naire . METHODS With a response rate of 91.8 % , the prevalence of SGER was 16.98 % ( 95 % CI , 14.2 - 18.92 ) in Xi'an adults , and no gender-related difference was observed ( P<0.05 ) . SGER was more common among subjects aged 30 - 70 years than in those aged 18 - 29 years ( P<0.01 ) . The prevalence of SGER in rural , urban and suburban subjects was 21.07 % , 17.44 % and 12.12 % , respectively , and there was a significant difference between rural , urban and suburban regions ( P<0.05 ) . Compared with subjects without SGER , the prevalence of symptoms suggestive of FD and IBS , pneumonia , asthma , bronchitis , laryngitis , pharyngitis , chronic cough , wheeze , globus sensation , oral ulcer and snore was significantly increased in subjects with SGER ( P<0.01 ) . Heavy smoking ( OR=5.76 ; CI , 3.70 - 6.67 ) , heavy alcohol use ( OR=2.85 ; CI , 1.67 - 4.49 ) , peptic ulcer ( OR=5.76 ; CI , 3.99 - 8.32 ) , cerebral palsy ( OR=3.97 ; CI , 1.97 - 8.00 ) , abdominal operation ( OR=2.69 ; CI , 1.75 - 4.13 ) , obesity ( OR=2.16 ; CI , 1.47 - 3.16 ) , excessive food intake ( OR=1.43 ; CI , 1.17 - 1.15 ) , sweet food ( OR=1.23 ; CI , 0.89 - 1.54 ) , and consumption of coffee ( OR=1.23 ; CI , 0.17 - 2.00 ) were independently associated with SGER . The episodes of GERD were commonly precipitated by dietary factors ( 66.05 % ) , followed by body posture ( 26.54 % ) , ill temper ( 23.72 % ) , fatigue ( 22.32 % ) and stress ( 10.93 % ) . CONCLUSION GERD is common in Xi'an 's adult population with a mild or moderate degree . The etiology and pathogenesis of GERD are probably associated with FD , IBS , and some respiratory , laryngopharyngeal and odontostological diseases or symptoms . Some lifestyles , diseases and dietary factors are the risk factors of GERD The purpose of this study was to analyse tracking ( i.e. relative stability over time/predictability of future values by early measurements ) of lung function parameters and their longitudinal relationship with lifestyle ( smoking , alcohol consumption , daily physical activity , neuromotor and cardiopulmonary fitness , and dietary intake of retinol and polyunsaturated fatty acids ( PUFA ) ) . Data were obtained from the observational Amsterdam Growth and Health Study , a longitudinal study with six repeated measurements between ages 13 - 27 yrs ( n=167 ) . The statistical analyses were carried out with generalized estimating equations . The following " stability " coefficients were found : for forced vital capacity ( FVC ) in males 0.66 ( 95 % confidence interval ( CI ) : 0.54 - 0.77 ) and in females 0.51 ( 95 % CI : 0.43 - 0.60 ) ; for forced expiratory volume in one second ( FEV1 ) in males 0.65 ( 95 % CI : 0.50 - 0.80 ) , in females 0.53 ( 95 % CI 0.46 - 0.60 ) ; for peak expiratory flow ( PEF ) in both males and females 0.41 ( 95 % CI : 0.31 - 0.51 ) . Positive relationships were found between alcohol consumption and FVC and FEV1 and between neuromotor fitness and PEF and ( only for males ) with FVC and FEV1 . Physical activity was inversely related to PEF and the intake of PUFA positively related to FVC and FEV1 . Smoking was related to a decrease in FVC and FEV1 ; changes in physical activity positively correlated to changes in FVC . In conclusion , high to moderate stability/tracking was observed for forced vital capacity and forced expiratory volume in one second ; for peak expiratory flow it was slightly lower . Preventive strategies regarding improvements of lung function should focus on smoking cessation and improving daily physical activity Leptin is a pleiotropic hormone believed to regulate body weight . Its function in wasting during inflammatory disease in humans is unknown . We studied the effect of repeated tumor necrosis factor ( TNF ) infusion on serum leptin levels in six patients with solid tumors .  TNF infusion on day 1 result ed in an increase in serum leptin levels from 3.1 ( SEM + /- 0.28 ) ng/mL to 5.2 ( SEM + /- 0.6 ) ng/mL after 12 h ( P < 0.001 ) . The serum levels returned to baseline within 24 h. Similar results were obtained when TNF was infused on subsequent days . The study shows that leptin serum levels are under control of TNF It has been suggested that changes in dietary habits , particularly increased consumption of omega-6 polyunsaturated fatty acids ( PUFA ) and decreased consumption of omega-3 PUFAs may explain the increase in atopic disease seen in recent years . Furthermore , it seems possible that it is mainly prenatal or very early life environmental factors that influence the development of allergic diseases . It has also been suggested that intrauterine risk factors may act differently if mother themselves suffer from allergic disease . The aim of this study was to investigate whether the consumption of fish , butter and margarine during pregnancy might influence the development of allergic sensitizations in the offspring . The study population was divided into the offspring of allergic and non-allergic mothers . This was a retrospective cohort study enrolling 295 offspring of allergic mothers and 693 of non-allergic mothers . Information regarding maternal intake of fish , butter and margarine during pregnancy as well as other prenatal and perinatal confounding factors were retrospectively assessed by parental report via a st and ardized question naire . Atopy was determined by skin-prick tests ( SPT ) to eight prevalent inhalant allergens and two foods . In the allergic mothers ' group there is no clear correlation between maternal intakes of fish , butter and margarine  and sensitizations to food or inhalants . In the non-allergic mothers ' group there was no correlation between butter and margarine  intake and food or inhalant sensitizations . On the contrary , a protective effect of fish intake on SPT positivity was observed . In particular , frequent maternal intake ( ' 2 - 3 times/wk or more ' ) of fish reduced the risk of food sensitizations by over a third ( aOR 0.23 ; 95 % CI : 0.08 - 0.69 ) . A similar trend , even if not significant , was found for inhalants . Finally , even in the whole study population , i.e. allergic group plus non-allergic group , there was a similar trend between increased consumption of fish and decreased prevalence of SPT positivity for foods . This study shows that frequent intake of fish during pregnancy may contrast the development of SPT sensitizations for foods in the offspring of mothers without atopic disease . Therefore , larger prospect i ve studies are needed , enrolling mothers with and without allergic disease , to confirm these results Intense physical activity in  children may either improve fitness and protect against asthma , or may trigger symptoms . The aim of this study was to determine whether physical fitness in childhood has an impact on the development of asthma . In this prospect i ve , community-based study , 757 ( 84 % ) asymptomatic children with an average age at inclusion of 9.7 yrs were followed for 10.5 yrs . In both surveys a maximal progressive exercise test on a bicycle ergometer was used to measure physical fitness ( maximal workload ) and to induce airway narrowing . A methacholine provocation test was performed in the subjects at follow-up . During the 10-yr study period , 51 ( 6.7 % ) of the previously asymptomatic children developed  asthma . These subjects had a lower mean physical fitness in 1985 than their peers : ( 3.63 versus 3.89 W x kg(-1 ) ; p=0.02 ) in boys and ( 3.17 versus 3.33 W x kg(-1 ) ; p=0.02 ) in girls . A weak correlation was found between physical fitness in childhood and airway responsiveness to methacholine at follow-up when adjusted for body mass index , age and sex ( r=0.11 ; p<0.01 ) . In a multiple regression analysis , physical fitness was inversely related to the development of physician diagnosed asthma , odds ratio=0.93 ( 0.87 - 0.99 ) . Thus , the risk for the development of asthma during adolescence is reduced 7 % by increasing the maximal workload 1 W x kg(-1 ) . In conclusion , this study showed that physical fitness in childhood is weakly correlated with the development of asthma during adolescence and that high physical fitness seems to be associated with a reduced risk for the development of asthma Objective To investigate trends in obesity prevalence in recent years and to predict the obesity prevalence in 2015 in European population s. Methods Data of 97 942 participants from seven cohorts involved in the European Prospect i ve Investigation into Cancer and Nutrition ( EPIC ) study participating in the Diogenes project ( named as “ Diogenes cohort ” in the following ) with weight measurements at baseline and follow-up were used to predict future obesity prevalence with logistic linear and non-linear ( leveling off ) regression models . In addition , linear and leveling off models were fitted to the EPIC-Potsdam data set with five weight measures during the observation period to find out which of these two models might provide the more realistic prediction . Results During a mean follow-up period of 6 years , the obesity prevalence in the Diogenes cohort increased from 13 % to 17 % . The linear prediction model predicted an overall obesity prevalence of about 30 % in 2015 , whereas the leveling off model predicted a prevalence of about 20 % . In the EPIC-Potsdam cohort , the shape of obesity trend favors a leveling off model among men ( R2 = 0.98 ) , and a linear model among women ( R2 = 0.99 ) . Conclusion Our data show an increase in obesity prevalence since the 1990ies , and predictions by 2015 suggests a sizeable further increase in European population s. However , the estimates from the leveling off model were considerably lower RATIONALE Heterogeneity in asthma expression is multidimensional , including variability in clinical , physiologic , and pathologic parameters . Classification requires consideration of these disparate domains in a unified model . OBJECTIVES To explore the application of a multivariate mathematical technique , k-means cluster analysis , for identifying distinct phenotypic groups . METHODS We performed k-means cluster analysis in three independent asthma population s. Clusters of a population managed in primary care ( n = 184 ) with predominantly mild to moderate disease , were compared with a refractory asthma population managed in secondary care ( n = 187 ) . We then compared differences in asthma outcomes ( exacerbation frequency and change in corticosteroid dose at 12 mo ) between clusters in a third population of 68 subjects with predominantly refractory asthma , clustered at entry into a r and omized trial comparing a strategy of minimizing eosinophilic inflammation ( inflammation-guided strategy ) with st and ard care . MEASUREMENTS AND MAIN RESULTS Two clusters ( early-onset atopic and obese , noneosinophilic ) were common to both asthma population s. Two clusters characterized by marked discordance between symptom expression and eosinophilic airway inflammation ( early-onset symptom predominant and late-onset inflammation predominant ) were specific to refractory asthma . Inflammation-guided management was superior for both discordant subgroups leading to a reduction in exacerbation frequency in the inflammation-predominant cluster ( 3.53 [ SD , 1.18 ] vs. 0.38 [ SD , 0.13 ] exacerbation/patient/yr , P = 0.002 ) and a dose reduction of inhaled corticosteroid in the symptom-predominant cluster ( mean difference , 1,829 mug beclomethasone equivalent/d [ 95 % confidence interval , 307 - 3,349 mug ] ; P = 0.02 ) . CONCLUSIONS Cluster analysis offers a novel multidimensional approach for identifying asthma phenotypes that exhibit differences in clinical response to treatment algorithms Abstract Objective : To investigate the influence of weight reduction on obese patients with asthma . Design : Open study , two r and omised parallel groups . Setting : Private out patients centre , Helsinki , Finl and . Participants : Two groups of 19 obese patients with asthma ( body mass index ( kg/m2 ) 30 to 42 ) recruited through newspaper advertisements . Intervention : Supervised weight reduction programme including 8 week very low energy diet . Main outcome measures : Body weight , morning peak expiratory flow ( PEF ) , forced vital capacity ( FVC ) , forced expiratory volume in one second ( FEV1 ) ; and also asthma symptoms , number of acute episodes , courses of oral steroids , health status ( quality of life ) . Results : At the end of the weight reducing programme , the participants in the treatment group had lost a mean of 14.5 % of their pretreatment weight , the controls 0.3 % . The corresponding figures after one year were 11.3 % and a weight gain of 2.2 % . After the 8 week dieting period the difference in changes in percentage of predicted FEV1 from baseline in the treatment and control groups was 7.2 % ( 95 % confidence interval 1.9 % to 12.5 % , P=0.009 ) . The corresponding difference in the changes in FVC was 8.6 % ( 4.8 % to 12.5 % , P<0.0001 ) . After one year the differences in the changes in the two groups were still significant : 7.6 % for FEV1 ( 1.5 % to 13.8 % , P=0.02 ) and 7.6 % for FVC ( 3.5 % to 11.8 % , P=0.001 ) . By the end of the weight reduction programme , reduction in dyspnoea was 13 mm ( on a visual analogue scale 0 mm to 100 mm ) in the treatment group and 1 mm in the control group ( P=0.02 ) . The reduction of rescue medication was 1.2 and 0.1 doses respectively ( P=0.03 ) . After one year the differences in the changes between the two groups were −12 for symptom scores ( range −1 to −22 , P=0.04 ) and −10 for total scores ( −18 to −1 , P=0.02 ) . The median number of exacerbations in the treatment group was 1 ( 0–4 ) and in the controls 4 ( 0–7 ) , P=0.001 . Conclusion : Weight reduction in obese patients with asthma improves lung function , symptoms , morbidity , and health status Forced expiratory volume in 1 second ( FEV(1 ) ) is a strong risk factor for cardiovascular disease , stroke , lung cancer , and all-cause mortality . One possible explanation for this association is that FEV(1 ) is a marker of other determinants of mortality risk , such as obesity and physical inactivity . In a population -based cohort study of 12,283 men and women aged 45 - 74 years from the European Prospect i ve Investigation into Cancer-Norfolk Study recruited in 1993 - 1997 , the cross-sectional association between physical activity and FEV(1 ) and that between physical activity and change in FEV(1 ) were analyzed . Indices of physical activity , including  participation in vigorous recreational activity , stair climbing , and television viewing  , were assessed with a vali date d question naire design ed to assess activity in the previous year . Television viewing was negatively associated with FEV(1 ) in men and women ( p < 0.001 ) , whereas stair climbing and participation in vigorous leisure time activities were positively associated with FEV(1 ) in men and women ( p < 0.001 ) . The associations remained after adjustment for known confounders , including age , height , vitamin C , and smoking . Climbing more stairs and participating in vigorous leisure-time activity predicted a slower rate in annual percent decline in FEV(1 ) ( p < 0.004 and p < 0.002 , respectively ) . In conclusion , physical activity is associated with higher levels of FEV(1 ) , whereas television viewing is associated with lower levels OBJECTIVE The objectives of our study were to compare patient characteristics and severity of disease in obese and normal-weight-confirmed people with asthma and to explore reasons for misdiagnosis of asthma , including potential interactions with obesity . METHODS We r and omly selected patients with physician-diagnosed asthma from eight Canadian cities . Asthma diagnosis was confirmed via a sequential lung function testing algorithm . Logistic analysis was conducted to compare obese and normal-weight-confirmed people with asthma and to assess characteristics associated with misdiagnosis of asthma . Interaction with obesity was investigated . RESULTS Complete assessment s were obtained on 496 subjects who reported physician-diagnosed asthma ( 242 obese and 254 normal-weight subjects ) ; 346 had asthma confirmed with sequential lung testing , and in 150 subjects a diagnosis of asthma was ruled out . Obese subjects with asthma were significantly more likely to be men , have a history of hypertension and gastroesophageal reflux disease , and have a lower FEV(1 ) compared with normal-weight subjects with asthma . Older subjects , men , and subjects with higher FEV(1 ) were more likely to have received misdiagnoses of asthma . Obesity was not an independent predictor of misdiagnosis , however there was an interaction between obesity and urgent visits for respiratory symptoms . The odds ratio for receiving a misdiagnosis of asthma for obese individuals as compared with normal-weight individuals was 4.08 ( 95 % CI , 1.23 - 13.5 ) for those with urgent visits in the past 12 months . CONCLUSIONS Obese people with asthma have lower lung function and more comorbidities compared with normal-weight people with asthma . Obese individuals who make urgent visits for respiratory symptoms are more likely to receive a misdiagnosis of asthma BACKGROUND Although obesity has been hypothesized to worsen asthma , data from studies of subjects with well-characterized asthma are lacking . OBJECTIVE We sought to evaluate the relationship between body mass index ( BMI ) , asthma impairment , and response to therapy . METHODS BMI ( in kilograms per meter squared ) and asthma phenotypic and treatment response data were extracted from Asthma Clinical Research Network studies . The cross-sectional relationship between BMI and asthma impairment was analyzed , as was the longitudinal relationship between BMI and response to asthma controller therapies . RESULTS One thous and two hundred sixty-five subjects with mild-to-moderate persistent asthma were evaluated . Analyses of lean versus overweight/obese asthmatic subjects demonstrated small differences in FEV1 ( 3.05 vs 2.91 L , P = .001 ) , FEV1/forced vital capacity ratio ( mean , 83.5 % vs 82.4 % ; P = .01 ) , rescue albuterol use ( 1.1 vs 1.2 puffs per day , P = .03 ) , and asthma-related quality of life ( 5.77 vs 5.59 , P = .0004 ) . Overweight/obese asthmatic subjects demonstrated a smaller improvement in exhaled nitric oxide levels with inhaled corticosteroid ( ICS ) treatment than did lean asthmatic subjects ( 3.6 vs 6.5 ppb , P = .04 ) . With ICS/long-acting beta-agonist treatment , overweight/obese asthmatic subjects demonstrated smaller improvements in lung function than lean asthmatic subjects , with an 80 mL ( P = .04 ) and 1.7 % ( P = .02 ) lesser improvement in FEV1 and FEV1/forced vital capacity ratio , respectively . Significant differences in therapeutic response to leukotriene modifiers between BMI categories were not observed . CONCLUSIONS Increased BMI is not associated with clinical ly significant worsening of impairment in subjects with mild-to-moderate persistent asthma . There is a modest association between increased BMI and reduced therapeutic effect of ICS-containing regimens in this patient population . Prospect i ve studies evaluating the effect of being overweight or obese on treatment response in asthma are warranted The aim of this study was to assess the influence of some risk factors for onset and remission of allergic rhinitis and asthma in Swedish adults . A r and om sample of 1,370 subjects , age 20 to 44 yr was investigated by means of postal question naires in 1990 and 1993 . Skin prick tests were conducted in 1991 - 1992 . The association between risk factors and onset or remission of allergic rhinitis and asthma was estimated using multivariate logistic regression analysis . Onset of allergic rhinitis was associated with sensitization to birch ( odds ratio [ OR ] = 6.5 ) , Parietaria ( OR = 7.4 ) ; and pets ( OR = 3.0 ) and with female sex ( OR = 1.9 ) . Onset of asthma was associated with allergic rhinitis ( OR = 4.9 ) , sensitization to pets ( OR = 2.4 ) ; and with smoking ( OR = 3.0 ) . Onset of asthma was strongly associated with allergic rhinitis among atopics ( OR = 5.7 ) , but onset of asthma and rhinitis also tended to be related among nonatopics ( OR = 3.5 ) . A strong association between smoking and onset of asthma was found among nonatopics ( OR = 5.7 ) . In conclusion , sensitization to pollens and pets were risk factors for onset of allergic rhinitis , whereas allergic rhinitis , sensitization to pets , and smoking were risk factors for onset of asthma We prospect ively evaluated the association of hormone replacement therapy and  asthma incidence in a cohort of pre- and postmenopausal women 34 to 68 yr of age . During 582 , 135 person-years of follow-up between 1980 and 1990 , 726 new cases of asthma were documented . Postmenopausal women who were never users of replacement hormones  had a significantly lower age-adjusted risk of asthma than premenopausal women ( relative risk = 0.65 ; 95 % confidence interval [ CI ] = 0.46 to 0.92 ) . Among naturally menopausal women , the age-adjusted relative risk of asthma for ever use of postmenopausal hormones was 1.49 ( 95 % CI = 1.10 to 2.00 ) ; for current use of hormones ( conjugated estrogens with or without progesterone ) , 1.50 ( 95 % CI = 0.98 to 2.30 ) ; and for past use , 1.52 ( 95 % CI = 1.08 to 2.13 ) , compared with never use of hormones . Ever users of 10 or more years ' duration had twice the age-adjusted risk of asthma compared with women who never used postmenopausal hormones ( 95 % CI = 1.39 to 2.87 ) . Among current users of conjugated estrogens , there was a positive dose-response demonstrated between daily dose and asthma risk ( p for trend = 0.007 ) . While confirmatory studies are warranted , these data suggest that estrogen plays a role in the pathophysiology of asthma and that long-term use and /or high doses of postmenopausal hormone therapy increase subsequent risk of asthma Glucocorticoid receptors ( GRs ) are cytoplasmaticreceptors regulating the expression of cortisol and bind to specific sites on chromatin . The glucocorticoid receptor gene ( GRL ) is located on chromosome 5q31 and encodes for either a 777-amino acid ( GRalpha ) or a 742-amino acid ( GRbeta ) polypeptide . The objective of the current study was to examine the prospect i ve association of 3 polymorphisms-a Tth111I restriction fragment in the promoter region , a BclI polymorphism in intron 2 , and an A/G polymorphism in exon 2-of the GRL gene on estimates of obesity , hypertension , and diabetes in 163 unrelated Swedish men born in 1944 . These data showed a significant increase in body weight , body mass index , abdominal obesity , fasting glucose , insulin , and homeostasis model assessment over the 5-year follow-up among homozygotes for the rare BclI allele . In contrast , no significant associations with the Tth111I or A/G polymorphism were detected . It is concluded that the genetic information about GRL would be useful for further genetic study of obesity , diabetes , and related metabolic diseases Previous studies have suggested that atopy is linked to the beta chain of the high affinity IgE receptor ( Fcepsilon R1-beta ) on chromosome 11q13 . Fcepsilon R1-beta polymorphisms , I181L , V183L , and E237 G , are reported to be associated with asthma and atopy . The aim of this study was to investigate linkage to Fcepsilon R1-beta in a UK population and to assess the frequency of the polymorphisms and their association with asthma and atopy . A sample of 131 families was recruited at r and om with a sample of 109 families ascertained via an asthmatic prob and . Each subject completed a written and video-assisted question naire and underwent bronchial challenge and skin prick testing .  Serum total and specific IgE levels were measured . Quantitative scores were derived for asthma and atopy using principal component analysis . Four microsatellite markers were genotyped , including Fcepsilon R1-beta . The frequency of the I181L and V183L polymorphisms were determined by sequencing , and the E237 G polymorphism was determined using the amplification refractory mutation system . We found no evidence for linkage to Fcepsilon R1-beta and only weak evidence for linkage to the less informative marker E237 G . We found no examples of the I181L/V183L polymorphism in our population sample . Our study has failed to strengthen the evidence for a c and i date gene on chromosome 11q13 AIMS The possibility of a relationship between gastroesophageal reflux disease ( GERD ) and asthma has been controversial . Using a nationwide population -based data set , this study aims to investigate the prevalence and risk of concurrent asthma  among GERD patients , compared with patients without GERD in Taiwan . METHODS This study used the National Health Insurance Research Data base . A total of 61 941 patients with GERD and 61 941 r and omly selected patients without GERD were included from the year 2006 .  Conditional logistic regression analyses were used to explore the risk of concurrent asthma for patients with and without GERD . Furthermore , the analyses performed were stratified by sex and age ( 18 - 44 , 45 - 64 , 65 - 74 and > 74 years ) to evaluate the association between GERD and concurrent asthma . RESULTS Of the 123 882 sample d patients , 3 % ( 3681 patients ) were diagnosed with asthma in 2006 , consisting of 3.9 % of the GERD patients ( 2427 from the study group ) and 2 % of the patients without GERD ( 1254 from the comparison group ) . Conditional logistic regression analysis showed that the odds of concurrent asthma for patients with GERD were 1.97 times greater [ 95 % confidence interval ( CI ) = 1.84 - 2.12 , P < 0.001 ] than the odds of asthma for patients without GERD . When stratifying by age groups , the odds ratios for GERD with concurrent asthma were 2.61 ( 95 % CI=2.24 - 3.03 , P<0.001 ) for patients 18 - 44 years of age , 2.00 for patients 45 - 64 years of age ( 95 % CI=1.79 - 2.23 , P<0.001 ) , 1.58 for those aged 65 - 74 ( 95 % CI=1.36 - 1.83 , P<0.001 ) and 1.80 for those aged 75 years or more ( 95 % CI=1.52 - 2.12 , P<0.001 ) . CONCLUSION Patients with GERD had a significantly higher risk of concurrent asthma compared with patients without GERD Background . Obesity is well recognized as a state of increased insulin resistance and has been implicated as a significant risk factor for both asthma prevalence and asthma severity in children and adolescents . However , little is known about the specific factors that relate asthma and obesity . Recently , the pro-inflammatory state in obesity and its association with insulin resistance have been recognized . We hypothesize that the effect of morbid obesity on asthma is related to insulin resistance . Methods . The patient cohort in the obesity management program at the Children 's Hospital of Wisconsin was retrospectively review ed . Variables were collected from the program data base and chart review was done for missing variables . Patients were considered to have asthma if the evaluating physician confirmed the diagnosis through history and /or the patient had been on inhaled corticosteroids .  Insulin resistance ( IR ) was calculated using a homeostasis model assessment ( HOMA ) . Multivariate logistic regression was performed to identify variables that were significantly related to the odds of having asthma . Results . Of the 415 patients included in the study , 146 ( 35 % ) were asthmatic and 269 ( 65 % ) were non-asthmatic . The asthma ( AG ) and non-asthma ( NAG ) groups were similar with respect to mean age ( 11.3 vs. 11.5 years ) , gender ( 45 % vs. 43 % males ) , mean body mass index ( BMI ) ( 36.4 vs. 34.9 ) , and exposure to smoking ( 43 % vs. 42 % ) . Fhx of asthma was significantly higher in AG ( 71 % ) compared to NAG ( 40 % ) . IR level ± SD was 8.5 ± 9.7 in AG compared to 5.3 ± 6.7 in NAG ( p < 0.0001 ) . Multivariate regression analysis found the following variables to be associated with having asthma : younger age ( p < 0.05 ) , smoking exposure ( p < 0.05 ) , positive Fhx of asthma ( p < 0.0001 , odds ratio of 3.1 ) , and IR ( p < 0.0001 , odds ratio of 4.1 ) . Conclusion . Morbidly obese asthma patients have a higher degree of insulin resistance compared to morbidly obese non-asthma patients . We speculate that the pro-inflammatory state of insulin resistance may contribute to the pathogenesis of asthma in obese patients . Future prospect i ve studies should address insulin resistance as a possible risk factor for asthma in obese children and adolescents STUDY OBJECTIVE Beta(2)-adrenoceptor Gly16 polymorphism has been associated with asthma severity and beta(2)-adrenoceptor receptor downregulation , but not with the diagnosis of asthma . Glu27 polymorphism may limit beta(2)-adrenoceptor downregulation and predict body mass index ( BMI ) , particularly among sedentary persons . In addition , BMI predicts asthma . We hypothesized that these DNA sequence variants predict adult-onset asthma only in sedentary women . DESIGN Nested case-control study . SETTING Nurses ' Health Study , a large , prospect i ve cohort study with participants throughout the United States . PARTICIPANTS Among lifelong nonsmokers , 171 women with adult-onset , medication-requiring asthma and 137 age-matched control subjects . MEASUREMENTS  Physical activity and BMI were self-reported by previously vali date d question naire items . Genomic DNA was obtained from buccal brushings collected via first-class mail . RESULTS Of 76 sedentary women , the adjusted odds ratios of Gly16 allele were 7.4 ( p = 0.047 ) for asthma and 13.8 ( p = 0.02 ) for steroid-requiring asthma . No similar associations were observed among 232 active women ( p = 0.91 ) . Sedentary individuals with both Gly16 and Glu27 alleles had a less elevated risk for asthma . BMI was associated with asthma and Glu27 allele among sedentary women . CONCLUSION This exploratory analysis suggests an important gene/environment interaction for asthma involving physical activity level . Further study in larger population s is warranted to confirm if sedentary lifestyle unmasks a genetic risk for asthma An epidemic rise in asthma has occurred concurrently with a rise in overweight among United States children , but it is unclear whether body weight affects the risk of incident childhood asthma . We studied the prospect i ve relation of  body-mass index ( BMI ) to incident asthma in a longitudinal study of 9,828 children aged 6 - 14 years , examined annually over a median follow-up time of 5 years in six US cities . An increased risk of a new asthma diagnosis in girls was associated with higher BMI at entry into the study ( P=0.009 ) and greater increase in BMI during follow-up ( P=0.0003 ) . Compared with girls in the leanest quintile of BMI at entry ( age taken into account ) , girls in the top quintile of adiposity had 2.2 times greater risk of incident asthma with any wheeze in subsequent years . Girls with the largest annual rate of increase in BMI ( top compared to bottom quintile , age taken into account ) had 1.5 times the risk of asthma with any wheeze , and 2.2 times the risk of asthma with persistent wheeze . Boys with the largest and smallest annual changes in BMI also had an increased risk of asthma . For girls , overweight contributes to development of asthma . For boys and girls , extremes of annual BMI growth rates increase the risk of asthma Background : It is unclear whether asthma is overdiagnosed in developed countries , particularly among obese individuals , who may be more likely than nonobese people to experience dyspnea . Methods : We conducted a longitudinal study involving nonobese ( body mass index 20–25 ) and obese ( body mass index ≥ 30 ) individuals with asthma that had been diagnosed by a physician . Participants were recruited from 8 Canadian cities by means of r and om-digit dialing . A diagnosis of current asthma was excluded in those who did not have evidence of acute worsening of asthma symptoms , reversible airflow obstruction or bronchial hyperresponsiveness , despite being weaned off asthma medications . We stopped asthma medications in those in whom a diagnosis of asthma was excluded and assessed their clinical outcomes over 6 months . Results : Of 540 individuals with physician-diagnosed asthma who participated in the study , 496 ( 242 obese and 254 nonobese ) could be conclusively assessed for a diagnosis of asthma . Asthma was ultimately excluded in 31.8 % ( 95 % confidence interval [ CI ] 26.3%–37.9 % ) in the obese group and in 28.7 % ( 95 % CI 23.5%–34.6 % ) in the nonobese group . Overdiagnosis of asthma was no more likely to occur among obese individuals than among nonobese individuals ( p = 0.46 ) . Of those in whom asthma was excluded , 65.5 % did not need to take asthma medication or seek health care services because of asthma symptoms during a 6-month follow-up period . Interpretation : About one-third of obese and nonobese individuals with physician-diagnosed asthma did not have asthma when objective ly assessed . This finding suggests that , in developed countries such as Canada , asthma is overdiagnosed There is evidence that the origin of obstructive lung disease may be traced back to foetal life . The associations between birth characteristics and asthma symptoms were studied in a r and om population sample of young Norwegian adults . Respiratory symptoms were recorded in a population -based question naire survey .  The records of all subjects aged 20 - 24 yrs were linked with the Medical Birth Registry of Norway . Of 868 subjects born in Norway , there were 690 ( 79 % ) responders . The associations between asthma symptoms and birth characteristics were analysed by logistic regression , adjusted for possible confounding factors . Asthma symptoms in young adults were inversely associated with birth weight ( odds ratio (OR)wheeze=0.82 ; 95 % confidence interval (CI)=0.69 - 0.96x500 g increase in birth weight(-1 ) ) ) , and after adjustment for gestational age , birth length , parity and maternal age ( ORwheeze=0.69 ; 95 % CI=0.50 - 0.95x500 g increase in birth weight(-1 ) ) . The association did not vary according to adult smoking habits or atopic status and remained when premature and low weight births were excluded ( ORwheeze=0.73 ; 95 % CI=0.60 - 0.90x500 g increase in birth weight(-1 ) ) . The association was consistent for all asthma symptoms . Adjusted for birth weight , asthma symptoms were further associated with low gestational age , high birth length and low maternal age . In a r and om sample of young adults , asthma symptoms were strongly associated with low birth weight , an association driven by the full-term births within the normal birth weight range . The findings show that the risk for adult asthma is partly established early in life and suggest that poor intrauterine growth is involved in the aetiology of asthma BACKGROUND Obesity and asthma are common disorders , and their prevalence rates continue to rise . Although individuals with asthma may gain weight as a result of activity limitations , the relationship between body mass index ( BMI ) , which is calculated as weight in kilograms divided by the square of height in meters , and risk of developing asthma is not known . METHODS We performed a prospect i ve cohort study of female US registered nurses in the Nurses ' Health Study II . In 1991 , after excluding women who died with probable asthma or with incomplete data , there were 85911 participants , aged 26 to 46 years . The main outcome measure was self-report of physician-diagnosed asthma with recent use of an asthma medication . RESULTS From 1991 to 1995 , we identified 1596 incident cases of asthma . In a multivariate model controlling for 9 potential confounding factors ( including age , race , smoking , physical activity , and energy intake ) , the relative risks of asthma for 6 increasing categories of BMI in 1991 were 0.9 , 1.0 ( reference ) , 1.1 , 1.6 , 1.7 , and 2.7 ( P for trend < .001 ) . Stronger associations were found using stricter definitions for asthma , and the finding was present in a variety of subgroups . In analyses controlling for the same variables , as well as BMI at age 18 , women who gained weight after age 18 were at significantly increased risk of developing asthma during the 4-year follow-up period ( P for trend < .001 ) . CONCLUSIONS The BMI has a strong , independent , and positive association with risk of adult-onset asthma . The increasing prevalence of obesity in developed nations may help explain concomitant increases in asthma prevalence BACKGROUND Asthma in obese subjects is poorly understood , and these patients are often refractory to st and ard therapy . OBJECTIVES We sought to gain insights into the pathogenesis and treatment of asthma in obese subjects by determining how obesity and bariatric surgery affect asthma control , airway hyperresponsiveness ( AHR ) , and markers of asthmatic inflammation . METHODS We performed a prospect i ve study of ( 1 ) asthmatic and nonasthmatic patients undergoing bariatric surgery compared at baseline and ( 2 ) asthmatic patients followed for 12 months after bariatric surgery .  RESULTS We studied 23 asthmatic and 21 nonasthmatic patients undergoing bariatric surgery .  At baseline , asthmatic patients had lower FEV(1 ) and forced vital capacity and lower numbers of lymphocytes in bronchoalveolar lavage fluid . After surgery , asthmatic participants experienced significant improvements in asthma control ( asthma control score , 1.55 to 0.74 ; P < .0001 ) and asthma quality of life ( 4.87 to 5.87 , P < .0001 ) . Airways responsiveness to methacholine improved significantly ( methacholine PC(20 ) , 3.9 to 7.28 , P = .03 ) . There was a statistically significant interaction between IgE status and change in airways responsiveness ( P for interaction = .01 ) . The proportion of lymphocytes in bronchoalveolar lavage fluid and the production of cytokines from activated peripheral blood CD4(+ ) T cells increased significantly . CONCLUSIONS Bariatric surgery improves AHR in obese asthmatic patients with normal serum IgE levels . Weight loss has dichotomous effects on airway physiology and T-cell function typically involved in the pathogenesis of asthma , suggesting that obesity produces a unique phenotype of asthma that will require a distinct therapeutic approach BACKGROUND Asthma prevalence has been increasing especially in developed countries . The change seems to be associated with changes in lifestyle . We have made a prospect i ve study to assess the effect of lifestyle factors , including smoking , educational level , physical activity and obesity on adult onset asthma . METHODS A population of 10,597 adult twins , initially free of asthma was followed for 9 years . The main outcome measure was question naire-based report of physician diagnosed asthma . Logistic regression  was used to estimate the risk of asthma predicted by lifestyle factors , with adjustment for atopy and respiratory symptoms . RESULTS Obesity at baseline increased asthma risk ( multivariable adjusted OR = 3.00 , 95 % CI : 1.64 - 5.50 for those with BMI > or = 30 compared to those with normal weight BMI : 20 - 24.99 ) . Taller height was associated to lower asthma incidence . Leisure time physical activity had a slightly protective effect on asthma risk  among men ( P for trend = 0.037 ) while smoking and education did not have significant effects on the risk of adult onset asthma . CONCLUSIONS Obesity was associated to the risk of adult onset asthma , while short height and low leisure time physical activity can be considered as other potential risk factors We tested whether asthma diagnosis is associated with  weight gain and physical activity  in 4,547 18 to 30-yr-old African American and white men and women , followed prospect ively for up to 10 yr . Baseline asthma was most frequent in African American men . Incident asthma was more frequent in women . Incident asthma was associated with highest and lowest baseline and change in body mass index ( BMI ) , in a J-shaped curve , after adjustment for other factors . When stratified by sex , this association was seen only in females . Subjects on average decreased physical activity and gained weight over time , but there was no significant difference in asthma prevalence by physical activity at baseline or asthma incidence by change in physical activity . Cigarette smoking in females was significantly associated with asthma incidence , but serum cotinine level at baseline among nonsmokers ( reflecting environmental tobacco smoke [ ETS ] exposure ) was not significantly associated with asthma . We conclude that gain in BMI predisposes to new asthma diagnosis in female young adults , but decreased physical activity does not explain the association of weight gain with asthma We hypothesized that hyperresponsiveness in asthma is caused by an impairment in the ability of inspiration to stretch airway smooth muscle . If the hypothesis was correct , we reasoned that the sensitivity to inhaled methacholine in normal and asthmatic subjects should be the same if the challenge was carried out under conditions where deep inspirations were prohibited . 10 asthmatic and 10 normal subjects received increasing concentrations of inhaled methacholine under conditions where forced expirations from a normal end-tidal inspiration were performed . When no deep inspirations were allowed , the response to methacholine was similar in the normal and asthmatic subjects , compatible with the hypothesis we propose . Completely contrary to our expectations , however , was the marked responsivity to  methacholine  that remained in the normal subjects after deep breaths were initiated . 6 of the 10 normal subjects had > 20 % reduction in forced expiratory volume in one second ( FEV 1 ) at doses of methacholine < 8 mg/ml , whereas there was < 15 % reduction with 75 mg/ml during routine challenge . The ability of normal subjects to develop asthmatic responses when the modulating effects of increases in lung volume was voluntarily suppressed suggests that an intrinsic impairment of the ability of inspiration to stretch airway smooth muscle is a major feature of asthma Leptin ( LEP ) and the uncoupling proteins 2 and 3 ( UCP2/UCP3 ) are key molecules involved in the regulation of food intake and energy expenditure . However , their contribution to variation of obesity phenotypes in the general population remains controversial . The present study is to investigate whether chromosomal regions 7q and 11q , which contain LEP and UCP2/UCP3 , respectively , can be excluded for linkage with obesity phenotypes . The obesity phenotypes include body mass index ( BMI ) , fat mass , and percentage fat mass ( PFM ) , with the latter two measured by dual-energy X-ray absorptiometry . We conducted exclusion linkage analyses using a variance component approach in a sample of 1816 individuals coming from 79 extended Caucasian pedigrees . In this study , we were able to exclude chromosomal region 7q containing LEP as having an effect on fat mass and PFM at effect sizes of 5 % or greater , and on BMI at effect sizes of 10 % or greater . We were able to exclude chromosomal region 11q containing UCP2/UCP3 as having an effect on fat mass and PFM at effect sizes of 10 % or greater , and on BMI at effect sizes of 5 % or greater . Our results suggest that the LEP and UCP2/UCP3 genes are unlikely to have a substantial effect on variation in obesity phenotypes in this particular US Caucasian population AIM To investigate the impact of airway lability , atopy , and tobacco smoking on the development of  asthma-like symptoms in asymptomatic subjects . METHODS In this prospect i ve , community-based study , 271 asymptomatic adolescents with an average age at inclusion of 13.9 years were followed for 6.4 years . Airway lability was assessed at baseline by three tests , including exercise challenge , airway provocation with methacholine , and monitoring of peak expiratory flow . Atopy was defined by one or more positive reactions ( > or = 3-mm weal ) to 10 common aeroallergens by skin prick testing . The influence of airway lability , atopy , and smoking on the development of asthma-like symptoms was assessed by logistic regression . RESULTS During the 6-year study period , 68 of the previously asymptomatic teenagers ( 25 % ) developed  asthma-like symptoms . Among those , 50 % reported cough only , 29 % reported wheezing only , and 21 % reported both wheezing and coughing . Hyperresponsiveness to methacholine ( odds ratio [ OR ] , 3.5 ; 95 % confidence interval [ CI ] , 1.1 to 11.6 ) , smoking ( OR , 2.1 ; 95 % CI , 1 . 2 to 3.8 ) , and atopy ( OR , 3.5 ; 95 % CI , 1.8 to 6.8 ) each contributed independently to explain symptom development ( wheezing and cough together ) . Girls , but not boys , with airway lability were less likely to take up smoking , compared with subjects of that set with no airway lability ( 32 % vs 51 % ; p < 0.05 ) . No effect of airway lability on the likelihood of giving up smoking could be demonstrated , nor did the presence of atopy have any significant impact on smoking behavior . CONCLUSION Hyperresponsiveness to methacholine , atopy , and smoking were independent risk factors for the development of asthma-like symptoms during adolescence . The presence of airway lability may prevent girls from taking up smoking The prevalence and factors associated with snoring and habitual snoring in Asian children are largely unknown . Our objectives were to evaluate the prevalence and factors associated with snoring and habitual snoring in preschool and primary school children in Singapore . A self-response question naire on snoring was administered to parents of children aged 4 - 7 years in r and omly selected preschools and primary schools in Singapore . The overall response rate was 91.3 % ( nt = 11,114 ) . Snoring and habitual snoring were reported in 28.1 % and in 6.0 % of the children , respectively . On multivariate logistic regression analysis , snoring was significantly associated with male gender , race , atopy ( asthma , allergic rhinitis , or atopic dermatitis ) , maternal atopy ( allergic rhinitis or atopic dermatitis ) , maternal smoking , and breastfeeding . Habitual snoring was significantly associated with obesity ( odds ratio ( OR ) , 3.75 ; 95 % confidence interval ( CI ) , 1.67 - 8.42 ) , allergic rhinitis ( OR , 2.90 ; 95 % CI , 2.06 - 4.08 ) , atopic dermatitis ( OR , 1.80 ; 95 % CI , 1.28 - 2.54 ) , maternal smoking ( OR , 2.22 ; 95 % CI , 1.09 - 4.53 ) , and breastfeeding ( OR , 1.49 ; 95 % CI , 1.11 - 1.98 ) . Atopy was the strongest risk factor for habitual snoring , and the effect was cumulative . The odds ratio of a child with all three atopic diseases ( asthma , allergic rhinitis , and atopic dermatitis ) to have habitual snoring was 7.45 ( 95 % CI , 3.48 - 15.97 ) . In conclusion , snoring and habitual snoring are common in Asian children . Atopy is strongly associated with snoring and habitual snoring . We suggest that children who are significantly atopic receive additional attention during screening for snoring , habitual snoring , and other features of obstructive sleep apnea syndrome STUDY OBJECTIVES To characterize asthma symptoms , pulmonary function , and responsiveness to beta 2-agonist stimulation , and in vitro beta 2-receptor density and cyclic adenosine 3',5'-monophosphate ( cAMP ) response throughout the menstrual cycle in women with premenstrual asthma ( PMA ) ; and to examine the effect of exogenous estradiol administration on asthma symptoms , pulmonary function and responsiveness , and beta 2-receptor density and function in these women . DESIGN Open-label , longitudinal , 9-week study . SETTING A university clinical research center . PATIENTS Seventeen women with mild to moderate asthma , of whom 14 completed the study . INTERVENTIONS Every morning on awakening during the entire 9-week study , each subject completed  visual analog scales for asthma symptomatology ( cough , wheezing , breathlessness , chest tightness ) and measured and recorded her peak expiratory flow rate ( PEFR ) with a peak flow meter . Also measured at various times throughout the menstrual cycle were dyspnea index scores , pulmonary function ( PEFR , forced expiratory volume in 1 sec [ FEV1 ] ) , pulmonary response to subcutaneous terbutaline , T lymphocyte beta 2-receptor density ( Bmax ) and function ( cAMP ) , and estradiol , progesterone , and catecholamine concentrations , both with and without exogenous estradiol administration . MEASUREMENTS AND MAIN RESULTS At the time of enrollment , only 5 subjects reported premenstrual worsening of asthma symptoms , but all 14 had greater than 20 % decrease in PEFR and /or increase in symptoms premenstrually during the study . Significant differences ( p < 0.05 ) existed in asthma symptoms and PEFR between day 13 ( highest estradiol concentrations ) and day 26 ( lowest estradiol concentrations ) of the menstrual cycle . Asthma symptoms and dyspnea index scores were significantly improved ( p < 0.05 ) after estradiol administration compared with baseline ( premenstrual period without exogenous estrogen ) . Pulmonary response to terbutaline , beta 2-receptor density and function , and catecholamine concentrations were not significantly altered after estradiol administration , but the trend was toward significant differences ( 0.05 < p < 0.2 ) in pulmonary function tests ( PEFR , FEV1 ) . CONCLUSIONS Even asthmatics not previously aware of PMA may experience premenstrual worsening of asthma symptoms and /or PEFR .  Estradiol is associated with a significant improvement in asthma symptoms and dyspnea index scores . This ameliorating effect does not appear to be related to beta 2-receptors We investigated the effects of body mass index ( BMI ) on functional residual capacity ( FRC ) , respiratory mechanics ( compliance and resistance ) , gas exchange , and the inspiratory mechanical work done per liter of ventilation during general anesthesia . We used the esophageal balloon technique , together with rapid airway occlusion during constant inspiratory flow , to partition the mechanics of the respiratory system into its pulmonary and chest wall components . FRC was measured by using the helium dilution technique . We studied 24 consecutive and unselected patients during general anesthesia , before surgical intervention , in the supine position ( 8 normal subjects with a BMI < or = to25 kg/m2 , 8 moderately obese patients with a BMI > 25 kg/m2 and < 40 kg/m2 , and 8 morbidly obese patients with a BMI > or = to40 kg/m2 ) . We found that , with increasing BMI : 1.FRC decreased exponentially ( r = 0.86 ; P < 0.01 ) 2.the compliance of the total respiratory system and of the lung decreased exponentially ( r = 0.86 ; P < 0.01 and r = 0.81 ; P < 0.01 , respectively ) , whereas the compliance of the chest wall was only minimally affected ( r = 0.45 ; P < 0.05 ) 3.the resistance of the total respiratory system and of the lung increased ( r = 0.81 ; P < 0.01 and r = 0.84 ; P < 0.01 , respectively ) , whereas the chest wall resistance was unaffected ( r = 0.06 ; P = not significant ) 4.the oxygenation index ( PaO2/PAo2 ) decreased exponentially ( r = 0.81 ; P < 0.01 ) and was correlated with FRC ( r = 0.62 ; P < 0.01 ) , whereas PaCO2 was unaffected ( r = 0.06 ; P = not significant ) 5.the work of breathing of the total respiratory system increased , mainly due to the lung component ( r = 0.88 ; P < 0.01 and r = 0.81 ; P < 0.01 , respectively ) . In conclusion , BMI is an important determinant of lung volumes , respiratory mechanics , and oxygenation during general anesthesia with patients in the supine position . Implication s : The aim of this study was to investigate the influence of body mass on lung volumes , respiratory mechanics , and gas exchange during general anesthesia . ( Anesth Analg 1998;87:654 - 60
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