DOI: 10.1542/peds.106.6.1436 2000;106;1436Pediatrics

Henry Lynn and Ellen F. CrainPeter F. Belamarich, Elisabeth Luder, Meyer Kattan, Herman Mitchell, Shaheen Islam,

Nonobese Children With Asthma?Do Obese Inner-City Children With Asthma Have More Symptoms Than

  

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of Pediatrics. All rights reserved. Print ISSN: 0031-4005. Online ISSN: 1098-4275.Boulevard, Elk Grove Village, Illinois, 60007. Copyright © 2000 by the American Academy published, and trademarked by the American Academy of Pediatrics, 141 Northwest Pointpublication, it has been published continuously since 1948. PEDIATRICS is owned, PEDIATRICS is the official journal of the American Academy of Pediatrics. A monthly

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Do Obese Inner-City Children With Asthma Have More Symptoms ThanNonobese Children With Asthma?

Peter F. Belamarich, MD*; Elisabeth Luder, PhD‡; Meyer Kattan, MD‡; Herman Mitchell, PhD§a;Shaheen Islam, MD, MPHi a; Henry Lynn, PhD§ a; and Ellen F. Crain, MD, PhD¶

ABSTRACT. Objective. To test whether obesity is as-sociated with decreased peak expiratory flow rates(PEFR), increased asthma symptoms, and increasedhealth service use.

Design/Methods. Secondary analysis of data from across-sectional convenience sample.

Setting. Emergency departments (EDs) and primarycare clinics in 8 inner-city areas in 7 cities.

Participants. One thousand three hundred twenty-two children aged 4 to 9 years with asthma.

Measures. Obesity was defined as a body mass index(BMI, weight/height2) >95th percentile. Nonobese chil-dren were those with a BMI between the 5th and 95thpercentile. Underweight children with a BMI <5th per-centile were eliminated from the study. Demographicand anthropometric data were obtained during a baselineinterview with the primary caretaker and the child.Symptoms, health service use data and measurements ofPEFR were obtained by parental report during the base-line interview and at 3-month intervals by telephoneinterview over the following 9-month period.

Results. Obese (n 5 249) and nonobese (n 5 1073)children did not differ in terms of age, gender, familyincome, passive smoke exposure, caretaker’s mentalhealth, and skin test reactivity to indoor allergens. Obesechildren were more often Latino (28% vs 17%) and, in the3 months before the baseline interview, were more likelyto have used oral steroids (30% vs 24%). There were nodifferences between groups in terms of baseline PEFRscores. During the 9 months after baseline assessment,the obese group had a higher mean number of days ofwheeze per 2-week period (4.0 vs 3.4), and a greaterproportion of obese individuals had unscheduled EDvisits (39% vs 31%). There were no differences betweenthe groups in terms of frequency of hospitalization, or innocturnal awakening.

Conclusions. In our sample of inner-city childrenwith asthma, obese children used more medicine,wheezed more, and a greater proportion had unsched-uled ED visits than the nonobese children. Pediatrics

2000;106:1436–1441; asthma, obesity, children, peak expi-ratory flow, inner-city.

ABBREVIATIONS. PEFR, peak expiratory flow rates; FVC, forcedvital capacity; FEV1, forced expiratory volume in 1 second;NCICAS, National Cooperative Inner-City Asthma Study; ED,emergency department; NHANES II, National Health and Nutri-tion Examination Survey; BMI, body mass index; NCHS, NationalCenter for Health Statistics; CBCL, Child Behavior Checklist.

Over the last 2 decades, the prevalence of bothchildhood asthma and childhood obesityhave increased markedly in the United

States.1–3 However, whether childhood obesity is as-sociated with a greater degree of asthma morbidityhas not been extensively studied. Luder et al studieda group of African-American and Latino childrenreferred to a pulmonary clinic for asthma and foundthat obesity was associated with a greater medicationuse, a higher relative risk of low peak expiratory flowrates (PEFR) scores, and more missed school days.4In addition, adverse effects of obesity on the pulmo-nary function of healthy children without asthmahave been noted.5–7 A study of 13 morbidly obesechildren found that both the forced vital capacity(FVC) and the forced expiratory volume in 1 second(FEV1) were substantially below predicted values.8 Asignificant proportion of the morbidly obese childrenexamined in that study experienced improvement inpulmonary function test results after receiving bron-chodilators. Exercise-induced bronchospasm hasalso been found in obese but otherwise healthy chil-dren.6 These studies suggest that obesity may beassociated with increased asthma morbidity.

Using the cohort of 1528 children recruited in theNational Cooperative Inner-City Asthma Study(NCICAS),8 we examined whether obesity was asso-ciated with lower PEFR scores, greater health serviceuse for asthma, and more asthma symptoms.

METHODS

ParticipantsThe study group consisted of a convenience sample of 1528

children aged 4 to 9 years with asthma recruited from emergencydepartments (EDs) and primary care clinics in 8 inner-city areas inthe United States (Bronx, NY; East Harlem, NY; St Louis, MO;Washington, DC; Baltimore, MD; Chicago, IL; Cleveland, OH; andDetroit, MI). Participants were recruited during ED visits forasthma or other acute illnesses or injuries, or from primary careclinics during visits for routine care or asthma follow-up care.Recruitment for the study began in November 1992 and wascompleted by October 1993. Participants had to live in census

From the *Division of General Pediatrics, Department of Pediatrics, AlbertEinstein College of Medicine, Children’s Hospital at Montefiore, Bronx,New York; the ‡Department of Pediatrics, Mount Sinai School of Medicine,New York, New York; §Rho, Inc, Chapel Hill, North Carolina; iMichiganState University, Flint, Michigan; and the ¶Department of Pediatrics, JacobiMedical Center, Albert Einstein College of Medicine, Bronx, New York.Presented in part at the Annual Meeting of the Ambulatory PediatricAssociation on May 2, 1997.aDrs Mitchell, Islam, and Lynn were formerly with New England ResearchInstitutes, Watertown, Massachusetts.Received for publication Apr 17, 2000; accepted May 31, 2000.Reprint requests to (P.F.B.) Pediatric Academic Associates, 1621 EastchesterRd, Bronx, NY 10461.PEDIATRICS (ISSN 0031 4005). Copyright © 2000 by the American Acad-emy of Pediatrics.

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tracts served by the study hospital in which 20% to 40% or moreof the households were below the 1990 federal guidelines forpoverty.

Definition of AsthmaAt recruitment, each study child was required to meet at least

1 of the following definitions of asthma: 1) having been told by aphysician that the child has asthma, in combination with cough,wheezing, shortness of breath, or whistling or tightness in thechest lasting for .3 days within the past 12 months or 2) cough,wheezing, or shortness of breath that lasted .6 weeks during theprevious 12 months and 3 out of the 5 following conditions: a)cough, wheezing, or shortness of breath present more than half thedays and nights during the 6-week period, b) cough, wheezing, orshortness of breath aggravated by exercise or cold air, c) a parentor sibling with asthma, d) no history of antibiotic therapy forsinusitis, accompanying the cough, or e) cough, wheezing, orshortness of breath that resulted in disturbance of the child’s sleep.

Anthropometric MeasurementsAfter the child removed shoes and heavy clothing, the height

and weight were measured at the study center during the baselineinterview. Weight and height measurements were made using abalance beam scale and sliding L-shaped arm in accordance withstandard clinical techniques.

Definition of ObesityBased on reference data collected as part of the second cycle of

the National Health and Nutrition Examination Survey (NHANESII) in 1976–1980, obesity was defined as a body mass index (BMI).95th percentile.9 The reference data chosen to represent the 95thpercentile of BMI was collected in 1976–1980, before a significantincrease in childhood obesity in the United States. Recently, per-centiles standards for BMI in United States children were pub-lished using data from more than 66 000 children.10 These valuesare in close agreement with the BMI values used in this analysis.The BMI is the weight in kilograms divided by the square of theheight in meters. There is a strong positive linear correlationbetween BMI and the percentage of body weight that is fat.11,12

There is growing international consensus that a BMI .95th per-centile is a valid and clinically useful definition of obesity.13

Analytic SampleOne thousand five hundred twenty-eight children were en-

rolled in the NCICAS. We screened out errors in anthropometricmeasurements, or data entry, by examining outliers using thefollowing criteria: 1) weight for age z score less than 26 or .6; 2)height for age z score less than 26 or .6; and 3) weight for heightz score less than 24 or .6. Two of the authors (P.F.B. and E.L.)independently reviewed the anthropometric data of the 58 chil-dren who met the criteria for outliers and using standard NationalCenter for Health Statistics (NCHS) growth charts agreed to ex-clude 15 of these children whose measurements seemed biologi-cally implausible. After these exclusions, full anthropometric data,including weight for height z scores, were available for 1380children. Fifty-eight children with a BMI ,5th percentile wereexcluded from analysis so that cachectic children would not beincluded in the analysis of nonobese children.

MeasurementsAfter enrollment, a structured interview was conducted with

the child’s primary caretaker concerning the demographic charac-teristics of the household, including self-reported race/ethnicity,the child’s access to medical care, adherence to medical therapy,and history of medication use in the 3 months before the baselineinterview. Information on the home environment and exposure totobacco smoke were also collected. Skin-testing to indoor allergens(cat, dog, rat, mouse, roach, mite, Alternaria, and Penicillium) wasperformed on the child, and urine was collected to assay forcotinine, a metabolite of nicotine.

The child’s psychological health was measured using a modi-fied version of the Child Behavior Checklist (CBCL). The CBCL isa 113-item questionnaire that generates a score for behavioralproblems and symptoms. A modification of the CBCL was devel-

oped for the NCICAS that eliminates 13 items which could beconfounded by asthma symptoms (eg, difficulty sleeping).14 Rawscores on the modified test were subsequently converted to T-scores by comparison with a normative population. A score of 64or greater was considered indicative of substantial psychologicalproblems in the child.

The mental health of the child’s primary caretaker was evalu-ated using the Brief Symptom Inventory, a standardized 53-itemquestionnaire that generates scores for 3 global dimensions.14 Forthe current study, summary scores were converted to T-scores bycomparison with a normative population that was matched to thepopulation recruited into the study in terms of ethnic compositionand socioeconomic status. A score above 63 was considered toindicate psychological problems in the caretaker.

At intervals of 3, 6, and 9 months from the baseline visit,measurements of health service use and asthma symptoms wereobtained from the primary caretaker by a trained interviewerusing a standard questionnaire. These assessments were com-pleted by telephone in 93% of cases and by in-person interview in7% of cases. Follow-up interviews at the 3, 6, and 9-month timepoints were completed for 90%, 92%, and 94% of the sample,respectively.

Measures of Health Service Use and Asthma SymptomsThe measurements of health service use examined for this

study included the following: 1) hospitalizations for asthma, 2)unscheduled doctor or clinic visits for asthma (including ED vis-its), and 3) ED visits for asthma. Hospitalizations, unscheduledvisits, and ED visits were dichotomized into the following cate-gories: 1) none, or 2) any, because the vast majority of participantsreported either none or 1 event. Results are expressed as theproportion of individuals reporting one or more events during the9-month period after the baseline assessment.

Questions assessing asthma symptoms included the number ofdays the child wheezed, the number of nights the child wasawakened by asthma, and the number of days the child’s play wasslowed because of asthma symptoms in the previous 2 weeks.Results of the symptom frequency reports are expressed as a meanper 2-week period.

Medication usage was not assessed during the follow-up pe-riod.

Peak Flow MeasurementsPeak flow measurements were obtained using a mini-Wright

peak flow meter (Clement Clarke, Columbus, OH). The researchstaff taught the child how to use the meter and observed the childusing it correctly. The recorded measurement was the highest of 3maximal expiratory maneuvers obtained during the baseline visit.For children recruited during an ED visit, measurements of base-line peak flow measurements were deferred for 4 weeks. Rawpeak flow measurements were converted to percentages of pre-dicted peak expiratory flow rates using gender- and race-specificnomograms.15 Mean PEFR at baseline were calculated for theobese and nonobese groups. In addition, PEFR measurementswere plotted against weight for height z score to seek a trend ofdecreasing PEFR with increasing obesity that would not be appar-ent in a dichotomous comparison of obese and nonobese individ-uals. Results of this analysis are presented in Fig 1.

Statistical AnalysisThe EPINUT module of EPI Info (EPI Info Version 6.04, Centers

for Disease Control and Prevention, Atlanta, GA) program wasused to calculate z scores for weight for age, height for age, andweight for height. Continuous morbidity measures such as thenumber of days of wheezing, the number of nights child wasawakened, and the number of days the child’s play was slowedwere square root transformed to make the data comply better withthe normality requirement. The t tests and x2 tests were used tocompare the obese and nonobese children for continuous anddichotomous variables respectively, and multiple regression andlogistic regression were used to compare the obese and nonobesegroups in terms of asthma morbidity after controlling for race/ethnicity. Baseline differences in medication use were believed tobe related to the other outcomes that were measured (asthmasymptoms and health care use), and therefore were not controlled.

The NCICAS was approved by the institutional review boards

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of each of the participating medical centers. Written informedconsent was obtained from each caretaker as well as assent fromthe child according to local institutional review board guidelines.

RESULTSOf the 1322 children enrolled in the NCICAS with

BMI values above the 5th percentile, 249 children(19%) had BMI values .95th percentile and werelabeled obese, whereas 1073 (81%) had BMI valuesbetween the 5th and 95th percentiles and were la-beled nonobese. The sample was composed of 967non-Hispanic black and 250 Hispanic children. Theremaining 91 children, designated other, were ofmixed racial/ethnic origin, white, or Asian.

The demographic and baseline characteristics byobesity are noted in Table 1. The groups were notdifferent in terms of age, gender composition, in-come, education, smoke exposure or in the numberof positive skin tests to indoor allergens. A relativelygreater proportion of the obese children were Latino(28% vs 17%; P , .01) and in the 3 months before thebaseline interview the obese children were morelikely to have used oral steroids (30% vs 24%; P ,.05) or a combination of 2 or more asthma medica-tions (63% vs 55%; P , .05)

Figure 1 presents a scatterplot of PEFR values ver-sus weight for height z score for the 749 individuals

with baseline PEFR measurements among our sam-ple. The trend line for PEFR (a cubic spline best fit)does not show appreciable decrease in participantswith extreme obesity.

Table 2 presents the results for mean percent-pre-dicted PEFR, health service use, and asthma symp-toms by obesity. A greater proportion of the obesechildren had ED visits (39% vs 31%; P , .04) and thisdifference was significant after adjusting for baselinedifferences in the racial/ethnic composition of thegroups. The obese children had a higher mean num-ber of days of wheezing per 2-week period (4.0 vs3.4; P , .02). After adjusting for differences in theracial/ethnic composition of the groups, this findinghad a P value of .05. Over the course of 1 year, thisrepresents 16 more days of wheezing among theobese group. There were no differences between theobese and nonobese groups in terms of PEFR, hos-pitalizations, unscheduled doctor or clinic visits, noc-turnal awakening, or slowed play.

DISCUSSIONIn this sample of inner-city children with asthma,

obese children used more asthma medication, hadmore reported days of wheezing, and were morelikely to visit an ED. These differences were of a

Fig 1. Percent predicted PEFR by weight for height z score.

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modest degree. The obese group had the equivalentof 2 additional weeks (worth of days) of reportedwheezing annually than the nonobese group. Overthe course of 9 months, the obese group had an 8%increase in ED use, and over the course of the 3months during which medication use was assessedthis group was 6% more likely to be prescribed oralsteroids. Although the burden of additional morbid-ity associated with obesity in this study is mild, thefindings are consistent in so far as it would be ex-pected that increased symptoms (wheezing) wouldprompt more health care use (ED visits) and moremedication use. The fact that the obese group werereported to have been prescribed oral steroids moreoften lends some validity to caregiver reports ofgreater symptoms. Our finding of greater medicationuse among obese asthmatics is consistent with thepreviously published study of Luder et al4 whichshowed that obese asthmatic children were twice aslikely to be prescribed $3 concurrent medicationsthan the nonobese group. Important negative find-ings in our study were that obese and nonobesechildren did not differ in terms of baseline PEFR, orin the other measures of asthma symptomatologyand health care use that we measured. Why theobese children in our study wheeze more and have

more ED visits, yet do not have more nocturnalawakening, limitation of play, or more hospitaliza-tion is not clear. In an analysis of the NHANES IIdata, composed of 5672 children ,11 years old,Schwartz et al16 found that parental reports ofwheezing but not physician-diagnosed asthma wereassociated with obesity.

The groups of obese and nonobese children in ourstudy were not different in a large number of com-monly measured social and demographic character-istics. These include age, gender composition, familyincome, maternal education, and measures of care-giver and child mental health. Of particular note isthe fact that exposure to household smoke and der-mal reactivity to a panel of common indoor allergensdid not differ between groups. This last finding issignificant insofar as it has been hypothesized thatobese individuals may have a relatively greater ex-posure to indoor allergens associated with asthma,and this hypothesis has not been previously tested.

In this study, the obese and nonobese group dif-fered in racial/ethnic composition. The obese groupwas composed of 28% Hispanic (predominantlyPuerto Rican) children versus 17% in the nonobesegroup. We do not believe that the observed increasedmorbidity among the obese group was attributable to

TABLE 1. Demographic and Baseline Characteristics by Obesity

Characteristic Obese* Nonobese*

N 5 249 (%) N 5 1073 (%)

Mean age/y 6 SD 6.11 6 1.69 6.04 6 1.61Male gender 163/249 (65) 707/1073 (66)Ethnicity

Black 158/247 (64) 809/1061 (76)Hispanic 69/247 (28) 181/1061 (17)†Other 20/247 (8) 71/1061 (7)

Annual family income,$15,000 138/232 (59) 592/949 (62)Mother completed high school 164/246 (67) 687/1059 (65)CBCL-T-Score 6 SD 57.58 6 12.33 57.35 6 11.45B.S.I.-T-Score 6 SD 56.88 6 11.75 55.90 6 11.10At least 1 smoker in house 138/248 (56) 639/1062 (60)Positive skin to indoor allergens 2.02 6 1.90 1.99 6 1.89Oral steroid use in previous

3 months75/246 (30) 250/1042 (24)‡

Used 2 or more medications inprevious 3 months

156/246 (63) 570/1042 (55)‡

* Denominators change because of missing data.† P , .001.‡ P , .05.

TABLE 2. Peak Flow, Health Service Utilization, and Symptoms by Obesity

Characteristic Obese* Nonobese* P Value P Value§

N 5 234 (6SD) N 5 1012 (6SD)

% Predicted peak flow-baseline† 85.54 (619.19) 83.18 (622.37) .21 .15Proportion hospitalized‡ 0.12 (60.33) 0.12 (60.32) .79 .81Proportion with unscheduled visits‡ 0.58 (60.50) 0.51 (60.50) .08 .23Proportion with ED visits‡ 0.39 (60.49) 0.31 (60.46) .02 .04Days of wheezing/2 wk 3.97 (63.22) 3.41 (62.78) .02 .05Noctural wakening/2 wk 1.68 (62.14) 1.78 (62.34) .77 .64Days of slowed activity/2 wk 2.03 (62.36) 1.95 (62.27) .40 .38

* Denominators change because missing data.† For peak flow, obese N 5 138, nonobese N 5 611.‡ During 9-month follow-up period.§ Adjusted for race/ethnicity.

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the difference in racial/ethnic composition becausethe association of obesity to an increase in reportedwheezing and unscheduled ED visits remained con-sistent after statistical adjustment for race/ethnicity.

Although we hypothesized that PEFR would bedecreased in the obese group, we did not find mea-surable decreases of PEFR despite greater symptomsand health care use. There are several potential ex-planations for this finding. First, the baseline PEFRvalues used in our study were obtained at least 4weeks from an acute exacerbation of asthma symp-toms, and therefore, would not reflect the greaterfrequency of asthma symptoms we observed in theobese group. More frequent measurement of PEFRmay be needed to detect the episodic decreases inPEFR among asthmatics with bronchospasm. Sec-ond, PEFR may be an inadequate test. There is agrowing body of literature that documents that nor-mal values of PEFR can be found in children whohave significant airflow obstruction as demonstratedby markedly decreased levels of FEV1, and forcedexpiratory flow between 25% and 75% of vital capac-ity.17

We questioned whether a threshold effect of obe-sity on PEFR might occur at a greater level of obesitythan .95th percentile of BMI (which corresponds toa weight for height z score of .1.65) and we con-structed a continuous graphic plot (examination) ofPEFR versus weight for height z score. The results ofthis analysis suggest that in obese asthmatic childrenfree from acute symptoms, impairment of airflow(detectable by PEFR tests) does not occur even inrelatively severe obesity. Ray et al18 showed that inseverely obese but otherwise healthy young adults,vital capacity was not significantly reduced until theweight/height ratio in kg/cm was .1.0 This corre-sponds to a weight of .335 pounds for a 5-foot tallindividual. A study of 13 very obese children whoweighed a mean of 212% of the average body weightfor their height also showed significant reductions inFEV1 and FVC.7 Other studies of obese children thathave used less severe definitions of obesity haveoften found inconsistent relationships between obe-sity and pulmonary function in otherwise normalindividuals. These inconsistent results likely reflectvarying degrees of severe obesity in the studygroups, as well as imprecision in the definitions ofobesity, which rely on height and weight, rather thanan assessment of total body fat. Lazarus et al19 haveclarified this issue by showing that height-adjustedFEV1 and FVC increase as a function of body weightin a population-based sample of children, but thatboth FEV1 and FVC decrease as a function of increas-ing percentage of body fat at any given height andweight. Taken together, these existing studies of obe-sity and pulmonary function show that increasinglean body mass has a strong positive effect on pul-monary function tests whereas increasing fat masshas a negative effect. This effect of body fat is smallwhen obesity is mild to moderate but becomes mea-surable when obesity is in the morbid range. Al-though our study sample included PEFR for 37 chil-dren who were .150% of the median weight forheight (weight for height z score: 4.5 to 5.6) it in-

cluded only 1 PEFR value for a child who was 200%of the median weight for height (z score: 6.9) andtherefore, we were unable to test whether a thresholdfor decreased PEFR occurred at this level of obesity.

Luder et al4 found a significant reduction of PEFRamong the obese asthmatic participants in theirstudy using a more liberal definition of obesity (BMI.85th percentile) than we did. The discrepancy be-tween our 2 studies likely reflects the fact that pa-tients in our study were required to wait 4 weeksafter an exacerbation of asthma symptoms whereasin the study of Luder et al, peak flow values wereobtained both during well and sick visits.

Our study design has several important limita-tions. Our study is limited by the fact that asthmasymptoms and health care use measures in the NCI-CAS are based on self-reported data. Although self-reported data forms a large part of several importantpediatric data sets such as the NHANES II, we can-not rule out the possibility that a caregiver bias tooverreport symptoms and a physician bias to over-prescribe asthma medication to obese children hasinfluenced our data. We are unaware of any existingliterature that documents such a bias.

Although we found an association of obesity withgreater asthma morbidity, the nature of our studydesign can not establish a causal relationship, nordoes it suggest a directionality to the causation if, infact, one exists.

Some authors have posited that asthma may be arisk factor for obesity.6,20 Indirect evidence for thishypothesis exists in a case-control study of asthmaticand nonasthmatic children done in an urban healthcenter by Gennuso et al20 that found a greater prev-alence of obesity in the asthmatic participants. How-ever, in this study a dose-effect relationship betweenasthma severity and degree of obesity was not found.Several longitudinal studies have examined thegrowth of asthmatic children. In a large cohort ofIsraeli children examined at age 17, boys with ahistory of mild asthma in childhood had higher BMIvalues than controls. However, boys with moderateor severe asthma and girls with all 3 classes ofasthma had BMI values that were no different fromcontrols.21 A recently published prospective 4-yearstudy of 3347 Scottish children with asthma showedno increase in weight for age z score over the courseof the study irrespective of asthma severity.22 Avail-able literature indicating that asthma can promotethe development of obesity is evidently conflicting.

Recently, evidence that obesity may increase one’srisk to acquire asthma has been presented by Ca-margo et al.23 Using prospectively obtained datafrom the Nurses Health Study II they found thatwomen who gained weight after the age of 18 wereat an increased risk to develop asthma; furthermore,the relative risk of developing asthma increased withincreasing levels of BMI. A pathophysiological expla-nation for this phenomenon has not been established.Further evidence that obesity directly affects asthmamorbidity has been recently demonstrated in mor-bidly obese adult asthmatics who showed markedimprovement in asthma morbidity after losingweight following laparoscopic gastric banding.24

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However, as stated previously, morbidly obese indi-viduals are at risk for significant decreases in pulmo-nary function, and whether these results would bereplicated among asthmatics with lesser degrees ofobesity is unknown.

CONCLUSIONIn summary, we found that obese asthmatic chil-

dren wheezed more, had more unscheduled ED vis-its, and received more medications. These differenceswere modest and were not associated with a de-crease in baseline PEFR or an increase in the rate ofhospitalization. Prospective studies of the effect ofweight loss on asthma morbidity may be required toprovide a better understanding of the relationshipbetween obesity and asthma morbidity, impairmentof pulmonary function, and health service use.

ACKNOWLEDGMENTSThe contract grant sponsor of this work was the National

Institute of Allergy and Infectious Disease (National Institute ofHealth, Bethesda, MD) Grants U01 A1-30751, A1-30752, A1-30756,A1-30772, A1-30773-01, A1-30777, A1-30779, A1-30780, and N01A1-15105.

We wish to thank Andrew Racine, MD, PhD, Alex Okun, MD,and Ruth Stein, MD, for their review of the manuscript.

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THE HAPPINESS BUSINESS

Only 2 years ago, no one in the United States had heard of Celexa. But since itslaunch in September 1998, it has captured over 13% of new prescriptions in the $6.3billion market for its class of antidepressants. . .

The reason for Celexa’s stunning success is not science but marketing. Drugindustry consultants Scott-Levin say US pharmaceutical companies spent about$10 billion last year on drug promotions. Most of that—$9 billion—went towardmarketing to doctors (about $12,000 for each doctor in the United States). Drugmakers command an army of more than 68,000 salespeople, 1 for every 11 doctorsin the United States. While pharmaceutical companies justify high drug prices bypointing to astronomical research and development costs, many which study theindustry say drug companies spend more on marketing and promotions.

Kirkpatrick DD. New York Times. May 15, 2000

Noted by JFL, MD

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