A quarter of the world's population experience wheezing. These sounds have been used for diagnosis since the time of the Ebers Papyrus (ca. 1500 BC), but the underlying physical mechanism responsible for the sounds is still poorly understood. The main purpose of this thesis is to change this, developing a theory for the onset of wheezing using both experimental and analytical approaches, with implications for both scientific understanding and clinical diagnosis. Wheezing is caused by a fluid structure interaction between the airways and the air flowing through them. We have developed the first systematic set of experiments of direct relevance to this physical phenomena. We have also developed new tools in shell theory using geometric algebra to improve our physical understanding of the self-excited oscillations observed when air flows through flexible tubes. In shell theory, the use of rotors from geometric algebra has enabled us to develop improved physical understanding of how changes of curvature, which are of direct importance to constitutive laws, come about. This has enabled a scaling analysis to be applied to the self-excited oscillations of flexible tubes, showing for the first time that bending energy is dominated by strain energy. We made novel use of multiple camera reconstruction to validate this scaling analysis by directly measuring the bending and strain energies during oscillations. The dominance of strain energy allows a simplification of the governing shell equations. We have developed the first theory for the onset of self-excited oscillations of flexible tubes based on a flutter instability. This has been validated with our experimental work, and provides a predictive tool that can be used to understand wheezing in the airways of the lung. Our theory for the onset of wheezing relates the frequency of oscillation to the airway geometry and material properties. This will allow diagnoses based on wheezing sounds to become more specific, which will allow the stethoscope, which has changed little in the last 200 years, to be brought into the 21st century.

The increasing prevalence of allergic diseases in affluent societies has been associated with changes in microbial exposure early in life and a less diverse gut flora. The objective of this thesis was to assess the development of allergic sensitisation and symptoms during the first four years of life in a non-selected birth cohort in relation to environmental factors, family history, gut microbiota and salivary IgA antibodies. The cohort comprised all 1,228 infants living in a Swedish county who were born over a one-year period. The parents replied to questionnaires, and 817 children (67 %) were skin prick tested both at 1 and 4 years of age. Saliva (n=279), faecal (n=139) and blood (n=253) samples were collected at 1 year of age from children with a positive skin prick test at 1 year and from a sample of children with a negative skin prick test. Faecal samples were also obtained from 53 children at 4 years of age. Dog keeping during infancy was associated with a decreased risk of sensitisation to pollen and late-onset wheezing at age 4, and the reduced odds ratios persisted after adjustment for heredity and avoidance measures, OR 0.3, 95% CI 0.1-0.9 and OR 0.5, 95% CI 0.2-1.0, respectively. In contrast, early dog keeping was associated with an increased risk of earlyonset transient wheezing but only in children with parental asthma (OR 2,8, 95% CI 1.3-6.4). Levels of short chain fatty acids (SCFAs) in faeces were assessed both at 1 and 4 years of age and related to the development of sensitisation and symptoms. The levels of acetic (p<.01) and propionic (p<.01) acids decreased from one to four years of age, whereas valeric acid (p<.001) increased which is in line with a more complex gut microbiota with age. Allergic children, compared with non-allergic children, had lower levels of i-butyric, i-valeric and valeric acid in faeces both at 1 and 4 years of age. Low levels of secretory IgA (SIgA) in saliva were associated with wheezing but only in sensitised children. In children with positive SPT to at least one allergen both at 1 and 4 years of age and in children with circulating IgE antibodies to egg or cat at one year of age, those who developed late-onset wheezing had lower levels of SIgA than those who did not, p=.04 and p=.02 respectively. Of 9 children with levels of SIgA in the upper quartile and persistent sensitisation, none developed wheezing, compared with 10/20 children with lower levels, (p=. 01). Having older siblings, more than three infections during infancy, at least one smoking parent and male gender were all associated with high levels (in the upper quartile) of total IgA and SIgA. The findings in this thesis indicate that the microbial load early in life could affect the development of allergy. A functional assessment of the gut flora demonstrated differences between allergic and non-allergic children both at 1 and 4 years of age. Salivary IgA was associated with infections during infancy, and high levels of secretory IgA protected from symptoms in sensitised children. Finally, dog keeping in infancy may offer protection from allergy, but the mechanism is uncertain.

Asthma is a chronic respiratory disease characterized by inflammation of the airway and the presence of recurrent attacks (exacerbations) of breathlessness, wheezing, cough, chest tightness, or some combination of these symptoms. In the US, about 53% of people with asthma had an asthma attack in 2008, and 57% of these, were children. One in ten children (10%) had asthma in 2009, and boys were more likely than girls to have asthma. Internationally, the prevalence of asthma varies widely in different countries, but the disparity is narrowing due to rising prevalence in low and middle income countries. Unfortunately, we do not have statistics for asthma in the Republic of Panama, neither epidemiological data nor costs, which is the reason why this research is needed. The Panamanian Social Security Fund (CSS) provides protection to workers, their immediate families and the pensioned. By the end of 2010, the total insured population was 2,862,202 (83% of the total population of Panama). Of the total insured population 58% were dependent. Of this, 1,205,607 (42%) were children. On the basis of this information, we decided to develop the research study using information from the CSS, specifically in the Hospital de Especialidades Pediatricas (HEPOTH). It is the only tertiary level of healthcare children's hospital of the CSS. A quantitative-descriptive design was used to develop this study. Data was collected from medical records of patients diagnosed with asthma in the HEPOTH from January to June 2012. We reviewed the medical records of each care area by month, and numbered each clinical record of children diagnosed with asthma in crisis and randomly selected 10% of the medical records from a minimum of 2000 records. Information on treatment costs was also obtained. Once all the information was collected, it was typed in the digital data log created for this study and the responses were code converted and the information was entered into a database. The data were exported to IBM SPSS Statistics 21. The average cost of asthma attacks in Panama is estimated at $205.52. We were able to confirm that there are variations in this average by gender, age, geographic area of residence, season, severity, whether treated in the emergency department or hospitalization, and the type of treatment received. It was also possible to obtain secondary information about the epidemiology of asthma that allowed us to confirm that our statistics matched international statistics.

Made available in DSpace on 2015-07-22T20:50:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-28 / Objetivo: Verificar a prevalência de siibilância no primeiro ano de vida em crianças da cidade do Recife, Pernambuco, e sua relação com o gênero e verificar fatores de risco a ela associados. Casuística e método: Estudo transversal realizado segundo o protocolo do “Estudio Internacional sobre Sibilância en Lactentes” (EISL) em crianças com idades entre doze e 15 meses. Os pais ou responsáveis pelas crianças responderam o questionário EISL padrão quando do seu atendimento por consulta de rotina ou imunização de rotina em Postos de Saúde ou creches municipais de Recife. A amostra foi analisada segundo a presença ou não de sibilância. A resposta afirmativa à pergunta: “Seu bebê teve chiado no peito, bronquite ou sibilâncias nos seus primeiros doze meses de vida?” identificou os com sibilância. Resultados: Foram entrevistados 1071 pais e/ou responsáveis por crianças com idades entre doze e 15 meses no período de Março a Dezembro de 2007. A prevalência de sibilância no primeiro ano de vida foi 43%, sem diferenças quanto o gênero. O relato de sibilância no primeiro ano de vida foi significantemente associado a ter tido pneumonia, ter familiares com asma, ter tido mais de nove episódios de infecções de vias aéreas superiores, e o primeiro episódio de resfriado antes de seis meses de vida (p<0,001). Conclusão: Foi demonstrado que início precoce e número elevado de resfriados, ter familiares com asma e ter apresentado pneumonia esteve associado a quadros de sibilância no primeiro ano de vida em crianças da cidade do Recife, Brasil. / Objective: To determine the prevalence of wheezing in the first year of life in infants aged from 12 to 15 months old living in the city of Recife, Pernambuco and to study its relationship with gender and to identify wheezing associated risk factors. Methods: This sectional study was done according to the protocol “Estudio Internacional sobre Sibilância en Lactentes” (EISL) in children between 12 and 15 months of age. Parents or caregivers answered the standard EISL questionnaire when children attended a routine medical or immunization visit in public health facilities in Recife – Brazil. The end point was the answer to the question: Have your baby had chest wheezing or bronchitis in the first year of life? Those who have answered “yes” were identified as wheezing babies. Results: The questionnaire was answered by 1,071 parents or caregivers, between March and December 2007. The prevalence of wheezing was 43% and there wasn´t any difference between gender. Wheezing was significantly associated with a past history of pneumonia, family history of asthma, have had more than 9 upper airway infection episodes and to have had the first cold episode before 6 months of life (all with p<0.001). Conclusion: We observed that early and recurrent upper airway infections, previous episode of pneumonia, and family history of asthma were associated with wheezing in the first year of life in children in Recife-Brazil. / TEDE

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No description available.

Die vorliegende Arbeit ist Teil einer Mutter -Kind -Kohortenstudie LiNA (Lebensstil und Umweltfaktoren und deren Einfluss auf das Neugeborenen-Allergierisiko), deren Ziel es ist, komplexe Expositionen gegenüber verschiedener Umweltbelastungen, insbesondere Chemikalien und deren Auswirkungen auf den Organismus zu betrachten. Viele Forschungsergebnisse lassen vermuten, dass gerade die Schwangerschaft ein sensibles Zeitfenster darstellt, in dem die pränatale Entwicklung des Kindes prädisponierend für das Auftreten bestimmter allergischer Krankheiten sein kann. Die Aufgabe dieser Arbeit bestand in einer epidemiologischen Untersuchung des Einflusses bestimmter Renovierungsmaßnahmen wie Malerarbeiten, Verlegen eines neuen Fußbodens und Aufstellen neuer Möbel während der Schwangerschaft bzw. im 1. Lebensjahr des Kindes auf die Ausbildung respiratorischer Erkrankungen des einjährigen Kindes. • Das Verlegen von Fußboden, sowie Malerarbeiten während der Schwangerschaft zeigten eine Risikoerhöhung an einer obstruktiven Bronchitis im ersten Lebensjahr zu erkranken (OR 4.39, 95% CI 1.01–19.05; OR 5.46, 95% CI 1.09–27.20). • Das Verlegen von neuem Fußboden während der gesamten Schwangerschaft korrelierte als einzige Renovierungsaktivität signifikant positiv mit „behandlungsbedürftigem Giemen“ im ersten Lebensjahr (OR= 5.20, 95% CI 1.8– 15.2). • Insbesondere das Verlegen von Laminatboden (OR= 4.46, 95% CI 1.01–19.63), Teppichboden (OR= 4.57 CI 1.14–18.39) und PVC Boden (OR= 24.7, 95% CI 2.18– 280.39) zeigte eine Risikoerhöhung an „behandlungsbedürftigem Giemen“ zu erkranken. • Das Verlegen neuer Fußböden mit und ohne Gebrauch von Klebstoffen war advers mit dem Auftreten von behandlungsbedürftigem Giemen assoziiert. • Kindern mit atopischer Familienanamnese haben ein fünffaches Risiko an „behandlungspflichtigem Giemen“ zu erkranken (OR= 5.68, 95% CI 1.17–27.53), wenn während der Schwangerschaft neuer Fussboden verlegt wurde. • Interessanterweise gab es keine signifikante Assoziation zwischen dem Verlegen eines neuen Fußbodenbelags im ersten Lebensjahr und dem Entstehen von „behandlungspflichtigem Giemen“. Darüber hinaus verglichen wir die Renovierungsmaßnahmen mit den gemessenen VOC-Werten aus der elterlichen Wohnung, um einen möglichen Zusammenhang zwischen Renovierung und Schadstoffbelastung herstellen zu können. • Die Konzentrationen von 6 VOC (Styrol, Isopropylbenzol, Ethylbenzol, Dekan, Undekan, Tridekan) waren in den Haushalten mit neuem Fußbodenbelag in der Schwangerschaft und im ersten Lebensjahr signifikant höher, als in den Haushalten, in denen nie renoviert wurde. Eine Konzentrationserhöhung ergab sich zudem wenn Kleber beim Verlegen des Fußbodens verwendet wurde. • Wir fanden 14 VOC (Propylbenzol, o- Xylol, m+ p-Xylol, 4-Ethyltoluol, 3-Ethyltoluol, 2- Ethyltoluol, 1,2,3-Trimethylbenzol, 1,2,4-Trimethylbenzol, 1,3,5-Trimethylbenzol, Oktan, Nonan, 3-Heptanon, Tetrahydrofuran, 1-Butanol), deren Konzentrationen nach dem Verkleben des Fußbodens signifikant höher waren. • Als einziges aromatisches VOC blieb Styrol die Verbindung, welche nach dem Verlegen von neuem Fußboden in der Schwangerschaft eine signifikante Konzentrationserhöhung im ersten Lebensjahr aufwies. Schließlich wurde nach einer Korrelation zwischen den gefundenen VOC-Werten und dem Auft reten von respi rator i s chen Er k rankungen innerha l b einer Querschnittspopulation der einjährigen Kinder gesucht. • Für 6 VOC (Styrol, Ethylbenzol, Tridekan, o-Xylol, Oktan, 1-Butanol)c konnten wir eine positive Assoziation mit „behandlungsbedürftigem Giemen“ nachweisen. • Eine Belastung mit Styrol in der Schwangerschaft und im ersten Lebensjahr war mit einem erhöhten Risiko an „behandlungspflichtigem Giemen“ zu erkranken, assoziiert (OR= 1.5, 95% CI 1.07–2.09). Vorangegangene Studien konnten bisher nur zeigen, dass eine Exposition mit VOC zu unmittelbaren Atemwegssymptomen bei Kindern führen kann. Diese Studie belegt den schädigenden Einfluss einer Belastung während der Schwangerschaft auf die respiratorische Gesundheit des Kindes im ersten Lebensjahr. Neuer Fußbodenbelag im Wohnumfeld von Schwangeren erhöht deutlich das Risiko von Kleinkindern an obstruktiven Atemwegssymptomen zu erkranken. Unsere Studie leistet hier einen wichtigen Beitrag zur Prävention umweltassoziierter Erkrankungen. Es ist deshalb von großer Bedeutung, Schwangere über potentielle pränatale Gesundheitsrisiken für ihr Kind aufzuklären. Demnach sollte eine offizielle Empfehlung ausgesprochen werden, auf aufwendige Renovierungsarbeiten während der Schwangerschaft und vor allem auf das Verlegen von neuem Fußboden zu verzichten. Dadurch könnten ca. 20.000 Fälle von behandlungspflichtigem Giemen im Kleinkindalter vermieden werden.:Inhaltsverzeichnis…..…………………………………………………………………………...2 Abkürzungsverzeichnis………………………………………………………………………...3 1.Einleitung……………………………………………………………………………………....4 1.1. Die LiNA-Studie……….…………………………………..…………………………........4 1.2. Der Einfluss der Innenraumluft auf die kindliche Gesundheit…...…………………....6 1.3. Flüchtige organische Verbindungen als Bestandteil der Innenraumluft..……...........7 1.4. Gesundheitliche Effekte durch VOC..………...……………………………………........7 1.5. Innenraumbelastung durch VOC und Auswirkungen auf das Immunsystem…........9 1.6. Relevanz des Expositionszeitpunktes..……………………………………………........9 1.7. Schlussfolgerungen und weiterer Forschungsbedarf….……………………….........10 2. Publikation………………………………………………………………………………......12 3. Zusammenfassung……..………………………...……………………………………......21 4. Literaturverzeichnis…………………………………………………………………….......24 5. Anlagen………………………………….……………………………….....……………….27 Erklärung über eigenständige Abfassung der Arbeit… ………………………………….28 Spezifizierung des eigenen Beitrags………………………………………………………...29 Lebenslauf……………………………………………………………………………………...33 Danksagung……………………………………………………………………………………35

Les phénotypes de l’asthme sont affectés par l’exposition à de multiples facteurs durant la grossesse. Pour évaluer cette hypothèse, deux études ont été menées : l’une en France, l’autre au Liban. Dans l'étude française, l'objectif était de décrire les phénotypes respiratoires de sifflement chez l’enfant entre l’âge de deux mois et d’un an, et d'évaluer les facteurs de risque associés à ces phénotypes de sifflement dans une grande cohorte de naissance. Dans l'étude libanaise, les objectifs étaient d'évaluer les associations entre l'utilisation de médicaments, d'alcool, de cigarettes et/ou de narguileh, et l'exposition aux pesticides/détergents pendant la grossesse avec l'asthme infantile au Liban et de valider la version arabe du test de contrôle de l'asthme (ACT) chez ces enfants et d’identifier les facteurs de risque qui pourraient affecter le contrôle de l'asthme.Méthodes: Nous avons étudié 18 041 nourrissons de la cohorte de naissance ELFE (Étude Longitudinale Française depuis l'Enfance). Les parents ont signalé une respiration sifflante et des symptômes respiratoires à deux et 12 mois, et ont répondu à un questionnaire complet (exposition pendant la grossesse, allergie parentale). Le plan d'étude du projet libanais consistait en une étude cas-témoins, menée entre Décembre 2015 et Avril 2016, recrutant 1503 enfants, âgés de 3 à 17 ans. Le questionnaire administré évaluait les caractéristiques sociodémographiques (âge, sexe, niveau d'éducation des deux parents), les antécédents familiaux d'asthme et d'autres facteurs de risque connus de l'asthme (système de chauffage à domicile, antécédents d'otites récidivantes, humidité dans la maison, enfant allant à une garderie, fumer et boire de l'alcool pendant la grossesse, exposition aux pesticides et aux détergents).Résultats: Les enfants sans symptômes (témoins) représentaient 77,2%, 2,1% avaient une respiration sifflante à deux mois mais pas de respiration sifflante à un an (sifflement intermittent), 2,4% avaient une respiration sifflante persistante et 18,3% avaient une respiration sifflante à un an. En comparant les sifflements persistants aux contrôles, on a observé qu’avoir un frère ou une sœur (ORa = 2,19) ou deux frères et sœurs (ORa = 2,23) contre aucun, une toux nocturne (OR = 5,2), une détresse respiratoire (OR = 4,1) et un excès de sécrétions bronchiques (OR = 3,47 ) à deux mois, un reflux chez l'enfant à 2 mois (OR = 1,55), des antécédents d'asthme maternel (OR = 1,46) et le tabagisme maternel pendant la grossesse (OR = 1,57) étaient significativement associés à une respiration sifflante persistante. Ces mêmes facteurs, avec en sus une éruption cutanée chez l'enfant à 2 mois (OR = 1,13) et des antécédents paternels d'asthme (OR = 1,32) étaient significativement associés à une augmentation de la probabilité d'une respiration sifflante. Avoir un frère (ORa = 1,9) en comparaison à ne pas en avoir, une toux nocturne à 2 mois (OR = 1,76) et un excès de sécrétions bronchiques à 2 mois (OR = 1,65) étaient significativement associés à une respiration sifflante persistante par rapport à une respiration sifflante intermittente.... / Asthma in childhood seems affected by exposure to various factors in early life. To assess this hypothesis, we conducted 2 studies: one in France, and the other in Lebanon. In the French study, we aimed at describing wheezing phenotypes between the ages of two months and one year, and assess risk factors associated with these wheezing phenotypes in a large birth cohort. In the Lebanese study, the aims were to evaluate the associations between caregiver-reported use of medications, alcohol, cigarette and/or waterpipe (WP), and exposure to pesticides/detergents during pregnancy with childhood-onset asthma in Lebanon and to validate the Arabic version of the Asthma Control Test (ACT) among these children and identify risk factors that might affect asthma control.Methods: We studied 18,041 infants from the ELFE (French Longitudinal Study of Children) birth cohort. Parents reported wheezing and respiratory symptoms at two and 12 months, and answered a complete questionnaire (exposure during pregnancy, parental allergy).The study design of the Lebanese project consisted of a case-control study, conducted between December 2015 and April 2016, recruited 1503 children, aged between 3-16 years old. A questionnaire assessed the sociodemographic characteristics (age, gender, education level of both parents), the family history of asthma, and other known risk factors of asthma (heating system at home, child history of recurrent otitis, humidity in the house, child went to a daycare, smoking and drinking alcohol during pregnancy, exposure to pesticides and detergents).Results: Children with no symptoms (controls) accounted for 77.2%, 2.1% had had wheezing at two months but no wheezing at one year (intermittent wheezing), 2.4% had persistent wheezing, while 18.3% had incident wheezing at one year. Comparing persistent wheezing to controls showed that having one sibling (ORa=2.19) or 2 siblings (ORa=2.23) compared to none, nocturnal cough (OR=5.2), respiratory distress (OR=4.1) and excess bronchial secretions (OR=3.47) at two months, reflux in the child at 2 months (OR=1.55), maternal history of asthma (OR=1.46) and maternal smoking during pregnancy (OR=1.57) were significantly associated with persistent wheezing. These same factors, along with cutaneous rash in the child at 2 months (OR=1.13) and paternal history of asthma (OR=1.32) were significantly associated with increased odds of incident wheezing. Having one sibling (ORa=1.9) compared to none, nocturnal cough at 2 months (OR=1.76) and excess bronchial secretions at 2 months (OR=1.65) were significantly associated with persistent compared to intermittent wheezing.In the Lebanese study, the multivariate analysis showed that children living in North and South Lebanon and the children living in areas where pesticides are frequently used had an increased risk of asthma (ORa=1.625; ORa=13.65; ORa=3.307) respectively. Smoking WP during pregnancy and cigarette during lactation would increase the risk of asthma in children (ORa=6.11; ORa=3.44 respectively). A high Cronbach’s alpha was found for the full scale (0.959). As for the asthma control scale (ACT), the correlation factors between each item of the ACT scale and the whole scale ranged between 0.710 and 0.775 (p<0.001 for all items). Mother’s low educational level as well as the history of asthma in the mother and the father would significantly increase the risk of uncontrolled asthma (Beta= 1.862; Beta= 3.534; and Beta= 1.885 respectively). Cigarette smoking during breastfeeding and waterpipe smoking by the mother during pregnancy were both significantly associated with uncontrolled asthma (Beta= 2.105; Beta=2.325 respectively). Mother’s high educational level was significantly associated with more asthma control (Beta= -0.715).

Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-12-04T13:59:30Z No. of bitstreams: 1 Elisângela Veruska.pdf: 9962603 bytes, checksum: d714b3ef5ef96281322806f3185e4720 (MD5) / Made available in DSpace on 2017-12-04T13:59:30Z (GMT). No. of bitstreams: 1 Elisângela Veruska.pdf: 9962603 bytes, checksum: d714b3ef5ef96281322806f3185e4720 (MD5) Previous issue date: 2017-09-29 / Wheezing is considered the most common respiratory symptom in childhood, causing an important role in infant morbimortality and being responsible for the great demand of outpatient medical appointments, in emergency services and presenting high rates of hospitalization. In this thesis, two studies were carried out. The first study aimed to determine the prevalence and associated factors for recurrent wheezing in children aged 13 to 35 months. The second study aimed to verify the prevalence of anemia in pregnancy and its association with respiratory problems. For the first cross-sectional study, a sample of 2,780 children with 13 to 35 months of age, living in the city of São Luís-MA participating in the BRISA cohort, was considered. In the second study, a cross-sectional study was conducted involving a sample of 3,279 children who participated in the BRISA cohort and the follow-up of this cohort, aged 13 to 35 months. To evaluate the factors associated with recurrent wheezing, a multivariate logistic regression model was adjusted, with the inclusion of variables in a hierarchical fashion using the theoretical model. The outcome of interest was the presence of recurrent wheezing. The independent variables evaluated were maternal age and her education, smoking, anemia in pregnancy, type of delivery, gender, birth weight, family history of asthma, rhinitis and dermatitis, exclusive breastfeeding, presence of mold, domestic animal and carpet at home, a history of respiratory problems and hospitalization. To verify the relation of presence of anemia in pregnancy and respiratory problems, the chi-square test was performed. In the first study, the prevalence of recurrent wheezing was 9%, with associated factors: age of the mother equal to or greater than 35 years (PR = 0.49, CI = 0.24 - 0.99, p = 0.049), male (PR = 1.62, CI = 1.23 - 2.14, p = 0.001), family history of asthma (PR = 1.55, CI = 1.09 - 2.19, p = 0.013), family history of rhinitis (PR = 1.71 CI = 1.26 - 2.30, p = 0.000), anemia during pregnancy (PR = 1.33, CI = 1.02 - 1.75, p = 0.034), exclusive breastfeeding (PR = 0.75, CI = 0.56 - 0.99, p = 0.044), presence of mold in the home (PR = 1.56, CI = 1.11 - 2.18, p = 0.009 ) and respiratory problems (PR = 3.90, CI = 2.53 - 0.99, p <0.001) .In the second study, the prevalence of anemic pregnant women was 47% and the problems related to anemia were maternal age lower than 20 years (p <0.001), inadequate maternal schooling (P <0.001), smoking in pregnancy (p=0.014), alcohol in pregnancy (p <0.001), normal labor (p <0.001), and in children, recurrent wheezing (p = 0.013), pneumonia (p = 0.040), and cough (p <0.001). The results obtained in this study have great relevance, as evidenced the prevalence of recurrent wheezing among children in São Luís and the associated factors, as well as, anemia prevalence and its relationship with respiratory problems in the child. / A sibilância é considerado o sintoma respiratório mais comum na infância, causando importante papel na morbimortalidade infantil e sendo responsável por grande demanda de consultas médicas ambulatoriais, em serviços de prontoatendimento e apresentando altas taxas de hospitalização. Nesta tese, foram realizados dois estudos. O primeiro estudo teve como objetivo determinar a prevalência e fatores associados para sibilância recorrente em crianças com 13 até 35 meses de idade. O segundo estudo teve como objetivo verificar a prevalência de anemia na gestação e sua associação com problemas respiratórios. Para o primeiro estudo, tipo transversal, foi considerado uma amostra de 2.780 crianças com 13 até 35 meses de idade, residentes no município de São Luís-MA participantes da coorte BRISA. No segundo estudo, foi realizado um estudo transversal, envolvendo amostra de 3.279 crianças que participaram da coorte BRISA e do seguimento dessa coorte, com idade de 13 a 35 meses. Para avaliação dos fatores associados à sibilância recorrente foi ajustado modelo de regressão logística multivariado, com inclusão das variáveis de modo hierarquizado a partir do modelo teórico. O desfecho de interesse foi a presença de sibilância recorrente. As variáveis independentes avaliadas foram: idade e escolaridade da mãe, fumo, anemia na gestação, tipo de parto, sexo da criança, peso ao nascer, história familiar de asma, rinite e dermatite, aleitamento exclusivo, presença de mofo, animal doméstico e carpete no domicílio, antecedentes de problema respiratório e internação. Para verificar a relação de presença de anemia na gestação e problemas respiratórios foi realizado o teste qui-quadrado. No primeiro estudo, a prevalência de sibilância recorrente foi de 9%, tendo como fatores associados: idade da mãe igual ou superior a 35 anos (RP=0,49; IC = 0,24 – 0,99; p=0,049), sexo masculino (RP=1,62; IC = 1,23 – 2,14; p=0,001), história familiar de asma (RP=1,55; IC = 1,09 – 2,19; p=0,013), história familiar de rinite (RP=1,71 IC = 1,26 – 2,30; p=0,000), anemia na gestação (RP=1,33; IC = 1,02 – 1,75; p=0,034), aleitamento materno exclusivo (RP=0,75; IC = 0,56 – 0,99; p=0,044), presença de mofo na residência (RP=1,56; IC = 1,11 – 2,18; p=0,009) e problemas respiratórios (RP=3,90; IC = 2,53 – 0,99; p<0,001). No segundo estudo, a prevalência de gestantes anêmicas foi de 47 % e os problemas relacionados a anemia foram idade materna menor que 20 anos (p<0,001), escolaridade materna inadequada (p<0,001), fumo na gestação (p=0,014), álcool na gestação (p<0,001), parto normal (p<0,001) e nas crianças, sibilância recorrente (p=0,013), pneumonia (p=0,040) e tosse (p<0,001). Os resultados obtidos neste estudo possuem grande relevância, pois evidenciou a prevalência de sibilância recorrente entre crianças em São Luís e os fatores associados, assim como, a prevalência de anemia e sua relação com problemas respiratórios na criança.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado / Background: There are no internationally validated questionnaires to investigate the prevalence of infant wheezing. This study was undertaken to validate a questionnaire for the International Study on the Prevalence of Wheezing in Infants (Estudio Internacional de Sibilancias en Lactantes, EISL). Material and Methods: Construct and criterion validity were tested for the question 'Has your baby had wheezing or whistling in the chest during his/her first 12 months of life?'. Construct validity (i.e. the ability of parents and doctors to refer to the same symptoms with the same words) was tested in a sample of 50 wheezing and 50 non-wheezy infants 12-15 months of age in each of 10 centres from 6 different Spanish- or Portuguese-speaking countries. Criterion validity (i.e. the ability of parents to correctly detect the symptom in the general population) was evaluated in 2 samples (Santiago, Chile and Cartagena, Spain) of 50 wheezing and 50 non-wheezing infants (according to parents) of the same age, randomly selected from the general population, who were later blindly diagnosed by a paediatric pulmonologist. Results: Construct validity was very high (κ test: 0.98-1) in all centres. According to Youden's index, criterion validity was good both in Cartagena (75.5%) and in Santiago (67.0%). Adding questions about asthma medication did not improve diagnosis accuracy. Conclusions: The EISL questionnaire significantly distinguished wheezy infants from healthy ones. This questionnaire has a strong validity and can be employed in large international multicentre studies on wheezing during infancy. / Revisión por pares