Objective: To determine the prevalence of smoking experimentation among adolescents with asthma or allergic rhinitis. Methods: This was a cross-sectional study involving adolescent students (13-14 years of age) in the city of Belo Horizonte, Brazil. The participants completed the Centers for Disease Control and Prevention and International Study of Asthma and Allergies in Childhood questionnaires, both of which have been validated for use in Brazil. We calculated the prevalence of smoking experimentation in the sample as a whole, among the students with asthma symptoms, and among the students with allergic rhinitis symptoms, as well as in subgroups according to gender and age at smoking experimentation. Results: The sample comprised 3,325 adolescent students. No statistically significant differences were found regarding gender or age. In the sample as a whole, the prevalence of smoking experimentation was 9.6%. The mean age for smoking experimentation for the first time was 11.1 years of age (range, 5-14 years). Among the adolescents with asthma symptoms and among those with allergic rhinitis symptoms, the prevalence of self-reported smoking experimentation was 13.5% and 10.6%, respectively. Conclusions: The proportion of adolescents with symptoms of asthma or allergic rhinitis who reported smoking experimentation is a cause for concern, because there is strong evidence that active smoking is a risk factor for the occurrence and increased severity of allergic diseases.

Keywords: Asthma/epidemiology; Rhinitis/epidemiology; Smoking/epidemiology.

Objective: To investigate whether there is an association between suicidal ideation (SI) and allergic diseases in adults. Methods: This was a comparative cross-sectional study involving individuals ranging from 20 to 50 years of age recruited from a university hospital in the city of Guadalajara, Mexico. We included patients with a confirmed diagnosis of allergic asthma, those with a confirmed diagnosis of allergic rhinitis, and healthy controls. All subjects completed the Beck Depression Inventory-II (BDI-II), which includes an item that evaluates the presence of suicidal thoughts or desires within the last two weeks, in order to identify SI. Results: The sample comprised 115 patients with allergic asthma, 111 patients with allergic rhinitis, and 96 healthy controls. The number of individuals identified with SI in the three groups were, respectively, 17 (14.8%), 13 (11.7%), and 8 (8.3%). Regarding the presence of SI, no statistically significant association was found in the allergic asthma group (OR = 1.98; 95% CI: 0.78-4.64; p = 0.154) or in the allergic rhinitis group (OR = 1.46; 95% CI: 0.58-3.68; p = 0.424) when they were compared with the control group. However, the presence of depression was associated with SI in the three groups: allergic asthma (OR = 12.36; 95% CI: 2.67-57.15; p = 0.001); allergic rhinitis (OR = 6.20; 95% CI: 1.66-23.14; p = 0.006); and control (OR = 21.0; 95% CI: 3.75-117.36; p < 0,001). Conclusions: In comparison with the control group, no association was found between SI and the groups with allergic diseases. In contrast, there was association between SI and depression in the three groups.

Keywords: Suicidal ideation; Asthma; Rhinitis, allergic; Adult.

Objective: To determine the prevalence of emotional and behavioral disorders in adolescents with asthma and to compare it with that of adolescents without asthma. Methods: A transversal study using the Strengths and Difficulties Questionnaire, administered to adolescents with or without asthma, ranging from 14 to 16 years of age and randomly selected from schools in the city of Belo Horizonte, Brazil. Results: The prevalence of emotional and behavioral disorders in adolescents with and without asthma was 20.4% (95% CI: 14.5-27.8%) and 9.0% (95% CI: 6.1-12.8%), respectively. Among adolescents with asthma, 56.6% (95% CI: 48.3-64.5%) presented normal scores, and 23.0% (95% CI 16.8-30.7%) presented borderline scores. Among adolescents without asthma, 75.0% (95% CI: 69.7-79.6%) presented normal scores, and 16.0% (95% CI: 12.2-20.7%) presented borderline scores. The median total score on the questionnaire was 14 and 12 among subjects with and without asthma, respectively (p < 0.01). In the final logistic regression model, adjusted for socioeconomic variables, the association between emotional/behavioral disorders and the following variables remained significant: being female (OR = 1.98; 95% CI: 1.10-3.56; p = 0.02) and having asthma (OR = 2.66; 95% CI: 1.52-4.64; p = 0.001). Conclusions: The prevalence of emotional and behavioral disorders is higher in adolescents with asthma than in those without asthma, underscoring the need for a holistic, interdisciplinary approach.

Keywords: Asthma; Epidemiology; Prevalence; Adolescent; Psychology; Behavioral symptoms.

Objective: The aim of this study was to analyze social characteristics and stress as correlates of cigarette smoking in adolescence. The main intent was to identify elements that distinguish adolescents who had experimented with smoking and did not progress to regular smoking from those who became current smokers. Methods: Students at 10 high schools in the city of Ribeirão Preto, Brazil, completed a questionnaire based on an instrument employed in a similar large-scale study. The students were classified as never-smokers or experimenters. The experimenters were subcategorized as having become current smokers or nonprogressors. Analyses were performed using adjusted logistic models. Results: A total of 2,014 students (mean age, 16.2  1.1 years; females, 53%) completed the questionnaire. We categorized 1,283 students (63.7%) as never-smokers, 244 (12.1%) as current smokers, and 487 (24.2%) as nonprogressors. We found that experimentation with smoking was associated with being held back a grade in school (OR = 1.80), alcohol intake (low/occasional, OR = 8.92; high/regular, OR = 2.64), illicit drug use (OR = 9.32), having a sibling or cousin who smokes (OR = 1.39), having a friend who smokes (OR = 2.08), and high levels of stress (in females only, OR = 1.32). Factors associated with an increased risk of transitioning from experimenter to current smoker were alcohol intake (low/occasional, OR = 3.28; high/regular, OR = 2.16), illicit drug use (OR = 3.61), and having a friend who smokes (OR = 7.20). Conclusions: Current smoking was associated with a profile of socioeconomic correlates different from that associated with experimentation only. Our data (showing that current smoking was associated with having a friend who smokes, alcohol intake, and illicit drug use) suggest the need for comprehensive approaches to discourage substance use during adolescence.

Keywords: Smoking; Tobacco use; Adolescent behavior; Stress, psychological.

Objective: To report demographic and clinical characteristics of patients with asthma who evolved to death, as well as to describe the conditions related to this outcome in a subgroup of patients admitted to the Program for the Control of Asthma and Rhinitis in Bahia (ProAR). Methods: A descriptive, retrospective, observational study. Data from clinical charts and death certificates of 16 patients of 930 subjects with severe asthma monitored at the ProAR Central Reference Center from December 2003 to June 2006 were reviewed. Results: Of the 930 patients participating in the program, 16 (1.72%) died. Of these, there were 10 males and 6 females, ranging in age from 39 to 74 years (median, 55 years); 12 (75%) of the patients were black. Time since diagnosis ranged from 1 to 68 years (median, 30 years). In 43.8 and 53.8%, respectively, there was a personal or family history of atopy. Ex-smokers (<10 pack-years) accounted for 37.5% of the cases. Causes of death listed on the death certificates were as follows: asthma or asthma exacerbations in 8 (50%); respiratory failure in 3 (18.75%); acute heart infarction in 2 (12.5%); hepatitis in 1 (6.25%); hypovolemic shock in 1 (6.25%); and cardiorespiratory arrest in 1 (6.25%). Of the 16 deaths, 13 (81.25%) occurred inside hospitals. Conclusion: Asphyxia and cardiovascular diseases were the most common atributed causes of mortality in this subgroup of patients with severe asthma. Hospital-based mortality, male gender, advanced age, long-term disease and fixed airflow obstruction were the aspects most frequently observed in the cases studied.

Keywords: Mortality; Rhinitis/treatment; Asthma/treatment; Cardiovascular diseases.

Objective: To evaluate, using computerized tomography, the frequency of paranasal sinus involvement in patients with allergic rhinitis. Methods: From among outpatients diagnosed with rhinitis and complaining of nasal obstruction, 60 were selected for evaluation. The patients were submitted to anterior rhinoscopy, skin prick test for reactivity to aeroallergens and computed tomography of the paranasal sinuses. In addition, questionnaires designed to evaluate symptom severity were administered. The Lund score was used to evaluate paranasal sinus involvement on computed tomography scans. Results: Computed tomography scans of the paranasal sinuses were abnormal in 31 patients (52%). The sum of the largest diameters of cutaneous reactions to the aeroallergens, symptom severity and anterior rhinoscopy findings did not differ between patients with paranasal sinus involvement and those without. All the patients with paranasal sinus abnormalities also presented osteomeatal complex abnormalities, whereas only 11 patients (38%) without paranasal sinus involvement presented such abnormalities (p < 0.01). Conclusion: In a sample of patients with allergic rhinitis, the frequency of paranasal sinus abnormalities on computed tomography scans was elevated and did not correlate with symptom severity or skin prick test reactivity but was correlated with osteomeatal complex obstruction.

Keywords: Rhinitis; Sinusitis; Tomography, X-ray computed; Paranasal sinuses/radiography

Objective: To evaluate the impact of the Programa de Controle da Asma e Rinite Alérgica em Feira de Santana (ProAR-FS, Program for the Control of Asthma and Allergic Rhinitis in Feira de Santana) on the frequency of hospitalizations for asthma in patients monitored at a referral center for one year. Methods: This was a historical control study involving 253 consecutive patients with asthma, ages ranging from 4 to 76 years. We compared the frequency of hospital admissions and visits to the emergency room (ER) in the 12 months prior to and after their admission to the ProAR-FS. During the program, patients received free treatment, including inhaled medications and education on asthma. Demographic and socioeconomic aspects were also assessed. Results: There was a significant reduction in the number of hospitalizations (465 vs. 21) and of visits to the ER (2,473 vs. 184) after their admission to ProAR-FS (p < 0.001 for both). Of the 253 patients who had been hospitalized and had had ER visits within the year prior to the admission to ProAR-FS, only 16 were hospitalized and 92 visited the ER during the follow-up year, representing a reduction of 94% and 64%, respectively. Conclusions: Implementing a referral center for the treatment of asthma and rhinitis in the Unified Health Care System, with the free distribution of inhaled corticosteroids and the support of an education program, is a highly effective strategy for the control of asthma.

Keywords: Hospitalization; Asthma; Rhinitis; Health services; Public health.

Objective: This study aimed to evaluate the prevalence of developmental defects of enamel (DDEs) in relation to asthma severity, symptom onset and pharmacological treatment in pediatric asthma patients. Methods: Children and adolescents (68 asthma patients and 68 controls), 5-15 years of age and residents of the city of Londrina, Brazil, were enrolled in the study. Medical and dental histories were collected through the use of a structured questionnaire. Each participant underwent a dental examination in which the examiner employed the DDE index. Results: Of the 68 asthma group subjects, 61 (89.7%) presented dental enamel defects, compared with only 26 (38.2%) of those in the control group. Using multivariate logistic regression analysis, we estimated the risk of DDEs in permanent dentition to be 11 times higher in pediatric subjects with asthma than in those without (OR = 11.88, p = 0.0001). The occurrence of dental enamel defects correlated with greater asthma severity (p = 0.0001) and earlier symptom onset (p = 0.0001). However, dental enamel defects did not correlate with the initiation of treatment (p = 0.08) or the frequency of medication use (p = 0.93). Conclusions: Pediatric patients with severe, early-onset asthma are at increased risk of dental enamel defects and therefore require priority dental care.

Keywords: Asthma/prevention & control; Bronchodilator agents; Adrenal cortex hormones/therapeutic use; Dental enamel; Amelogenesis.

Objective: To describe the prevalences of asthma and rhinitis in adolescents (13-14 years of age) in the city of Fortaleza, Brazil, in 2010, comparing the results with those obtained in a prevalence survey conducted in 2006-2007. Methods: This was a cross-sectional study involving probabilistic samples of 3,015 and 3,020 adolescents in surveys conducted in 2006-2007 and 2010, respectively. The International Study of Asthma and Allergies in Childhood protocol was used on both occasions. Results: Comparing the two periods, there were no significant differences regarding cumulative wheezing, active asthma, four or more wheezing attacks within the last year, sleep disturbed by wheezing more than one night per week, and speech-limiting wheezing. The prevalences of exercise-induced wheezing, dry cough at night, and physician-diagnosed asthma were significantly higher in 2010 than in the 2006-2007 period (p < 0.01 for all). The prevalence of physician-diagnosed rhinitis was significantly lower in 2010 (p = 0.01), whereas there were no significant differences between the two periods regarding cumulative rhinitis, current rhinitis, and rhinoconjunctivitis. In both periods, dry cough at night, current rhinitis, and rhinoconjunctivitis were significantly more prevalent in females than in males (p < 0.01 for all). Also in both periods, active asthma, current rhinitis, and rhinoconjunctivitis were more prevalent in private school students than in public school students (p < 0.01 for all). Conclusions: Our data show that the prevalences of asthma and rhinitis symptoms remain high among 13- and 14-year-olds in Fortaleza, predominantly among females and private school students.

Keywords: Asthma/epidemiology; Rhinitis/epidemiology; Adolescent.

Objective: To assess the prevalences of asthma, allergic rhinitis, and allergic rhinoconjunctivitis in adolescents in the city of Belo Horizonte, Brazil, in 2012 by administering the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, as well as to compare the observed prevalences with those found in studies performed 10 years earlier and employing the same methodology used here. Methods: This was a cross-sectional study conducted between May and December of 2012 and involving adolescents in the 13- to 14-year age bracket. Participants were randomly selected from among adolescents studying at public schools in Belo Horizonte and completed the ISAAC questionnaire. Proportions were calculated in order to assess the prevalences of asthma, allergic rhinitis, and allergic rhinoconjunctivitis in the sample as a whole, and the chi-square goodness-of-fit test was used in order to compare the prevalences observed in 2012 with those found in 2002. Results: The prevalences of symptoms of asthma, allergic rhinitis, and allergic rhinoconjunctivitis in 2012 were 19.8%, 35.3%, and 16.3%, respectively, being significantly higher than those found in 2002 (asthma, p = 0.006; allergic rhinitis, p < 0.01; and allergic rhinoconjunctivitis, p = 0.002). Conclusions: The prevalences of asthma, allergic rhinitis, and allergic rhinoconjunctivitis among adolescents in 2012 were found to be high, having increased in comparison with those found 10 years earlier, despite efforts in prevention, diagnosis, and treatment.

Keywords: Asthma; Rhinitis, allergic; Prevalence; Adolescent.

Smoking causes an intense inflammatory reaction in the airways and is associated with worse clinical outcomes in patients with asthma. The objective of this study was to determine the prevalence of active and passive smoking in a population of patients with asthma. The sample of asthma patients (n = 100) consisted of 47 nonsmokers, 33 former smokers, 17 passive smokers and 3 active smokers. Most had moderate or severe asthma. Mean exhaled CO was 9.34 ppb in smokers, 4.19 ppb in passive smokers, 3.98 ppb in nonsmokers and 3.98 ppb in former smokers. We conclude that the prevalence of exposure to tobacco smoke is high among asthma patients.

Keywords: Smoking; Asthma; Prevalence.

Objective: To determine the risk factors for ER visits due to asthma exacerbations in patients monitored at a referral center. Methods: Prospective cohort study of 253 outpatients (children and adults) with asthma who were monitored for 12 months at the Referral Center of the Program for the Control of Asthma and Allergic Rhinitis in the city of Feira de Santana, Brazil. Results: Exacerbations were common, and 36.5% of the patients sought ER treatment within the twelve-month period. The risk factors for asthma exacerbations were being over 20 years of age (OR = 1.34: (95% CI: 1.06-1.70), residing in an urban area (OR = 1.19; 95% CI: 1.06-1.33); having a low level of education (OR = 1.53: 95% CI: 1.00-2.39); having severe asthma (OR = 1.65; 95% CI: 1.24-2.18); and having chronic rhinitis (OR = 2.20; 95% CI: 1.00-4.80). Conclusions: In this cohort, having chronic rhinitis, having asthma that is more severe and having a low level of education were the main risk factors for ER visits due to asthma exacerbations. These results are similar to those reported for asthma patients who are receiving no regular treatment.

Keywords: Asthma/etiology; Health services; Program evaluation.

To evaluate the characteristics of users of inhalers and the frequency of inhaler use among adolescents and adults with self-reported physician-diagnosed asthma, bronchitis, or emphysema. Methods: A population-based study conducted in the city of Pelotas, Brazil, involving 3,670 subjects ≥ 10 years of age, evaluated with a questionnaire. Results: Approximately 10% of the sample reported at least one of the respiratory diseases studied. Among those individuals, 59% reported respiratory symptoms in the last year, and, of those, only half reported using inhalers. The use of inhalers differed significantly by socioeconomic status (39% and 61% for the lowest and the highest, respectively, p = 0.01). The frequency of inhaler use did not differ by gender or age. Among the individuals reporting emphysema and inhaler use, the use of the bronchodilator-corticosteroid combination was more common than was that of a bronchodilator alone. Only among the individuals reporting physician-diagnosed asthma and current symptoms was the proportion of inhaler users higher than 50%. Conclusions: In our sample, inhalers were underutilized, and the type of medication used by the individuals who reported emphysema does not seem to be in accordance with the consensus recommendations.

Keywords: Metered dose inhalers; Asthma; Pulmonary disease, chronic obstructive; Bronchitis; Emphysema; Dry powder inhalers.

The objective of this review was to present evidence of the relationship between allergic rhinitis and impairment of quality of life. The data sources were original articles, reviews and consensus statements entered into the Medline and LILACS databases between 1997 and 2008. The following search terms were used: "allergic rhinitis"; "quality of life"; and "sleep disorders". Quality of life is often impaired in patients with allergic rhinitis, due to the classic symptoms of the disease (sneezing, pruritus, rhinorrhea and nasal obstruction). In addition, the pathophysiology of allergic rhinitis often disrupts sleep, leading to fatigue, irritability, memory deficits, daytime sleepiness and depression. The total burden of this disease goes beyond impairment of physical and social functioning. It has also a financial impact, which becomes greater when we consider the evidence that allergic rhinitis is a possible causal factor of comorbidities, such as asthma and sinusitis. Nasal obstruction, the most prominent symptom, is associated with sleep disorders, which can have a profound effect on mental health, learning, behavior and attention. Finally, allergic rhinitis-a chronic condition that affects adults, adolescents and children-is often underdiagnosed or inadequately treated. The deleterious impact that allergic rhinitis-related sleep disorders have on patient capacity to perform activities of daily living is an important component of the morbidity of the disease. With an accurate diagnosis, there are various available treatments that can reduce the burden of allergic rhinitis.

Keywords: Rhinitis, allergic, perennial; Rhinitis, allergic, seasonal; Quality of life; Sleep disorders.

Objective: To determine the prevalence of allergic bronchopulmonary aspergillosis (ABPA) in patients with cystic fibrosis treated at a referral center in the state of Bahia, Brazil. Methods: A cross-sectional study, with prospective data collection, carried out at the Cystic Fibrosis Referral Center of Bahia of the Octávio Mangabeira Specialized Hospital. We evaluated 74 patients diagnosed with cystic fibrosis, older than six years of age, treated between December 9, 2003 and March 7, 2005. We analyzed the following variables: gender, age, forced vital capacity, forced expiratory volume in one second, pharmacodynamic response, chest X-ray findings, facial sinus X-ray findings, wheezing, cultures for Aspergillus spp., total immunoglobulin E (IgE), specific IgE for Aspergillus fumigatus and immediate skin test reactivity to A. fumigatus antigen. Results: Of the 74 patients, 2 were diagnosed with ABPA. We found total IgE levels > 1,000 IU/mL in 17 (23%), positive immediate skin reactivity to A. fumigatus antigen in 19 (25.7%) and wheezing in 60 (81.1%). Conclusions: The prevalence of ABPA was 2.7%. The high levels of total IgE, high incidence of wheezing and high rate of immediate skin test reactivity to A. fumigatus antigen suggest that these patients should be carefully monitored due to their propensity to develop ABPA.

Keywords: Cystic fibrosis; Aspergillosis, allergic bronchopulmonary; Immunoglobulin E/diagnostic use; Hypersensitivity, immediate/diagnosis; Gliotoxin.

Objective: To assess the prevalence of and factors associated with smoking experimentation among adolescents. Methods: Cross-sectional study, using a specific questionnaire to interview 2,883 students from 7th to 10th grade in schools located in the urban area of the city of Cuiabá, in the state of Mato Grosso, Brazil. Prevalence was estimated, and the principal factors related to cigarette experimentation were analyzed. Subsequently, a hierarchical logistic model was used to describe the chances of cigarette experimentation related to the variables being investigated. Results: The prevalence of cigarette experimentation was 30.2%. In the final model of the analysis, the main variables related to cigarette experimentation were low maternal level of education (OR = 2.44; 95% CI: 1.72-3.47); low socioeconomic level (OR = 1.39; 95% CI: 1.01-1.93); studying in a public school (OR = 1.56; 95% CI: 1.22-2.00); being in 10th grade (OR = 3.45; 95% CI: 2.63-4.54); attending school in the evening (OR = 2.44; 95% CI: 1.85-3.22); having divorced parents (OR = 1.23; 95% CI: 1.02-1.49); having been held back for one school year (OR = 2.17; 95% CI: 1.78-2.70); having friends who smoke (OR = 3.75; 95% CI: 2.99-4.70) having a sibling who smokes (OR = 2.44; 95% CI: 1.82-3.27); and being older (age 17-19 years) (OR = 2.44; 95% CI: 1.39-4.17). Conclusions: A high proportion of adolescents have experimented with smoking. After adjusting for confounding variables, the factors most strongly associated with cigarette experimentation were maternal level of education, age of the adolescent, attending school in the evening, having been held back for one school year and having a sibling who smokes. Preventive measures must be directed at adolescents in schools in order to control smoking.

Keywords: Smoking; Adolescent; Students; Risk factors.

Objective: Smoking prevalence is frequently estimated on the basis of self-reported smoking status. That can lead to an underestimation of smoking rates. The aim of this study was to evaluate the difference between self-reported smoking status and that determined through the use of objective measures of smoking at a pulmonary outpatient clinic. Methods: This was a cross-sectional study involving 144 individuals: 51 asthma patients, 53 COPD patients, 20 current smokers, and 20 never-smokers. Smoking status was determined on the basis of self-reports obtained in interviews, as well as through tests of exhaled carbon monoxide (eCO) and urinary cotinine. Results: All of the asthma patients and COPD patients declared they were not current smokers. In the COPD and asthma patients, the median urinary cotinine concentration was 167 ng/mL (range, 2-5,348 ng/mL) and 47 ng/mL (range, 5-2,735 ng/mL), respectively (p < 0.0001), whereas the median eCO level was 8 ppm (range, 0-31 ppm) and 5 ppm (range, 2-45 ppm), respectively (p < 0.05). In 40 (38%) of the patients with asthma or COPD (n = 104), there was disagreement between the self-reported smoking status and that determined on the basis of the urinary cotinine concentration, a concentration > 200 ng/mL being considered indicative of current smoking. In 48 (46%) of those 104 patients, the self-reported non-smoking status was refuted by an eCO level > 6 ppm, which is also considered indicative of current smoking. In 30 (29%) of the patients with asthma or COPD, the urinary cotinine concentration and the eCO level both belied the patient claims of not being current smokers. Conclusions: Our findings suggest that high proportions of smoking pulmonary patients with lung disease falsely declare themselves to be nonsmokers. The accurate classification of smoking status is pivotal to the treatment of lung diseases. Objective measures of smoking could be helpful in improving clinical management and counseling.

Keywords: Asthma; Pulmonary disease, chronic obstructive; Cotinine; Carbon monoxide; Smoking.

Objective: To analyze adolescents clinically diagnosed with asthma, in terms of the physiological changes occurring during acute hypoxia and during a maximal stress test. Methods: This was a descriptive, cross-sectional study involving 48 adolescents (12-14 years of age) who were divided into three groups: mild intermittent asthma (MIA, n = 12); mild persistent asthma (MPA, n = 12); and control (n = 24). All subjects were induced to acute hypoxia and were submitted to maximal stress testing. Anthropometric data were collected, and functional variables were assessed before and after the maximal stress test. During acute hypoxia, the time to a decrease in SpO2 and the time to recovery of SpO2 (at rest) were determined. Results: No significant differences were found among the groups regarding the anthropometric variables or regarding the ventilatory variables during the stress test. Significant differences were found in oxygen half-saturation pressure of hemoglobin prior to the test and in PaO2 prior to the test between the MPA and control groups (p = 0.0279 and p = 0.0116, respectively), as was in the oxygen extraction tension prior to the test between the MIA and MPA groups (p = 0.0419). There were no significant differences in terms of the SpO2 times under any of the conditions studied. Oxygen consumption and respiratory efficiency were similar among the groups. The use of a bronchodilator provided no significant benefit during the hypoxia test. No correlations were found between the hypoxia test results and the physiological variables. Conclusions: Our findings suggest that adolescents with mild persistent asthma have a greater capacity to adapt to hypoxia than do those with other types of asthma.

Keywords: Asthma; Adolescent; Cell hypoxia; Exercise test.

Objective: To analyze the prevalence of asthma and asthma symptoms in students of two distinct age brackets residing in the city of Tangará da Serra, Brazil. Methods: Cross-sectional, population-based study of the prevalence of asthma in children from 6 to 7 years of age and adolescents from 13 to 14, using the standardized International Study of Asthma and Allergies in Childhood, phase 1 questionnaire, validated for use in Brazil. Students who responded affirmatively to question 2 (presence of wheezing in the preceding 12 months) were classified as suffering from asthma. Results: The study comprised 3,362 students, of whom 1,634 (48.6%) were children and 1,728 (51.4%) were adolescents. Of the 1,634 children, 816 (49.9%) were male and 818 (50.1%) were female. Of the 1,728 adolescents, 773 (45.0%) were male and 955 (55.0%) were female. The prevalence of asthma among the children was 25.2%, whereas that among the adolescents was 15.9% (χ2 = 8.34; p = 0.00). The children presented higher prevalences of the following symptoms of asthma than did the adolescents: wheezing ever (54.3%), nocturnal dry cough (43.9%), wheezing in the preceding 12 months (25.2%), and from 1 to 3 attacks of wheezing in the preceding 12 months (19.1%). There were no differences between the two groups regarding physician-diagnosed asthma (approximately 4.5%). There were no statistical differences regarding the prevalence of asthma by gender in the two groups. Conclusions: Tangará da Serra has a high prevalence of asthma in children and adolescents, and this result is compatible with other studies carried out in Brazil and Latin America using the same methodology.

Keywords: Asthma/epidemiology; Child; Adolescent.

Objective: To determine the prevalence of asthma among adolescents (13-14 years of age) in the city of Fortaleza, Brazil. Methods: This was a cross-sectional study involving 3,015 adolescents at public and private schools between 2006 and 2007. The participants completed the International Study of Asthma and Allergies in Childhood questionnaire. Results: The prevalences of "wheezing ever", "wheezing within the last 12 months" (active asthma) and "asthma ever" (physician-diagnosed asthma) were 44.1%, 22.6% and 11.6%, respectively. The prevalences of "wheezing ever" (p = 0.001), "1-3 wheezing attacks within the last 12 months" (p = 0.001), active asthma (p = 0.002), "sleep disturbed due to wheezing less than one night per week" (p < 0.001) and "dry cough at night" (p < 0.001) were higher among girls. Private school students presented higher prevalences of "wheezing ever", active asthma, "1-3 wheezing attacks within the last 12 months", "4-12 wheezing attacks within the last 12 months" and physician-diagnosed asthma (p < 0.001 for all), as well as of "exercise-induced wheezing" (p = 0.032). Conclusions: The prevalence of asthma and asthma-related symptoms in students aged 13-14 years in the city of Fortaleza, Brazil, was high, predominantly among girls and private school students. The difference between the prevalence of physician-diagnosed asthma and that of active asthma suggests that asthma was underdiagnosed in the population studied.

Keywords: Asthma/diagnosis; Asthma/epidemiology; Asthma/prevalence.