Sugar-Sweetened Beverages and Allergy Traits at Second Year of Life: BRISA Cohort Study

Sugar-Sweetened Beverage (SSBs) consumption has risen in early life and it is plausible that it might increase children's risk of allergies. In this paper, we analyzed the association of SSB consumption with allergies in children's second year of life. This study analyzed data from a São Luís BRISA prenatal cohort in the follow-up of children (n = 1144) in their second year of life. Allergy Traits were a latent variable deduced from medical diagnoses of allergic rhinitis, atopic dermatitis, and food allergies. SSBs were investigated as a percentage of daily calories based on 24 h recalls, including industrialized fruit juices, soft drinks, and ready-made chocolate milk. Other variables analyzed were socioeconomic status, age, body mass index z-score, episodes of diarrhea, and breastfeeding. Our finds were that higher consumption of daily calories from SSBs was associated with higher Allergy Trait values (SC = 0.174; p = 0.025); older age (SC = -0.181; p = 0.030) was associated with lower Allergy Trait values; and episodes of diarrhea were correlated with Allergy Traits (SC = 0.287; p = 0.015). SSB exposure was associated with Allergy Traits in children's second year of life; thus, abstaining from these beverages may also confer additional advantages in curtailing allergic diseases during early childhood.

Asthma-associated bacterial infections: Are they protective or deleterious?

Eosinophilic, noneosinophilic, or mixed granulocytic inflammations are the hallmarks of asthma heterogeneity. Depending on the priming of lung immune and structural cells, subjects with asthma might generate immune responses that are TH2-prone or TH17-prone immune response. Bacterial infections caused by Haemophilus, Moraxella, or Streptococcus spp. induce the secretion of IL-17, which in turn recruit neutrophils into the airways. Clinical studies and experimental models of asthma indicated that neutrophil infiltration induces a specific phenotype of asthma, characterized by an impaired response to corticosteroid treatment. The understanding of pathways that regulate the TH17-neutrophils axis is critical to delineate and develop host-directed therapies that might control asthma and its exacerbation episodes that course with infectious comorbidities. In this review, we outline clinical and experimental studies on the role of airway epithelial cells, S100A9, and high mobility group box 1, which act in concert with the IL-17-neutrophil axis activated by bacterial infections, and are related with asthma that is difficult to treat. Furthermore, we report critically our view in the light of these findings in an attempt to stimulate further investigations and development of immunotherapies for the control of severe asthma.

Factors associated with allergy traits around the 2nd year of life: a brazilian cohort study

BACKGROUND

Allergic status has been strongly influenced by early exposures; however, allergic diseases are hard to measure in early life. Thus, this study proposed a latent variable allergy traits around the second year of life and analyzed pre- and perinatal factors associated with this phenomenon.

METHODS

The study used data from the BRISA birth cohort, Ribeirão Preto, Brazil (n = 3644). The theoretical model included: family allergy (history of allergic rhinitis, atopic dermatitis, and asthma); gestational period variables (socioeconomic status, mother's skin color, pregestational body mass index - BMI, smoking, gestational diabetes, and hypertension); birth variables (gestational age, 5-minute Apgar score, birth weight, type of delivery), and early life factor (exclusive breast feeding). The outcome was allergy traits around the 2nd year of life, a latent variable deduced from the shared variance among medical diagnosis of allergic rhinitis, atopic dermatitis, and food allergy. The model was analyzed by structural equation modeling.

RESULTS

Higher socioeconomic status (SC = 0.256; p < 0.001) and higher family allergy values (SC = 1.224; p < 0.001) were associated with higher allergy trait values. Hypertension during pregnancy was associated with higher values (SC = 0.170; p = 0.022) and exclusive breast feeding (SC = -0.192; p < 0.001) with low allergy trait values.

CONCLUSION

Although socioeconomic and environmental factors were associated with allergy traits around the 2nd year of life, the family component of allergy was the exposure that best explained this outcome.

Comparison of body composition parameters in the study of the association between body composition and pulmonary function

Background

The excess adiposity, even in the absence of diseases, is responsible for a decline in pulmonary function, which is considered a predictor of mortality and a risk factor for diseases in several epidemiological studies. However, studies on the association between obesity and pulmonary function have found only few associations or inconclusive results. The aim of the study is to evaluate the association between body composition and spirometric parameters, comparing simple obesity measures such as body mass index (BMI) and waist circumference with more precise body composition measurements such as dual-energy X-ray absorptiometry (DXA) and air-displacement plethysmography (BOD POD).

Methods

This is an observational, cross-sectional study that used data from the 1978/79 Ribeirão Preto birth cohort (São Paulo, Brazil). The study included 1746 participants from the 5th follow-up of the cohort. Linear regressions were calculated to evaluate the association between BMI, waist circumference, waist–height ratio (WHtR), BOD POD- and DXA-measured fat mass percentage, and spirometric parameters FEV1, and FVC.

Results

For every 1-kg/m² BMI increase, FVC decreased by 13 ml in males and by 6 ml in females and FEV1 decreased by 11 ml and 5 ml, respectively. Regarding body composition measurements, for a 1% increase in fat mass assessed by BOD POD, FVC decreased by 16 ml in males and by 8 ml in females and FEV1 decreased by 13 ml and 7 ml, respectively. Hence, negative associations between body measurements and FEV1 and FVC were observed in both genders, especially when using the fat mass measurement and were more expressive in men.

Conclusion

The anthropometric and body composition parameters were negatively associated with the spirometric variables FVC and FEV1. We have also observed that simple measures such as waist-height ratio were sufficient to detect the association of body composition with pulmonary function reduction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01543-1.

Pathways in the association between sugar sweetened beverages and child asthma traits in the 2nd year of life: Findings from the BRISA cohort

Studies on the exposure of children to sugar-sweetened beverages (SSBs) at an early age may contribute to better understand the common causes and the temporal order of the relationships between obesity and asthma in early childhood. The objective of this study was to estimate the association between SSB and child asthma traits in the 2nd year of life, modeling direct and indirect pathways mediated by the highest BMI-z of the child and allergic inflammation. Data from the BRISA cohort, São Luís-MA, Brazil (n = 1140), were obtained from the baseline and from the follow-up performed at the 2nd year of life. The main explanatory variable was the calories from added sugars in SSBs as a percentage of the total daily energy intake. The outcome child asthma traits was a latent variable deduced from four indicators: medical diagnosis of asthma, wheezing, emergency visit due to intense wheezing, and medical diagnosis of rhinitis. A high percentage of daily calories from sugars added to SSBs was directly associated with higher values of child asthma traits (standardized coefficient (SC = 0.073; P = .030)). High levels of eosinophils were also directly associated with child asthma traits (SC = 0.118; P = .049). No mediation pathways were observed via greater BMI-z or eosinophil counts. Therefore, early exposure of children to SSB may contribute to increased risk of childhood asthma, preceding the link between sugar consumption and overweight/obesity, not yet evident in children in the first 2 years of life.

Provision of inhaled corticosteroids is associated with decrease in hospital admissions in Brazil: A longitudinal nationwide study

OBJECTIVE

To describe trends of hospital admissions due to asthma from 2008 to 2015 and to evaluate their relationship with trends of inhaled corticosteroids (ICS) provision by the government in Brazil.

METHODS

We used Brazilian Government data to calculate hospital admission rates due to asthma, number of physicians, number of hospital beds, number of subjects that received ICS per 100,000 inhabitants in Brazil and in each of its municipalities for each year of the study. We performed Poisson Multilevel Regression Analyses to evaluate the relationship between the trends of hospital admission rates due to asthma with the trends of the number of subjects that had been receiving ICS during the study period. The analyses were adjusted for the number of physicians and hospital beds.

FINDINGS

The number of patients who received ICS/100,000 inhabitants increased from 2008 to 2015 (943.9-1988.5). Hospital admissions/100,000 inhabitants decreased in patients aged 5-14 years (148.3-110.9) and in patients aged 15-39 years (59.9-32.3); the reduction was greater in municipalities in which ICS provision increased. The number of physicians/100,000 inhabitants increased and the number of hospital beds/100,000 inhabitants decreased in the study period. The increase in the number of physicians and in the number of subjects that received ICS were associated with reduction in hospital admissions.

CONCLUSION

We found that provision of ICS by the Brazilian Government was associated with a decrease of hospital admissions for asthma in the municipalities and country levels from 2008 to 2015.

Lifetime overweight and adult asthma: 1978/1979 Ribeirão Preto Birth Cohort, São Paulo, Brazil

Studies focusing on obesity and asthma frequently consider the weight at a given time; thus, modeling pathways through lifetime overweight may contribute to elucidate temporal aspects in this relationship. This study modeled the pathways in the association of lifetime overweight with asthma in adult life, using data from the 1978/1979 Birth Cohort, Ribeirão Preto, São Paulo, Brazil (n = 2,063) at birth (baseline), school age (9/11 years) and adult age (23/25 years). A theoretical model was proposed to explore the effects of lifetime overweight on asthma in adult life analyzed by structural equation modeling. Parental obesity (SC - standardized coefficenttotal = 0.211, p < 0.001; SCdirect = 0.115, p = 0.007) and overweight at school age (SCtotal = 0.565, p < 0.0001; SCdirect = 0.565, p < 0.0001) were associated with overweight in adult life. Parental obesity (SCdirect = 0.105, p = 0.047) and nutritional status at birth (SCtotal = -0.124, p = 0.009; SCdirect = -0.131, p = 0.007) were associated with asthma in adult life. A higher "current adult socieconomic situation" was inversely associated to overweight (SCdirect = -0.171, p = 0.020) and to asthma in adult life (SCtotal = -0.179, p = 0.041; SCdirect = -0.182, p = 0.039). Parental obesity showed a transgenerational effect in weight, triggering to childhood and adulthood overweight. Parallel to underweight at birth, parental obesity was also a risk to asthma in adult life. While, the socioeconomic status in adult life protected from both, overweight and asthma.

2020 Brazilian Thoracic Association recommendations for the management of asthma

The pharmacological management of asthma has changed considerably in recent decades, as it has come to be understood that it is a complex, heterogeneous disease with different phenotypes and endotypes. It is now clear that the goal of asthma treatment should be to achieve and maintain control of the disease, as well as to minimize the risks (of exacerbations, disease instability, accelerated loss of lung function, and adverse treatment effects). That requires an approach that is personalized in terms of the pharmacological treatment, patient education, written action plan, training in correct inhaler use, and review of the inhaler technique at each office visit. A panel of 22 pulmonologists was invited to perform a critical review of recent evidence of pharmacological treatment of asthma and to prepare this set of recommendations, a treatment guide tailored to use in Brazil. The topics or questions related to the most significant changes in concepts, and consequently in the management of asthma in clinical practice, were chosen by a panel of experts. To formulate these recommendations, we asked each expert to perform a critical review of a topic or to respond to a question, on the basis of evidence in the literature. In a second phase, three experts discussed and structured all texts submitted by the others. That was followed by a third phase, in which all of the experts reviewed and discussed each recommendation. These recommendations, which are intended for physicians involved in the treatment of asthma, apply to asthma patients of all ages.

Cat ownership is associated with increased asthma prevalence and dog ownership with decreased spirometry values

The association between pet ownership and the development of allergic and respiratory diseases has been the aim of several studies, however, the effects of exposure in adults remain uncertain. The aims of the present study were to investigate the prevalence of asthma and lung function status among dog and cat owners. This cross-sectional study was performed at two universities with students and workers who were allocated into 3 groups according to pet ownership in the previous year: cat owners, dog owners, and no pets (control group). Subjects underwent spirometry, bronchial challenge test with mannitol, skin prick tests, and questionnaires about animal exposures and respiratory symptoms. Control group comprised 125 subjects; cat owner group, 51 subjects; and dog owner group, 140 subjects. Cat owners had increased asthma prevalence (defined by symptoms and positive bronchial challenge test), but no changes in lung function compared to the control group. The dog owner group had lower spirometry values (forced expiratory volume in one second and lower forced vital capacity), but similar asthma prevalence, compared to the control group. In the cat owner group, excess of asthma may have an immunological basis, since we found an association with atopy. Although we did not have endotoxin data from volunteers' households, we postulated that low values of lung function were associated to exposure to endotoxins present in environments exposed to dogs.

Evaluation of the preference, satisfaction and correct use of Breezhaler® and Respimat® inhalers in patients with chronic obstructive pulmonary disease - INHALATOR study

The INHALATOR study was a randomized, multicentre, open label, two-period of 7 days each, crossover study, with 7 days of washout in-between, aiming to evaluate the correct use, satisfaction and preference between Breezhaler^® and Respimat^® devices in patients under daily use of open Spiriva^® or open Onbrize^®, as monotherapy for treatment of mild or moderate COPD. Patients aged ≥40 years with a smoking history of at least 10 pack-year were included in the study. Primary endpoint was the rate of correct use of each device at the first day of treatment after reading the drug leaflet information and was evaluated under the supervision of a trained evaluator. At the end of each treatment phase, the inhaler use was re-evaluated and a satisfaction questionnaire was completed. The patients' preference for the inhaler devices was assessed at the end of the study. After exclusions due to screening failures, 140 patients were randomized: 136 received at least one dose of Breezhaler^® and 135 of Respimat^®. At treatment start, the rate of correct inhaler use was 40.4% (95%CI: 32.2%-48.7%) for Breezhaler^® and 36.3% (95%CI: 28.2%-44.4%) for Respimat^® (p = 0.451). After 7 days, the rates were 68.9% (95%CI: 61.1%-76.7%) and 60.4% (95%CI: 52.2%-68.7%), respectively (p = 0.077). According to the Feeling of Satisfaction with Inhaler Questionnaire - FSI 10 patients were more satisfied using Breezhaler^® than Respimat^® and 57.1% preferred using Breezhaler^® (p = 0.001) while 30.1% preferred Respimat^® (p < 0.001).

Allergic sensitization to laboratory animals is more associated with asthma, rhinitis, and skin symptoms than sensitization to common allergens

BACKGROUND

Workers exposed to laboratory animals have a high risk of developing laboratory animal allergy (LAA). Atopy seems to be the main risk factor for LAA. We hypothesized that occupational sensitization is a better predictor for the development of asthma, rhinitis, and bronchial hyperresponsiveness (BHR) than common sensitization.

OBJECTIVE

To investigate the association between occupational sensitization to laboratory animals and clinical outcomes.

METHODS

This was a cross-sectional study performed at two universities on students and employees dealing with small rodents. The subjects were allocated in groups: non-sensitized, common sensitization, or occupational sensitization, according to the results of the skin prick test (SPT). All subjects answered a questionnaire about animal exposures, symptoms, allergic diseases, and underwent spirometry and bronchial challenge test with mannitol. Multivariate analysis was performed using Poisson regression to estimate the prevalence ratio (PR).

RESULTS

Data from 453 volunteers were analysed. Non-sensitized group comprised 237 subjects; common sensitization group, 142 subjects; and occupational sensitization group, 74 subjects. Occupational sensitization was associated with greater risk for all outcomes studied. When the common sensitization group was reference, skin symptoms had PR of 1.36, 95% confidence interval (CI): 1.01-1.85; wheezing had PR of 1.75, CI 95%: 1.21-2.53; rhinitis had PR of 1.25, 95%: 1.11-1.40; nocturnal dyspnoea had PR of 2.40, 95% CI: 1.31-4.40; bronchial hyperresponsiveness (BHR) had PR of 2.47, 95% CI: 1.50-4.09; and confirmed asthma had PR of 2.65, 95% CI: 1.45-4.85. In addition, the overlap of asthma, rhinitis, and skin symptoms in a same subject was significantly more prevalent in the occupational sensitization group, 16.2% versus 4.9% in the common sensitization group.

CONCLUSION AND CLINICAL RELEVANCE

Occupational sensitization is associated with allergic symptoms and respiratory diseases. SPT with occupational allergens along with other parameters may contribute to detection of risk for allergic and respiratory diseases associated with exposure to laboratory animals.

Accuracy of spirometry for detection of asthma: a cross-sectional study

BACKGROUND

Asthma is a chronic inflammatory disease with airway hyperresponsiveness. Spirometry is the most commonly used test among asthmatic patients. Another functional test used for diagnosing asthma is the bronchial challenge test. The aim of this study was to analyze the accuracy of spirometry for detecting asthma in the general population.

DESIGN AND SETTING

Cross-sectional study with data analysis to evaluate the accuracy of spirometry through calculating sensitivity, specificity and predictive values and through the kappa agreement test.

METHODS

Subjects who constituted a birth cohort were enrolled at the age of 23 to 25 years. Spirometric abnormality was defined as reduced forced expiratory volume in one second, i.e. lower than 80% of the predicted value. Measurement of bronchial responsiveness was performed by means of the bronchial challenge test with methacholine. The gold-standard diagnosis of asthma was defined as the presence of bronchial hyperresponsiveness in association with respiratory symptoms.

RESULTS

Asthma was detected in 200 subjects (10.4%) out of the sample of 1922 individuals. Spirometric abnormality was detected in 208 subjects (10.9%) of the sample. The specificity of spirometric abnormality for detecting asthma was 90%, sensitivity was 23%, positive predictive value was 22%, and negative predictive value was 91%. The kappa test revealed weak agreement of 0.13 (95% confidence interval, CI: 0.07-0.19) between spirometry and the diagnosis of asthma.

CONCLUSION

Spirometry, as a single test, has limitations for detecting asthma in the general population.

Asthma self-management model: randomized controlled trial

Information for patients provided by the pharmacist is reflected in adhesion to treatment, clinical results and patient quality of life. The objective of this study was to assess an asthma self-management model for rational medicine use. This was a randomized controlled trial with 60 asthmatic patients assigned to attend five modules presented by a pharmacist (intervention group) and 59 patients in the control group. Data collection was performed before and after this 4-month intervention and included an evaluation of asthma knowledge, lifestyle, inhaler techniques, adhesion to treatment, pulmonary function and quality of life. An economic viability analysis was also performed. The intervention group obtained an increase in asthma knowledge scores of 58.3-79.5% (P < 0.001). In this group, there was also an increase in the number of individuals who practiced physical exercise (36-43%), in the number of correct replies regarding the use of inhalers, in the percentage of adherent patients, and in quality of life scores for all domains. We concluded that this asthma self-management model was effective in improving the quality of life of asthma patients.

Exposure to high endotoxin concentration increases wheezing prevalence among laboratory animal workers: a cross-sectional study

Background

Endotoxin from Gram-negative bacteria are found in different concentrations in dust and on the ground of laboratories dealing with small animals and animal houses.

Methods

Cross-sectional study performed in workplaces of two universities. Dust samples were collected from laboratories and animal facilities housing rats, mice, guinea pigs, rabbits or hamsters and analyzed by the “Limulus amebocyte lysate” (LAL) method. We also sampled workplaces without animals. The concentrations of endotoxin detected in the workplaces were tested for association with wheezing in the last 12 months, asthma defined by self-reported diagnosis and asthma confirmed by bronchial hyperresponsiveness (BHR) to mannitol.

Results

Dust samples were obtained at 145 workplaces, 92 with exposure to animals and 53 with no exposure. Exposed group comprised 412 subjects and non-exposed group comprised 339 subjects. Animal-exposed workplaces had higher concentrations of endotoxin, median of 34.2 endotoxin units (EU) per mg of dust (interquartile range, 12.6–65.4), as compared to the non-exposed group, median of 10.2 EU/mg of dust (interquartile range, 2.6–22.2) (p < 0.001). The high concentration of endotoxin (above whole sample median, 20.4 EU/mg) was associated with increased wheezing prevalence (p < 0.001), i.e., 61 % of workers exposed to high endotoxin concentration reported wheezing in the last 12 months compared to 29 % of workers exposed to low endotoxin concentration. The concentration of endotoxin was not associated with asthma report or with BHR confirmed asthma.

Conclusion

Exposure to endotoxin is associated with a higher prevalence of wheezing, but not with asthma as defined by the mannitol bronchial challenge test or by self-reported asthma. Preventive measures are necessary for these workers.

Study of risk factors for atopic sensitization, asthma, and bronchial hyperresponsiveness in animal laboratory workers

OBJECTIVES

The aim of this estudy was to investigate the influence of allergen exposure levels and other risk factors for allergic sensitization, asthma, and bronchial hyperresponsiveness (BHR) in workers exposed to laboratory animals.

METHODS

This was a cross-sectional study performed at two universities, 123 workplaces with 737 subjects. Dust samples were collected from laboratories and animal facilities housing rats, mice, guinea pigs, rabbits, or hamsters and analyzed by enzyme-linked immunosorbent assay (ELISA) to measure allergen concentrations. We also sampled workplaces without animals. Asthma was defined by both symptoms and BHR to mannitol. The concentrations of allergens were tested for association with a skin prick test, respiratory symptoms, spirometry data, and BHR. This multivariate analysis was performed by using Poisson regression to estimate the relative risk (RR) for the exposed group.

RESULTS

Our sample comprised students and workers, with 336 subjects in the nonexposed group and 401 subjects in the exposed group. Sixty-nine subjects (17%) had positive results in the skin prick test for animal allergens in the exposed group; in the nonexposed group, 10 subjects had positive results (3%) (p<0.001). Exposure to laboratory animals over 2.8 years was associated with atopic sensitization (RR=1.85; 95% confidence interval: 1.09-3.15; p=0.02). Allergen concentration was not associated with sensitization, asthma, or BHR.

CONCLUSION

Exposure to laboratory animals was associated with atopic sensitization. However, we did not find a cutoff allergen concentration that increased the risk for sensitization. Duration of exposure seems to be more relevant to sensitization than concentration of allergens in dust.

Characteristics of undiagnosed COPD in a senior community center

Objective

To determine the characteristics of undiagnosed chronic obstructive pulmonary disease (COPD) in a senior community center.

Methods

We performed a cross-sectional, observational study with the following procedures: questionnaire to record demographic and health status data, anthropometry, questionnaire about COPD risk factors and symptoms, spirometry, and socioeconomic evaluation. Simple logistic regression and multiple analyses were carried out to assess associations. The studied variables were tested for associations with previous COPD diagnosis.

Results

Three hundred and thirty-five subjects aged 50 years or older were recruited and 318 completed the protocol. Seventy-one (22%) had presumptive COPD. Among them, 57 (80%) did not have a previous physician-made diagnosis of COPD. We found no associations between previous diagnosis and socioeconomic status, anthropometric data, or risk factors. Regarding respiratory symptoms, there was an association between previous COPD diagnosis and wheezing (P=0.011). FEV₁ and FVC values were lower in the previous diagnosis group compared to the group without a previous diagnosis (P<0.001, Student’s t-test). We found an association of lower FEV₁ (<50% predicted value) with a previous diagnosis (P=0.028).

Conclusion

Our results showed a high prevalence of undiagnosed obstructive ventilatory defects in a senior community center. Previous COPD diagnosis was associated with more severe disease and more frequent wheezing. This study highlights the potential of these centers to increase COPD diagnosis and to reduce its risks.

Cryptococcosis, silicosis, and tuberculous pseudotumor in the same pulmonary lobe

Tuberculosis and cryptococcosis are infectious diseases that can result in the formation of single or multiple nodules in immunocompetent patients. Exposure to silica is known to raise the risk of infection with Mycobacterium tuberculosis. We report the case of an elderly man with no history of opportunistic infections and no clinical evidence of immunodeficiency but with a six-month history of dry cough and nocturnal wheezing. A chest X-ray revealed a mass measuring 5.0 × 3.5 cm in the right upper lobe. The diagnostic approach of the mass revealed tuberculosis. The histopathological analysis of the surrounding parenchyma reveled silicosis and cryptococcosis. Cryptococcosis was also found in masses identified in the mediastinal lymph nodes. The surgical approach was indicated because of the degree of pleuropulmonary involvement, the inconclusive results obtained with the invasive and noninvasive methods applied, and the possibility of malignancy. This case illustrates the difficulty inherent to the assessment of infectious or inflammatory pulmonary pseudotumors, the differential diagnosis of which occasionally requires a radical surgical approach. Despite the presence of respiratory symptoms for six months, the first chest X-ray was performed only at the end of that period. We discuss the possible pathogenic mechanisms that might have led to the combination of three types of granulomatous lesions in the same lobe, and we emphasize the need for greater awareness of atypical presentations of pulmonary tuberculosis.

Fluticasone/formoterol dry powder versus budesonide/formoterol in adults and adolescents with uncontrolled or partly controlled asthma

This 12-week study compared the efficacy and safety of a fixed combination of fluticasone propionate plus formoterol (FL/F) 250/12 μg b.i.d. administered via a dry powder inhaler (DPI) (Libbs Farmacêutica, Brazil) to a combination of budesonide plus formoterol (BD/F) 400/12 μg b.i.d. After a 2-week run-in period (in which all patients were treated exclusively with budesonide plus formoterol), patients aged 12-65 years of age (N = 196) with uncontrolled asthma were randomized into an actively-controlled, open-labeled, parallel-group, multicentre, phase III study. The primary objective was to demonstrate non-inferiority, measured by morning peak expiratory flow (mPEF). The non-inferiority was demonstrated. A statistically significant improvement from baseline was observed in both groups in terms of lung function, asthma control, and the use of rescue medication. FL/F demonstrated a statistical superiority to BD/F in terms of lung function (FEV(1)) (p = 0.01) and for asthma control (p = 0.02). Non-significant between-group differences were observed with regards to exacerbation rates and adverse events. In uncontrolled or partly controlled asthma patients, the use of a combination of fluticasone propionate plus formoterol via DPI for 12-weeks was non-inferior and showed improvements in FEV(1) and asthma control when compared to a combination of budesonide plus formoterol. (

CLINICAL TRIAL NUMBER

ISRCTN60408425).

Influence of asthma definition on the asthma-obesity relationship

Background

Epidemiological studies suggest an association between obesity and asthma in adults and children. Asthma diagnosis criteria are different among studies. The aim of this study was to test the influence of asthma definition on the asthma-obesity relationship.

Methods

In a cross-sectional analysis of 1922 men and women, subjects completed a translated questionnaire from the European Community Respiratory Health Survey and underwent spirometry and a bronchial challenge test. Weight, height and waist circumference were measured. Multiple logistic regression analysis was carried out to assess the association of variables related to obesity and asthma. Asthma was defined either by the presence of symptoms with bronchial hyperresponsiveness (BHR) or by a self-report of a physician-made diagnosis. The following variables were separately tested for associations with asthma: socioeconomic characteristics, schooling, physical activity, smoking status, anthropometry and spirometry.

Results

No association was detected between asthma confirmed by BHR and obesity indicators, odds ratio (OR) = 1.08 (95% confidence interval: 0.69 - 1.68) for obesity assessed by body mass index ≥ 30 kg/m²; OR = 1.02 (0.74 - 1.40) for obesity assessed by abnormal waist-to-height ratio; and, OR = 0.96 (0.69 - 1.33) for abnormal waist circumference. On the contrary, a previous diagnosis of asthma was associated with obesity, OR = 1.48 (1.01 - 2.16) for body mass index ≥ 30 kg/m²; OR = 1.48 (1.13 - 1.93) for abnormal waist-to-height ratio; and, OR = 1.32 (1.00 – 1.75) for abnormal waist circumference. Female gender, schooling ≥ 12 years and smoking were associated with BHR-confirmed asthma. Physically inactive subjects were associated with a previous diagnosis of asthma.

Conclusions

Our findings indicate that the relationship between asthma and obesity in epidemiological studies depends on the definition adopted. Certain components of asthma, for instance, symptoms may be more prone to the obesity influence than other ones, like bronchial hyperresponsiveness.

The effect of acute magnesium loading on the maximal exercise performance of stable chronic obstructive pulmonary disease patients

OBJECTIVE

The potential influence of magnesium on exercise performance is a subject of increasing interest. Magnesium has been shown to have bronchodilatatory properties in asthma and chronic obstructive pulmonary disease patients. The aim of this study was to investigate the effects of acute magnesium IV loading on the aerobic exercise performance of stable chronic obstructive pulmonary disease patients.

METHODS

Twenty male chronic obstructive pulmonary disease patients (66.2 + 8.3 years old, FEV1: 49.3+19.8%) received an IV infusion of 2 g of either magnesium sulfate or saline on two randomly assigned occasions approximately two days apart. Spirometry was performed both before and 45 minutes after the infusions. A symptom-limited incremental maximal cardiopulmonary test was performed on a cycle ergometer at approximately 100 minutes after the end of the infusion.

RESULTS

Magnesium infusion was associated with significant reductions in the functional residual capacity (-0.41 l) and residual volume (-0.47 l), the mean arterial blood pressure (-5.6 mmHg) and the cardiac double product (734.8 mmHg.bpm) at rest. Magnesium treatment led to significant increases in the maximal load reached (+8 w) and the respiratory exchange ratio (0.06) at peak exercise. The subgroup of patients who showed increases in the work load equal to or greater than 5 w also exhibited significantly greater improvements in inspiratory capacity (0.29 l).

CONCLUSIONS

The acute IV loading of magnesium promotes a reduction in static lung hyperinflation and improves the exercise performance in stable chronic obstructive pulmonary disease patients. Improvements in respiratory mechanics appear to be responsible for the latter finding.

Atopy risk factors at birth and in adulthood

OBJECTIVE

To study the association between atopy and variables such as weight, length, and socioeconomic level at birth and in young adulthood.

METHODS

A total of 2,063 subjects were investigated in a prospective birth cohort study of individuals born in Ribeirão Preto, Brazil, in 1978/1979, and examined at the age of 23-25 years. Skin prick tests (SPT) for eight common allergens in Brazil were performed. Subjects with a wheal reaction ≥ 3 mm to one or more of the eight allergens tested were considered to be atopic. We used the log-binomial model (generalized linear model) in order to assess the association between atopy and birth or adult variables.

RESULTS

The prevalence of positive SPT was 47.6%. Male gender was associated with an increased risk of atopy (relative risk [RR] = 1.18; 95% confidence interval [95%CI] 1.07-1.30). Low level of schooling was a protective factor against atopy, with a RR = 0.74; 95%CI 0.62-0.89. Living with a smoker in childhood was also associated with lower risk of atopy (RR = 0.87; 95%CI 0.79-0.96). Birth weight, length and order, maternal age, and intrauterine growth restriction were not associated with positive SPT.

CONCLUSIONS

This study showed that male gender was associated with an increased risk of atopy. Low socioeconomic status, assessed by low level of schooling, was a protective factor against atopy. These data agree with the hygiene hypothesis.

Bronchial provocation tests in clinical practice

Bronchial hyperresponsiveness, which consists of an exaggerated response of the airways to bronchoconstrictor stimuli, is one of the main characteristics of asthma, presented in nearly all asthmatic patients. Bronchial hyperresponsiveness may also be present in other diseases, such as allergic rhinitis, chronic obstructive pulmonary disease, cystic fibrosis, heart failure and respiratory infection, and with some medications, such as β-blockers. Bronchial provocation tests (also known as bronchial challenges) are used to evaluate bronchial responsiveness. These tests have become increasingly used over the last 20 years, with the development and validation of accurate, safe and reproducible tests, and with the publication of well-detailed protocols. Several stimuli can be used in a bronchial challenge, and they are classified as direct and indirect stimuli. There are many indications for a bronchial challenge. In this review, we discuss the main differences between direct and indirect stimuli, and the use of bronchial challenges in clinical practice, especially for confirming diagnoses of asthma, exercise-induced bronchoconstriction and cough-variant asthma, and for use among elite-level athletes.

Asthma and pregnancy: repercussions for neonates

OBJECTIVE

To describe socioeconomic and behavioral aspects of pregnant women with asthma and to analyze the effects of maternal asthma on certain perinatal parameters in a birth cohort.

METHODS

An observational crosssectional analytical study using data regarding the mothers of a birth cohort at maternity hospitals in the greater metropolitan area of Aracaju, Brazil, between the 8th of March and the 15th of July of 2005. In the pregnant women, asthma was self-reported, based on previous medical diagnosis. Epidemiological, obstetric and perinatal variables were studied.

RESULTS

Of the 4,757 mothers included in the study, 299 (6.3%) had asthma. The mothers with asthma had lower family incomes and more frequently made use of the public health care system (for prenatal care and delivery) than did those without asthma. Although only 9.4% of the mothers with asthma smoked and only 27.6% consumed alcoholic beverages, these proportions were higher than were those observed for the control group. Asthma was not found to be associated with obstetric problems or with problems involving the neonates. Nor did we find asthma to be associated with cesarean delivery, prematurity or small-for-gestational-age neonates.

CONCLUSIONS

Low socioeconomic level seems to be a risk factor for asthma.

Development and validation of an asthma knowledge questionnaire for use in Brazil

OBJECTIVE

To develop and validate an asthma knowledge questionnaire for use in adult asthma patients in Brazil.

METHODS

A 34-item self-report questionnaire was constructed and administered to adult asthma patients and adult controls. The maximum total score was 34.

RESULTS

The questionnaire was shown to be discriminatory, with good reliability and reproducibility. The mean score for asthma patients and controls was, respectively, 21.47 +/- 4.11 (range: 9-31) and 17.27 +/- 5.11 (range: 7-28; p < 0.001). The Kaiser-Meyer-Olkin measure of sampling adequacy was 0.53, and the Bartlett's test of sphericity demonstrated a satisfactory suitability of the data to factor analysis (p < 0.001). There was no significant difference between the total scores obtained in the first and in the second application of the questionnaire within a two-week interval (p = 0.43). The internal consistency reliability (KR-20 coefficient) was 0.69.

CONCLUSIONS

This study has validated an asthma knowledge questionnaire for use in Brazil.

Effects of ipratropium on exercise-induced bronchospasm

Exercise-induced bronchospasm (EIB) is the transient narrowing of the airways that follows vigorous exercise. Ipratropium bromide may be used to prevent EIB, but its effect varies among individuals. We hypothesized that time of administration of ipratropium interferes with its action. This was a prospective, double-blind, cross-over study carried out to evaluate the bronchoprotective and bronchodilatory effect of ipratropium at different times of day. The study consisted of 4 exercise challenge tests (2 at 7 am and 2 at 6 pm). In the morning, one of the tests was performed after placebo administration and the other one after ipratropium (80 microg) and the two tests (placebo and ipratropium) were repeated in the evening. Twenty-one patients with severe or moderate asthma and previous confirmation of EIB were enrolled in this prospective trial. The bronchodilatory effect of ipratropium was 0.25+/-0.21 L or 13.11+/-10.99% (p=0.001 compared to baseline values) in the morning, and 0.14+/-0.25 L or 7.25+/-11.37% (p>0.05) in the evening. In the morning, EIB was 0.58+/-0.29 L on the placebo day and 0.38+/-0.22 L on the treatment day (p=0.01). In the evening, EIB was 0.62+/-0.28 L on the placebo day and 0.51+/-0.35 L on the treatment day (p>0.05). We suggest that the use of ipratropium for the treatment of asthma and EIB should take into consideration the time of administration.

Knowledge of and technique for using inhalation devices among asthma patients and COPD patients

OBJECTIVE

To evaluate knowledge of and techniques for using prescribed inhalation devices among patients with asthma or COPD treated at a tertiary teaching hospital.

METHODS

Patients were assessed after medical visits, and their physicians were blinded to this fact. Patients were asked to demonstrate their inhaler technique and were then interviewed regarding their knowledge of inhalation devices, control of the disease and instructions received during medical visits.

RESULTS

We included 120 volunteers: 60 with asthma and 60 with COPD. All of the asthma patients and 98.3% of the COPD patients claimed to know how to use inhaled medications. In the sample as a whole, 113 patients (94.2%) committed at least one error when using the inhalation device. Patients committed more errors when using metered-dose inhalers than when using the dry-powder inhalers Aerolizer (p < 0.001) or Pulvinal (p < 0.001), as well as committing more errors when using the Aerolizer inhaler than when using the Pulvinal inhaler (p < 0.05). Using the metered-dose, Pulvinal and Aerolizer inhalers, the COPD group patients committed more errors than did the asthma group patients (p = 0.0023, p = 0.0065 and p = 0.012, respectively).

CONCLUSIONS

Although the majority of the patients claimed to know how to use inhalation devices, the fact that 94.2% committed at least one error shows that their technique was inappropriate and reveals a discrepancy between understanding and practice. Therefore, it is not sufficient to ask patients whether they know how to use inhalation devices. Practical measures should be taken in order to minimize errors and optimize treatment.

Protective effect of bronchial challenge with hypertonic saline on nocturnal asthma

Inhalation of hypertonic saline (HS) causes bronchoconstriction in asthmatic subjects. Repeated inhalation of HS leads to substantially reduced bronchoconstriction, known as the refractory period. Refractoriness due to different stimuli has also been described (cross-refractoriness). Nocturnal asthma is defined as an increase in symptoms, need for medication, airway responsiveness, and/or worsening of lung function that usually occurs from 4 to 6 am. Our objective was to determine the effect of refractoriness on nocturnal asthma. The challenge test consisted of inhalations of 4.5% saline with increasing durations until a reduction of 20% in forced expiratory volume in 1 s (FEV1) (PD20HS) or total time of 15.5 min. Twelve subjects with nocturnal asthma were challenged with HS at 16:00 and 18:00 h and FEV1 was measured at 4:00 h. One to 2 weeks later, FEV1 was determined at 16:00 and 4:00 h. LogPD20HS at 18:00 h was significantly greater than logPD20HS at 16:00 h, 0.51 +/- 0.50 and 0.69 +/- 0.60 mg, respectively (P = 0.0033). When subjects underwent two HS challenges in the afternoon, mean (+/- SD) FEV1 reduction was 206 +/- 414 mL or 9.81 +/- 17.42%. On the control day (without challenge in the afternoon) FEV1 reduction was 523 +/- 308 mL or 22.75 +/- 15.40% (P = 0.021). Baseline FEV1 values did not differ significantly between the control and study days, 2.48 +/- 0.62 and 2.36 +/- 0.46 L, respectively. The refractory period following HS challenges reduces the nocturnal worsening of asthma. This new concept may provide beneficial applications to asthmatic patients.

Impact of specific sensitization on asthma and rhinitis in young Brazilian and Chilean adults

BACKGROUND

The pattern of associations and the attributable fractions (AF) of atopic conditions due to specific sensitizations vary between countries.

OBJECTIVE

To assess the level of associations and AF between sensitization to five allergens and atopic conditions in two settings.

METHODS

We studied 2063 Brazilians and 1231 Chileans of both sexes using representative samples selected at birth in the 1970s. Information on asthma and rhinitis was based on the European Community Respiratory Health Survey questionnaire. We assessed bronchial hyperresponsiveness (BHR) to methacholine and sensitization to Dermatophagoides pteronyssinus, cat, dog, grass blend and Alternaria alternata.

RESULTS

The prevalence of sensitization to one or more allergens was 50% in Brazilians and 22% in Chileans. The level of associations varied according to the outcome used. Strong associations between sensitization and asthma, defined as wheeze or awakening with breathlessness at night and positive BHR, were found for each of the five allergens in Chileans [varying from odds ratio (OR) 3.24, 95% confidence interval (CI) 1.47, 7.15 for D. pteronyssinus to 8.44, 95% CI 3.82, 18.66 for cat], whereas the level of associations was restricted to D. pteronyssinus, cat and dog in Brazilians and was somewhat weaker (highest OR 3.90, 95% CI 2.80-5.44). The AF of sensitization on asthma was 54% in Brazil and 44% in Chile. D. pteronyssinus and cat made an independent contribution to asthma in the two samples. The patterns of associations between sensitization and rhino-conjunctivitis were similar to those for asthma.

CONCLUSION

The associations between sensitization, and asthma and rhinitis were high in Chile and moderately high in Brazil, but the AF were higher in Brazil, reflecting a higher prevalence of sensitization. In Brazil, dust mite had the greatest impact on atopic conditions while in Chile several allergens had an impact. Sensitization is as serious a problem in Chile and Brazil as in developed countries.

Respiratory effects of tobacco smoking among young adults

BACKGROUND

Respiratory symptoms associated with smoking habit seem to be age dependent. However, there are few reports about the effect of tobacco in young populations. The objective of this study was to analyze the effect of smoking on respiratory symptoms and lung function in 23- to 25-year-old adults in Brazil. This study had a cross-sectional design and included 2063 young people in the city of Ribeirão Preto, São Paulo State.

METHODS

Subjects completed a questionnaire used by the European Community Respiratory Health Survey and underwent spirometry and bronchial challenge test with methacholine. Multiple logistic regression analysis and multiple linear regression analysis were carried out to assess the association between smoking and respiratory symptoms, bronchial hyperresponsiveness, forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC), adjusted for confounding variables.

RESULTS

Prevalence of smoking habit was 17.2% with consumption (median) of 10 cigarettes per day (interquartile range 3-20). There was a significant association between smoking and respiratory symptoms. Smoking was associated to wheezing with odds ratio (95%CI) of 6.11 (4.03-9.28) among those smoking>or=10 cigarettes per day and 3.36 (2.11-5.37) among those smoking<10 cigarettes per day. Associations were found for other respiratory symptoms. Smoking was associated with lower FEV1/FVC ratio. No association was detected between smoking and FEV1 or bronchial hyperresponsiveness.

CONCLUSIONS

These findings highlight the early health consequences of smoking among young adults. These results prompt the necessity to elaborate urgent programs to reduce tobacco habit in young populations.

Investigation of factors associated with difficult-to-control asthma

OBJECTIVE

To determine the prevalence of factors associated with difficult-to-control asthma.

METHODS

Patients with severe asthma were selected from the outpatient asthma clinic of the Ribeirão Preto School of Medicine Hospital das Clínicas. The patients were divided into two groups: controlled severe asthma and difficult-to-control severe asthma. After new attempts to optimize the severe asthma treatment, a questionnaire was applied, and additional tests for factors associated with difficult-to-control asthma, such as environmental and occupational exposure, smoking history, social factors, rhinitis/sinusitis, gastroesophageal reflux disease (GERD), obstructive sleep apnea, congestive heart failure (CHF), pulmonary embolism, cystic fibrosis, vocal cord dysfunction, alpha-1 antitrypsin deficiency, and Churg-Strauss syndrome, were performed.

RESULTS

77 patients with severe asthma were selected, of which 47 suffered from hard-to-control asthma, being 68.1% female, with mean age of 44.4 years (+/-14.4), and forced expiratory volume in one second of 54.7% (+/-18.3). The most factors most often associated with difficult-to-control asthma were noncompliance with treatment (68%), rhinitis/sinusitis (57%), GERD (49%), environmental exposure (34%), occupational exposure (17%), smoking history (10%), obstructive sleep apnea (2%), and CHF (2%). At least one of these factors was identified in every case.

CONCLUSIONS

Noncompliance with treatment was the factor most often associated with difficult-to-control asthma, underscoring the need to investigate comorbidities in the evaluation of patients with this form of the disease.

Asthma definitions, relative validity and impact on known risk factors in young Brazilians

BACKGROUND

An asthma score was proposed in the European Community Respiratory Health Survey (ECRHS) framework, as dichotomous definitions could be less appropriate in the study of chronic diseases. The aims of this study were to assess the value of this asthma score in comparison with other definitions of asthma in another population setting, using as criteria bronchial hyperresponsiveness (BHR) to methacholine and diagnosed asthma, and the association of these definitions to known risk factors of asthma.

METHODS

We used the ECRHS questionnaire on 2063 Brazilians, aged 23-25 years, and measured their BHR. We assessed the positive and negative likelihood ratios (PLR and NLR) of the asthma score (0-8), a three question score (ECRHS definition) and single asthma symptoms in relation to BHR and diagnosed asthma.

RESULTS

The PLR were relatively low for all asthma definitions with odd ratios varying from 1.47 for asthma score to 5.50 for wheeze and waking with breathlessness without a cold. The NLR were near 1. The PLR were lower for assessments using the score than for dichotomous assessments or the ECRHS definition. The PLR increased with asthma scores, but the prevalence with higher scores was too low for useful analysis. The asthma score was slightly better for identifying associations from a set of known risk factors than the other two approaches.

CONCLUSION

Our study provided little support for a greater validity of this asthma score over other asthma definitions, and only marginal advantage for identifying risk factors.

Eotaxin-2 in sputum cell culture to evaluate asthma inflammation

The aim of the present study was to elucidate whether the culture of cells recovered from induced sputum may represent a suitable model to evaluate cytokine and chemokine production by airway inflammatory cells. Sputum induction was performed in 21 normal subjects and 30 asthmatic patients. A total of 21 out of the 30 asthmatic patients were taking inhaled corticosteroids, while the remaining nine were steroid-naive asthmatics. The steroid-naive group was evaluated before and after a 14-day treatment with oral prednisone (40 mg.day(-1)). The supernatant of lysed and centrifuged sputum and the supernatant of sputum cell culture were analysed. Tumour necrosis factor-alpha, interleukin (IL)-8 (CXCL8), IL-1beta, IL-13 and eotaxin-2 (CCL24) concentrations were determined by specific ELISA. Eotaxin-2 production by cell culture was higher in the asthma group (131+/-108 pg.mL(-1)) than in the control group (36+/-41 pg.mL(-1)) and treatment with oral corticosteroids eliminated this difference. In addition, reduction of eotaxin-2 levels by corticosteroid treatment was greater in cell culture (81.3% reduction) than in sputum (26.4%). There was correlation between the decrease in eotaxin-2 production and the decrease in blood eosinophil number and between eotaxin-2 and eosinophils in sputum. Eotaxin-2 may play an important role in asthma and the response to corticosteroid treatment suggests that analysis of sputum cell culture is relevant as an inflammatory parameter.

Prevalence and risk factors for work related asthma in young adults

OBJECTIVES

To investigate the prevalence and predictors of work related asthma in young adults from the general population.

METHODS

A total of 1922 subjects randomly selected from a birth cohort 1978/79 in Brazil, aged 23-25 years, completed a respiratory symptoms questionnaire based on the European Community Respiratory Health Survey, and underwent spirometry, bronchial challenge test with methacholine, and skin prick test. For subjects presenting with bronchial hyperresponsiveness, workplace exposure and its relationship with symptoms were assessed by a specific questionnaire and individualised job description to define cases of work related asthma.

RESULTS

The prevalence of work related asthma was 4.2% (81 cases): 1.5% (29 cases) were classified as aggravated asthma and 2.7% (52 cases) as occupational asthma. Work related asthma was associated with atopy and education. Lower educational level (1-8 years of schooling) was associated with work related asthma (odds ratio 7.06, 95% CI 3.25 to 15.33). There was no association between work related asthma and smoking, gender, or symptoms of rhinitis.

CONCLUSION

The prevalence of work related asthma was high (4.2%), and was associated with low schooling, probably because of low socioeconomic level. The disease may therefore be a consequence of poverty.

Comparison of morning and afternoon exercise training for asthmatic children

Fitness improvement was used to compare morning with afternoon exercise periods for asthmatic children. Children with persistent moderate asthma (according to GINA criteria), 8 to 11 years old, were divided into 3 groups: morning training group (N = 23), afternoon training group (N = 23), and non-training group (N = 23). The program was based on twice a week 90-min sessions for 4 months. We measured the 9-min running distance, resting heart rate and abdominal muscle strength (sit-up number) before and after the training. All children took budesonide, 400 microg/day, and an on demand inhaled ss-agonist. The distance covered in 9 min increased (mean +/- SEM) from 1344 +/- 30 m by 248 +/- 30 m for the morning group, from 1327 +/- 30 m by 162 +/- 20 m for the afternoon group, and from 1310 +/- 20 m by 2 +/- 20 m for the control group (P < 0.05 for the comparison of morning and afternoon groups with the control group by ANOVA and P > 0.05 for morning with afternoon comparison). The reduction of resting heart rate from 83 +/- 1, 85 +/- 2 and 86 +/- 1 bpm was 5.1 +/- 0.8 bpm in the morning group, 4.4 +/- 0.8 bpm in the afternoon group, and -0.2 +/- 0.7 bpm in the control group (P > 0.05 for morning with afternoon comparison and P < 0.05 versus control). The number of sit-ups in the morning, afternoon and control groups increased from 22.0 +/- 1.7, 24.3 +/- 1.4 and 23 +/- 1.1 sit-ups by 9.8 +/- 0.9, 7.7 +/- 1.4, and 1.9 +/- 0.7 sit-ups, respectively (P > 0.05 for morning with afternoon comparison and P < 0.05 versus control). No statistically significant differences were detected between the morning and afternoon groups in terms of physical training of asthmatic children.

Avaliação de um programa de treinamento físico por quatro meses para crianças asmáticas

OBJETIVO: Avaliar condicionamento físico e força muscular de crianças asmáticas antes e depois de quatro meses de participação num programa de exercícios físicos. MÉTODOS: Dois grupos de crianças com asma moderada e idade entre oito e onze anos foram formados. Ambos realizaram testes pré e pós-treinamento físico, duas vezes por semana, por quatro meses, em sessões de 90 minutos, com exercícios em solo e em água. Orientações sobre asma, seu controle e tratamento foram fornecidos a ambos os grupos. RESULTADOS: Na avaliação final, observou-se aumento das variáveis antropométricas em ambos os grupos. O grupo exercício apresentou melhora significativa na distância percorrida em nove minutos (inicial 1,333 + 0,03 km e final 1,440 + 0,03 km; p < 0,05), número de flexões abdominais (inicial 24,3 + 1,4 abdominais e final 33,2 + 1,1 abdominais; p < 0,05), pressão inspiratória máxima (inicial 73 + 5 cmH2O e final 103 + 5 cmH2O; p < 0,05), pressão expiratória máxima (inicial 75 + 4 cmH2O e final 102 + 4 cmH2O; p < 0,05) e na freqüência cardíaca de repouso (inicial 84,3 + 1,6 bpm e final 77,1 + 2,7 bpm; p < 0,05). O grupo controle não mostrou variação significativa em nenhum desses parâmetros. CONCLUSÃO: Um programa de treinamento físico com menor freqüência e maior duração de cada sessão, para facilitar a participação das crianças, propicia melhora do condicionamento físico e aumento de força muscular em crianças asmáticas.

Efeito da acidificação esofágica na obstrução brônquica de pacientes asmáticos com refluxo gastroesofágico

INTRODUÇÃO: A relação entre asma e refluxo gastroesofágico permanece pouco compreendida. O reflexo vagal e a microaspiração estão entre os mecanismos propostos para explicar a piora da asma pelo refluxo gastroesofágico. OBJETIVO: Avaliar o volume expirado forçado no primeiro segundo após a acidificação esofágica. MÉTODO: O estudo investigou os efeitos da infusão ácida em treze voluntários portadores de asma moderada e refluxo gastroesofágico. Foram realizadas espirometrias antes e depois da inserção esofágica de uma sonda nasogástrica 8F e um cateter de pHmetria. Outras medidas de volume expirado forçado no primeiro segundo foram realizadas depois de quinze minutos de infusão de solução salina no ponto médio entre o esfíncter esofágico superior e o inferior, e depois de quinze minutos da acidificação esofágica, a cada cinco minutos mantida a acidificação, até a obtenção de um valor estável (variação < 5%). RESULTADOS: O volume expirado forçado no primeiro segundo (média do grupo) apresentou-se estável durante os procedimentos de sondagem, infusão de solução salina, infusão de ácido clorídrico e manutenção de ácido clorídrico (p = 0,72). Dois casos apresentaram queda do volume expirado forçado no primeiro segundo (de 11% e 22%) devida à sondagem, outros dois pela infusão de solução salina (13% e 14%) e um caso após a infusão ácida (de 22%). CONCLUSÃO: A acidificação esofágica por pequenos períodos não desencadeia alterações espirométricas num grupo de asmáticos com refluxo gastroesofágico. Entretanto, há casos em que a simples manipulação esofágica ou infusões causam broncoespasmo.

Bronchodilators and corticosteroids in the treatment of asthma

Despite advancements in treatment, the incidence of asthma, asthma-related deaths and hospitalizations for asthma have increased significantly during the past decade. Although asthma mortality may now be decreasing, reasons for the worsening of morbidity and mortality in asthma remain unclear. These unexpected changes in asthma severity have sparked renewed interest in research into the pathogenesis and treatment of the condition. Beta(2)-Adrenergic agonists are the most commonly used class of drugs for the treatment of asthma. Recent concerns about safety issues for beta-agonists caused reevaluation of prescribing practices, and using them on an as-needed basis is now more frequently accepted and recommended. In acute asthma, a beta(2)-adrenergic agonist is still the medication of choice. Long-acting salmeterol and formoterol, administered only twice daily, can decrease symptoms of asthma during day and nighttime. On the other hand, the role of tolerance to their bronchodilator and bronchoprotective effects is still to be determined in the treatment of asthma. Theophylline, whose use has been limited by the potential for serious toxicity, may regain an important position in asthma treatment with the development of the knowledge about its antiinflammatory actions. Dosing theophylline on a time- related basis also improves the risk/benefit ratio and makes it a useful drug for nocturnal asthma. Ipratropium bromide, an anticholinergic drug, still awaits a defined role in the treatment of asthma. Studies on its use for acute asthma have not achieved consensus and, for nocturnal asthma, the short duration of effect limits the benefits. Corticosteroids, including inhaled steroids, have measurable effects on symptoms, lung function, bronchial responsiveness and inflammation associated with asthma. Side effects of chronic use limit systemic, but not inhaled administration. Newer preparations, like budesonide, flunisolide and fluticasone, decrease the incidence of possible side effects related to inhaled steroids by having better ratio of topical to systemic potency. Daily doses up to 1600 micro g of beclomethasone (or equivalent) are considered safe and higher doses should be reserved for patients with moderate to severe asthma. Although future trials are necessary to clarify many issues related to dosing of inhaled steroids, chronotherapy studies have shown that single administration between 3 and 5:30 p.m. may be as effective as 4 times a day dosing.

Recent innovations in asthma therapy

Guidelines for the diagnosis and management of asthma have been published since 1990 and already new versions are being published. The recommendations for the treatment of asthma were organized around four components of effective asthma management: i) use of objective measures of lung function to assess the severity of asthma and to monitor the course of therapy, ii) environmental control measures to avoid or eliminate factors that precipitate asthma symptoms or exacerbations, iii) comprehensive pharmacologic therapy for long-term management designed to reverse and prevent the airway inflammation characteristic of asthma as well as pharmacologic therapy to manage asthma exacerbations, and iv) patient education that fosters a partnership among the patient, family and clinicians. Newly released medications include anti-leukotriene (LTs) agents which function either by blocking the interaction of LTs with receptors (receptor antagonists) or by inhibiting leukotriene synthesis (synthesis inhibitors). Representatives of the antagonists discussed here are zafirlukast, pranlukast and montelukast. Zafirlukast (20 mg twice daily) improves pulmonary function indices and days without symptoms and decreases the asthma exacerbation frequency. Pranlukast, the first leukotriene receptor antagonist to be marketed, improves lung function and symptoms when 450 mg twice daily is used. A study with montelukast demonstrated similar positive results irrespective of the use of concomitant inhaled corticosteroid. This indicates that leukotriene receptor antagonists may have additive effects to steroid therapy. They may also be a potential alternative to inhaled steroids, although more studies need to be performed before defining the role of receptor antagonists in the treatment of asthma. Zileuton, a leukotriene synthesis inhibitor, has been shown to improve lung function, reduce symptoms and reduce use of beta-agonists and asthma exacerbations. These positive effects are dose-dependent and liver function abnormalities seem to be a relevant issue during zileuton use in some patients. Other compounds that inhibit LTs synthesis are in development and, like zileuton, need more tests. Phosphodiesterases (PDE), enzymes that break down cAMP and cGMP, have been a target for new compounds developed to treat asthma. Inhibition of PDE enzymes increases intracellular cAMP or cGMP which then produces bronchodilation. Recent studies have also shown antiinflammatory effects by suppressing some PDE isoenzymes, including PDE III and PDE IV. These effects were detected by studies in vitro and in animal models. Clinical trials are necessary to determine which PDE inhibitors can be useful for the treatment of asthma.

Sputum induction: review of literature and proposal for a protocol

Since the 1980s, sputum induction by inhalation of hypertonic saline has been successfully used for diagnosing Pneumocystis carinii pneumonia in patients infected with HIV. In recent years, sputum induction and its subsequent processing has been refined as a noninvasive research tool providing important information about inflammatory events in the lower airways, and it has been used for studying various illnesses. In asthma, one application is to use sputum inflammatory indices to increase our understanding of complex relationships between inflammatory cells, mediators, and cytokine mechanisms. In chronic obstructive pulmonary disease, sputum assessment could be used as a screening test before deciding on long-term corticosteroid treatment. In tuberculosis, sputum induction is a valuable diagnostic tool for HIV-seropositive patients who do not produce sputum. Sputum induction appears to be a relatively safe, noninvasive means of obtaining airway secretions from subjects with cystic fibrosis, especially from those who do not normally produce sputum. Moreover, sputum induction can also be used in chronic cough and lung cancer. Generally, induction is performed through ultrasonic nebulizers, using hypertonic saline. It is recommended that sputum be processed as soon as possible, with complete homogenization by the use of dithiothreitol. We have also shown in this article an example of a protocol for inducing and processing sputum employing a nebulizer produced in Brazil.

Rapid effect of inhaled steroids on nocturnal worsening of asthma

BACKGROUND

Inhaled steroids are the most commonly used anti-inflammatory agents for asthma and are increasingly recognised as having a more rapid onset of action than was previously thought. We have investigated the effect of a single dose of inhaled steroid on nocturnal worsening of asthma.

METHODS

Ten patients with steroid naive moderate asthma and nocturnal asthma participated in a randomised, double blind, placebo controlled, crossover trial. Participants spent three nights in the laboratory, one week apart. On each night they underwent spirometric testing at 16.00 hours and received one of the three treatments (placebo, beclomethasone 1000 micro g, or fluticasone 1000 micro g) delivered by metered dose inhaler. Spirometric tests were repeated at 04.00 hours the following morning.

RESULTS

Following placebo administration the mean (SE) overnight fall in FEV(1) was 0.65 (0.27) l compared with -0.02 (0.13) l following fluticasone (p=0.019) and 0.23 (0.12) l following beclomethasone (p=0.048 v placebo).

CONCLUSION

A single dose of inhaled steroid (within the therapeutic range) reduced the fall in FEV(1) in patients with nocturnal asthma when administered at 16.00 hours. Nocturnal worsening of asthma is a useful model for testing inhaled steroid activity in a single night study.

Pulmonary function, cholinergic bronchomotor tone, and cardiac autonomic abnormalities in type 2 diabetic patients

This prospective study analyzed the involvement of the autonomic nervous system in pulmonary and cardiac function by evaluating cardiovascular reflex and its correlation with pulmonary function abnormalities of type 2 diabetic patients. Diabetic patients (N = 17) and healthy subjects (N = 17) were evaluated by 1) pulmonary function tests including spirometry, He-dilution method, N2 washout test, and specific airway conductance (SGaw) determined by plethysmography before and after aerosol administration of atropine sulfate, and 2) autonomic cardiovascular activity by the passive tilting test and the magnitude of respiratory sinus arrhythmia (RSA). Basal heart rate was higher in the diabetic group (87.8 +/- 11.2 bpm; mean +/- SD) than in the control group (72.9 +/- 7.8 bpm, P<0.05). The increase of heart rate at 5 s of tilting was 11.8 +/- 6.5 bpm in diabetic patients and 17.6 +/- 6.2 bpm in the control group (P<0.05). Systemic arterial pressure and RSA analysis did not reveal significant differences between groups. Diabetes intragroup analysis revealed two behaviors: 10 patients with close to normal findings and 7 with significant abnormalities in terms of RSA, with the latter subgroup presenting one or more abnormalities in other tests and clear evidence of cardiovascular autonomic dysfunction. End-expiratory flows were significantly lower in diabetic patients than in the control group (P<0.05). Pulmonary function tests before and after atropine administration demonstrated comparable responses by both groups. Type 2 diabetic patients have cardiac autonomic dysfunction that is not associated with bronchomotor tone alterations, probably reflecting a less severe impairment than that of type 1 diabetes mellitus. Yet, a reduction of end-expiratory flow was detected.

Do steroids interfere in dyspnoea sensation?

Dyspnoea remains a remarkable clinical problem and a therapeutic challenge, mainly in chronic respiratory conditions. This study investigated the potential effects of steroids on dyspnoea sensation regardless of their pulmonary anti-inflammatory actions. Sixteen healthy men (mean age +/- SD = 22.5 +/- 1.6 years) developed uncomfortable breathing by the use of inspiratory resistors (loads of 0, 7, 14 and 21 cm H2O/l/s) and breathholding 6 h after taking 40 mg of prednisone (Pred) or placebo (Plac). Respiratory discomfort during breathing with loads was evaluated with a 100 mm visual analog scale. The maximum voluntary apnoea time did not differ between the prednisone and placebo days (Plac = 96 +/- 11.8 s x Pred = 105 +/- 12.2 s) and prednisone did not influence the dyspnoea sensation induced by different inspiratory loads (0 cm H2O/l/s: Pred = 2.8 mm x Plac = 1.9 mm; 7 cm H2O/l/s: Pred = 18.3 mm x Plac = 18.6 mm; 14 cm H2O/l/s; Pred = 33.0 mm x Plac = 34.1 mm; 21 cm H2O/l/s: Pred = 48.1 mm x Plac = 49.6 mm). Prednisone intake was associated with a significant increase in minute ventilation during breathing with no inspiratory loads (Pred = 11.91 +/- 1.28 l/min- x Plac = 9.95 +/- 0.86 l/min). Although steroids certainly may improve respiratory conditions due to anti-inflammatory actions, available evidence does not support any specific beneficial effect of these drugs on these perception of dyspnoea itself.

Dyspnea scales in the assessment of illiterate patients with chronic obstructive pulmonary disease

BACKGROUND

Multiple physiological, psychological, social and environmental factors may affect the perception of dyspnea. Although different scales have been used to record the severity of dyspnea in subjects with chronic obstructive pulmonary disease (COPD), none has reported evaluating the properties of such tools in illiterate patients. The objective of this study was to evaluate the reliability and features of concurrent validity of 4 dyspnea scales in illiterate (IL) subjects with COPD.

METHODS

One hundred COPD patients submitted to spirometry and were asked to score their breathlessness using a visual analogue scale (VAS), a numerical rating scale (NRS), the Borg scale (BS), and the basal dyspnea index (BDI). Each scale was presented to the patients before and after they had performed spirometry and measurement of residual volume. The obtained scores were analyzed according to the literacy status of the patients.

RESULTS

Thirty-three patients were classified as IL and 67 as literate (L). Both groups showed similar respiratory impairment and median scores of dyspnea (VAS, L = 45.0, IL = 49.0; NRS, L = 5.0, IL = 5.0; BS, L = 3.0, IL = 3.0; BDI, L = 5.0, IL = 4.0). No significant differences were found between the dyspnea scores obtained before and after spirometry for all scales in both groups. The degree of correlation between forced expiratory volume in 1 second (FEV1) and usual dyspnea evaluated by BDI did not show a statistical difference between the two groups (L, r = 0.37; IL, r = 0.51).

CONCLUSION

The employed dyspnea scales showed comparable reliability in both L and IL COPD subjects.

Allergic airway inflammation in hypothyroid rats

BACKGROUND

Hormones play a modulating role in allergic inflammation. Hyperthyroidism may increase the severity of asthma, and hypothyroidism may ameliorate coexistent asthma. The mechanisms regulating this interaction are not completely understood.

OBJECTIVE

The purpose of this study was to test the hypothesis that thyroid hormones influence the development of allergic airway inflammation after antigen challenge in rats.

METHODS

The experimental design included either sensitized or nonsensitized surgically thyroidectomized and sham-operated rats. Experiments were performed 50 days after surgery. Thyroidectomized rats and sham-operated controls were sensitized by subcutaneous injection of ovalbumin (OVA) and Al(OH)(3) and challenged 14 days later by OVA inhalation. Bronchoalveolar lavages were performed 24 hours after challenge.

RESULTS

Compared with controls, thyroidectomized animals presented markedly decreased cell yields from bronchoalveolar lavage fluid after OVA challenge. The impaired response was not related to changes in the number of circulating leukocytes. Determination of antibody serum concentrations indicated that thyroidectomized rats presented a marked reduction in the level of anti-OVA IgE compared with controls, without significant differences in IgG(1) and IgG(2a) serum concentrations. Reversal of the impaired responses was attained by 16-day treatment of hypothyroid animals with thyroxine, but not by 1- or 3-day treatment.

CONCLUSION

The data presented suggest that the continuing deficiency of thyroid hormones influences the development of the inflammatory component of asthma. This is due, at least in part, to a decrease in the production of IgE.

The effects of upper respiratory infection on T-cell proliferation and steroid sensitivity of asthmatics

BACKGROUND

The common cold is a potent trigger for asthma symptoms. Although the mechanisms are not completely understood, inflammatory events may play an important role.

OBJECTIVE

We tested the hypothesis that changes in steroid responsiveness are implicated in the relationship between asthma and the common cold.

METHODS

We investigated the steroid sensitivity of T cells from 10 patients with asthma (not taking steroids) and 10 control subjects, during upper respiratory infection and at recovery (6 weeks later). We stimulated peripheral blood mononuclear cells with phytohemagglutinin to measure T-cell proliferation, sensitivity to the inhibitory effects of steroids, and cytokine production.

RESULTS

During infection compared with recovery, the asthma group exhibited lower responsiveness to dexamethasone at 10(-10) and 10(-9)mol/L and to 10(-10)mol/L hydrocortisone (P <.05) and both groups had decreased T-cell proliferation (P <.05). During recovery, patients with asthma had greater T-cell proliferation than control subjects (P <.02); the values expressed as uptake of [3H]-thymidine were 60119+/-3944 cpm (asthma) and 39078+/-6459 cpm (control subjects). The asthma group had higher TNF-alpha and IFN-gamma production during infection (P <.05); changes in IL-8 and IL-10 levels were not significant, and IL-4 was not detected.

CONCLUSION

During infection, asthmatic subjects exhibit decreased T-cell responsiveness to steroids. The T-cell proliferative response to phytohemagglutinin, higher in asthma, is decreased with a common cold. These findings are associated with changes in the cytokine profile. Thus viral-induced upper respiratory infections can produce an inflammatory milieu with altered steroid function and selective increases in cytokines.

Human corticotropin-releasing hormone improves overnight FEV1 in nocturnal asthma

Corticotropin-releasing hormone (CRH) exhibits anti-inflammatory properties independent of its effect on adrenal function. We investigated the safety and effect of CRH in nocturnal asthma, a disease where inflammation is prominent. Five subjects underwent an overnight infusion of placebo on the first night, CRH at a 2.5 micrograms/kg/hr on the second night, and three subjects received CRH at 4.0 micrograms/kg/hr on the third night. A significant improvement occurred in overnight change in forced expiratory volume 1 sec. % (delta FEV1) with CRH (+17.4 +/- 9.1%) as opposed to placebo (-25.9 +/- 7.1%), p = 0.024, CRH was well tolerated. Further research with CRH may clarify the pathophysiology of nocturnal asthma.

Allergen-induced airway inflammation in rats. Role of insulin

Clinical asthma appears to be less severe when diabetes mellitus is superimposed. To examine whether insulin influences the development of allergic reactions in the airway mucosa antigen challenge, normal and diabetic rats sensitized against ovalbumin (OA) were used. Compared with controls, animals rendered diabetic by the injection of alloxan presented markedly decreased cell yields from bronchoalveolar lavage after OA challenge. The impaired response was not related to antibody production because enhanced IgE antibody titers of the same magnitude were found in both control and diabetic animals. Similarly, the mechanism underlying the inhibited responses could not be ascribed to hyperglycemia or intracellular glucopenia, first, because correction of blood glucose levels through fasting did not restore the decreased response, and second, because administration of 2-deoxyglucose, which blocks glucose utilization, did not affect the bronchoalveolar reaction to OA challenge in normal animals. Reversal of the impaired responses was attained by treatment of diabetic animals with insulin. There is evidence that insulin exerts proinflammatory effects. We conclude that insulin might modulate the inflammatory component of asthmatic responses.