Are risk factors of childhood asthma predicting disease persistence in early adulthood different in the developing world?

Spanish Consensus on Remission in Asthma (REMAS)

The concept of "remission" in asthma has been around for a long time and it has been a controversial topic. Despite the attempts of some studies to characterize this entity, the discussion continues. In the case of asthma there is still no clear definition, either in terms of its meaning or the parameters that should be included or whether it should be divided into clinical or complete remission. To help defining these controversial concepts, SEPAR has advocated the multidisciplinary working group REMAS (REMission in ASthma). Following the Delphi methodology and with the involvement of more than 120 specialists in asthma management, this group has arrived at a consensus on the definitions of remission in asthma and establishing the criteria and characteristics that will be of use in future studies evaluating the efficacy or effectiveness of treatments.

No remission in 60% of those with childhood-onset asthma - A population-based cohort followed from 8 to 28 years of age

BACKGROUND

Although remission occur, childhood-onset asthma may persist until adulthood. Since few longitudinal population-based studies have followed a cohort from childhood until adulthood, the knowledge on predictors of persistence of asthma is sparse.

AIM

To estimate persistence of asthma from 8 to 28 years and its associated factors.

METHODS

Within the OLIN (Obstructive Lung Disease in Northern Sweden) studies, a cohort was recruited in 1996 (age 8y, n = 3430) and followed annually with questionnaires about asthma and risk factors until 19y. Clinical examinations included skin prick tests (at 8, 12 and 19y) and lung function tests (17 and 19y) whereof a subsample performed bronchial hyperreactivity test. We identified n = 248 with asthma at 8y whereof 170 (69%) participated in a follow-up at 28y (73% of possible to invite).

RESULTS

Of the 170 participants at 28y, 105 (61.8%) had persistent asthma (women: 49/76, 64.5%; men: 56/94, 59.6%, p = 0.513). Factors collected at recruitment: allergic sensitization (OR7.8, 95%CI 3.0-20.2), severe respiratory infection (OR2.6, 95%CI 1.1-6.3) and higher asthma severity score (OR1.6, 95%CI 1.1-2.4) were associated with asthma at 28y after adjustment for sex, family history of asthma, breastfeeding <3 months and eczema. Replacing allergic sensitization with rhinoconjunctivitis in the model yielded OR3.4 (95%CI 1.5-8.0). Bronchial hyperreactivity at age 17y associated with asthma at 28y (OR9.0, 95%CI 1.7-47.0).

CONCLUSIONS

Among children with asthma onset by 8y, 62% still had asthma at age 28 years. Persistent asthma was associated with allergic sensitization, rhinoconjunctivitis, severe respiratory infection, a more severe asthma and bronchial hyperreactivity.

Poor Asthma Control in Schoolchildren May Lead to Lower Lung Function Trajectory from Childhood to Early Adulthood: A Japanese Cohort Study

Purpose

Although childhood asthma is a risk factor for adult lung function disorders, the correlation between childhood asthma control level and lung function growth remains unclear in Japan. The correlation between childhood asthma control and early adulthood lung function growth was investigated in this study.

Patients and Methods

We included 505 children with asthma from the Omuta City Air Pollution-Related Health Damage Cohort Program. The characteristics and lung function of girls and boys aged 6–11 years and 12–17 years were compared between poor and good asthma control groups.

Results

Among the 505 children, 214 (42.4%) showed poor asthma control. The mean percentage forced expiratory volume in 1 second predicted for girls and boys aged 6–11 years (80.2% and 79.2%, respectively) and 12–17 years (80.0% and 81.1%, respectively) in the poor control group was significantly lower than those of girls and boys aged 6–11 years (87.9% and 87.3%, respectively) and 12–17 years (88.1% and 87.8%, respectively) in the good control group. However, a linear regression model did not reveal between-group differences in the slopes of lung function growth for both sexes. Girls (24.6%, P < 0.0001) and boys (24.4%, P = 0.0026) in the poor control group had a significantly higher proportion of young adults with obstructive ventilatory patterns than girls (1.4%) and boys (8.1%) in the good control group.

Conclusion

Our findings revealed that poor childhood asthma control leaded to lung function disorders, which suggest the importance of early asthma control in school children.

Levels of indoor particulate matter and association with asthma in children in Benin City, Nigeria

The relationship between indoor particulate matter and asthma in children was assessed in this study. Forty-five (45) locations were randomly selected across the five local government areas in Benin City, Edo State, for air quality assessment. Indoor and outdoor particulates (PM_1.0, PM_2.5, and PM₁₀) were monitored monthly using a handheld BLATN particulate sampler (Br-Smart-126S series). Reported clinical cases of asthma in children from 2008 to 2017 were collected from two major hospitals in the metropolis. The data obtained were analysed with SPSS for Windows version 21.0. The average concentrations of indoor and ambient PM ranged between 10.7-26.2 and 19.0-49.4 µg/m³ (PM_1.0), 27.4-59.6 and 45.6-93.0 µg/m³ (PM_2.5), and 33.5-67.9 and 60.9-106.1 µg/m³ (PM₁₀) in the wet and dry seasons. PM_2.5 and PM₁₀ concentrations were observed above the WHO standards. Indoor particulate concentration was significantly (p = 0.001-0.012) higher in the dry season across the locations. Outdoor PM correlated positively (R = 0.568-0.855, p < 0.05; R² = 0.322-0.724, p < 0.001) with their corresponding indoor PM concentration. The hazard ratio (HR) values of PM_2.5 and PM₁₀ exceeded 1 in all the sampling locations during the dry season, while the mean total hazard ratio (THR) of both PM metrics was considerably higher during the dry season than in the wet season. Indoor PM concentrations showed a significant positive correlation with reported cases of asthma (R = 0.498-0.542, p < 0.001) and accounted for 40.6% of the asthma cases during the dry season. The study showed that children in the selected households are at risk of increased asthma exacerbation due to exposure to particulate matter pollution.

Perimenstrual Asthma in Adolescents: A Shared Condition in Pediatric and Gynecological Endocrinology

Asthma is a frequent medical condition in adolescence. The worsening of the most common symptoms perimenstrually is defined as perimenstrual asthma (PMA). The cause of PMA remains unclear, but a role for hormonal milieu is plausible. Data on PMA in adolescents are limited, and its management is not fully established. We aimed to discuss the PMA phenomenon in young females from pathophysiology to preventive strategies, focusing on the relationship with the hormonal pattern. The fluctuation of estrogens at ovulation and before menstruation and the progesterone secretion during the luteal phase and its subsequent withdrawal seem to be the culprits, because the deterioration of asthma is cyclical during the luteal phase and/or during the first days of the menstrual cycle. Conventional asthma therapies are not always effective for PMA. Preventive strategies may include innovative hormonal contraception. Even a possible beneficial effect of other hormonal treatments, including estrogens, progestogens, and androgens, as well as leukotriene receptor antagonists and explorative approach using microbial-directed therapy, is considered. The underlying mechanisms, through which sex-hormone fluctuations influence asthma symptoms, represent a challenge in the clinical management of such a distressing condition. Further studies focused on young females are mandatory to promote adolescent health.

Prospective study of disease persistence and lung function trajectories of childhood asthma

BACKGROUND

A proportion of asthmatic children outgrow their disease by adulthood, but there are limited data on predictors for asthma persistence. This prospective study characterized the trajectory of spirometric indices and identified predictors for the persistence of childhood asthma.

METHODS

Chinese asthmatic children aged 6-15 years from pediatric allergy clinic underwent annual visits for ≥5 years and until their adulthood. Pre-bronchodilator spirometry and anti-asthma medications were recorded at baseline and then at least annually. Asthma resolution was defined when patients were free from asthma symptoms and use of anti-asthma drugs for ≥2 years. Logistic regression was used to identify predictors for asthma persistence. Generalized estimating equation was used to analyze longitudinal changes in lung function parameters in relation to asthma persistence.

RESULTS

181 asthmatic children aged [mean (SD)] 10.0 (2.7) years were followed for [mean (SD)] 12.5 (2.8) years. One third of them outgrew asthma during follow-up. Female was 3.36 times more likely to have persistent asthma. Inhaled corticosteroid (ICS) treatment ever and frequent asthma exacerbation (AE) predicted asthma persistence with respective odds ratios of 3.19 (95% confidence interval [CI] 1.44-7.09) and 3.05 (95% CI 1.39-6.68). Persistent asthma was inversely associated with baseline forced expiratory volume in 1-second (FEV₁ %) with an odds ratio of 0.96 (95% CI 0.93-1.00). Throughout follow-up, patients with persistent asthma had generally lower forced expiratory indices than those with asthma resolution. Children with persistent asthma experienced poorer lung function growth.

CONCLUSIONS

Female, ICS ever, and frequent AE predicted persistent asthma. Patients with persistent asthma had lower forced expiratory indices and poorer lung function growth into adulthood.

Lung function trajectories and bronchial hyperresponsiveness during childhood following severe RSV bronchiolitis in infancy

BACKGROUND

Children with severe respiratory syncytial virus (RSV) bronchiolitis in infancy have increased risks of asthma and reduced lung function in later life. There are limited studies on the longitudinal changes of lung function and bronchial hyperreactivity from early to late childhood in infants hospitalized for RSV bronchiolitis.

METHODS

In a prospective cohort of 206 children with their first episode of RSV-confirmed bronchiolitis in the first year of life, 122 had spirometry performed at least twice between 5-16 years of age. Methacholine bronchoprovocation was available in 127 and 79 children at 7 and 12 years of age, respectively. Longitudinal changes in FEV₁ , FVC, and FEV₁ /FVC z-scores and methacholine PC₂₀ were analyzed.

RESULTS

55% of the study cohort (N = 122) were male, and 55% were Caucasian. During follow-up, longitudinal changes in z-scores for pre- and post-bronchodilator FEV₁ (P < .0001) FVC (P < .0001) and FEV₁ /FVC (P < .0001 for pre- and 0.007 for post-bronchodilator) from age 5 to 10-16 years were observed. Declined lung function in late childhood was significantly associated with gender, physician diagnosis of asthma, and allergic sensitization. PC₂₀ geometric mean increased from 0.28 mg/mL at 7 years to 0.53 mg/mL at 12 years of age, and the frequency of abnormal bronchial hyperreactivity decreased from 96% to 78% (P = .0003).

CONCLUSIONS

Following severe RSV bronchiolitis, there appear to be significant longitudinal changes in pre- and post-bronchodilator lung function during childhood. The study has several limitations including significant dropouts and the lack of a control group and post-bronchodilator measurements. Bronchial hyperreactivity is common in children following severe RSV bronchiolitis; however, it appears to decrease as they enter late childhood.

A review on the pathophysiology of asthma remission

Asthma is a chronic respiratory condition, which is highly prevalent worldwide. Although no cure is currently available, it is well recognized that some asthma patients can spontaneously enter remission of the disease later in life. Asthma remission is characterized by absence of symptoms and lack of asthma-medication use. Subjects in asthma remission can be divided into two groups: those in clinical remission and those in complete remission. In clinical asthma remission, subjects still have a degree of lung functional impairment or bronchial hyperresponsiveness, while in complete asthma remission, these features are no longer present. Over longer periods, the latter group is less likely to relapse. This remission group is of great scientific interest due to the higher potential to find biomarkers or biological pathways that elicit or are associated with asthma remission. Despite the fact that the definition of asthma remission varies between studies, some factors are reproducibly observed to be associated with remitted asthma. Among these are lower levels of inflammatory markers, which are lowest in complete remission. Additionally, in both groups some degree of airway remodeling is present. Still, the pathological disease state of asthma remission has been poorly investigated. Future research should focus on at least two aspects: further characterisation of the small airways and airway walls in order to determine histologically true remission, and more thorough biological pathway analyses to explore triggers that elicit this phenomenon. Ultimately, this will result in pharmacological targets that provide the potential to steer the course of asthma towards remission.

The impact of gender on asthma in the daily clinical practice

OBJECTIVES

It is up-to-date to consider the potential gender impact on a disease. There are few data about gender difference in asthma. Therefore, the present cross-sectional study tested this hypothesis in a real-life setting to investigate possible difference between genders.

METHODS

This study was cross-sectional, considering 554 consecutive outpatients suspected of asthma, who were referred for a first specialist visit. Clinical and functional parameters were evaluated.

RESULTS

Females with asthma could have a worse perception of asthma control, assessed by asthma control test (ACT), and more anxiety than asthmatic males. However, there was no difference regarding asthma control grading, asthma severity, and asthma medication use between genders; the differences in lung function were without clinical relevance.

CONCLUSIONS

In the daily clinical practice, it is relevant to consider gender in the management of asthma.

Severity of rhinitis and wheezing is strongly associated in preschoolers: A population-based study

BACKGROUND

In preschool children, no study assessed the relation between wheezing and rhinitis severity. Our aims were to estimate the prevalence of current wheezing (CW) in preschoolers and to study the association between CW and current rhinitis (CR), considering its severity/persistency.

METHODS

This is a cross-sectional, nationwide, population-based study including a representative sample of 5003 Portuguese children aged 3-5 years. Data were collected by a face-to-face interview with caregivers using an adapted ISAAC questionnaire. CW was defined as presence of ≥1 wheezing episode in the previous 12 months. Rhinitis severity/persistency was classified according to Allergic Rhinitis and its Impact on Asthma.

RESULTS

Current wheezing prevalence was 24.5% [95% CI 23.3-25.7]; 9.4% of the participants had ≥4 wheezing episodes in the previous year. Children with CR had an odds ratio (OR) of 4.0 [95% CI 3.4-4.5] for CW; it was highest for children with moderate-severe persistent rhinitis (11.5 [95% CI 8.1-16.3]), even after adjusting for possible confounders. Wheezers with CR reported more wheezing treatment use (p = 0.024) than those without CR. There was a trend for a higher number of wheezing episodes with more persistent and severe nasal disease - 48.4% of children with moderate-severe persistent rhinitis had >4 wheezing episodes vs. 28.9% in moderate-severe intermittent, 20.0% in mild persistent, 10.8% in mild intermittent, and 3.6% in those without CR; p < 0.001.

CONCLUSIONS

Current wheezing was present in almost 25% of preschool children and was strongly associated with rhinitis, especially moderate-severe persistent disease. Preschoolers with both CW and rhinitis seem to have a more severe phenotype, emphasizing the need for concurrent evaluation of nasal and bronchial symptoms even in small children.

Asthma is Different in Women. Curr Allergy Asthma Rep. 2015;15:28. [PMID: 26141573 DOI: 10.1007/s11882-015-0528-y]

Gender differences in asthma incidence, prevalence and severity have been reported worldwide. After puberty, asthma becomes more prevalent and severe in women, and is highest in women with early menarche or with multiple gestations, suggesting a role for sex hormones in asthma genesis. However, the impact of sex hormones on the pathophysiology of asthma is confounded by and difficult to differentiate from age, obesity, atopy, and other gender associated environmental exposures. There are also gender discrepancies in the perception of asthma symptoms. Understanding gender differences in asthma is important to provide effective education and personalized management plans for asthmatics across the lifecourse.

Prognosis of adult asthma: a 7-year follow-up study

BACKGROUND

Studies on adult-onset asthma and the contributing factors for its prognosis are few in the literature.

OBJECTIVE

To evaluate asthma prognosis, remission rate, and contributing factors in an adult patient population.

METHODS

Two hundred patients with a diagnosis of adult-onset asthma in 2006 were included in this study. Of these, 160 were contacted in 2013 and participated in the study. Their demographic features, family history, clinical symptoms, pulmonary function test results, and Asthma Control Test scores were re-evaluated. Patients' asthma control status was determined. Patients who had total control and had not used any asthma treatment for at least 2 years were classified as in remission.

RESULTS

The study group consisted of 160 patients (144 women and 16 men, mean age 52.9 ± 10.3 years). Nearly 70% of patients had adult-onset asthma before 40 years of age. According to asthma control status, 21.9% of patients had uncontrolled asthma, 29.4% had partially controlled asthma, and 48.8% had totally controlled asthma. Remission was observed in 11.3% of the entire study group. The mean age of the remission group was significantly younger. Disease duration was shorter and the proportion of patients with atopy was larger in the totally controlled and remission groups. Except in the remission group, patients showed weight gain from 2006 through 2013.

CONCLUSION

According to these 7-year follow up data, the remission rate of asthma was 11.3%. Patients with younger age, younger onset, atopy, allergic rhinitis, and few comorbidities seemed to have a greater possibility of remission.

Development of rhinitis may be an indicator for the persistence of childhood asthma

OBJECTIVES

Results of previous studies have established several factors related with the natural course of childhood asthma. The aim of this study is to investigate the prognosis of childhood asthma and to determine possible risk factors for disease persistence.

METHODS

An outpatient cohort with a median (interquartile range) follow-up duration of 19.4 (17.7-21.8) years was re-evaluated. Current clinical remission (CR) was defined as no asthma symptoms and no use of controller medication within the past year.

RESULTS

Out of 115 patients, 78 could be surveyed with questionnaire and 46 patients with a median age of 25.3 (23.9-27.0) years were further investigated with clinical work-up. Nineteen (24.4%) patients were in CR in both visits (adolescence and young adulthood). A further 7 patients (9.0%) who were not in CR at adolescence were in CR at the young adulthood visit. However, 21 patients (26.9%) who were in CR at adolescence were not in CR at the young adulthood visit. Thirty-one patients (39.7%) with persistent symptoms at adolescence were not in CR at young adulthood, either. In multivariate logistic models, the presence of obstructive pattern (forced expiratory volume in 1s (FEV1)/forced vital capacity (FVC) <80% vs. ≥80%) in pulmonary function tests during the adolescence period (odds ratio; [95% confidence interval] (6.71 [1.65-27.29]; p=0.008) and later-onset rhinitis (10.27 [1.18-89.13]; p=0.035) predicted the absence of CR at young adulthood.

CONCLUSION

A substantial number of patients who were in CR during adolescence have re-emerging disease. The presence of obstructive pattern in adolescence and later-onset rhinitis were associated with the absence of CR in young adults with asthma. Awareness of risk factors along with early interventions may provide better results in childhood asthma.

The long-term outcomes of persistent childhood allergic asthma: a cross-sectional study from western Anatolia: childhood persistent asthma in western Anatolia

BACKGROUND

Prospective cohort studies have provided useful knowledge about the natural history of asthma. However, most of the studies are conducted in western countries but the course of the disease and long-term outcomes may differ between countries due to environmental and cultural factors.

OBJECTIVE

The aim of this study is to describe the long-term outcomes of childhood asthma, with data from a follow-up study of at least 10 years, in western Anatolia, Turkey.

METHODS

Fifty-two patients diagnosed with persistent allergic asthma participated in the study. The patient's demographics, findings on admission, age at onset of disease, time of diagnosis, history of other allergic conditions, history of parental asthma and allergic disorders, presence of pharmacotherapy and immunotherapy were obtained from patients' records. The factors influencing remission at the end of 10 years follow-up were evaluated.

RESULTS

A total of 20 patients (38.5%) were on remission at the end of 10 years. The type of allergen, multi-allergen sensitivity, eosinophilia and elevated serum immunoglobulin E on admission, accompanying allergic disorders and atopy in parents, and allergen immunotherapy did not affect the remission rate (p>0.05).

CONCLUSION

Childhood persistent asthma is not a homogeneous clinical entity but high clinical remission rates are obtained in western Anatolia. There is no significant predictor of clinical remission in long term follow-up. Prospective studies should be performed in larger asthmatic populations to obtain further data about the natural course of childhood asthma.

Remission and persistence of asthma followed from 7 to 19 years of age

BACKGROUND AND OBJECTIVE

To date, a limited number of population-based studies have prospectively evaluated the remission of childhood asthma. This work was intended to study the remission and persistence of childhood asthma and related factors.

METHODS

In 1996, a questionnaire was distributed to the parents of all children aged 7 to 8 years in 3 municipalities in northern Sweden, and 3430 (97%) participated. After a validation study, 248 children were identified as having asthma; these children were reassessed annually until age 19 years when 205 (83%) remained. During the follow-up period lung function, bronchial challenge testing, and skin prick tests were performed. Remission was defined as no use of asthma medication and no wheeze during the past 12 months as reported at endpoint and in the 2 annual surveys preceding endpoint (ie, for ≥ 3 years).

RESULTS

At age 19 years, 21% were in remission, 38% had periodic asthma, and 41% persistent asthma. Remission was more common among boys. Sensitization to furred animals and a more severe asthma (asthma score ≥ 2) at age 7 to 8 years were both inversely associated with remission, odds ratio 0.14 (95% confidence interval 0.04-0.55) and 0.19 (0.07-0.54), respectively. Among children with these 2 characteristics, 82% had persistent asthma during adolescence. Asthma heredity, damp housing, rural living, and smoking were not associated with remission.

CONCLUSIONS

The probability of remission of childhood asthma from age 7- to 8-years to age 19 years was largely determined by sensitization status, particularly sensitization to animals, asthma severity, and female gender, factors all inversely related to remission.

Spirometry testing in a population of Italian children: age and gender differences

AIM

To estimate how many asthmatic children underwent spirometry testing in one year in a large Italian region, and evaluate sociodemographic determinants.

METHODS

Data were retrieved from the administrative databases that store all pharmacological and diagnostic prescriptions issued to individuals living in the Lombardy Region. The analysis involved prescriptions dispensed to all 6-17 year olds (1,047,241 subjects) during 2008. Youths were identified as asthmatics by a previously validated strategy. Number of subjects having ≥1 spirometry claims was calculated, and factors associated with the probability of undergoing spirometry were evaluated by multivariate analysis.

RESULTS

A total of 40,528 (3.9%) asthmatic subjects were identified. Only 30% of them underwent ≥1 spirometry during 2008, with differences between local health units (range 22-45%) and degree of anti-asthmatic use (26-35%). Moreover, in a multivariate analysis, the chance of undergoing spirometry was greater in boys than in girls (OR=2.3).

CONCLUSIONS

A low percentage of asthmatic children, especially girls (who are more at risk of developing severe disease in adulthood), underwent spirometry during 1-year period. This highlights a low compliance with guidelines in the monitoring of childhood asthma. Educational intervention is needed in order to encourage use of spirometry in primary care settings.

Predictive factors for airway hyperresponsiveness in children with respiratory symptoms

BACKGROUND

Asthma diagnosis is a challenging condition, particularly in patients without obstructive pattern and reversibility on spirometry. Determination of airway hyperresponsiveness (AHR) may be helpful, but the procedure is time-consuming and not always practical.

OBJECTIVE

To determine the potential factors that may predict the presence of AHR in children with asthmalike symptoms but without obstructive pattern and reversibility on spirometry.

METHODS

All patients with asthmalike symptoms but without obstructive pattern and reversibility on spirometry were analyzed retrospectively between January 9, 2007, and December 30, 2009. The features of clinical history and laboratory results were analyzed with univariate and multivariate regression analysis.

RESULTS

A total of 111 children between 6 and 18 years of age, with a median age of 10.2 years, were analyzed, and AHR was detected in 67 patients (60.3%). Multivariate logistic regression analysis revealed coexistence of nocturnal cough and exercise-induced cough (odds ratio [OR], 22.1; 95% confidence interval [CI], 3.1-159.2; P = .004), eosinophilia (OR, 18.7; 95% CI, 1.9-178.7; P = .01), and borderline bronchodilator response in forced expiratory volume in 1 second (between 7% and 11%) (OR, 10.1; 95% CI, 2.1-49.1; P = .004) as significant risk factors for the presence of AHR, whereas exercise-induced dyspnea was found to be related to the absence of AHR (OR, 0.2; 95% CI, 0.1-0.8; P = .02).

CONCLUSION

In children with asthmalike symptoms but with normal spirometry, certain features of clinical history and laboratory results can strongly predict the presence of AHR and may help less frequent use of challenge tests.

A multicenter survey of childhood asthma in Turkey. II: Utilization of asthma drugs, control levels and their determinants

Many surveys worldwide have consistently demonstrated a low level of asthma control and under-utilization of preventive asthma drugs. However, these studies have been frequently criticized for using population-based samples, which include many patients with no or irregular follow-ups. Our aim, in this study, was to define the extent of asthma drug utilization, control levels, and their determinants among children with asthma attending to pediatric asthma centers in Turkey. Asthmatic children (age range: 6-18 yr) with at least 1-yr follow-up seen at 12 asthma outpatient clinics during a 1-month period with scheduled or unscheduled visits were included and were surveyed with a questionnaire-guided interview. Files from the previous year were evaluated retrospectively to document control levels and their determinants. From 618 children allocated, most were mild asthmatics (85.6%). Almost 30% and 15% of children reported current use of emergency service and hospitalization, respectively; and 51.4% and 53.1% of children with persistent and intermittent disease, respectively, were on daily preventive therapy, including inhaled corticosteroids. Disease severity [odds ratio: 12.6 (95% confidence intervals: 5.3-29.8)], hospitalization within the last year [3.4 (1.4-8.2)], no use of inhaled steroids [2.9 (1.1- 7.3)], and female gender [2.3 (1.1-5.4)] were major predictors of poor asthma control as defined by their physicians. In this national pediatric asthma study, we found a low level of disease control and discrepancies between preventive drug usage and disease severity, which shows that the expectations of guidelines have not been met even in facilitated centers, thus indicating the need to revise the severity-based approach of asthma guidelines. Efforts to implement the control-based approach of new guidelines (Global Initiative for Asthma 2006) would be worthwhile.

Asthma in infants and children

Asthma is the most common chronic illness in childhood and represents a significant burden to health care and educational systems. Between one quarter and two thirds of childhood asthma cases persist into adulthood. Childhood asthma may be particularly difficult to diagnose because of the high prevalence of episodic wheezing and cough in childhood illnesses such as upper respiratory tract infections. National and worldwide guidelines for the management of asthma in children are continually being updated. These guidelines recommend first establishing a diagnosis and assessing the severity of disease, initiating pharmacologic therapy based on symptoms and lung function, and adjusting doses and agents as required based on the level of asthma control. Inhaled corticosteroids are the cornerstone of long-term asthma management in children of all ages. Recent research efforts have focused on ways to improve inhalant drug delivery to the lungs and minimize oral and systemic bioavailability so as to improve the therapeutic benefit:risk ratio.

Airway responsiveness in mild to moderate childhood asthma: sex influences on the natural history

RATIONALE

Airway responsiveness is a prognostic marker for asthma symptoms in later life.

OBJECTIVES

To evaluate characteristics responsible for persistence of airway responsiveness in children with asthma.

METHODS

A total of 1,041 children, initially aged 5-12 years, with mild to moderate persistent asthma enrolled in the Childhood Asthma Management Program (CAMP) were studied prospectively for 8.6 +/- 1.8 years with methacholine challenges yearly.

MEASUREMENTS AND MAIN RESULTS

Least squares geometric mean models were fit to determine effects of sex and age on airway responsiveness (provocative concentration producing 20% decrease in FEV(1) [PC(20)]). Multiple linear regression analysis was performed to determine factors at baseline and over time, which were associated with PC(20) at end of follow-up. A total of 7,748 methacholine challenges were analyzed. PC(20) increased with age, with boys having greater increase after age 11 years than girls (P < 0.001). The divergence coincided with the mean age for Tanner stage 2. Postpubertal girls had greater airway responsiveness, even after adjustment for FEV(1) and other potential confounders. Although multivariable regression analyses noted a variety of factors that influenced airway responsivness in both sexes, a history of hay fever (beta= -0.30, P = 0.005), respiratory allergy (beta= -0.32, P = 0.006), or recent inhaled corticosteroid usage (beta= -0.18, P = 0.02) were associated with decrements in final log PC(20) only in girls.

CONCLUSIONS

Airway responsiveness (PC(20)) is more severe in the postpubertal female with asthma than in males. Although there are factors associated with airway responsiveness in both males and females, sex-specific factors may contribute to new insights into asthma pathogenesis.