Prognostic factors for the outcome of childhood asthma in adolescence

Supraventricular tachycardia diagnosis in asthma patients is associated with adverse health outcomes

INTRODUCTION

Supraventricular tachycardia (SVT) can occur during treatment of an acute asthma exacerbation. There are, however, no data on the long-term outcomes of children who are diagnosed with both asthma and SVT. This study aims to analyze the impact of SVT in asthmatic children on mortality and/or cardiac arrest, hypothesizing asthmatic subjects with SVT have increased mortality and/or cardiac arrest compared to asthmatic subject with no-SVT.

METHODS

This was a retrospective cohort study, utilizing the TriNetX© electronic health record (EHR) database that included asthmatic subjects 2-18 years of age. The study population was divided into two groups (subjects with SVT diagnosis and no-SVT diagnosis). Data related to demographics, diagnostic, procedural, and medication codes were collected. The primary outcome was any death and/or cardiac arrest in a patient after the first asthma diagnosis date.

RESULTS

This study included 91,066 asthmatic subjects (244 [0.27%] with SVT and 90,822 [99.73%] with no-SVT). Multivariable logistic regression analysis demonstrated that after controlling for demographic and clinical features, the odds of all-cause death and/or cardiac arrest after the first reported asthma exacerbation was significantly higher in asthmatic children with SVT compared to no-SVT (odds ratio [OR]: 4.30, confidence interval [CI]: 2.50-7.39, p < .001).

CONCLUSIONS

Our large nationwide EHR study suggests that asthmatic pediatric patients with documented SVT diagnosis at any point in their EHR may be at increased risk of adverse health outcomes compared to no-SVT. Further studies are needed to determine the factors contributing to the increased risk of mortality and/or cardiac arrest in children with asthma and SVT.

Age-specific incidence of allergic and non-allergic asthma

Background

Onset of allergic asthma has a strong association with childhood but only a few studies have analyzed incidence of asthma from childhood to late adulthood in relation to allergy. The purpose of the study was to assess age-specific incidence of allergic and non-allergic asthma.

Methods

Questionnaires were sent to 8000 randomly selected recipients aged 20–69 years in Finland in 2016. The response rate was 52.3% (n = 4173). The questionnaire included questions on e.g. atopic status, asthma and age at asthma diagnosis. Asthma was classified allergic if also a physician-diagnosed allergic rhinitis was reported.

Results

The prevalence of physician-diagnosed asthma and allergic rhinitis were 11.2 and 17.8%, respectively. Of the 445 responders with physician-diagnosed asthma, 52% were classified as allergic and 48% as non-allergic. Median ages at diagnosis of allergic and non-allergic asthma were 19 and 35 years, respectively. Among subjects with asthma diagnosis at ages 0–9, 10–19, 20–29, 30–39, 40–49, 50–59 and 60–69 years, 70, 62, 58, 53, 38, 19 and 33%, respectively, were allergic. For non-allergic asthma, the incidence rate was lowest in children and young adults (0.7/1000/year). It increased after middle age and was highest in older age groups (2.4/1000/year in 50–59 years old).

Conclusions

The incidence of allergic asthma is highest in early childhood and steadily decreases with advancing age, while the incidence of non-allergic asthma is low until it peaks in late adulthood. After approximately 40 years of age, most of the new cases of asthma are non-allergic.

Asthma diagnosed in late adulthood is linked to work disability and poor employment status

BACKGROUND

Age at asthma onset is associated with severity and outcomes of the disease.

OBJECTIVE

We studied if age at asthma diagnosis is related to employment and outcomes in working career.

PATIENTS AND METHODS

A questionnaire was sent to 2613 adults with asthma in Tampere, Finland, and a follow-up questionnaire was sent after six years. Asthmatics were divided into groups based on their employment status: working full-time or work disability. Logistic regression was used to study the association of age at asthma diagnosis with employment status at baseline and with the risk of exiting full-time work during follow-up period.

RESULTS

In cross-sectional analysis, asthma diagnosed in late adulthood (50 + years) was associated with higher OR for having work-disability compared to childhood onset asthma (OR [95% CI] 3.60 [1.43-9.06]). During follow-up, asthma diagnosed in late adulthood was associated with higher OR for exiting full time work compared to childhood-onset asthma (OR 10.87 [3.25-36.40]).

CONCLUSIONS

Asthma diagnosed in late adulthood is a higher risk for poor employment than asthma diagnosed earlier in life. Adult-onset of asthma is an important factor in view of work ability and early rehabilitation procedures.

Value of past clinical history in differentiating bronchial asthma from COPD in male smokers presenting with SOB and fixed airway obstruction

Objective:

Differentiating asthma from chronic obstructive pulmonary disease (COPD) is difficult. Steroid trial may be of help but has several pitfalls. The present study aims to assess the value of past clinical profile of asthma and its differential diagnosis from COPD in male smokers and thereby to formulate clinical parameters to diagnose bronchial asthma in such patients.

Patients and Methods:

Male smokers who reported at the Respiratory Medicine Department of the National Institute of Medical Sciences (NIMS) Hospital, Jaipur, (India), with shortness of breath (SOB) and showing less than 12% postbronchodilator bronchial reversibility (BR) on spirometry were recruited. These patients were given oral prednisolone 1 mg/kg for two weeks. Post steroid (PS) spirometry was performed to ascertain BR. The past clinical history was recorded and analyzed to determine if it is of any use in differentiating asthma from COPD.

Result:

Out of 104 patients, four were lost to follow up, 52 were diagnosed as bronchial asthma, and the remaining 48 as COPD. It was revealed that past history of (H/O) seasonal variation, wheezing, eye allergy, nasal allergy, dust allergy, skin allergy, and family H/O asthma/allergy were positive in 50, 40, 34, 30, 18, 14, and 12 asthma patients as compared to 10, 8, 2, 4, 6, 0, and 0 in 48 COPD patients (P < 0.001). The odds ratio (OR) for diagnosing asthma was highest for the presence of any other two symptoms/variables, besides SOB, in the past (OR = 275, P < 0.0001).

Conclusion:

Past clinical history is of immense value in differentiating asthma from COPD in male smokers presenting with SOB and fixed airway obstruction.

Long-term follow-up after two years of asthma treatment guided by airway responsiveness in children

INTRODUCTION

Children with persistent asthma may have diminished lung function in early adulthood. In our previous study ('CATO') we showed preservation of lung function in asthmatic children, during 2 years of treatment that was guided by airway hyperresponsiveness (AHR). The aim of the present prospective follow up study was to investigate whether the positive effect of the AHR strategy on lung function had persisted beyond the duration of the intervention study, after several years of usual care by paediatrician and general practitioner.

METHODS

With a mean interval of 4.4 y after the last visit, 137 subjects (67% of the original CATO population) participated in this follow-up study. Evaluation consisted of spirometry (n = 137), a methacholine challenge test (n = 83), data on inhaled steroid treatment and asthma exacerbations (n = 137), and an asthma symptom diary during 6 weeks (n = 90).

RESULTS

At follow-up, lung function, % symptom-free days and exacerbation rates of both treatment strategy groups was similar. The mean dose of inhaled corticosteroids had diminished from 550 μg/day at the end of CATO to 235 μg/day at follow-up. The decrease in AHR measured at the end of CATO was maintained at follow-up for both treatment strategy groups.

CONCLUSION

The beneficial effect on lung function of 2 years treatment guided by AHR was lost after 3-7 years of usual care. This suggests that an AHR-guided treatment strategy may need to be sustained in order to preserve lung function.

Local and systemic immunological parameters associated with remission of asthma symptoms in children

The immunological and clinical parameters that are associated with asthma remission are poorly understood. The cytokine and local mediator changes associated with the resolution of asthma symptoms were examined in three groups of subjects 12-18 years of age (n = 15 in each group): (a) continuing asthma group (CA) who had persistent symptoms since early childhood, (b) an age, sex and atopic status-matched group who had persistent symptoms in early childhood but in whom these had resolved (RA), and (c) a non-atopic, non-asthmatic control group. Clinical parameters, sputum cell counts, peripheral blood mononuclear cell (PBMC) cytokine production and activation marker expression were determined. All of the CA had methacholine airway hyperresponsiveness compared with only half of the RA subjects. The CA showed elevated numbers of eosinophils and increased ECP and IL-5 in sputum, which were not observed in the RA. PBMC cytokine studies revealed increased production of the type 1 cytokines IL-12, IFN-γ and TNF-α in the CA group compared with the RA group, under a range of activation conditions, however, the production of IL-4 and IL-5 were unchanged. These findings suggest that decreased type 1 cytokine expression as well as decreased eosinophilic inflammation is associated with the resolution of asthma symptoms.

Why are some children with early onset of asthma getting better over the years?--diagnostic failure or salutogenetic factors

Among children earlier having been identified with a hospital or primary care diagnosis of asthma at least once between 0-7 years of age, almost 40 % of their parents reported in the ISAAC-questionnaire as never having had asthma (NA). These are further analysed and compared with the persisting asthma cases (A) in this study. All these children's medical records were scrutinized concerning their asthma diagnose retrospectively.The aim of this study was to analyse possible factors related to the outcome in an Asthma diagnosis reassessment by parental questionnaire at the age of ten of the children earlier having been identified with a hospital or primary health care diagnosis of asthma at least once between 0-7 years of age in a total birth-year cohort in a defined Swedish geographical area.A multiple logistic analysis revealed four significant and independent factors associated to the improvement/non-report of asthma at the age of ten. These factors were; not having any past experiences of allergic symptoms (p<0.0001), only having one or two visits at the hospital for asthma diagnosis in the 0-7 interval (p=0.001), not living in a flat but a villa at the age of ten (p=0.029) and no previous perception of mist or mould damage in the house (p=0.052).In the early postnatal stage, obstructive and bronchospastic symptoms typical of asthma may be unspecific, and those cases not continuing to persisting disease tend to have identifiable salutogenetic factors of constitutional rather than environmental nature, namely, an overall reduced allergic predisposition.

Training improves physical fitness and decreases CRP also in asthmatic conscripts

To study the respiratory and physical health of young men, 224 asthmatic and 668 non-asthmatic military conscripts were recruited from the intake groups of July 2004 and January 2005 in Kajaani, Finland. Factors affecting respiratory health were elicited by a questionnaire at the beginning of the service, and results of high sensitive C-reactive protein (hsCRP) determination, peak expiratory flow (PEF), and 12-minute running test were collected at the beginning and the end of the service. Respiratory infections were diagnosed by a study physician. Upon entering military service, asthmatics had frequent exercise- and cold-related asthma symptoms (69.6% and 76.3%), and 48% of them had no medication for asthma. At the beginning, 25.8% of asthmatics and 19.1% of non-asthmatics had a poor result of less than 2,200 m (p = 0.05) in the 12-minute running test, and after 180 to 362 days of service, the corresponding percentages were 11.7% and 9.7% (p = 0.434). The levels of hsCRP, a marker of low-grade systemic inflammation, decreased significantly among both asthmatics, 1.5 (p = 0.001), and non-asthmatics, 1.6 mg/L (p < 0.001). Asthmatic men had 0.2 and non-asthmatics 0.1 respiratory infections per month (p < 0.001). In summary, asthmatic conscripts can enhance their physical fitness by training similarly to non-asthmatic ones. Their levels of hsCRP also decrease.

Not all children with under-control asthma are controlled

Subclinical lung function alterations can sometimes be discovered in asthmatic patients under clinical control. This study aimed to identify the burden of asthmatic children with subclinical airways abnormalities who may benefit from an adjustment in asthma therapy. 134 6-to-17-year-old asthmatic children were enrolled. Of them, 98 presented apparently under clinical control disease and all performed spirometry before and after bronchodilation: 17 (17.3%) had a positive bronchodilation test, in addition to significantly lower lung function indexes as compared to those with under-control asthma who had a negative bronchodilation test. These patients were randomized and re-evaluated: patients (n=8) receiving an adjustment in their therapy showed an improvement in lung function tests and quality of life indexes as compared to 7 without therapy adjustment. In conclusion, a substantial number of apparently-under-control asthmatic children show airways alterations that can be improved by adjusting their therapy, which also seems to enhance their quality of life.

[Risk factors for asthma in adults in Pelotas, Rio Grande do Sul State, Brazil]

Asthma incidence and mortality rates have increased in recent years. The present cross-sectional survey aimed to measure asthma prevalence and risk factors in a random sample of 1,968 individuals (20-69 years of age) in Pelotas, Rio Grande do Sul State, Brazil. Overall prevalence of "current asthma symptoms" was 6%, varying according to diagnostic criteria. Associated risk factors in the crude analyses were: female gender, age 60-69 years, non-white skin color, low education, low family income, family history of atopy and asthma, personal history of atopic disease, smoking, low body mass index, and minor psychiatric disorders. In the multivariate analysis the following risk factors remained associated with "current asthma symptoms": mother and father with asthma history, minor psychiatric disorders, age 60-69 years, household income less than 1.01 minimum wage, history of atopic disease, and female gender. The results highlight the variation in asthma prevalence according to diagnostic criteria and confirm the importance of genetic, social, and lifestyle factors.

Psychological, academic, and work functioning in college students with childhood-onset asthma

This study investigated differences in psychological, academic, and work functioning between college students with and without asthma and identified predictors of functioning. Both participants with asthma (n = 121) and age-and gender-matched healthy control subjects (n = 121) completed measures of psychological distress, provided information on missed school and work days, and consented to have their grade point averages released from the registrar. College students with asthma also completed measures of illness uncertainty and illness intrusiveness. Participants with asthma reported greater anxiety, general psychological distress, and more missed school and work days compared to healthy control subjects. Within the asthma group, both illness uncertainty and illness intrusiveness independently predicted anxious and depressive symptoms and general psychological distress; illness intrusiveness also predicted missed school days. Although enrollment in college implies resilient functioning, college students with asthma remain at risk for problems with psychological and academic functioning.

The prevalence of atopy and asthma among university freshmen in Seoul, Korea: association with obesity

The aims of this study were to investigate the prevalence of atopy, asthma, and obesity in university freshmen and to determine whether leptin is associated with bronchodilator reversibility in obesity. A total of 537 university freshmen completed International Study of Asthma and Allergies in Children (ISAAC) questionnaire and underwent skin prick testing and bronchodilator reversibility test. The prevalences of asthma, wheeze, and atopy were 10 (1.9%), 84 (15.6%), and 198 (36.9%), respectively. The mean (+/- SD) bronchodilator response (5.1 +/- 4.4%) was higher in the overweight/obese men than in the normal male subjects (3.7 +/- 3.2%, p < 0.05). The mean leptin level in the overweight/obese men was 5.55 +/- 3.48 ng/mL, which was significantly higher than that (2.78 +/- 1.65 ng/mL) of the normal male subjects. The prevalence of asthma among university freshmen is seriously under-diagnosed and leptin may play a role in bronchodilator reversibility in overweight/obese young men.

Percentage fall in FVC at the provocative concentration of methacholine causing a 20% fall in FEV1 in symptomatic asthma and clinical remission during adolescence

BACKGROUND

Many children with asthma go into long-term clinical remission at adolescence, but bronchial hyperresponsiveness (BHR) persists in approximately one half of these subjects. BHR is usually assessed by measuring the provocative concentration of methacholine causing a 20% fall in FEV1 (PC20). The percentage fall in FVC at the PC20 (deltaFVC) has been suggested to be a more useful index of disease severity in asthma than PC20.

STUDY OBJECTIVE

The aim of this study was to determine whether deltaFVC is higher in adolescents with symptomatic asthma than in those with clinical remission.

PATIENTS AND METHODS

Forty adolescents with symptomatic asthma and 80 adolescents with asthma remission underwent methacholine challenge testing. DeltaFVC and PC20 were measured on the methacholine dose-response curve.

RESULTS

The mean (95% confidence interval [CI]) deltaFVC (15.5% [95% CI, 14.1 to 16.9%]) in the symptomatic group (n = 40) was significantly higher (p = 0.017) than that (12.8% [95% CI, 11.5 to 14.1%]) in the BHR-positive (PC20 < 16 mg/mL) remission group (n = 44) or that (11.5% [95% CI, 10.2 to 12.8%]) of the BHR-negative remission group (n = 36), with no difference between the two latter groups (p = 0.581). No significant correlation was found between deltaFVC and PC20 in the symptomatic group (r = -0.156, p = 0.336) or in the whole remission group (r = -0.187, p = 0.097).

CONCLUSIONS

Adolescents with symptomatic asthma had a higher deltaFVC than those with clinical remission, irrespective of the presence of BHR in the latter group. This finding suggests that deltaFVC may serve as an adjunct marker for differentiating between asthma persistence and remission during adolescence.

Prevalência de asma em adolescentes urbanos de Santa Maria (RS): Projeto ISAAC - International Study of Asthma and Allergies in Childhood

INTRODUÇÃO: A asma é a doença crônica mais comum entre adolescentes. OBJETIVO: Determinar a prevalência de asma e sintomas relacionados utilizando o protocolo do International Study of Asthma and Allergies in Childhood (ISAAC) em adolescentes de Santa Maria (RS). MÉTODO: Estudo transversal, em que foram avaliados 3.066 escolares urbanos (13-14 anos) de Santa Maria (RS), selecionados por amostragem aleatória, conforme protocolo do ISAAC. Os dados foram coletados de março a junho de 2003 utilizando-se questionário padronizado do ISAAC. O questionário foi respondido pelos adolescentes em sala de aula, na presença dos pesquisadores. RESULTADOS: O número de questionários válidos devolvidos foi de 3.066 (95,5%). A prevalência dos sintomas de asma nos adolescentes foi: sibilos alguma vez na vida em 42,1% dos adolescentes; sibilos nos últimos doze meses em 16,7%; quatro crises ou mais de sibilos nos últimos doze meses em 1,9%; sono perturbado em uma ou mais noites por semana nos últimos doze meses em 3,8%; prejuízo na fala nos últimos doze meses em 3,8%; asma alguma vez na vida em 14,9%; sibilos após exercícios nos últimos doze meses em 19%; tosse seca à noite nos últimos doze meses em 32,4% deles. Houve valores significativamente superiores no sexo feminino. CONCLUSÃO: A prevalência dos sintomas relacionados à asma em adolescentes urbanos de Santa Maria mostrou-se elevada, predominando entre as meninas. Ficou entre a média internacional e foi inferior aos dados observados nas capitais brasileiras. Estes dados reforçam a necessidade de estudos regionais para o melhor entendimento da prevalência da asma no Brasil.

Persistence of asthma symptoms during adolescence: role of obesity and age at the onset of puberty

Little is known about rates and predictors of remission of childhood asthma after the onset of puberty. We used data collected at ages 6, 8, 11, 13, and 16 years from the Tucson Children's Respiratory Study, a population-based birth cohort. The onset of puberty was defined as the age of appearance of the first pubertal signs as reported by parents. Information on wheezing both before and after onset of puberty (mean +/- SD follow-up from onset of puberty, 4.2 +/- 1 year) was available for 781 children. Of these, 166 had asthma (either frequent wheezing or a physician-confirmed diagnosis plus any wheezing) in at least one survey before puberty. In this group, 58% of the children (97 of 166) reported the presence of wheezing after the onset of puberty (unremitting asthma). In contrast, only 30% (39 of 131) of the children with infrequent wheezing before puberty experienced wheezing episodes after the onset of puberty (unremitting wheezing). In addition to frequent wheezing before puberty, obesity, early onset of puberty, active sinusitis, and skin test sensitization were significant and independent predictors of unremitting asthma after the onset of puberty. Our findings from a population-based longitudinal cohort challenge the commonly held view that asthma usually remits during adolescence.

Asthma management across the life span: the child with asthma

Childhood asthma has an adverse impact on children, families, and society. Treatment of asthma presents special challenges related to diagnosis, ongoing symptom monitoring, and treatment when the patient is a child. To be effective, treatment needs to be medically sound and developmentally appropriate.

Early intervention with budesonide in mild persistent asthma: a randomised, double-blind trial

BACKGROUND

Although inhaled glucocorticosteroids are recommended for persistent asthma, their long-term effect on recent onset, mild, persistent asthma has yet to be established.

METHODS

We did a randomised, double-blind clinical trial in 7241 patients in 32 countries to assess the effects of budesonide in patients who had had mild persistent asthma for less than 2 years and who had not had previous regular treatment with glucocorticosteroids. Patients aged 5-66 years received either budesonide or placebo once daily for 3 years in addition to their usual asthma medications. The daily budesonide dose was 400 microg, or 200 microg for children younger than 11 years. The primary outcome was time to first severe asthma-related event, and analysis was by intention to treat.

FINDINGS

198 of 3568 patients on placebo and 117 of 3597 on budesonide had at least one severe asthma exacerbation; hazard ratio 0.56 (95% CI 0.45-0.71, p<0.0001). Patients on budesonide had fewer courses of systemic corticosteroids and more symptom-free days than did those on placebo. Compared with placebo, budesonide increased postbronchodilator forced expiratory volume in 1 s (FEV1) from baseline by 1.48% (p<0.0001) after 1 year and by 0.88% (p=0.0005) after 3 years (expressed as percent of the predicted value). The corresponding increase in prebronchodilator FEV1 was 2.24% after 1 year and 1.71% after 3 years (p<0.0001 at both timepoints). The effect of treatment on all outcome variables was independent of the baseline lung function (prebronchodilator or postbronchodilator) or baseline medication. In children younger than 11 years, 3-year growth was reduced in the budesonide group by 1.34 cm. The reduction was greatest in the first year of treatment (0.58 cm) than years 2 and 3 (0.43 cm and 0.33 cm, respectively).

INTERPRETATION

Long-term, once-daily treatment with low-dose budesonide decreases the risk of severe exacerbations and improves asthma control in patients with mild persistent asthma of recent onset.

Association of CCR5Delta32 with reduced risk of childhood but not adult asthma

BACKGROUND

A number of potential candidate genes have been implicated in the pathogenesis of asthma. A 32 base pair deletion in the CCR5 gene renders this chemokine receptor non-functioning and has been shown to be associated with a reduced prevalence of asthma in childhood. The mechanism may be related to impairment of pathogen entry into cells and modified host inflammatory response. We sought to determine the influence of the CCR5Delta32 mutation on asthma and allergy in the transition from childhood to adulthood.

METHODS

627 individuals first studied as part of a whole population schoolchildren cohort in 1989 when aged 8-12 years were followed up 10 years later for respiratory and allergy symptoms and laboratory markers of atopy. CCR5Delta32 status was also characterised and the association with childhood and adulthood symptoms determined.

RESULTS

The follow up sample was representative of the original cohort except for a slightly greater prevalence of symptomatic individuals. As children, none who were homozygous for the CCR5Delta32 mutation had a current physician's diagnosis of asthma. In multivariate analysis and controlling for known confounders, the protective effect of carrying the allele in childhood was highly significant (OR 0.31, 95% CI 0.14 to 0.72, p=0.006). There was no protective association with "current asthma" as classified in adulthood within the same population. Subjective or laboratory markers of atopy in childhood or adulthood were not associated with the CCR5Delta32 mutation. Methacholine bronchial hyperresponsiveness in adulthood was also unrelated to gene carrier status.

CONCLUSIONS

In a population with a high allelic frequency for the CCR5Delta32 mutation, a significant protection against childhood asthma is evident which is independent of atopy. This protection is lost in the transition between childhood and early adulthood. The contribution of different genetic candidates to the expression of asthma may change with advancing maturity and confound the interpretation of association and linkage studies unless age is taken into account.

Epidemiology of asthma and recurrent wheeze in childhood

To summarize, wheeze is common throughout childhood, although it decreases as children age. However, the characteristics of wheeze, its relations with asthma, and its risk factors all change with age. Longitudinal studies have shown that "transient early wheezing" predominates during the first years of life. The principal risks for this type of wheezing are largely mechanical, relating to small airways, and infectious, relating to the risk of becoming infected with respiratory viruses. Associated with passive exposure to cigarette smoke, exposure to other children, and not being breastfed, this form of wheezing was unrelated to increased airway liability or atopy in the child. For the majority of children, particularly those with low lung function at birth, wheezing with early LRIs is a benign condition, not associated with subsequent wheeze or risk for asthma. During the middle part of the first decade of life, wheezing appears to reflect a mix of infectious and allergic wheezing. By 6 yr of age, some children have already wheezed persistently. This group is more likely to have high total IgE levels, to be skin-test positive, and to be given a diagnosis of asthma. Further, their immunologic response to their early LRIs was consistent with a Th2 bias: persistent wheezers produced high levels of IgE, and did not demonstrate the normal pattern of decreased eosinophils. Nevertheless, the children who wheeze in middle childhood are a mixed group, with some being less allergic. Thus, although markers of allergy become increasingly important predictors of wheezing for the group as a whole, wheezing in middle childhood is not associated with later methacholine hyperresponsiveness (42). Finally, persistent allergic wheezing, usually associated with a diagnosis of asthma, predominates by the end of the first decade of life. Wheezing at this age is associated with methacholine responsiveness, peak-flow variability, and markers of atopy, such as total IgE and allergy skin-test response. Although children who wheezed early in life are more likely to wheeze later, early wheeze does not increase the risk of atopy, suggesting that early LRIs are markers of increased risk rather than causes. The gender differences in wheeze disappear, with boys becoming less likely to wheeze and to have asthma, whereas both conditions appear to increase in girls. Finally, some of the risk factors for early LRIs, such as exposure to other children in infancy, appear to be associated with protection from later allergic wheezing. Clearly, asthma and wheeze during childhood are complex entities, presenting with different characteristics at different ages, and implicating varied and changing causes. Genetic factors are important determinants of the intermediate phenotypes. However, environmental factors operating at different developmental stages also appear to influence the development of asthma. Additional research regarding these relationships is essential, both to elucidate possible causal mechanisms and to provide insight into the primary prevention of asthma.

Risk factors for the persistence of respiratory symptoms in childhood asthma

OBJECTIVE

To evaluate the parameters which could predict the persistence of respiratory symptoms in asthmatic children who have been treated with a considerably uniform therapy.

METHODS

A retrospective review was performed on the records of 279 children with asthma. An end of study visit, results of spirometry and prick tests completed the data. The mean age at referral and at final visit was 6.2 +/- 3.7 years and 8.9 +/- 4.1 years, respectively; and the children were followed up for a mean of 3 +/- 1.2 years.

RESULTS

Eighty-five of the 279 patients (30%) experienced no respiratory symptoms in the previous 12 months. There was no significant difference between those with and without current respiratory symptoms with respect to age, sex, age at onset of symptoms, duration of followup, age at referral, therapeutic choice, severity of asthma and duration of symptoms at referral. For subjects with current respiratory symptoms the initial serum total IgE level, and the percentage of RAST/prick test positivity was significantly higher than those without current respiratory symptoms (P = 0.0027, P = 0.011, respectively). Although the initial FEF 25%-75%, FEV1, and FEV1/FVC was significantly lower in those with current respiratory symptoms (P = 0.003; P = 0.005; and P = 0.04, respectively), there was no statistically significant difference between lung functions of the two groups at the end of followup. The persistence of respiratory symptoms was significantly predicted by initial FEF25%-75% and sensitivity to allergens (P = 0.03 and P = 0.04, respectively).

CONCLUSIONS

We concluded that the risk factors for the persistence of respiratory symptoms in our patient population have been low FEF25%-75% value and sensitivity to allergens at referral.

Development of bronchial hyperresponsiveness during childhood

Bronchial hyperresponsiveness (BHR) produces the characteristic pathological abnormalities seen in asthma and clearly plays a central role in the pathophysiology of asthma. The presence of BHR has been demonstrated in infants with asthma, as has the possibility of BHR persisting through the childhood period. The level of BHR may not only reflect the state of the airways, as a marker of airway dysfunction, but may also predict the persistent prognosis of the disease. Thus, measurement of BHR may provide important information about the symptoms and lung function in children with asthma. In view of multiple pathophysiological mechanisms, BHR does not seem to have a single cause. Many potential confounding variables, such as age, gender and genetic status, and some environmental factors, such as allergens, infections, and pollutants, could be responsible for the establishment of childhood BHR. There may be differences between the mechanisms that induce transient BHR and the mechanisms that induce persistent BHR. Also, there may be differences between the causes that induce BHR in the infantile period and the causes that maintain persistent BHR during childhood asthma. There is also disagreement as to the most suitable method to measure BHR in children, especially in infants. The assessment of BHR in young children has not been uniformly successful, and measurements of BHR changes over the childhood period (are associated with a number of problems. To resolve these problems, there may be two ways to study childhood BHR. One is to use age-matched specific techniques to clarify the precise BHR in each age group; the other is to use simple techniques that can be performed over the childhood period on a large number of subjects. In studies of infantile respirator, dysfunction the ultimate goal is to establish a simple, noninvasive method by which measurements of respiratory function may be obtained in infants. Further investigations and acceptable methods will be needed to clarify, the mechanisms involved in the establishment of asthma throughout the childhood period.

The role of viruses in the induction and progression of asthma

Viral respiratory infections have been related to asthma in several ways. It is well established that viral common colds precipitate exacerbations of asthma. Severe bronchiolitis in early life is related to subsequent wheezing and therefore may represent a marker of susceptibility to asthma; alternatively, it could be involved in the initiation of the disease. Finally, it is possible that some infections may protect from the development of asthma and allergies by promoting a type-1 host response. However, whether respiratory or other viruses could mediate such a protective effect is debated. The design and implementation of novel anti- or proviral strategies targeting asthma depends on the resolution of these questions. This review presents current evidence on the epidemiologic correlations and proposed mechanisms for the involvement of viral infections in the development and progression of asthma.

Bronchial hyperresponsiveness to 4.5% hypertonic saline indicates a past history of asthma-like symptoms in children

SUMMARY. To evaluate the importance of a past history of asthma-like symptoms over a period of 2 years and current bronchial hyperreactivity (BHR), 538 randomly selected schoolchildren, initially aged 7-8 years, were examined. At yearly intervals, three standardized questionnaires, including items from the ISAAC panel, were answered by parents. Following the last questionnaire, BHR to 4.5% hypertonic saline (HS) was recorded. In survey 1, lifetime prevalence of asthma was 4.9%. During the 12-month period, prevalence of wheeze and dyspnea ranged between 9.3 and 5.2% (Survey 1) and 5.9% and 4.4% (Survey 2). Among children with wheeze or dyspnea in Survey 3, BHR (defined as a fall of baseline FEV(1) > or = 15%) was significantly more frequent (50.0% and 60.7%, respectively) than among children without these symptoms (12.8%, P < 0.001, and 12.8%, P < 0.001, respectively). The negative predictive value of BHR to have neither wheeze nor dyspnea was about 88% and did not vary throughout the study (Survey 1, 87%; Survey 2, 88%; Survey 3, 88%). The relative risk of showing BHR was significantly increased in children with wheeze (survey 2, odds ratio (OR) 3.0 (95% confidence interval (CI) 1.0-8.7)) or dyspnea (Survey 1: OR 5.9 (95% CI 1.9-18.5), Survey 3: 5.2 (1.7-16.2), but not in children with dry cough or nocturnal cough (data not shown). Wheeze and dyspnea occurred repeatedly in the same individuals with BHR in a high percentage of children (83.3% and 76.5%, respectively). In conclusion, there is a strong association between recent and previous dyspnea and current BHR, and it indicates intraindividual persistence of symptom history.

Asthma in adults: comparison of adult-onset asthma with childhood-onset asthma relapsing in adulthood

The prevalence of asthma in children and young adults is rising. Although the general features of asthma are similar in children and adults, there are several differences. Studies of the differences between childhood- and adult-onset asthma may provide new insight into the phenotypic heterogeneity of asthma. The aim of this cross-sectional study was to compare the characteristics of asthmatic adults who reported having (n = 84) or not having (n = 235) asthma in childhood. The participating patients were recruited by chest specialists throughout France and were examined from March to November 1995. The specialists completed a standardized questionnaire, and carried out a clinical examination and spirometric tests. Male sex; greater severity, particularly lower spirometry values related to small airways; greater severity and earlier onset of allergy; and maternal history of atopic dermatitis and perennial rhinitis were found to be associated with reported childhood asthma. This study exhibits highly internally consistent results and indicates that subjects who did have childhood asthma and relapse in adulthood appeared to have a potentially more severe form of asthma.

Asthma from childhood to adulthood: asthma severity, allergies, sensitization, living conditions, gender influence and social consequences

The course of asthma severity, clinical allergies, allergic sensitization, changes in living conditions and social outcome were studied prospectively over five follow-up visits from the mean age of 9 to 30 years in a cohort of 28 boys and 27 girls, selected randomly among asthmatic children attending a paediatric outpatient unit. Asthma severity improved from childhood to adulthood, judged by symptom and medication scores and by the number of hospital admissions, but only nine subjects (16%) had been free from symptoms and medication over the last year of follow-up. After adolescence, asthma continued to improve among the males but not among the females. This difference could not be explained by gender differences in the course of clinical allergies or sensitization (skin-prick-tests and RAST) to common inhaled allergens, or by differences in environmental or social conditions. Sensitization to relevant perennial inhaled allergens correlated with asthma severity during adulthood. In general, clinical allergies and sensitization to inhaled allergens adopted during childhood persisted into adulthood. Approximately 10% of the subjects never adopted a clinical allergy or a positive allergy test. The social outcome was good.

Scottish Confidential Inquiry into Asthma Deaths (SCIAD), 1994-6

BACKGROUND

There have been important changes in the organisation of care for patients with asthma since asthma deaths were studied in the 1980s by the British Thoracic Association (BTA), with greater emphasis on long term control of symptoms and the use of preventive therapy. Recent trends in routine statistics show a decline in population death rates.

METHODS

A confidential review was undertaken of general practice and hospital records and interviews with general practitioners of patients dying in mainland Scotland between January 1994 and December 1996 with a principal diagnosis of asthma recorded by the Registrar General's Office. Panel assessment of the cause of death was carried out and a number of possible adverse factors were identified. The data from the 15-64 year age group were compared with similar data from the earlier study by the BTA.

RESULTS

Over the three year period 95 deaths of 235 studied (40%) were confirmed as being due to asthma. Taking account of different methods of case ascertainment used in the BTA and this study, a fall in the calculated rate of "deaths assessed as due to asthma" was found from 2.51 (95% CI 2.34 to 2.68) per 100,000 population in 1979 to 1.26 (95% CI 1.19 to 1.33) per 100,000 population in 1994-6. Fewer individual adverse factors were identified in clinical management, with appropriate routine management in 59% and management of the final attack satisfactory in 71%. Patient factors such as poor compliance, lack of peak expiratory flow (PEF) measurements, and overuse of reliever medication without inhaled corticosteroids, and psychosocial problems, notably depression, were confirmed as important contributing factors. Four of five patients under 16 years of age who died were found to have problems with routine management.

CONCLUSIONS

This population based study documents important improvements in the standard of asthma care as well as a significant decline in the rate of deaths due to asthma over a period during which the organisation of care has changed and the chronic nature of the disease has been acknowledged. Strategies which might have a further impact include the greater use of PEF recordings, particularly during acute attacks, to document recovery, prescription monitoring of the underuse of inhaled corticosteroids, consideration of the use of combined preparations where persistent overuse of bronchodilators is occurring, and increased input for young patients whose routine management is proving difficult.

A comparison of active and simulated chiropractic manipulation as adjunctive treatment for childhood asthma

BACKGROUND

Chiropractic spinal manipulation has been reported to be of benefit in nonmusculoskeletal conditions, including asthma.

METHODS

We conducted a randomized, controlled trial of chiropractic spinal manipulation for children with mild or moderate asthma. After a three-week base-line evaluation period, 91 children who had continuing symptoms of asthma despite usual medical therapy were randomly assigned to receive either active or simulated chiropractic manipulation for four months. None had previously received chiropractic care. Each subject was treated by 1 of 11 participating chiropractors, selected by the family according to location. The primary outcome measure was the change from base line in the peak expiratory flow, measured in the morning, before the use of a bronchodilator, at two and four months. Except for the treating chiropractor and one investigator (who was not involved in assessing outcomes), all participants remained fully blinded to treatment assignment throughout the study.

RESULTS

Eighty children (38 in the active-treatment group and 42 in the simulated-treatment group) had outcome data that could be evaluated. There were small increases (7 to 12 liters per minute) in peak expiratory flow in the morning and the evening in both treatment groups, with no significant differences between the groups in the degree of change from base line (morning peak expiratory flow, P=0.49 at two months and P=0.82 at four months). Symptoms of asthma and use of 3-agonists decreased and the quality of life increased in both groups, with no significant differences between the groups. There were no significant changes in spirometric measurements or airway responsiveness.

CONCLUSIONS

In children with mild or moderate asthma, the addition of chiropractic spinal manipulation to usual medical care provided no benefit.