Adrenal suppression in asthmatic children receiving low-dose inhaled budesonide: comparison between dry powder inhaler and pressurized metered-dose inhaler attached to a spacer.

BACKGROUND: Dry powder inhalers (DPI) have in recent years become a common mode for administration of inhaled corticosteroids for preventive therapy of asthma. Inhaled steroids delivered by DPI achieve increased lung deposition compared with pressurized metered-dose inhalers (pMDI), which is associated with increased therapeutic effect. This may be associated with increased systemic absorption. OBJECTIVE: The purpose of this study was to evaluate the prevalence of adrenal suppression in children using low-dose budesonide given by DPI, as compared with pMDI attached to a large-volume spacer device (pMDI + spacer). METHODS: In an open-labeled crossover study, 15 asthmatic children aged 5 to 15 years received 200 microg of inhaled budesonide twice daily by DPI (Turbuhaler, Astra, Draco AB, Lund, Sweden) and by pMDI + spacer, 1 month each, in a randomized order. Twenty-four-hour urine collections were performed at baseline and at the end of each of the 2 months of the study period, and urinary cortisol and creatinine were measured. RESULTS: Baseline urinary cortisol:creatinine was 0.038 +/- 0.012 microg/mg, similar in both groups. After 1 month of DPI therapy, urinary cortisol:creatinine was reduced by 27 +/- 16% to 0.028 +/- 0.012 microg/mg (P = 0.018). Urinary cortisol:creatinine after 1 month of pMDI + spacer therapy was similar to baseline 0.037 +/- 0.019 microg/mg (P = 0.78). CONCLUSIONS: Treatment of asthmatic children with budesonide 400 microg daily given via a DPI for 1 month was associated with hypothalamic-pituitary-adrenal axis suppression. This effect was not observed with the same dose of budesonide administered via pMDI + spacer. This indicates that systemic absorption might be reduced with pMDI + spacer therapy.     

Once-daily budesonide inhalation suspension for the treatment of persistent asthma in infants and young children.

BACKGROUND: Inhaled glucocorticosteroids (GCS) are the most effective long-term controller medications for the treatment of persistent asthma. Currently, however, available delivery devices limit their use in young children. A nebulized formulation of budesonide has been developed to address the needs of infants and young children. OBJECTIVE: To evaluate the efficacy and safety of once-daily budesonide inhalation suspension in children 6 months to 8 years old with mild persistent asthma not on inhaled GCS. METHODS: Three hundred fifty-nine children were randomized to receive once-daily budesonide inhalation suspension (0.25 mg, 0.50 mg, or 1.0 mg) or placebo via a Pari LC-Jet Plus nebulizer for 12 weeks. Efficacy assessments included nighttime/daytime asthma symptoms, pulmonary function (subset of patients), rescue medication use, and treatment discontinuations. Safety was based on adverse events and assessment of HPA-axis function. RESULTS: Demographics, baseline characteristics, asthma symptoms, and pulmonary function were similar across treatment groups. Mean nighttime/daytime asthma symptom scores were 1.19 +/- 0.63 and 1.34 +/- 0.53, respectively. Mean duration of asthma was 36.3 months and mean FEV1 was 81.3% of predicted with 27.7% reversibility. Following 12 weeks of treatment, all budesonide inhalation suspension doses produced significant improvements in nighttime/daytime symptoms (P < or = .049) and significant decreases in rescue medication use (P < or = .038) compared with placebo. Significant improvements (P < or = .044) in FEV1 were observed in the 0.5- and 1.0-mg budesonide inhalation suspension groups. There were no differences between doses of budesonide inhalation suspension. Adverse events and basal and ACTH-stimulated cortisol levels were similar among all groups. CONCLUSION: Once-daily administration of budesonide inhalation suspension was well tolerated and effective for the treatment of mild persistent asthma in infants and young children not adequately controlled with bronchodilators or non-GCS antiinflammatory treatments.     

Effects of inhaled corticosteroids on exhaled leukotrienes and prostanoids in asthmatic children

BACKGROUND: Lipid mediators play an important pathophysiologic role in atopic asthmatic children, but their role in the airways of atopic nonasthmatic children is unknown. OBJECTIVE: We sought (1) to measure leukotriene (LT) E 4 , LTB 4 , 8-isoprostane, prostaglandin E 2 , and thromboxane B 2 concentrations in exhaled breath condensate in atopic asthmatic and atopic nonasthmatic children; (2) to measure exhaled nitric oxide (NO) as an independent marker of airway inflammation; and (3) to study the effect of inhaled corticosteroids on exhaled eicosanoids. METHODS: Twenty healthy children, 20 atopic nonasthmatic children, 30 steroid-naive atopic asthmatic children, and 25 atopic asthmatic children receiving inhaled corticosteroids were included in a cross-sectional study. An open-label study with inhaled fluticasone (100 microg twice a day for 4 weeks) was undertaken in 14 steroid-naive atopic asthmatic children. RESULTS: Compared with control subjects, exhaled LTE 4 ( P <.001), LTB 4 ( P <.001), and 8-isoprostane ( P <.001) levels were increased in both steroid-naive and steroid-treated atopic asthmatic children but not in atopic nonasthmatic children (LTE 4 , P=.14; LTB 4 , P=.23; and 8-isoprostane, P=.52). Exhaled NO levels were increased in steroid-naive atopic asthmatic children ( P <.001) and, to a lesser extent, in atopic nonasthmatic children ( P <.01). Inhaled fluticasone reduced exhaled NO (53%, P <.0001) and, to a lesser extent, LTE 4 (18%, P <.01) levels but not LTB 4 , prostaglandin E 2 , or 8-isoprostane levels in steroid-naive asthmatic children. Conclusions Exhaled LTE 4 , LTB 4 , and 8-isoprostane levels are increased in atopic asthmatic children but not in atopic nonasthmatic children. In contrast to exhaled NO, these markers seem to be relatively resistant to inhaled corticosteroids.     

Therapy with nebulized beta2 agonists (procaterol) in asthmatic children: pulmonary function and plasma levels after inhalation]

BACKGROUND: Relationship between post administrative changes in plasma drug levels and bronchodilation remains unknown. In this study, we measured plasma levels of procaterol, a beta2-agonist, when being inhaled through nebulizers in children with bronchial asthma to examine relationship between improvement of pulmonary function and the plasma levels. METHOD: Six asthmatic children with the mean age of 9.8 years, inhaled 0.3 ml of 0.01% procaterol solution through a nebulizer. We examined changes in pulmonary function and plasma procaterol levels before and after inhalation. RESULTS: Procaterol was detected in the plasma 2 minutes after inhalation when it already rose to the maximum level, and kept the steady until showing a decline in 30 minutes. The measured highest value was 87.8+/-45.1 pg/ml. FEV 1.0 remarkably increased 2 minutes after inhalation and was maintained until 60 minutes after inhalation. Other lung function parameters also improved. There was no significant change in the heart rate, but serum potassium concentrations significantly dropped in all patients 60 minutes after inhalation. CONCLUSION: Plasma procaterol levels promptly rose to the peak at 2 minutes after inhalation and decreased 30 minutes later. Improvement of pulmonary function started promptly at minutes after inhalation and it became a peak 60 minutes later.     

Once-daily budesonide inhalation suspension in infants and children < 4 and > or = 4 years of age with persistent asthma.

BACKGROUND: Budesonide inhalation suspension (Pulmicort Respules; AstraZeneca LP, Wilmington, DE), a nebulized corticosteroid, was developed for use in infants and young children with persistent asthma. OBJECTIVE: To compare the efficacy and safety of once-daily budesonide inhalation suspension in children < 4 years of age and in those > or = 4 years of age with persistent asthma. METHODS: A retrospective analysis stratified by age group was performed on data from two randomized, double-blind, placebo-controlled, parallel-group studies that evaluated the efficacy and safety of budesonide inhalation suspension 0.25 mg, 0.5 mg, or 1.0 mg once daily for 12 weeks in children 6 months to 8 years of age with persistent asthma. Clinical assessments included nighttime and daytime asthma symptoms, breakthrough medication use, adverse events, and hypothalamic-pituitary-adrenal-axis function. RESULTS: In both randomized studies, budesonide inhalation suspension demonstrated statistically significant improvement in nighttime and daytime asthma symptom scores compared with placebo. In the retrospective analysis of pooled data from these studies, the efficacy of budesonide was maintained when children were stratified by age group. Clinical improvements from baseline in nighttime and daytime asthma symptom scores were observed in both age groups at all budesonide inhalation suspension dose levels. No significant differences were observed between age groups in breakthrough medication use in any of the treatment groups. No differences were observed in the incidence of adverse events between the two age groups, and significant (P < 0.01) effect on hypothalamic-pituitary-adrenal-axis function was apparent only in children < 4 years of age at the 0.25-mg dose level. CONCLUSIONS: Once-daily budesonide inhalation suspension is effective in the treatment of persistent asthma in children aged < 4 and > or = 4 years of age.     

Onset of effect of budesonide and formoterol administered via one pressurized metered-dose inhaler in patients with asthma previously treated with inhaled corticosteroids

BACKGROUND: Onset of bronchodilation of budesonide/formoterol in one pressurized metered-dose inhaler (pMDI) has not been evaluated in asthma. OBJECTIVE: To evaluate time to onset of clinically significant bronchodilation (> or = 15% improvement in forced expiratory volume in 1 second) and patient-perceived onset of effect (OE) in patients previously receiving inhaled corticosteroids. METHODS: In two 12-week studies, patients 12 years and older with moderate to severe (study 1; n = 596) and mild to moderate (study 2; n = 480) persistent asthma received budesonide/formoterol pMDI, budesonide pMDI plus formoterol dry powder inhaler (study 1 only), budesonide pMDI, formoterol dry powder inhaler, or placebo. Postdose time to 15% or greater improvement in forced expiratory volume in 1 second and patient-perceived OE (assessed in a subset of patients 18 years and older [study 1, n=553; study 2, n=405]) were evaluated [corrected] RESULTS: More budesonide/formoterol-treated patients achieved onset of clinically significant bronchodilation within 15 minutes (median, 13 minutes) of administration at randomization vs those taking budesonide or placebo (P < .001). More patients receiving budesonide/formoterol vs budesonide and placebo reported feeling their study medication begin to work right away (P < or = .004; end of week 1). Similar results (P < .001) were observed for patient satisfaction with how quickly they felt their medication begin to work (except budesonide/formoterol vs budesonide, study 1 [P = .073]). Time to onset of clinically significant bronchodilation and patient-perceived OE of budesonide/formoterol and formoterol were similar. CONCLUSION: Budesonide/formoterol demonstrated a more rapid onset of clinically significant bronchodilation and a greater percentage of patients who perceived their medication working right away vs budesonide or placebo.     

Tai Chi Chuan training improves the pulmonary function of asthmatic children.

BACKGROUND AND PURPOSE: Tai Chi Chuan, a traditional Chinese exercise, is thought to improve cardiopulmonary function in patients with chronic disease. This study investigated the effect of Tai Chi Chuan on the pulmonary function and daily symptoms of asthmatic children. METHODS: Thirty asthmatic children were enrolled into the study. Fifteen of the 30 children participated in a 12-week Tai Chi Chuan program and the remaining 15 constituted the control group. Prior to study participation, the pulmonary function of all enrolled children was assessed at rest, after exercise, and after exercise plus iced water. A 3-day symptoms questionnaire was also completed and a score obtained after each pulmonary function test. RESULTS: There were no significant differences between the two groups in baseline pulmonary function and severity of asthmatic symptoms before study commencement, at rest, after exercise, or after exercise plus iced water. However, after the 12-week program, children in the Tai Chi Chuan group had a significant improvement in pulmonary function compared to the control group. Although there were no significant differences in post-training symptom scores at rest and after exercise between the two groups, under the stronger challenge of exercise plus iced water, children in the Tai Chi Chuan group had milder symptoms than those in the control group. CONCLUSION: Our data show that Tai Chi Chuan can improve the pulmonary function of asthmatic children. However, long-term follow-up is required to determine the impact of Tai Chi Chuan on the severity of asthmatic symptoms.     

Effects of budesonide inhalation suspension on hypothalamic-pituitary-adrenal-axis function in infants and young children with persistent asthma.

BACKGROUND: The initial 12-week, double-blind phases of three studies demonstrated that budesonide inhalation suspension (BIS) is effective and well tolerated in infants and young children (6 months to 8 years of age) with persistent asthma. OBJECTIVE: Open-label, 52-week extensions to these studies were conducted to evaluate long-term safety of BIS, including effects of treatment with the lowest effective dose of BIS on hypothalamic-pituitary-adrenal (HPA)-axis function, as compared with conventional asthma therapy (CAT). Complete results of the earlier phases of the studies and of long-term safety are reported elsewhere; only results pertaining to HPA-axis function are summarized here. METHODS: Patients eligible for the open-label phases of the three trials were randomized to treatment with nebulized BIS (n = 447) or CAT (n = 223). CAT included short-acting oral or inhaled beta2-agonists, methylxanthines, or cromolyn sodium; in two of the studies, CAT could have included other inhaled corticosteroids. HPA-axis function, which had been evaluated during the 12-week double-blind studies, was again evaluated at the beginning and end of the 52-week study period using basal plasma cortisol concentrations and response to stimulation with a 250-microg dose of adrenocorticotropic hormone. RESULTS: There was no evidence of altered HPA-axis function attributable to BIS treatment. No clinically or statistically significant differences in basal or adrenocorticotropic hormone-stimulated plasma cortisol concentrations were observed between BIS and CAT in either the 12-week, double-blind or 52-week, open-label phases of the three studies. CONCLUSIONS: The results indicate that treatment with BIS does not result in clinically significant suppression of HPA-axis function in infants and young children.     

Lymphocyte transformation test with house dust mite (Dermatophagoides pteronyssinus) in normal children, asthmatic children and asthmatic children receiving hyposensitization

In the first part of this study the proliferative response of lymphocytes (lymphocyte transformation test) to house dust mite (HDM) stimulation in cultures was studied in normal children (n= 16), asthmatic children who never received hyposensitization (HS) (n = 50) and asthmatic children receiving HS with HDM for at least 6 months (n = 20). The results are expressed as disintegrations per minute (d.p.m.) and as stimulation index (SI = d.p.m. in the presence of the allergen/d.p.m. in the control culture). A positive SI (> 2) was found in 54% of the asthmatic children who never received HS, in 30% of the asthmatics receiving HS and in none of the normal children. Furthermore, between asthmatics with and without HS, the SI was not statistically different, although asthmatics without HS tended to have a higher SI (median value: 2.13 vs 1.38) (P= 0.10). In a second series of experiments the effect of adding interleukin-2 (IL-2) to the lymphocyte cell culture was studied in asthmatic children with and without HS. Interleukin-2 induced an additional stimulatory effect on the lymphoproliferative response to HDM and to phytohaemagglutinin in patients who never received HS, but had no effect in patients receiving HS. We conclude that HS treatment seems to have an inhibiting effect upon this proliferative response, not only inhibiting the degree of the allergen-induced lymphocyte proliferation, but also inhibiting the sensitivity of proliferating lymphocytes for IL-2. These inhibiting effects upon lymphocytic activation could be responsible for the anti-inflammatory effects (i.e. suppression of the late asthmatic reaction) of HS.     

Comparisons of the complementary effect on exhaled nitric oxide of salmeterol vs montelukast in asthmatic children taking regular inhaled budesonide.

BACKGROUND: Inhaled, long-acting beta2-agonists or antileukotrienes are alternatives as add-on therapy for asthmatic children taking regular inhaled steroids. Any complementary effects would be relevant to the choice between these alternatives. Exhaled nitric oxide (FeNO) may reflect these effects. OBJECTIVE: To compare the control of FeNO provided by salmeterol or montelukast add-on therapy in asthmatic children undergoing regular maintenance treatment with a daily dose of 400 microg of budesonide. METHODS: The study included children with increased FeNO despite regular treatment with budesonide, 400 microg/d, and normal lung function. Montelukast, 5 mg/d, salmeterol, 50 microg twice daily, or placebo was compared as add-on therapy to budesonide, 400 microg, in a randomized, double-blind, double-dummy, crossover study. RESULTS: Twenty-two children completed the trial. The geometric mean FeNO level was 20 ppb (95% confidence interval [CI], 15-27 ppb) after salmeterol, which was significantly higher than after montelukast (mean, 15 ppb; 95% CI, 11-18 ppb; P = 0.002) and placebo (mean, 15 ppb; 95% CI, 10-21 ppb; P = 0.03). There was no difference in FeNO between the montelukast and placebo groups. Mean forced expiratory volume in 1 second (FEV1) was significantly increased after salmeterol (mean, 2.63 L; 95% CI, 2.34-2.91 L) compared with placebo (mean, 2.48 L; 95% CI, 2.19-2.77 L). Montelukast (mean, 2.57 L; 95% CI, 2.33-2.80 L) was no different than placebo. CONCLUSIONS: The FeNO levels were significantly higher after salmeterol add-on treatment compared with both placebo and montelukast add-on treatment. Salmeterol significantly improved lung function (FEV1) compared with placebo and nonsignificantly compared with montelukast. Montelukast failed to reduce FeNO and improve lung function compared with placebo in this group of children taking regular budesonide, 400 microg.     

Local side-effects of inhaled corticosteroids in asthmatic children: influence of drug, dose, age, and device

BACKGROUND: The objective was to investigate the local side-effects of inhaled corticosteroids (ICS) in daily life in asthmatic children, particularly the younger ones, by an observational prospective cross-sectional cohort study. METHODS: Asthmatic children (n=639, 75.9+/-48.9 months, 61.3% boys), treated with beclomethasone dipropionate (BDP) (721.0+/-287.3 microg per day) or budesonide (BUD) (835.5+/-684.9 microg per day) for at least 1 month, were recruited at the time of a scheduled visit. Local side-effects were researched by questionnaire (cough during inhalation, hoarseness, dysphonia, and thirsty feeling) and clinical examination (perioral dermatitis, oral candidiasis, and tongue hypertrophy). RESULTS: Exactly 63.3% of the children aged under 6 years and 59.5% of the older ones reported one local side-effect. Cough (39.7%) was dependent on young age, use of BDP, and mainly use of spacer device, with an OR of 4.7 (95% CI: 2.7-8.2). Thirsty feeling (21.9%) and hoarseness (14.1%) occurred in children using ICS and long-acting beta2-agonists. Dysphonia (11.1%) was favored by high doses of BDP and BUD, and by inhalation from spacer devices or nebulizers. No factor favored oral candidiasis (10.7%). Perioral dermatitis (2.9%) and tongue hypertrophy (0.1%) were associated with nebulization. CONCLUSION: Local side-effects of ICS are common in asthmatic children of all ages, and the device used constitutes the most influential factor.     

High-dose inhaled steroids in the management of asthma A comparison of the effects of budesonide and beclomethasone dipropionate on pulmonary function, symptoms, bronchial responsiveness and the adrenal function

Svendsen UG, Frølund L, Heinig JH, Madsen F, Nielsen NH, Weeke B. High-dose inhaled steroids in the management of asthma. A comparison of the effects of budesonide and beclomethasone dipropionate on pulmonary function, symptoms, bronchial responsiveness and the adrenal function.
The efficacy of budesonide (800 μg b.d.) and beclomethasone dipropionate (750 μg b.d.) in controlling the symptoms of asthma, pulmonary function, bronchial responsiveness to histamine, and adrenal function, was assessed in a double-blind, double-dummy cross-over study of 36 adult chronic asthmatic patients. The patients, the majority of whom were assessed to be affected to a severe degree, were insufficiently controlled in their current regimen of inhaled steroids and/or inhaled and oral bronchodilators. A 2 weeks baseline period preceded 6 weeks of treatment with each of the study drugs. Both treatment groups showed improvements from baseline in clinical assessment of lung function carried out after the first 6 weeks of treatment. No significant differences were seen throughout the entire 12 weeks study, when comparing the effects of the treatments on FEV₁ FVC, PEF or the histamine PC₂₀. Asthma severity, symptom score and inhaled bronchodilator use showed the same results after both treatments. It is concluded that inhalations of budesonide and beclomethasone dipropionate in high doses are equally potent in the treatment of severe asthma. There is no significant influence on the adrenal function and no significant side effects during a period equal to that of the present study.     

Effects of procaterol on arterial blood gas and pulmonary function in asthmatic children

We examined the changes in arterial blood gas, FEV1 and V50 after the inhalation of procaterol on 19 occasions in 16 asthmatic children. The initial value of PaO2 had statistically significant correlation with the initial values of %FEV1 and %V50. PaO2 fell down in 11 out of 19 (57.9%) and remarkably decreased more than 5 mmHg in 6 out of 19 (31.6%). The fall in PaO2 was most significant at 5 min after the inhalation in almost subjects. The changes in PaO2 after the inhalation had good correlation with the initial value of %FEV1 and %V50. The initial values were quite lower in the patients with decreased PaO2 more than 5 mmHg than those with increased PaO2. Severe patients showed statistically low values of the initial PaO2 and %V50 and showed a fall in PaO2 after inhalation compared with moderate patients. An increase in A-aDO2 elicited that deteriorations of V/Q ratio caused a decrease in PaO2 after inhalation. There were no significant changes in heart rates and no complaints of nausea, headache or tremor.     

Treatment with 400 microg of inhaled budesonide vs 200 microg of inhaled budesonide and oral montelukast in children with moderate persistent asthma: randomized controlled trial.

BACKGROUND: Montelukast is reported to be beneficial in asthma as add-on therapy to inhaled corticosteroids and may reduce the need for the latter. OBJECTIVE: To evaluate whether a combination of oral montelukast and 200 microg of inhaled budesonide has comparable efficacy to 400 microg of inhaled budesonide alone in children with moderate persistent asthma. METHODS: In this prospective, blinded, hospital-based randomized controlled trial, 71 children with moderate persistent asthma were randomized to receive either montelukast, 5-mg chewable tablet, with 200 microg of inhaled budesonide or only 400 microg of inhaled budesonide daily for 12 weeks. Baseline and serial measurements of forced expiratory volume in 1 second, peak expiratory flow rate, and Asthma Symptom Score were performed; the frequency and severity of exacerbations were also recorded. RESULTS: Measurements of forced expiratory volume in 1 second, peak expiratory flow rate, and Asthma Symptom Score showed no significant differences between the 2 groups at baseline, during the serial follow-up visits, and at the end of the study. However, children who received montelukast had a greater frequency of exacerbations vs those who did not (33.3% vs 9.1%; P < .01). CONCLUSION: The overall control of asthma with 5 mg of oral montelukast and 200 microg of inhaled budesonide is inferior to that with 400 microg of inhaled budesonide in children with moderate persistent asthma.     

The use of inhaled corticosteroids for persistent asthma in infants and young children.

OBJECTIVE: To review pediatric trials of inhaled corticosteroid (ICS) therapy and summarize data on the pediatric use of devices to facilitate delivery of ICSs. DATA SOURCES: Relevant articles regarding ICS treatment of persistent asthma in children younger than 5 years were identified from MEDLINE and reference lists of review articles. STUDY SELECTION: Key articles were selected by the authors. RESULTS: Clinical trials from the United States and Europe consistently demonstrated that ICS therapy is the most favorable treatment option with regard to safety and efficacy for infants and young children with persistent asthma. This contention is supported by numerous trials of budesonide inhalation suspension in children ranging from 6 months through 8 years of age and data from older children treated with fluticasone propionate. CONCLUSIONS: As the only corticosteroid available in the United States as a nebulized formulation and the only ICS product extensively studied in young children and infants, budesonideinhalation suspension is an appropriate first-line therapy for treatment of persistent asthma in this population.     

Influence of changing from chlorofluorocarbon (CFC)-beclomethasone dipropionate (BDP) to hydrofluoroalkane (HFA)-BDP on pulmonary function in asthmatic children]

The discontinuation of chlorofluorocarbon- beclomethasone dipropionate (CFC-BDP) products has made it necessary to switch to hydrofluoroalkane (HFA)-BDP. We studied the influence of the changing from CFC-BDP to HFA-BDP on pulmonary function in asthmatic children. METHODS: In twenty asthmatic children (mean: 10.5 years of age) who were clinically well-controlled with CFC-BDP for longer than 6 months, CFC-BDP was switched to HFA-BDP, at half the dose of CFC-BDP. We examined the changes in spirometric parameters at 3-6 months after the switch. RESULTS: FEV1.0% ([FEV1.0/FVC]x100) and %V50 ([V50 measured/V50 predicted]x100) were significantly improved (FEV1.0%: pre 81.7+/-4.7-->post 84.1+/-4.1 [p<0.05], % V50: pre 66.9+/-6.9-->post74.4+/-11.3 [p<0.05]). Comparison between patients with greater than 10% improvement in %V50 and those with less than 10% improvement revealed differences in the duration of using CFC-BDP (former 2.8+/-0.9 years, latter 5.2+/-2.4 years [p<0.05]) despite lack of difference in age at initiation of treatment with CFC-BDP. CONCLUSION: The changing from CFC-BDP to HFA-BDP showed the improvement of lung function in a part of asthmatic children. We should keep in mind that there are some differences of efficacy among the inhaled corticosteroid products. The long-term anti-inflammatory medication should be adjusted to normalize the pulmonary function on the basis of the degree of airway inflammation.     

Differences in respiratory symptoms and pulmonary function in children in 2 Saskatchewan communities.

BACKGROUND: Asthma prevalence is known to vary among different geographical regions both nationally and internationally. However, there is limited understanding of the nature of differences within geographical regions. OBJECTIVE: To evaluate the prevalence of asthma in 2 prairie communities and differences in the patterns of respiratory symptoms between the communities. METHODS: A cross-sectional questionnaire survey was sent through schools in Estevan and Swift Current, Saskatchewan, to parents of 2,231 children in grades 1 to 6. Asthma prevalence was determined by questionnaire report of physician-diagnosed asthma. Pulmonary function tests (PFTs) using spirometry were conducted in children in grades 1 to 4. To evaluate respiratory morbidity without the use of a diagnostic label, similar comparisons were made between communities for respiratory symptoms. RESULTS: The overall response rate to the survey questionnaire was 91.3%. The prevalence of ever asthma in Estevan was 21.4% (95% confidence interval [CI], 20.1%-22.7%) compared with 16.2% (95% CI, 15.1%-17.3%) in Swift Current. A higher proportion of girls in Estevan (19.7%; 95% CI, 17.9%-21.5%) compared with girls in Swift Current (12.5%; 95% CI, 11.1%-13.9%) reported a history of asthma. There was no difference found between towns for boys. These findings were supported by findings for respiratory symptoms, including wheeze and cough. For both boys and girls, the forced expiratory flow at 25% to 75% of forced vital capacity and the ratio of forced expiratory volume in 1 second to forced vital capacity were lower in Estevan compared with Swift Current. CONCLUSIONS: Differences in the distribution of childhood asthma can be found within regions. These results are strengthened by PFTs and cannot be fully explained by diagnostic biases.