The link between early childhood lower airway symptoms, airway hyperresponsiveness, and school-age lung function.

BACKGROUND: The role of early airway hyperresponsiveness (AHR) in the lung function of school-age children is currently unclear. OBJECTIVE: To conduct a prospective follow-up study of lung function in schoolchildren with a history of lower airway symptoms and AHR to methacholine in early childhood and to compare the findings to schoolchildren with no previous or current lung diseases. We also explored symptoms and markers of type 2 inflammation. METHODS: In 2004 to 2011, data on atopic markers, lung function, and AHR to methacholine were obtained from 193 symptomatic children under 3 years old. In 2016 to 2018, a follow-up sample of 84 children (median age, 11 years; IQR, 11-12) underwent measurements of atopic parameters, lung function, and AHR to methacholine. Moreover, in 2017 to 2018, 40 controls (median age, 11 years; IQR, 9-12) participated in the study. RESULTS: Schoolchildren with early childhood lower airway symptoms and increased AHR had more frequent blood eosinophilia than their peers without increased AHR and lower prebronchodilator forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity Z-scores than those without increased AHR and controls. Post-bronchodilator values were not significantly different between the two AHR groups. Atopy in early childhood (defined as atopic eczema and at least 1 positive skin prick test result) was associated with subsequent lung function and atopic markers, but not AHR. CONCLUSION: In symptomatic young children, increased AHR was associated with subsequent obstructive lung function, which appeared reversible by bronchodilation, and blood eosinophilia, indicative of type 2 inflammation.

The continuous laryngoscopy exercise test in severe or in difficult-to-treat asthma in adults: a systematic review.

OBJECTIVE: A systematic review was performed to determine if the continuous laryngoscopy exercise test (CLE) has been used in the diagnostics of exercise dyspnea in adults with asthma, and whether inducible laryngeal obstruction (ILO) is found in those with asthma or with severe or difficult-to-treat asthma. DATA SOURCES: We used Scopus and PubMed databases. The articles published up to 13 August 2019 were considered. STUDY SELECTIONS: We excluded manuscripts that did not contain information about adult patients with asthma. We included six studies from 59 search results in Scopus and none from the 17 search results in PubMed. RESULTS: The articles included 455 study individuals. Of these, 229 (50.3%) had diagnosed asthma or were treated with asthma medication. Altogether 31/229 (13.5%) subjects with diagnosis of asthma or previous asthma treatment had exercise-induced laryngeal obstruction (EILO) as comorbidity. The CLE test was performed on 229 patients with asthma. The method was used only for differential diagnosis of exercise-induced dyspnea to confirm EILO. At least 10/455 (2.2%) out of the 455 subjects experienced adverse events. CONCLUSIONS: This systematic review revealed that only a small proportion of patients with asthma had undergone the CLE test to assess exercise-induced dyspnea. None of the selected manuscripts reported severity of asthma. Whether CLE provides a valuable diagnostic tool for patients with severe or difficult-to-treat asthma cannot be determined according to this review.

Overweight and exercise-induced bronchoconstriction - Is there a link?

BACKGROUND: The objective of this study was to evaluate the role of body mass index with regard to exercise performance, exercise-induced bronchoconstriction (EIB), and respiratory symptoms in 7- to 16-year-old children. METHODS: A total of 1120 outdoor running exercise challenge test results of 7- to 16-year-old children were retrospectively reviewed. Lung function was evaluated with spirometry, and exercise performance was assessed by calculating distance per 6 minutes from the running time and distance. Respiratory symptoms in the exercise challenge test were recorded, and body mass index modified for children (ISO-BMI) was calculated for each child from height, weight, age, and gender according to the national growth references. RESULTS: Greater ISO-BMI and overweight were associated with poorer exercise performance (P < .001). In addition, greater ISO-BMI was independently associated with cough (P = .002) and shortness of breath (P = .012) in the exercise challenge. However, there was no association between ISO-BMI and EIB or with wheeze during the exercise challenge. CONCLUSION: Greater ISO-BMI may have a role in poorer exercise performance and appearance of respiratory symptoms during exercise, but not in EIB in 7- to 16-year-old children.

Airway hyperresponsiveness in young children with respiratory symptoms: A five-year follow-up.

BACKGROUND: Recurrent wheezing in early life is transient in most children. The significance of airway hyperresponsiveness (AHR) in persistence of respiratory symptoms from infancy to early childhood is controversial. OBJECTIVE: We evaluated whether AHR in wheezy infants predicts doctor-diagnosed asthma (DDA) or AHR at the age of 6 years. METHODS: Sixty-one wheezy infants (age 6-24 months) were followed up to the median age of 6 years. Lung function and AHR with methacholine challenge test were assessed at infancy and 6 years. The exercise challenge test was performed at the age of 6 years. Atopy was assessed with skin prick tests. RESULTS: At 6 years, 21 (34%) of the children had DDA. Children with DDA had higher logarithmic transformed dose-response slope (LOGDRS) to methacholine in infancy than children without DDA (0.047 vs 0.025; P = .033). Furthermore, AHR to methacholine in infancy and at 6 years were associated with each other (r = 0.324, P = .011). Children with exercise-induced bronchoconstriction (EIB) at 6 years were more reactive to methacholine in infancy than those without EIB (P = .019). CONCLUSION: Increased AHR in symptomatic infants was associated with increased AHR, DDA, and EIB at median the age of 6 years, suggesting early establishment of AHR.

Small airway function in children with mild to moderate asthmatic symptoms.

BACKGROUND: Clinical significance of small airway obstruction in mild pediatric asthma is unclear. OBJECTIVE: To evaluate small airway properties in children with mild to moderate asthmatic symptoms and the association of small airway function with asthma control and exercise-induced bronchoconstriction (EIB). METHODS: Children (5-10 years old) with recurrent wheezing (n = 42) or persistent troublesome cough (n = 16) and healthy controls (n = 19) performed impulse oscillometry (IOS), spirometry, and a multiple-breath nitrogen washout (MBNW) test. Exhaled nitric oxide (NO) was measured at multiple flow rates to determine alveolar NO concentration (Calv). Asthma control was evaluated with the Childhood Asthma Control Test (C-ACT), short-acting ß2-agonist (SABA) use within the past month, and asthma exacerbations within the past year. RESULTS: IOS, spirometry, and exhaled NO indexes that are related to small airway function differed between children with recurrent wheezing and healthy controls, whereas only forced expiratory flow at 25% to 75% of the forced vital capacity was associated with persistent cough. The MBNW indexes showed no difference between the groups. Among symptomatic children, conducting airway ventilation inhomogeneity and Calv were associated with asthma exacerbations (P = .03 and P = .002, respectively), and lung clearance index and Calv were associated with EIB (P = .04 and P = .004, respectively). None of the proposed small airway indexes was associated with the C-ACT score or SABA use. CONCLUSION: Subtle changes were observed in the proposed small airway indexes of IOS, spirometry, and exhaled NO among children with mild to moderate recurrent wheezing. Small airway dysfunction, expressed as ventilation inhomogeneity indexes and Calv, was also associated with asthma exacerbations and EIB.

Abnormal lung function at preschool age asthma in adolescence?

BACKGROUND: Asthma often begins early in childhood. However, the risk for persistence is challenging to evaluate. OBJECTIVE: This longitudinal study relates lung function assessed with impulse oscillometry (IOS) in preschool children to asthma in adolescence. METHODS: Lung function was measured with IOS in 255 children with asthma-like symptoms aged 4-7 years. Baseline measurements were followed by exercise challenge and bronchodilation tests. At age 12-16 years, 121 children participated in the follow-up visit, when lung function was assessed with spirometry, followed by a bronchodilation test. Asthma symptoms and medication were recorded by a questionnaire and atopy defined by skin prick tests. RESULTS: Abnormal baseline values in preschool IOS were significantly associated with low lung function, the need for asthma medication, and asthma symptoms in adolescence. Preschool abnormal R5 at baseline (z-score ≥1.645 SD) showed 9.2 odds ratio (95%CI 2.7;31.7) for abnormal FEV1/FVC, use of asthma medication in adolescence, and 9.9 odds ratio (95%CI 2.9;34.4) for asthma symptoms. Positive exercise challenge and modified asthma-predictive index at preschool age predicted asthma symptoms and the need for asthma medication, but not abnormal lung function at teenage. CONCLUSION: Abnormal preschool IOS is associated with asthma and poor lung function in adolescence and might be utilised for identification of asthma persistence.

Influence of mouthwashes on extended exhaled nitric oxide (FENO) analysis.

Fractional exhaled nitric oxide (FENO) is used to assess eosinophilic inflammation of the airways. FENO values are influenced by the expiratory flow rate and orally produced NO. We measured FENO at four different expiratory flow levels after two different mouthwashes: tap water and carbonated water. Further, we compared the alveolar NO concentration (CANO), maximum airway NO flux (J'awNO) and airway NO diffusion (DawNO) after these two mouthwashes. FENO was measured in 30 volunteers (healthy or asthmatic) with a chemiluminescence NO-analyser at flow rates of 30, 50, 100 and 300 mL/s. A mouthwash was performed before the measurement at every flow rate. The carbonated water mouthwash significantly reduced FENO compared to the tap water mouthwash at all expiratory flows: 50 mL/s (p < .001), 30 mL/s (p = .001), 100 mL/s (p < .001) and 300 mL/s (p = .004). J'awNO was also significantly reduced (p = .017), however, there were no significant differences in CANO and DawNO. In conclusion, a carbonated water mouthwash can significantly reduce oropharyngeal NO compared to a tap water mouthwash at expiratory flows of 30-300 mL/s without affecting the CANO and DawNO. Therefore, mouthwashes need to be taken into account when comparing FENO results.

Vitamin D, high-sensitivity C-reactive protein, and airway hyperresponsiveness in infants with recurrent respiratory symptoms.

BACKGROUND: Vitamin D insufficiency might be associated with biased T-cell responses resulting in inflammatory conditions such as atopy and asthma. Little is known about the role of vitamin D in low-grade systemic inflammation and airway hyperresponsiveness (AHR) in young children. OBJECTIVE: To evaluate whether vitamin D insufficiency and increased serum high-sensitivity C-reactive protein (hs-CRP) are linked to AHR in symptomatic infants. METHODS: Seventy-nine infants with recurrent or persistent lower respiratory tract symptoms underwent comprehensive lung function testing and a bronchial methacholine challenge test. In addition, skin prick tests were performed and serum 25-hydroxyvitamin D (S-25-OHD), hs-CRP, total immunoglobulin E, and blood eosinophil levels were determined. RESULTS: S-25-OHD was lowest in infants with blood eosinophilia and AHR (n = 10) compared with those with eosinophilia only (n = 6) or AHR only (n = 50) or those with neither (n = 13; P = .035). Moreover, vitamin D insufficiency (S-25-OHD <50 nmol/L) was most common in infants with blood eosinophilia and AHR (P = .041). Serum hs-CRP was lower in infants with recurrent physician-diagnosed wheezing (P = .048) and in those with blood eosinophilia (P = .015) than in infants without these characteristics and was not associated with S-25-OHD or AHR. S-25-OHD levels were significantly lower (median 54 nmol/L) during the autumn-winter season than in the spring-summer season (median 63 nmol/L; P = .026). CONCLUSION: Vitamin D insufficiency could underlie eosinophilia and AHR in infants with troublesome lung symptoms, whereas hs-CRP-mediated low-grade systemic inflammation is rare in early childhood wheezing.

Tidal flow variability measured by impedance pneumography relates to childhood asthma risk.

Lung function variability is a fundamental feature of asthma but has been difficult to quantify in children due to methodological limitations. We assessed the feasibility and clinical implications of overnight flow variability measurement at home using impedance pneumography in young children.44 children aged 3-7 years with recurrent or persistent lower airway symptoms were recruited. Patients were divided into high- or lower-risk groups (HR and LR groups) based on their risk of asthma (modified Asthma Predictive Index), and a third group was formed of children who had a history of wheeze and who were treated with inhaled corticosteroids (ICS group). Tidal volume and the derived flow were recorded through skin electrodes using impedance pneumography at home during sleep. Quantities describing overnight change in expiratory flow-volume minimum curve shape correlation (CSRmin) and respiratory chaoticity (minimum noise limit (NLmin)) were derived.Recordings were successful in 34 children. CSRmin differed between the HR and LR groups (p=0.002) and between the HR and ICS groups (p=0.003), indicating a stronger change in flow profile shape in the HR group. NLmin differed between the HR and LR groups (p=0.014), indicating momentarily lowered chaoticity in the HR group.Impedance pneumography was found feasible for quantifying nocturnal lung function variability and the measured variability was associated with risk of asthma in young children.

Lung function, airway remodeling, and inflammation in infants: outcome at 8 years.

BACKGROUND: Associations between early deficits of lung function, infant airway disease, and outcome at school age in symptomatic infants are still unclear. OBJECTIVE: To report follow-up data on a unique cohort of children investigated invasively in infancy to determine predictive value of airway disease for school-aged respiratory outcomes. METHODS: Fifty-three infants previously studied using bronchoscopy and airway conductance were approached at 8 years of age. Symptoms, lung volumes, and airway responsiveness were reassessed. Data on lifetime purchase of asthma medication were obtained. Lung function was compared with that of 63 healthy nonasthmatic children. RESULTS: Forty-seven children were reevaluated. Physician-diagnosed asthma was present in 39 children (83%). Twenty-five children (53%) had current and 14 children (30%) had past asthma. No pathologic feature in infancy correlated with any outcome parameter. As expected, study children had significantly reduced lung function and increased airway responsiveness compared with healthy controls, and very early symptoms were risk factors for reduced lung function. Current asthma was associated with reduced infant lung function and parental asthma. Reduced lung function in infancy was associated with purchase of inhaled corticosteroids when 6 to 8 and 0 to 8 years of age. CONCLUSION: The lack of predictive value of any pathologic measure in infancy, reported here for the first time to our knowledge, demonstrates that pathologic processes determining the inception of asthma, which are as yet undescribed, are different from the eosinophilic inflammation associated with ongoing disease.

Assessing direct and indirect airway hyperresponsiveness in children using impulse oscillometry.

BACKGROUND: Airway hyperresponsiveness (AHR) is a hallmark of asthma but its assessment is usually restricted to older children who are capable of performing the maneuvers involved in spirometry. In younger children, a feasible option to perform the lung function measurement is impulse oscillometry (IOS), which requires less cooperation. OBJECTIVE: To evaluate whether assessment of AHR by IOS could differentiate children with various obstructive symptoms from one another. METHODS: One hundred twenty-one children (median age 6.0 years, range 3.7-8.1 years) were examined: 31 with probable asthma characterized by current troublesome lung symptoms, 61 with a history of early wheezing disorder (recurrent wheezing ≤24 months of age), 15 with a history of bronchopulmonary dysplasia, and 14 healthy controls. Indirect AHR was assessed by exercise and mannitol challenge tests, and direct AHR was assessed with methacholine using IOS. AHR to exercise was defined as an increase of at least 40% in respiratory resistance at 5 Hz. In the mannitol and methacholine challenges, the dose causing an increase of 40% in respiratory resistance at 5 Hz was calculated. RESULTS: AHR to exercise was good at differentiating children with current troublesome lung symptoms from those in the other groups (P < .001). AHR to methacholine separated children with current troublesome lung symptoms, early wheezing disorder, and bronchopulmonary dysplasia from the controls (P < .001), whereas the mannitol test did not distinguish among the study groups (P = .209). CONCLUSION: The methacholine and exercise challenge tests with IOS identify children with probable asthma characterized by troublesome lung symptoms and therefore may represent a practical aid in the evaluation of AHR in young children.

Maternal smoking affects lung function and airway inflammation in young children with multiple-trigger wheeze.

BACKGROUND: Exposure to tobacco smoke is a well-known risk factor for childhood asthma and reduced lung function, but the effect on airway inflammation in preschool-aged children is unclear. OBJECTIVE: To examine the effect of parental smoking on lung function and fractional concentration of exhaled nitric oxide (Feno) in relation to both parental reports and children's urine cotinine concentrations in preschool-aged children with multiple-trigger wheeze. METHODS: A total of 105 3- to 7-year-old children with multiple-trigger wheeze and lung function abnormalities were recruited. Lung function was assessed by impulse oscillometry, and Feno measurements were performed. Exposure to tobacco smoke was determined by parental reports and measurement of children's urinary cotinine concentrations. RESULTS: Forty-three percent of the children were exposed to environmental tobacco smoke according to parental reports. The Feno level was significantly higher in children with a smoking mother (n = 27) than in children with a nonsmoking mother (23.4 vs 12.5 ppb, P = .006). The Feno level expressed as z score and the cotinine level correlated significantly (P = .03). Respiratory resistance at 5 Hz was higher in children exposed to maternal smoking than in others (0.99 vs 0.88 kPas/L, P = .005). Urinary cotinine concentrations reflected well parental reports on their daily smoking and increased relative to the number of cigarettes smoked in the family (P < .01). Atopy was found in 75% of the children, but it was not associated with the Feno value (P = .65). CONCLUSION: Maternal smoking was associated with increased Feno value and poorer lung function in steroid-naive preschool children with multiple-trigger wheeze. Larger controlled trials are needed to generalize the results.

Diagnosing new-onset asthma in a paediatric clinical trial setting in school-age children.

Asthma is a common chronic disease in children. It is a dynamic condition-symptoms change over time, and the outcome of diagnostic tests can vary. Consequently, evaluating the onset of asthma at a single point in time, perhaps when patients are asymptomatic with limited impairment of the lung function, may result in false diagnostic conclusions. The absence of consistent gold-standard diagnostic criteria in children challenges the ability of any study to ascertain an effect of treatment on asthma prevention. A comprehensive review of the diagnostic criteria used for new-onset asthma in school-age children was conducted based on existing recommendations from published clinical guidance, alongside evidence from paediatric asthma prevention trials. Findings from the review were used to propose suggestions for diagnosing new-onset asthma in future asthma prevention trials. Despite an overall lack of consensus in the published clinical guidance, there are similarities between the various recommendations for diagnosing asthma in children, which typically involve assessing the variable symptoms and supplementing the medical history with objective measures of lung function. For future paediatric asthma prevention trials, we suggest that paediatric clinical trials should use a new-onset asthma definition that incorporates the concepts of "possible", "probable" and "confirmed" asthma. "Possible" asthma would capture self-reported features of chronic symptoms and symptom relief with ß2-agonist bronchodilator (suggesting reversibility). "Probable" asthma would include symptom chronicity, self-reported symptom relief with ß2-agonist bronchodilator, and objective features of asthma (reversibility or bronchial hyper-responsiveness). A "confirmed" diagnosis would be made only if there is a positive response to controller therapy. These suggestions aim to improve the diagnosis of new-onset childhood asthma in clinical trials, which will be useful in the design and conduct of future paediatric asthma prevention trials.

Salbutamol Easyhaler provides non-inferior relief of methacholine induced bronchoconstriction in comparison to Ventoline Evohaler with spacer: A randomized trial.

BACKGROUND: Salbutamol is a cornerstone for relieving acute asthma symptoms, typically administered through a pressurized metered-dose inhaler (pMDI). Dry powder inhalers (DPIs) offer an alternative, but concerns exist whether DPIs provide an effective relief during an obstructive event. OBJECTIVE: We aimed to show non-inferiority of Salbutamol Easyhaler DPI compared to pMDI with spacer in treating methacholine-induced bronchoconstriction. Applicability of Budesonide-formoterol Easyhaler DPI as a reliever was also assessed. METHODS: This was a randomized, parallel-group trial in subjects sent to methacholine challenge (MC) test for asthma diagnostics. Participants with at least 20 % decrease in forced expiratory volume in 1 s (FEV1) were randomized to receive Salbutamol Easyhaler (2 × 200 µg), Ventoline Evohaler with spacer (4 × 100 µg) or Budesonide-formoterol Easyhaler (2 × 160/4.5 µg) as a reliever. The treatment was repeated if FEV1 did not recover to at least -10 % of baseline. RESULTS: 180 participants (69 % females, mean age 46 yrs [range 18-80], FEV1%pred 89.5 [62-142] %) completed the trial. Salbutamol Easyhaler was non-inferior to pMDI with spacer in acute relief of bronchoconstriction showing a -0.083 (95 % LCL -0.146) L FEV1 difference after the first dose and -0.032 (-0.071) L after the last dose. The differences in FEV1 between Budesonide-formoterol Easyhaler and Salbutamol pMDI with spacer were -0.163 (-0.225) L after the first and -0.092 (-0.131) L after the last dose. CONCLUSION: The study confirms non-inferiority of Salbutamol Easyhaler to Ventoline Evohaler with spacer in relieving acute bronchoconstriction, making Easyhaler a sustainable and safe reliever for MC test and supports its use during asthma attacks.

The effect of montelukast on respiratory symptoms and lung function in wheezy infants.

Our aim was to investigate the effectiveness of montelukast in recurrently wheezy infants. We randomised 113, 6-24-month-old children with recurrent wheezing to receive either placebo or montelukast daily for an 8-week period. The primary end-point was symptom-free days. The secondary aims were to evaluate the effect of montelukast on rescue medication, on lung function, airway responsiveness and exhaled nitric oxide fraction (FeNO). Clinical response and FeNO were determined, the functional residual capacity (FRC) and specific airway conductance (sGaw) were measured using an infant whole-body plethysmograph, the maximal flow at functional residual capacity (V'max,FRC) was recorded using the squeeze technique and airway responsiveness was evaluated by performing a dosimetric methacholine challenge test. There was no significant difference in changes in weekly symptom-free days between the montelukast and the placebo group (3.1-3.7 days versus 2.7-3.1 days, p = 0.965). No significant differences were detected in the secondary end-points, i.e. use of rescue medication, FRC, sGaw, V'max,FRC, FeNO or airway responsiveness between groups. Montelukast therapy did not influence the number of symptom-free days, use of rescue medication, lung function, airway responsiveness or airway inflammation in recurrently wheezy, very young children.

Factors associated with elevated exhaled nitric oxide fraction in infants with recurrent respiratory symptoms.

Exhaled nitric oxide fraction (F(eNO)) has been proposed as a noninvasive marker of eosinophilic bronchial inflammation in active asthma, and supposed to reflect responsiveness to corticosteroid therapy. There are several factors influencing F(eNO), and its role in early childhood respiratory disorders needs to be established. Between 2004 and 2008, 444 children aged <3 yrs with recurrent lower respiratory tract symptoms were referred to a tertiary centre for further investigation. 136 full-term, steroid-free, infection-free infants, median age of 16.4 months (range 4.0-26.7 months), successfully underwent measurement of F(eNO), lung function tests, and a dosimetric methacholine challenge test. The median level of F(eNO) was 19.3 ppb (interquartile range 12.3-26.9 ppb). Elevated F(eNO) (≥ 27 ppb, the highest quartile) was associated with maternal history of asthma (adjusted OR 3.2, 95% CI 1.3-8.1; p=0.012), and increased airway responsiveness (the provocative dose of methacholine causing a 40% fall in maximal expiratory flow at functional residual capacity ≤ 0.30 mg) (adjusted OR 4.1, 95% CI 1.4-12.7; p=0.012). Atopy, blood eosinophilia and lung function were not associated with elevated F(eNO). In conclusion, maternal history of asthma, and increased airway responsiveness are associated with elevated F(eNO) in infants with recurrent lower respiratory tract symptoms.

Very low birth weight and respiratory outcome: association between airway inflammation and hyperresponsiveness.

BACKGROUND: The respiratory outcomes after preterm birth have changed, and it is unclear whether increased airway hyperresponsiveness (AHR) later in childhood is associated with airway inflammation. OBJECTIVE: To investigate the association between AHR and fractional exhaled nitric oxide (FeNO), including the alveolar concentration of nitric oxide, in school-age children with very low birth weight (VLBW). METHODS: Twenty-nine children with VLBW, 33 children with a history of early wheeze, and 60 healthy controls underwent a FeNO measurement and bronchial challenge test with histamine. Atopy was assessed with skin prick tests. RESULTS: Children with VLBW had well-preserved baseline lung function but significantly increased AHR, expressed as the dose response slope (P < .001). Geometric mean FeNO levels were similar between VLBW children and healthy controls, and a history of bronchopulmonary dysplasia had no effect. In the VLBW and early wheeze groups, AHR was associated with FeNO (r = 0.47, P = .01, and r = 0.43, P = .013, respectively), but in a stratified analysis, this association was significant only in atopic individuals. By using the multiple flow FeNO technique, the bronchial nitric oxide flux rather than alveolar nitric oxide concentrations were associated with AHR in both children with early wheeze and VLBW. CONCLUSION: We conclude that in VLBW children AHR is related to FeNO but only in atopic individuals. Similar to children with early wheeze, this association is dependent on bronchial flux rather than alveolar nitric oxide concentration. It is likely that AHR is modified by atopic inflammation rather than by inflammatory process due to prematurity.

Subtypes of Adult-Onset Asthma at the Time of Diagnosis: A Latent Class Analysis.

INTRODUCTION: Only a few previous studies have investigated the subtypes of adult-onset asthma. No previous study has assessed whether these subtypes are different between men and women, or whether these subtypes have different risk factors. METHODS: We applied latent class analyses to the Finnish Environment and Asthma Study population, including 520 new cases of adult-onset asthma. We formed subtypes separately between women and men and analyzed the following determinants as potential predictors for these subtypes: age, body mass index, smoking, and parental asthma. RESULTS: Among women, the subtypes identified were: 1. Moderate asthma, 2. Cough-variant asthma, 3. Eosinophilic asthma, 4. Allergic asthma, and 5. Difficult asthma. Among men, the subtypes were: 1. Mild asthma, 2. Moderate asthma, 3. Allergic asthma, and 4. Difficult asthma. Three of the subtypes were similar among women and men: Moderate, Allergic, and Difficult asthma. In addition, women had two distinct subtypes: Cough-variant asthma, and Eosinophilic asthma. These subtypes had different risk factor profiles, e.g., heredity was important for Eosinophilic and Allergic asthma (RR for Both parents having asthma in Eosinophilic 3.55 (1.09 to 11.62)). Furthermore, smoking increased the risk of Moderate asthma among women (RR for former smoking 2.21 (1.19 to 4.11)) and Difficult asthma among men but had little influence on Allergic or Cough-variant asthma. Conclusion: This is an original investigation of the subtypes of adult-onset asthma identified at the time of diagnosis. These subtypes differ between women and men, and these subtypes have different risk factor profiles. These findings have both clinical and public health importance for the etiology, prognosis, and treatment of adult-onset asthma.

Salmeterol and fluticasone in young children with multiple-trigger wheeze.

BACKGROUND: Treatment guidelines recommend using an inhaled corticosteroid (ICS) plus a long-acting ß(2)-agonist (LABA) for childhood asthma when the symptoms are not controlled by ICS alone, but the appropriate use of LABAs in children continues to be debated. OBJECTIVE: To compare the efficacy of an inhaled salmeterol and fluticasone propionate combination, 50/100 µg twice daily, with fluticasone propionate, 100 µg twice daily, or salmeterol, 50 µg twice daily, in children with multiple-trigger wheeze. METHODS: A total of 105 children 4 to 7 years of age with multiple-trigger wheezing based on respiratory symptoms and bronchodilator responsiveness and/or exercise-induced bronchoconstriction without a viral cold were randomized to salmeterol-fluticasone, fluticasone propionate alone, or salmeterol alone via a metered-dose inhaler and a spacer device for 8 weeks. The primary efficacy outcome was exhaled nitric oxide level. Secondary outcomes were lung function measurements via impulse oscillometry, respiratory symptoms, and rescue medication use. RESULTS: The exhaled nitric oxide levels decreased after all treatments, significantly more so after salmeterol-fluticasone and fluticasone than with salmeterol (adjusted geometric means at 8 weeks: salmeterol-fluticasone, 9.4 ppb; fluticasone, 9.3 ppb; salmeterol, 13.9 ppb; salmeterol-fluticasone vs salmeterol, P = .02; fluticasone vs salmeterol, P = .01). No treatment differences were found with respect to respiratory symptoms or median rescue use. Salmeterol-fluticasone resulted in a small but statistically significant improvement in baseline lung function compared with fluticasone. All treatments were equally well tolerated. CONCLUSION: The effects of salmeterol-fluticasone and fluticasone were comparable, although lung function improvement was better with salmeterol-fluticasone than with fluticasone alone. There is no obvious benefit in initiation therapy with salmeterol-fluticasone rather than fluticasone alone in the treatment of steroid-naive children with multiple-trigger wheeze. TRIAL REGISTRATION: Pathway of clinical trial registry of Helsinki University:http://www.hus.fi/?Path=1;28;2530;9899;9900;23618;23903;33578.