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.Peer reviewe

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 hyper-responsiveness (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. (C) 2019 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.Peer reviewe

Expiratory variability index is associated with asthma risk, wheeze and lung function in infants with recurrent respiratory symptoms

Non peer reviewe

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

Nocturnal Heart Rate Variability Spectrum Characterization in Preschool Children with Asthmatic Symptoms

Asthma is a chronic lung disease that usually develops during chilhood. Despite that symptoms can almost be controlled with medication, early diagnosis is desirable in order to reduce permanent airway obstruction risk. It has been suggested that abnormal parasympathetic nervous system (PSNS) activity might be closely related with the pathogenesis of asthma, and that this PSNS activity could be reflected in cardiac vagal control. In this work, an index to measure the spectral regularity of the high frequency (HF) component of heart rate variability (HRV) spectrum, named peakness (P), is proposed. Three different implementations of P, based on electrocardiogram (ECG) recordings, impedance pneumography (IP) recordings and a combination of both, were employed in the characterization of a group of pre-school children classified attending to their risk of developing asthma. Peakier componentswere observed in the HF band of those children classified as high-risk (p < 0.005), who also presented reduced sympathvoagal balance. Results suggest that high-risk of developing asthma might be related with a lack of adaptability of PSNS

Heart Rate Variability Analysis in Risk of Asthma Stratification

Early diagnosis of asthma is crucial to avoid long-term effects such as permanent airway obstruction. Pathogenesis of asthma has been related with autonomic nervous system (ANS) dysfunction, concretely with abnormal parasympathetic activity. As heart rate variability (HRV) analysis does reflect ANS activity, it has been employed here in risk of asthma stratification

Serum soluble T-H cell activity markers and high-sensitivity C-reactive protein in multiple-trigger wheezers

Peer reviewe

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-CRPemediated low-grade systemic inflammation is rare in early childhood wheezing. (C) 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.Peer reviewe

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 (CAIN). Asthma control was evaluated with the Childhood Asthma Control Test (C-ACT), short-acting beta(2)-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. (C) 2018 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.Peer reviewe