Biomedical subjects

Kai-Håkon Carlsen

Publications and source records attributed to Kai-Håkon Carlsen.

11 recordsLinked to original sources

PubMed2006

Reduced lung function at birth and the risk of asthma at 10 years of age.

BACKGROUND: Reduced lung function in early infancy has been associated with later obstructive airway diseases. We assessed whether reduced lung function shortly after birth predicts asthma 10 years later. METHODS: We conducted a prospective birth cohort study of healthy infants in which we measured lung function shortly after birth with the use of tidal breathing flow-volume loops (the fraction of expiratory time to peak tidal expiratory flow to total expiratory time [t(PTEF)/t(E)]) in 802 infants and passive respiratory mechanics, including respiratory-system compliance, in 664 infants. At 10 years of age, 616 children (77%) were reassessed by measuring lung function, exercise-induced bronchoconstriction, and bronchial hyperresponsiveness (by means of a methacholine challenge) and by conducting a structured interview to determine whether there was a history of asthma or current asthma. RESULTS: As compared with children whose t(PTEF)/t(E) shortly after birth was above the median, children whose t(PTEF)/t(E) was at or below the median were more likely at 10 years of age to have a history of asthma (24.3% vs. 16.2%, P=0.01), to have current asthma (14.6% vs. 7.5%, P=0.005), and to have severe bronchial hyperresponsiveness, defined as a methacholine dose of less than 1.0 micromol causing a 20% fall in the forced expiratory volume in 1 second (FEV1) (9.1% vs. 4.9%, P=0.05). As compared with children whose respiratory-system compliance was above the median, children with respiratory compliance at or below the median more often had a history of asthma (27.4% vs. 14.8%; P=0.001) and current asthma (15.0% vs. 7.7%, P=0.009), although this measure was not associated with later measurements of lung function. At 10 years of age, t(PTEF)/t(E) at birth correlated weakly with the maximal midexpiratory flow rate (r=0.10, P=0.01) but not with FEV1 or forced vital capacity. CONCLUSIONS: Reduced lung function at birth is associated with an increased risk of asthma by 10 years of age.

Asthma↗

PubMed2006

CFTR gene mutations and asthma in the Norwegian Environment and Childhood Asthma study.

BACKGROUND: Several candidate genes have been implicated in the etiology of asthma, including the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR). Mutations in the CFTR gene result in derangements of mucociliary clearance. Homozygotes for CFTR mutations develop cystic fibrosis (CF), a disorder characterized mainly by lung and pancreas disease. OBJECTIVE: To investigate whether there was an increased frequency of CFTR mutations in asthma patients. METHODS: Seven hundred and three subjects aged 10-11 years from the environment and childhood asthma (ECA) study were included in the present study. Possible associations between asthma, reduced lung function, bronchial hyperresponsiveness (BHR), and increased or decreased nitrogen oxide (NO) levels (based on structural parental interview, spirometry, PD20 methacholine challenge test and exhaled NO measurements), and the five most common CFTR mutations in Norway (DeltaF508, R117H, R117C, 4005+2T-->C, 394delTT), the modulating polymorphisms IVS8(TG)mTn and the IVS8-5T were investigated. RESULTS: No association were found between asthma, reduced lung function, BHR or exhaled NO levels and CF heterozygosity. However, the IVS8(TG)11T7 haplotype was associated with normal lung function. CONCLUSIONS: Our results do not support the hypothesis that CFTR mutations or polymorphisms play a role in the pathogenesis of asthma in children. However, the distribution of Tn(TG)m haplotypes differed between individuals with reduced lung function and individuals with normal lung function.

Asthma↗

PubMed2006

The effect of formoterol inhalation on endurance performance in hypobaric conditions.

INTRODUCTION: Inhaled beta2-agonists are important therapeutic agents for the treatment of exercise-induced asthma in athletes but are restricted by international antidoping regulations. PURPOSE: To investigate whether 18 mug of inhaled formoterol affects endurance performance during running at high altitudes until exhaustion among 20 nonasthmatic male athletes aged 21-35 yr. METHODS: : In a randomized, double-blind, placebo-controlled crossover study, the athletes performed one screening test and two similar performance tests. Each performance test consisted of 20 min of warm-up and a running test until exhaustion, which lasted 210-300 s in hypobaric conditions equal to 2000 m above sea level. Maximal oxygen consumption (VO2max) and peak ventilation (VEpeak) were measured during running, and pulmonary function was measured before and after exercise. The screening test was used to determine running speed on days 2 and 3, with inhaled formoterol or placebo in a randomized manner before exercise. VO2, VE, arterial oxyhemoglobin saturation (SPO2), and heart rate (HR) were measured during exercise, and maximum plasma lactate concentration was measured after exercise. RESULTS: Inhaled formoterol did not improve running time to exhaustion, VO2, VE, SPO2, or HR (P > 0.05) in hypobaric conditions compared with placebo, although formoterol significantly improved lung function (FEV1 and FEF50) 15 and 30 min before exercise and 3, 6, 10, and 15 min after exercise. CONCLUSIONS: Inhaled formoterol did not improve endurance performance in healthy nonasthmatic athletes at hypobaric conditions equal to 2000 m above sea level. Inhaled formoterol can thus be used by asthmatic athletes in sports under extreme conditions.

Administration, Inhalation↗

PubMed2005

Effects of early intake of fruit or vegetables in relation to later asthma and allergic sensitization in school-age children.

AIM: To assess the associations between nutrition supplements in infancy and later asthma and allergy in school-age children, and to explore the impact of environmental factors in early life. METHODS: Five hundred and two children underwent clinical examination, skin prick test and a second parentally completed questionnaire within 2 y of a cross-sectional questionnairebased study, including 4585 primary school children (6-16 y old) in 1994 from urban Oslo (37%), the mountainous area of Hallingdal (42%), and the industrial, coastal area of Odda (21%). The children were selected from the 1994 survey on the basis of reported diagnosed asthma (n=166), wheeze in the last 12 mo (n=155) and no asthma/no wheeze (n=181). Questions were related to nutrition and environmental exposure in early life. Possible associations between allergic sensitization or asthma at school age and exposures were estimated by logistic regression analysis, adjusting for potential confounders. RESULTS: Daily intake of fresh fruit or vegetables, but not extra vitamins or cod liver oil supplements, in infancy decreased the risk of asthma (adjusted odds ratio (aOR) 0.57 (95% confidence interval (CI): 0.37-0.88). Early supplements of cod liver oil and extra vitamins were associated with increased allergic sensitization (aOR 1.78 (95% CI: 1.03-3.07) and 1.71 (95% CI: 1.01-2.88), respectively). A significantly higher prevalence of allergic sensitization was found in children living in Hallingdal compared to Odda, while the latter children, on the other hand, had the highest prevalence of house dust mite allergy (p = 0.001 vs Hallingdal and p = 0.04 vs Oslo). CONCLUSION: The present study suggests that the early introduction of daily fresh fruit or vegetables may decrease the risk of asthma after 1 y of life, whereas allergic sensitization at school age seemed to increase with extra vitamin and cod liver oil supplements during infancy. Living area influenced allergic sensitization, with differences between coastal and inland areas.

Adolescent↗

PubMed2005

Parental smoking and childhood asthma: clinical implications.

Environmental tobacco smoke and constituents are global risks for human health. Considerable evidence shows that environmental tobacco smoke exposure contributes to, and exacerbates, respiratory disorders. This review assesses the causal role of environmental tobacco smoke exposure for childhood respiratory disorders, and in particular asthma. Tobacco smoke and environmental tobacco smoke exposure during pregnancy have an effect upon lung function in newborn infants; exposure after birth also has an effect upon lung function. An effect upon bronchial responsiveness has been suggested but the evidence is not as strong as for lung function. From 1997 to 1999 a comprehensive set of systematic reviews concerning the relationship between exposure to environmental tobacco smoke and respiratory health in children summarized the results from hundreds of published papers. The evidence for a causal relationship between environmental tobacco smoke exposure and asthmatic symptoms on the one hand, and between environmental tobacco smoke exposure and reduction in lung function on the other hand, was quite strong, whereas the evidence between environmental tobacco smoke exposure and development of allergy was much weaker. Here we present an overview of the effects of environmental tobacco smoke exposure on lung health in children. A hypothesis has been put forward regarding upregulation of pulmonary neuroendocrine cells in relationship to mechanisms of tobacco smoke products (TSP)-induced pulmonary disease. It has also been reported that genetic variation makes part of the population especially vulnerable to environmental tobacco smoke exposure during pregnancy. Furthermore, there is a need for intervention to reduce environmental tobacco smoke exposure in young children, by educating parents and adolescents about the health effects of environmental tobacco smoke exposure. Studies are needed to identify possible critical periods when environmental tobacco smoke exposure is more likely to induce harmful effects on lung health in young children in order to implement effective preventive strategies.

Asthma↗

PubMed2005

Pharmaceutical treatment of asthma in children.

The present review article gives an overview of the present treatment modalities of asthma during childhood and discusses the existing controversies in asthma treatment. Present guidelines of asthma treatment concentrate on treatment for adults and only marginally concern treatment of childhood asthma. The few exceptions are the British Scottish guidelines and the Nordic guidelines, which have separate paragraphs on paediatric asthma management. The main controversy in paediatric asthma treatment is that how early (in age) and how soon (after diagnosis of asthma has been established) should inhaled steroids be instituted. Does treatment with early inhaled steroids influence lung development? Also possible side effects of inhaled steroids as possible impact upon growth and effect upon the hypothalamic adrenal axis are discussed. What is the place of leukotriene antagonists in childhood asthma treatment? Other issues discussed are prevention of asthma (primary, secondary and tertiary) in relationship to treatment of asthma. Primary prevention regards preventive measures to be taken to prevent initial allergic diseases; secondary prevention aims at preventing development of further allergic disease after the initial allergic disorder, as preventing debut of asthma after atopic eczema. Tertiary prevention aims at reducing already existing allergic illness and preventing further progression. For asthma, tertiary prevention regards treatment. During later years, there has been a focus on the respiratory tract as a continuum, and how allergic rhinitis and asthma should be treated when they are coexistent. Treating exercise induced asthma optimally is regarded as an important aim in the general treatment of asthma in childhood. Particularly in childhood asthma, compliance (concordance) with treatment is an important issue. Also some controversial aspects of acute asthma treatment in young children are discussed.

Administration, Inhalation↗

PubMed2004

Therapeutic strategies for allergic airways diseases.

Asthma and allergic rhinitis are airways allergic diseases and different aspects of these diseases are discussed in this paper. Both diseases require specific treatment but the airways are a continuum and it has been shown that concomitant treatment in patients suffering from both diseases has a better effect than treating only one of the diseases. Furthermore, treatment of allergic rhinitis in asthmatic patients reduces the risk of hospital admission due to asthma and improves bronchial hyper-responsiveness. Anti-inflammatory therapy, particularly with local steroids, is the single most important treatment for airways allergic diseases. Some studies have shown the importance of starting early after diagnosing asthma but the issue of how early in life to start inhaled steroids is still being debated. Also leukotriene antagonists have been shown to have beneficial effects in many patients and can be used in conjunction with inhaled steroids. Combination therapy with inhaled steroids and inhaled beta(2)-agonists has been shown to be effective in adults but this has not yet been fully documented in children. Optimal treatment of exercise-induced asthma is important to enable children and adolescents to fulfill their developmental possibilities. Allergy vaccination has traditionally been used for treating airways allergic diseases. It is often given for allergic rhinitis when pharmacotherapy is not providing full symptom control. One recent study has suggested that allergy vaccination may possibly help to prevent the development of asthma in the child with allergic rhinitis. More research is needed on asthma allergy vaccination. Concordance with treatment may often be difficult and efforts should be taken to ensure the best concordance possible.

Administration, Inhalation↗

PubMed2004

Dietary prevention of allergic diseases in infants and small children. Part III: Critical review of published peer-reviewed observational and interventional studies and final recommendations.

The role of primary prevention of allergic diseases has been a matter of debate for the last 40 years. In order to shed some light on this issue, a group of experts of the Section of Pediatrics EAACI reviewed critically the existing literature on the subject. An analysis of published peer-reviewed observational and interventional studies was performed following the statements of evidence as defined by WHO. The results of the analysis indicate that breastfeeding is highly recommended for all infants irrespective of atopic heredity. A dietary regimen is unequivocally effective in the prevention of allergic diseases in high-risk children. In these patients breastfeeding combined with avoidance of solid food and cow's milk for at least 4-6 months is the most effective preventive regimen. In the absence of breast milk, formulas with documented reduced allergenicity for at least 4-6 months should be used.

Breast Feeding↗

PubMed2004

Dietary prevention of allergic diseases in infants and small children. Part II. Evaluation of methods in allergy prevention studies and sensitization markers. Definitions and diagnostic criteria of allergic diseases.

The role of primary prevention of allergic disease has been a matter of debate for the last 40 years. In order to shed some light into this issue a group of experts of the Section of Pediatrics EAACI critically reviewed the existing literature on the subject. The design of observational and interventional studies was evaluated with relevance to the important factors influencing outcome of studies on allergy development/prevention. in this analysis the statements of evidence as defined by WHO were applied. Best evidence of recommendations are those fulfilling the criteria for statements category 1 and 2 and grade of recommendations A and B as proposed by WHO. This survey include target group for dietary prevention and methods and diagnostic criteria of atopic dermatitis, asthma and food allergy for prevention studies.

Asthma↗

PubMed2004

Is bronchodilator response in 2-yr-old children associated with asthma risk factors?

Factors that might influence lung function bronchodilator response by 2 yr of age is largely unknown, thus we aimed to assess this in the 'Environment and Childhood asthma' (ECA) study in Oslo. A clinical investigation at mean age 26 months was attended by 516 (84%) children included in a nested case-control study [children with recurrent bronchial obstruction (rBO)] (n = 265) and controls without a history of lower respiratory disease (n = 251). Tidal lung function measures before and after inhaled nebulized salbutamol (bronchodilator response) (when clinically without BO) were obtained in 46%. Clinical characteristics and personal and family history of allergic/respiratory diseases (asthma risk factors) were ascertained by structured interview and clinical examination. Allergic sensitization was assessed by skin prick test/specific IgE antibody analyses to common allergens. Mean (95% CI) per cent change in time to reach peak flow/total expiratory time (t(PTEF)/t(E)) from before to after salbutamol was significantly larger in children with rBO [17.3 (9.4-25.3) than controls (-2.2 (-7.7 to 3.0)]. The bronchodilator response increased significantly (p = 0.001) with increasing number of asthma risk factors, but was not significantly associated with allergic sensitization, parental 'atopy', or maternal smoking alone. Children treated with inhaled corticosteroids had greater bronchodilator response than those treated with bronchodilators alone. Bronchodilator response in asymptomatic 2-yr-old children was most closely associated with the presence of rBO, but increasing number of asthma risk factors and treatment with inhaled corticosteroids were associated with increased bronchodilator response.

Administration, Inhalation↗

PubMed2002

Exercise-induced asthma.

Exercise-induced asthma (EIA) is common in asthmatic children and adolescents. Since it may cause limitations to daily life activities in up to 30%, mastering EIA is important in asthma management. EIA consists of bronchial obstruction occurring immediately, or soon after, physical exercise as a result of increased respiratory water and heat loss due to increased ventilation during exercise, with the subsequent release of mediators and stimulation of airways receptors. Diagnosis is best made by standardised exercise tests, preferably running on a treadmill for 6-8 minutes at an exercise load of 95% of maximum. The sensitivity of the test may be increased by cold air inhalation. EIA is best treated by inhaled steroids in addition to pre-treatment before exercise by inhaled beta(2)-agonists, short or long acting, and/or leukotriene antagonists. Physical training may improve physical fitness and quality of life in asthmatic children but baseline lung function and bronchial responsiveness are not improved.

Adolescent↗