Oxidative stress and genetic and epidemiologic determinants of oxidant injury in childhood asthma

BACKGROUND: The factors contributing to the oxidant/antioxidant imbalance in asthma are incompletely understood. OBJECTIVE: To determine the factors associated with oxidative stress including asthma severity and the genotype of the antioxidant enzymes. METHODS: A total of 196 children with mild asthma, 116 children with moderate-severe asthma, and 2 healthy control groups (187 and 68 children) were included in the study. Plasma levels of malondialdehyde were measured as the indicator of oxidative stress, and reduced glutathione levels as the indicator of antioxidant defense. Children were genotyped for null variants of glutathione S transferase (GST) T1 and GSTM1, and ile105val variant of GSTP1. Risk factors were analyzed with multivariate logistic regression. RESULTS: Systemic levels of malondialdehyde increased and reduced glutathione levels decreased significantly from healthy controls to patients with mild asthma and then to patients with moderate-severe asthma (P < .001 for each). Multivariate logistic regression identified asthma and asthma severity as independent factors associated with oxidative stress (odds ratio between 17 and 56; P < .001). Children with asthma with GSTP1 val/val genotype had higher malondialdehyde and lower glutathione levels compared with other genotypes (P = .023 and P = .014, respectively). GSTP1 val/val genotype was independently associated with asthma severity (odds ratio, 4.210; 95% CI, 1.581-11.214; P = .004). CONCLUSION: Our study indicates the presence of a strong oxidative stress in children with asthma that increases with the severity of the disease. In this population, val/val genotype at GSTP1 ile105val locus may be an important factor in determining the degree of oxidant injury. CLINICAL IMPLICATIONS: Children with asthma with val/val genotype at GSTP1 ile105val locus may be good candidates for supplemental antioxidant therapy.     

The polymorphisms of interleukin 17A (IL17A) gene and its association with pediatric asthma in Taiwanese population

Background:  The interleukin 17A ( IL17A ) gene, located on chromosome 6p and linked to asthma phenotype, is a highly potential candidate gene conferring asthma susceptibility. The purpose of this study was to investigate the genetic association between single nucleotide polymorphisms (SNPs) of IL17A and asthma in Taiwanese children.
Methods:  We selected and performed genotyping on nine SNPs that encompass the genomic region of IL17A in Taiwanese children with or without asthma. A total of 1939 subjects containing 1027 subjects in testing group and 931 subjects in validation group were recruited in this study.
Results:  After Bonferroni correction, SNP rs8193036 was found to have a weak association ( P  = 0.0074 × 9 = 0.066) in genotype frequency test. This association was confirmed by validation group. Logistic regression adjusted allergy comorbidity and gender showed a slightly weaker association.
Conclusions:  The results indicated an independent role of IL17A promoter polymorphism rs8193036 in the association with pediatric asthma in Taiwanese population.     

Ambient ozone modifies the effect of tumor necrosis factor G-308A on bronchitic symptoms among children with asthma

Background:  Tumor necrosis factor (TNF)-α has a recognized role in respiratory pathophysiology. One genetic variant (G-308A) in the promoter region affecting the expression of this cytokine may contribute to airway inflammatory diseases, but the studies on bronchitic symptoms were still inconclusive. Because ozone produces oxidative stress, increased airway TNF, and inflammation, the associations of the TNF-308 polymorphism with bronchitic symptoms may vary by ambient ozone exposure.
Methods:  We studied associations of TNF-308 genotype with bronchitic symptoms among asthmatic children in Children's Health Study. The association of TNF G-308A polymorphism with bronchitic symptoms was investigated and we also determined whether the associations vary with ambient ozone exposure.
Results:  Asthmatic children with TNF-308 GG genotype had a significantly reduced risk of bronchitic symptoms with low-ozone exposure (adjusted OR: 0.53; 95% CI: 0.31–0.91). The risk was not reduced in children living in high-ozone communities (adjusted OR: 1.42; 95% CI: 0.75–2.70). This difference in genotypic effects between low- and high-ozone environments was statistically significant among asthmatics ( P for interaction = 0.01), but insignificant among nonasthmatic children.
Conclusion:  Our findings suggest a role of gene–environmental interactions on the occurrence of bronchitic symptoms among children with asthma.     

Genetic mechanism of aspirin-induced urticaria/angioedema

PURPOSE OF REVIEW: Aspirin-induced urticaria/angioedema is a major aspirin-related hypersensitivity often associated with aspirin-intolerant asthma. Genetic studies on aspirin-intolerant asthma have shown chronic overproduction of cysteinyl leukotrienes. The genetic analysis of aspirin-induced urticaria/angioedema is limited, however. RECENT FINDINGS: A recent study on HLA genotypes has suggested that the HLA alleles DRB11302 and DQB10609 may be genetic markers for aspirin-induced urticaria/angioedema. A polymorphism study that examined nine single-nucleotide polymorphisms of five leukotriene-related genes [ALOX5 (encoding 5-lipoxygenase), ALOX5AP (5-lipoxygenase-activating protein), PTGS2 (cyclooxygenase 2), LTC4S (leukotriene C4 synthase), and CYSLTR1 (cysteinyl leukotriene receptor 1)] found that promoter polymorphisms of ALOX5 (-1708A>G) and CYSLTR1 (-634C>T) were significantly different between aspirin-intolerant asthma and aspirin-induced urticaria/angioedema, suggesting different contributions to the lipoxygenase pathway. A second polymorphism study, conducted on histamine-related genes, did not find any significant associations with aspirin-induced urticaria/angioedema for the genes HNMT (encoding histamine N-methyltransferase), HRH1 or HRH2 (encoding histamine receptor types 1 and 2 respectively), or the gene encoding high-affinity IgE receptor Ibeta (FcepsilonRIbeta); however, the FcepsilonRIalpha gene promoter polymorphism was significantly associated with aspirin-induced urticaria/angioedema. This finding has been supported by in vitro functional studies. SUMMARY: The HLA alleles DRB11302 and DQB10609, and the ALOX5 and FcepsilonRIalpha promoter polymorphisms, may contribute to the pathogenesis of aspirin-induced urticaria/angioedema. Further investigation to identify candidate genetic markers would help to elucidate the pathogenic mechanism of this condition.     

The effect of BDNF gene variants on asthma in German children

Background:  Allergic inflammation can trigger neuronal dysfunction and structural changes in the airways and the skin. Levels of brain-derived neurotrophic factor (BDNF) are strongly up regulated at the location of allergic inflammation.
Aim:  We systematically investigated whether polymorphisms in the BDNF gene influence the development or severity of asthma and atopic diseases.
Methods:  The BDNF gene was screened for mutations in 80 chromosomes. Genotyping of six BDNF tagging polymorphisms was performed in a cross-sectional study population of 3099 children from Dresden and Munich (age 9–11 years, ISAAC II). Furthermore, polymorphisms were also investigated in an additional 655 asthma cases analysed with a random sample of 767 children selected from ISAAC II. Associations were calculated via chi-square test and anova using SAS Genetics and spss .
Results:  We identified nine polymorphisms with minor allele frequency ≥0.03, one of them leading to an amino acid change from Valine to Methionine. In the cross-sectional study population, no significant association was found with asthma or any atopic disease. However, when more severe asthma cases from the MAGIC study were analysed, significant asthma effects were observed with rs6265 (odds ratio 1.37, 95% confidence interval 1.14–1.64, P  = 0.001), rs11030101 (OR 0.82, 95%CI 0.70–0.95, P  = 0.009) and rs11030100 (OR 1.19, 95%CI 1.00–1.42, P  = 0.05).
Conclusions:  As in previous studies, effects of BDNF polymorphisms on asthma remain controversial. The data may suggest that BDNF polymorphisms contribute to severe forms of asthma.     

Impact of allergic rhinitis on asthma: effects on bronchial hyperreactivity

Background:  Remarkable relationship exists between upper and lower airways. Bronchial hyperreactivity (BHR) is a paramount feature of asthma and may be considered a strong risk factor for the onset of asthma in patients with allergic rhinitis.
Objective:  This study is aimed at evaluating the presence of BHR in a large group of patients with moderate-severe persistent allergic rhinitis alone, and at investigating possible risk factors related to severe BHR.
Methods:  Three hundred and forty-two patients with moderate-severe persistent allergic rhinitis were prospectively and consecutively evaluated. Clinical examination, skin prick test, spirometry and bronchial methacholine (MCH) test were performed in all patients.
Results:  Twenty-two (6.4%) patients had severe BHR, 74 (21.6%) patients had mild BHR and 192 (56.2%) had borderline BHR; 54 (15.8%) patients had a negative MCH test. The logistic regression analysis evidenced that trees and house dust mites sensitization (OR_Adj: 8.1), rhinitis duration > 5 years (OR_Adj: 5.4) and FEV₁ ≤ 86% of predicted (OR_Adj: 4.0) were significantly associated with severe BHR. The discriminative ability of this model is appreciably satisfactory, being the AUC = 0.90.
Conclusion:  This study highlights the close link between upper and lower airways and the role of some risk factors, such as tree and mite sensitization, > 5-year duration, and ≤ 86% FEV₁ values, as risk factors for severe BHR in patients with moderate-severe persistent allergic rhinitis alone. Therefore, BHR is frequently present in patients with chronic rhinitis and should be suspected in the presence of defined risk factors.     

Sputum neurokinin A in Egyptian asthmatic children and adolescents: relation to exacerbation severity

Background:  Neurogenic inflammation may participate in the development and progression of bronchial asthma. The molecular mechanisms underlying neurogenic inflammation are orchestrated by a large number of neuropeptides including tachykinins such as neurokinin A (NKA) and substance P. Tachykinins are secreted from sensory airway nerves and inflammatory cells after allergens exposure. In clinical practice, assessment of airway inflammation is difficult. Therefore, detection of biological markers of airway inflammation in sputum might offer help for proper monitoring of asthma severity.
Aim of the study:  We aimed to measure sputum NKA in relation to acute asthma exacerbations of varying severity.
Methods:  Sputum NKA was measured by enzyme-linked immunosorbent assay in 24 children and adolescents during and after acute asthma exacerbation and 24 healthy matched controls.
Results:  Sputum NKA was significantly higher in asthmatic patients during acute exacerbation than controls [217.5 (284) vs 10 (7) ng/ml, P  < 0.001]. When patients with acute asthma exacerbation were followed-up till remission, sputum NKA levels decreased significantly, but they remained significantly higher than controls. Sputum NKA levels were significantly higher in severe than moderate and in moderate than mild exacerbations, and was negatively correlated to peak expiratory flow rate ( r  = −0.9, P  < 0.001). Sputum NKA had significant positive correlations to eosinophil counts in blood and sputum ( r  = 0.6, P  < 0.001 and r  = 0.7, P  < 0.001 respectively).
Conclusions:  Sputum NKA is up-regulated during acute asthma exacerbation and it positively correlates to its severity. Thus, NKA may aid in objective classification of the exacerbation severity. In addition, NKA may be a target for new asthma therapy.     

Filaggrin null mutations are associated with increased asthma exacerbations in children and young adults

Background:  Filaggrin ( FLG ) null mutations are important genetic predisposing factors for atopic asthma and have recently been shown to influence controller and reliever medication needs in asthmatic children. Our objective was to study the role of FLG null alleles in asthma exacerbations.
Methods:  FLG mutations R501X and 2282del4 were assayed in 1135 individuals ranging from 3 to 22 years old with asthma from Tayside and Dumfries, Scotland. Asthma exacerbations over the previous 6 months were also studied.
Results:  The FLG mutations were significantly associated with greater risk of exacerbations in children with asthma. Exacerbations were significant for the R501X but not the 2282del4 mutation and the combined genotype compared to the wild-type with odds ratios of 1.97 (95% CI, 1.19–3.22; P  = 0.009) and 1.61 (95% CI, 1.08–2.40; P  = 0.021), respectively. Individuals with FLG null alleles were more likely to require oral steroids (31.4% vs 19.5%; OR = 1.89; P  =   0.021) for their exacerbations. There was also a 1.71-fold increased risk (42.6% vs 30%; P  =   0.041) of school absence owing to asthma exacerbations in asthmatic individuals with FLG null mutation. On sub-group analysis, the effect of FLG mutations on asthma exacerbations is significant ( P  =   0.045) only for participants with relatively mild asthma controlled on inhaled steroids, with inhaled albuterol according to need.
Conclusion:  In addition to their effect on asthma medication requirements reported previously, there is an association between the presence of FLG null mutations and the risk of asthma exacerbations in asthmatic children and young adults.     

Resolution of remodeling in eosinophilic esophagitis correlates with epithelial response to topical corticosteroids

Background:  Esophageal remodeling occurs in eosinophilic esophagitis (EE) patients but whether the components of remodeling in the subepithelium are reversible by administration of topical oral corticosteroids is unknown.
Methods:  We quantitated the degree of lamina propria remodeling in esophageal biopsies obtained before and after at least 3 months of therapy with budesonide in 16 pediatric EE subjects. In addition, we investigated whether corticosteroid therapy modulated vascular activation (expression of VCAM-1; level of interstitial edema), TGFβ₁ activation (levels of TGFβ₁, phosphorylated Smad2/3), and performed a pilot analysis of a polymorphism in the TGFβ₁ promoter in relation to EE subjects who had reduced remodeling with budesonide therapy.
Results:  EE subjects were stratified based on the presence ( n  = 9) or absence ( n  = 7) of decreased epithelial eosinophilia following budesonide. Patients with residual eosinophil counts of ≤7 eosinophils per high power field in the epithelial space (responders) demonstrated significantly reduced esophageal remodeling with decreased fibrosis, TGFβ₁ and pSmad2/3 positive cells, and decreased vascular activation in association with budesonide therapy. Responders were more likely to have a CC genotype at the −509 position in the TGFβ₁ promoter.
Conclusions:  Reductions in epithelial eosinophils following budesonide therapy were associated with significantly reduced esophageal remodeling.     

Persistent airflow obstruction in asthma of patients with Churg–Strauss syndrome and long-term follow-up

Background:  Little is known about the long-term outcome of airflow obstruction in asthma of patients with Churg–Strauss syndrome (CSS).
Methods:  We conducted a retrospective study of 24 consecutive patients (aged 41.1 ± 13.5 years) with CSS in a single center. All had asthma (starting 8.1 ± 9.5 years prior to the diagnosis of CSS), blood eosinophilia (6.1 ± 4.4 × 10⁹/l) and systemic manifestations of CSS. Antineutrophil cytoplasmic antibodies were found in 7 of 22 tested patients. Seven patients had smoked (a mean of 10 pack-years). All patients received oral corticosteroids, 11 cyclophosphamide and 23 inhaled corticosteroids.
Results:  Airflow obstruction was found in 14 patients (70%) at diagnosis, and in 11 of 22 patients (50%) at the time of the clinical remission of CSS. The mean postbronchodilator FEV1/FVC and FEV1 were 69 ± 12% and 74 ± 21% of predicted at diagnosis ( n  = 20); 71 ± 10% and 92 ± 19% of predicted at the clinical remission ( n  = 22); and 64 ± 13% and 80 ± 21% at last visit ( n  = 13), respectively. During follow-up, postbronchodilator FEV1 increased by 30 ± 28% in six patients with FEV1/FVC < 70% despite inhaled therapy who received higher dose of oral corticosteroids. At last visit, 5 of 13 patients (38%) with more than 3 years of follow-up had persistent airflow obstruction as defined by postbronchodilator FEV1/FVC < 70% and FEV1 < 80% of predicted.
Conclusion:  Airflow obstruction due to uncontrolled asthma is present despite corticosteroids in many patients at diagnosis and at clinical remission of CSS, and during follow-up. It may be still partly reversible with increased oral corticosteroid treatment.     

Asthma, body mass, gender, and Hispanic national origin among 517 preschool children in New York City

Background:  Striking differences in asthma prevalence have been reported among Hispanic adults and children living in different cities of the USA. Prevalence is highest among those of Puerto Rican and lowest among those of Mexican origin. We hypothesized that body size would mediate this association.
Methods:  Parents of children in New York City Head Start programs completed a questionnaire including demographic factors, health history, a detailed history of respiratory conditions, lifestyle, and home environment. Children's height and weight were measured in home visits. Logistic regression was used to model the association of asthma with body mass index percentile (<85th percentile, gender/age specific vs ≥85th percentile, gender/age specific), national origin, and other factors.
Results:  Of 517 children at mean age of 4.0 ± 0.6 years, 34% met the study criteria for asthma, and 43% were above the 85th percentile. Asthma was strongly associated with non-Mexican national origin, male gender, allergy symptoms, and maternal asthma, and marginally with body size. The odds of asthma among boys of non-Mexican origin was 5.9 times that among boys of Mexican origin [95% confidence interval (CI): 2.9–12.2]; the comparable odds ratio (OR) among girls was 1.8 (95% CI: 0.9–3.6). Body mass was associated with asthma among girls [OR = 2.0 (95% CI: 1.1–3.7)], but not boys [OR = 1.4 (95% CI: 0.8–2.6)].
Conclusions:  The association of asthma with both body mass and national origin was gender-specific among the children in our study. Ours is one of the first studies to report on pediatric asthma in different Hispanic populations in the same city, by gender.     

Role of symptoms and lung function in determining asthma control in smokers with asthma

Background:  Cigarette smoking in asthma increases the severity and accelerates the decline in lung function. The relative role of symptoms and lung function in determining asthma control in smokers with asthma is not known.
Aim of the study:  The aim of this study was to compare asthma control in smokers vs never-smokers with asthma, using the validated Juniper asthma control questionnaire (ACQ), and assess if any difference was because of a particular symptom or the forced expiratory volume in one second (FEV₁) value.
Methods:  This was a cross-sectional study of 134 asthmatics (74 never-smokers and 60 smokers) with ≥15% reversibility in FEV₁ after salbutamol. All subjects completed the ACQ, recording FEV₁ and asthma symptoms (night awakening, morning symptoms, dyspnoea, wheeze, activity limitation and use of reliever inhaler).
Results:  Compared with the never-smokers, smokers with asthma had significantly worse median (IQR) total asthma control score [1.6 (1.1–2.3) vs 2.8 (1.7–3.4); ( P  < 0.0001)] and in each of the six individual symptom question scores ( P  < 0.001), but no difference in FEV₁ levels ( P  = 0.908).
Conclusion:  Asthma control is significantly worse in asthmatics who smoke compared with never-smokers, with all symptoms related to asthma control uniformly worse in smokers, independent of FEV₁.     

ALOX5 variants associated with susceptibility to human pulmonary tuberculosis

The 5-lipoxygenase (ALOX5)-derived lipid mediators leukotrienes and lipoxins have regulatory functions in inflammation by modulating activities of immune cells and cytokine production. Recently, it was shown in ALOX5-/- mice that host control of Mycobacterium tuberculosis is regulated by 5-lipoxygenase (5-LO). ALOX5 polymorphisms were genotyped in 1916 sputum-positive patients with pulmonary tuberculosis (TB) from Ghana and in 2269 exposed, apparently healthy controls. Polymorphisms of a variable number of tandem repeats (VNTR) of the ALOX5 promoter and of the exonic non-synonymous variant g.760G>A were analysed by fragment length determination and fluorescence resonance energy transfer, respectively, and DNA sequencing. Mycobacterial lineages of >1400 isolates were differentiated biochemically and genetically. Carriers of one variant (n repeats not equal 5) and one wild-type VNTR allele (n = 5) or of the exonic allele g.760A had a higher risk of TB [P(corrected) = 0.026, odds ratio (OR) 1.19 (95% CI 1.04-1.37) and P(corrected) = 0.026, OR 1.21 (95% CI 1.04-1.41), respectively]. The association of the exonic variant was stronger in infections caused by the mycobacterial lineage M. africanum West-African 2 [P(corrected) = 0.024, OR 1.70; (95% CI 1.2-2.6)]. Determination of haplotypes revealed the strongest associaton with TB for the 'non-5/760A' haplotype compared with the 'non-5/760G' haplotype (P = 0.003, OR 1.50). Our observation of an association of ALOX5 variants with susceptibility to TB contributes evidence of the importance of 5-LO products to the regulation of immune responses to M. tuberculosis.     

Genetic variation in ORM1-like 3 (ORMDL3) and gasdermin-like (GSDML) and childhood asthma

Background:  A genome-wide association study identified ORM1-like 3 (orosomucoid 1-like 3, ORMDL3 ) as an asthma candidate gene. Single nucleotide polymorphisms (SNPs) in the region including ORMDL3 on chromosome 17q21 were related to childhood asthma risk and ORMDL3 expression levels in Europeans.
Objective:  We examined whether polymorphisms in ORMDL3 and the adjacent gasdermin-like ( GSDML ) gene associated with asthma in the genome-wide association study are related to childhood asthma and atopy in a Mexico City population.
Methods:  We genotyped rs4378650 in ORMDL3 and rs7216389 in GSDML in 615 nuclear families consisting of asthmatic children aged 4–17 years and their parents. Atopy was determined by skin prick tests to 25 aeroallergens.
Results:  Individuals carrying the C allele of rs4378650 or the T allele of rs7216389 had increased risk of asthma [relative risk (RR) = 1.73, 95% confidence interval (CI) 1.19–2.53, P  = 0.003 for one or two copies of rs4378650 C, and RR = 1.64, 95% CI 1.12–2.38, P  = 0.009 for one or two copies of rs7216389 T). Linkage disequilibrium between the two SNPs was high ( r ² = 0.92). Neither of the SNPs was associated with the degree of atopy. A meta-analysis of five published studies on rs7216389 in nine populations gave an odds ratio for asthma of 1.44 (95% CI, 1.35–1.54, P  < 0.00001).
Conclusions:  Our results and the meta-analysis provide evidence to confirm the finding from a recent genome-wide association study that polymorphisms in ORMDL3 and the adjacent GSDML may contribute to childhood asthma.     

Polymorphisms in the 5-lipoxygenase activating protein (ALOX5AP) gene are not associated with asthma in an Australian population

BACKGROUND: The cysteinyl-leukotrienes (cys-LTs) are important pro-inflammatory mediators in asthma, and have been shown to have a role in specific disease subtypes, including asthma severity. Few studies have investigated the role of polymorphisms in the ALOX5AP gene, encoding 5-lipoxygenase activating protein (FLAP), and asthma. We hypothesized that polymorphisms in this gene are associated with asthma and in particular, with asthma severity, in an Australian population. OBJECTIVE: To screen the coding region of the ALOX5AP gene for polymorphisms and to determine the association between previously described polymorphisms and asthma and asthma severity in an Australian population. METHODS: We used PCR-SSCP and PCR-RFLP analysis to examine a previously described promoter polyA variable repeat polymorphism and two intronic polymorphisms (IVS2+12C>A, IVS2+105T>C), and to screen all five exons of the gene for new polymorphisms, in a large Australian population of randomly selected, non-asthmatic controls (n=457), mild asthmatics (n=274), moderate asthmatics (n=231) and severe asthmatics (n=79). RESULTS: We confirmed the presence of two polymorphisms in intron 2 and found no association between these polymorphisms and asthma or asthma severity, nor between a promoter polymorphism in the ALOX5AP gene and asthma or asthma severity. Gene fragment analysis of the promoter polymorphism revealed novel, conserved repeat numbers in our population, and no new polymorphisms were found in the coding region of the gene. CONCLUSION: These findings in a large, well characterized asthma population, reveal that, while FLAP is an important enzyme in cys-LTs biosynthesis, polymorphisms in the ALOX5AP gene are not likely to be functionally associated with the asthma phenotype.     

Asthma symptoms in rural living Tanzanian children; prevalence and the relation to aerobic fitness and body fat

Objective:  To determine the prevalence of asthma symptoms in children from a rural district in North-Tanzania, and their relationship to aerobic fitness and body fat.
Methods:  In Manyara region in Tanzania, children (aged 9–10 years) were randomly selected to participate in the present cross-sectional study. Hundred and seventy two participants completed a video questionnaire showing the symptoms and signs of asthma. Lung function was measured by maximum forced expiratory flow-volume curves. Aerobic fitness was estimated from a standardized indirect maximal cycle ergometer test and sum of three skinfolds reflected body fat.
Results:  Twenty four per cent reported asthma symptoms last year. Severe wheezing attacks last year were reported in 5% of the participants. Thirty seven per cent of the participants were underweight. Underweight children had significantly lower ( P  < 0.02) lung function (per cent of predicted). Lower body fat was associated with higher occurrence of asthma symptoms (odds ratio and 95% CI; 0.45 (0.22–0.95; P  = 0.04). Aerobic fitness was not associated with asthma symptoms.
Conclusions:  More than every fifth 9–10 year old child from a rural district in North-Tanzania reported asthma symptoms. Lower body fat was associated with higher occurrence of asthma symptoms, but aerobic fitness was not associated with asthma symptoms.     

Fitness, daily activity and body composition in children with newly diagnosed, untreated asthma

Background:  Information about how the asthma disease affects the life style and health in children is sparse.
Aim:  To measure fitness, daily physical activity and body composition in children with newly diagnosed, untreated asthma and healthy controls, and to assess the association between the level of asthma control and these parameters.
Methods:  Daily physical activity measured using accelerometry, cardiovascular fitness and body composition (per cent fat, per cent lean tissue and bone mineral density) were measured in 57 children with newly diagnosed, untreated asthma and in 157 healthy age- and sex-matched controls. The level of asthma control was assessed by measurements of a variety of asthma outcomes.
Results:  Children with asthma were less fit (35.1 vs 39.3 ml O₂/min/kg) ( P  < 0.001), had a higher body per cent fat (22.8 vs 19.5%) ( P  < 0.01) and a higher frequency of overweight (24.6 vs 14.2%) ( P  < 0.05) than healthy controls. Per cent body fat correlated negativly to overall daily activity ( P  < 0.001) and to time spent in high or vigorous activity ( P  < 0.001). Fitness corrrelated positively to time spent in high and vigorous activity ( P  < 0.001). Within the asthma group, the level of asthma control, fitness and the time spent in vigorous activity correlated positively ( P  < 0.02).
Conclusion:  Children with untreated asthma are less fit and have a higher body per cent fat and frequency of obesity than their healthy peers. Uncontrolled asthma is associated with a reduced fitness and daytime spent in intensive activity. Overweight children are physically less active than normal weight children.     

Polymorphism in the gene regulatory region of MCP-1 is associated with asthma susceptibility and severity.

BACKGROUND: Chemokines play an important role in the pathophysiology of asthma and allergy. Recently, polymorphisms in the gene regulatory region of monocyte chemoattractant protein 1 (MCP-1) and in the promoter region of RANTES have been found; these polymorphisms increase the expression of the chemokines. OBJECTIVE: We investigated whether the presence of the polymorphisms was associated with atopy or asthma and whether these alleles influenced the severity of asthma in affected individuals. METHODS: Three groups of subjects-160 children with asthma (disease severity being classified according to the Global Initiative for Asthma guidelines, modified for children), 151 children with nonasthmatic but allergic phenotype, and 303 children without allergic or asthmatic disorders-were screened with a PCR-based assay for genotyping. RESULTS: The frequency of the -2518G polymorphism in the gene regulatory region of MCP-1 was significantly higher in asthmatic children than in controls (P <.001; odds ratio [OR] = 2.0 [1.4-2.6]) and nonasthmatic atopic children (P <.001; OR = 2.0 [1.4-2.9]). The MCP-1 G/G genotype correlated with asthma severity. In asthmatic children, the MCP-1 -2518G allele was also associated with an increased blood eosinophil level. The promoter polymorphisms in the RANTES gene did not have a detectable effect on the susceptibility to asthma or allergy or on the blood eosinophil count. CONCLUSION: In this cohort of children, there are associations between carrying G at -2518 of the MCP-1 gene regulatory region and the presence of asthma as well as between asthma severity and homozygosity for the G allele. In asthmatic children, the MCP-1 -2518G polymorphism correlated with increased eosinophil levels. This variant of MCP-1 might belong to the predictor gene set for asthma.