Biomedical subjects

G Ihorst

Publications and source records attributed to G Ihorst.

9 recordsLinked to original sources

PubMed2002

Natural history of hay fever and pollen sensitization, and doctors' diagnosis of hay fever and pollen asthma in German schoolchildren.

BACKGROUND: In order to prevent pollen asthma by immunotherapy it is mandatory to know the best time to initiate it. Children with hay fever complaints are at considerable risk of developing pollen asthma. Population-based data on their natural history is urgently needed. METHODS: A longitudinal cohort study was conducted over four years in six rural towns in Baden-Württemberg, Germany. A questionnaire with questions taken from the International Study of Asthma and Allergies in childhood (ISAAC) was filled in every spring and autumn. Hay fever complaints, asthma defining symptoms and new doctors' diagnosis of hay fever and asthma were recorded. Additionally a skin prick test with pollen allergens was performed every autumn. RESULTS: In 1996, 19.7% of 1101 elementary school children (age: 8.1-9.9 years (5-95%)) were found to be sensitized to pollen and 8.7% had already been diagnosed as having hay fever. In a pooled analysis of 2478 children-summers, children with positive pollen sensitization had a significantly higher risk of developing hay fever symptoms (2.63; 2.17-3.10 odds ratio (OR); 95% confidence interval (CI)) and of being diagnosed as suffering from hay fever (7.88; 4.70-13.20). Furthermore, although their OR for the development of asthma symptoms during the pollen season was 3.88 (2.48-6.07 CI), it was only 0.69 (0.24-2.01 CI) for doctors' diagnosis of pollen asthma. CONCLUSION: Children of elementary school age with pollen sensitization and a history of hay fever are at considerable risk of getting pollen asthma, but they are not quickly diagnosed as such. Specific immunotherapy might be a means of preventing asthma completely in such a situation. Our data helps to estimate the sample size for intervention studies of this kind.

Air Pollutants↗

PubMed2001

Bronchial hyperresponsiveness to 4.5% hypertonic saline indicates a past history of asthma-like symptoms in children.

SUMMARY. To evaluate the importance of a past history of asthma-like symptoms over a period of 2 years and current bronchial hyperreactivity (BHR), 538 randomly selected schoolchildren, initially aged 7-8 years, were examined. At yearly intervals, three standardized questionnaires, including items from the ISAAC panel, were answered by parents. Following the last questionnaire, BHR to 4.5% hypertonic saline (HS) was recorded. In survey 1, lifetime prevalence of asthma was 4.9%. During the 12-month period, prevalence of wheeze and dyspnea ranged between 9.3 and 5.2% (Survey 1) and 5.9% and 4.4% (Survey 2). Among children with wheeze or dyspnea in Survey 3, BHR (defined as a fall of baseline FEV(1) > or = 15%) was significantly more frequent (50.0% and 60.7%, respectively) than among children without these symptoms (12.8%, P < 0.001, and 12.8%, P < 0.001, respectively). The negative predictive value of BHR to have neither wheeze nor dyspnea was about 88% and did not vary throughout the study (Survey 1, 87%; Survey 2, 88%; Survey 3, 88%). The relative risk of showing BHR was significantly increased in children with wheeze (survey 2, odds ratio (OR) 3.0 (95% confidence interval (CI) 1.0-8.7)) or dyspnea (Survey 1: OR 5.9 (95% CI 1.9-18.5), Survey 3: 5.2 (1.7-16.2), but not in children with dry cough or nocturnal cough (data not shown). Wheeze and dyspnea occurred repeatedly in the same individuals with BHR in a high percentage of children (83.3% and 76.5%, respectively). In conclusion, there is a strong association between recent and previous dyspnea and current BHR, and it indicates intraindividual persistence of symptom history.

Asthma↗

PubMed2001

[Lung function reference data in school-age children].

UNLABELLED: The practical interpretation of lung function data depends to a very great extent on the quality of reference values. METHODS: From a population of n = 2615 schoolchildren between 6 and 12 years of age 15,404 lung function measurements were taken in accordance with commonly accepted guidelines. In the present study the validity of reference equations from the literature is examined with regard to our measured data. RESULTS: Employing linear regression analysis, the natural logarithm (ln) of forced vital capacity in ml (FVC) and expiratory volume in one second in ml (FEV1) were explained on the basis of the equation ln y = a + b* ln x (y = FVC, FEV1 (ml); x = height (cm)). Analyses were performed for girls (lnFVC = -4.8789 + 2.5504* lnheight, lnFEV1 = -4.3078 + 2.4070* lnheight) and boys (lnFVC = -4.5241 + 2.4917* lnheight, lnFEV1 = -3.7338 + 2.2985* lnheight), separately. Our coefficients correspond best to the literature dealing with a population of the same age group. On the other hand, for example, if reference values are derived from equations from the literature for the age group 6 to 18 years, they result at 6 years in an underestimation of the volume measured by us (FVC -150 ml) and at 12 years to an overestimation (FVC + 120 ml). CONCLUSIONS: The extent of the proven systematic deviations of the reference values from the measured values is of clinical and epidemiological relevance. To avoid misinterpretations, special reference values should be applied for preadolescents, at least with regard to FVC and FEV1.

Body Height↗

PubMed2000

[Reproducibility in induced sputum in children with asthma].

In asthmatic children sputum-induction with hypertonic saline is useful to quantify the eosinophilic inflammation. However, only few data are available about feasibility and safety of the procedure in children. Therefore, taking 9 non-atopic healthy control children (mean age 11.8 years) and 34 asthmatic children (mean age 11.4 years), inhaling n = 25 Budesonid (400-1200 micrograms/die) and n = 9 DNCG (60 mg/die), sputum induction was performed twice within 6 weeks. Briefly, 10 minutes after inhalation of 200 micrograms salbutamol subjects inhaled hypertonic saline (3, 4 and 5%) for in all 30 minutes, while all 5 minutes lung function was checked and expectoration of sputum was supported. Adequate sputum plugs were separated from contaminating saliva and processed immediately employing native chamber and cytospin cell count as well as measurement of eosinophilic cationic protein (ECP). Sputum-induction could be performed in 84 out of 86 planed tests (97.7%) without any objective clinical adverse effects. The mean fall in FEV1 was 3.0%, the maximum 11.0%. The reproducibility of eosinophil, neutrophil and lymphocyte differential cell count (5-95%-values Test1: 0.0-4.2%, 0.8-11.4%, and 3.2-35.1%, respectively) was moderate for eosinophils and neutrophils (Intraclass-Correlation-Coefficient (ICC) 0.41) as well as for lymphocytes (ICC = 0.49). For ECP 5-95%-values Test1: 39.8-8000.0 micrograms/l) only a fair reproducibility (ICC = 0.24) was found. The ICC levels for total cell count (ICC = 0.31) and for weight of the sputum plug (ICC = 0.30) were also fair. Based on the procedure presented induced sputum is a feasible and safe method in childhood. The differential sputum cell count of eosinophils, neutrophils and lymphocytes can be recommended as parameters with moderate reproducibility.

Adolescent↗

PubMed2000

Effects of ambient ozone on lung function in children over a two-summer period.

There is a general consensus that short term exposure to ozone (O3) causes a decrease in lung function parameters such as forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). The objective of this study was to assess the reproducibility of lung function decrements after ambient O3 exposure over a two-summer period. The authors studied 797 children with a mean age of 8.2 yrs (95% confidence interval: 6.9-9.5) from the second and third grades of ten elementary schools in Austria and southwestern Germany. At the outset the various study locations were stratified into three groups with low (L), medium (M) and high (H) O3 exposure (range of mean O3 concentration in the locations April-October 1994: 24-30 (L); 33-38 (M); 44-52 (H) parts per billion (ppb)). Four lung function tests were performed on each child between March 1994 and November 1995. The increases in FVC and FEV1 recorded from one test period to the next were expressed as mL x day(-1). A significantly lower FVC and FEV1 increase was observed in children exposed to high ambient O3 concentration during the summer season. (FVC in summer 1994: 0.83 (L); 0.56 (M); 0.55 (H) mL x day(-1); p=0.004; and summer 1995: 0.80 (L); 0.63 (M); 0.56 (H) mL x day(-1); p=0.011; FEV1 in summer 1994: 0.48 (L); 0.34 (M); 0.18 (H) mL x day(-1); p=0.004 and summer 1995: 0.68 (L); 0.45 (M); 0.41 (H) mL x day(-1), p=0.006). There was no significant difference in FVC or FEV1 increase between the groups during the winter period. Adjusting for sex, age, height and passive smoke exposure, linear regression revealed a statistically significant negative association of average ambient O3 concentration with the FVC and FEV1 increase in both summers. During the winter period no association of O3 with FVC or FEV1 was observed. In conclusion, in two consecutive summer periods the authors found reproducible lung function decrements in children exposed to high levels of ambient ozone. Reoccurrence of ozone associated lung function deficits might increase the likelihood of persisting effects on the childrens' airways.

Child↗

PubMed1999

Upper airway inflammation in children exposed to ambient ozone and potential signs of adaptation.

In order to investigate nasal inflammation and subsequent adaptation after ambient ozone exposure, nasal lavage (NL) fluid was collected from 170 schoolchildren on 11 occasions (time points) between March and October. Eosinophil cationic protein (ECP), albumin and leukocytes were quantified as markers of nasal inflammation. The highest half-hour outdoor O3 concentration for each individual on the day prior to the NL was used as a measure of exposure (O3indiv). To avoid confounding with exposure to common environmental allergens, the study population was restricted to children without sensitization to inhalant allergens. In the initial period of increased O3 levels in May (time point 4), with a median O3indiv of 135 microg x m(-3) (5th-95th percentile 100-184 microg x m(-3)), the highest medians of all 11 leukocyte and ECP measurements were observed. The highest O3indiv were observed in June at time point 7 (O3indiv 173 microg x m(-3), 5th-95th percentile 120-203 microg x m(-3)). Cross-sectional analysis of all 11 time points revealed no significant association of O3indiv on the one hand and ECP, albumin and leukocyte levels on the other. A multivariable model estimated using generalized estimating equations showed a statistically significant association of O3indiv and leukocytes and ECP as the dependent variable, when time points 1-4 were analysed (p<0.05). In the same model, this association diminished continuously when time points 5-11 were added stepwise, in spite of high O3 exposure. Not even a tendency towards an O3 effect could be recognized when time points 1-8 were considered. The results indicate: 1) acute inflammation of the nasal mucosa after the first increase in ambient ozone levels, with 2) a significant dose-dependent increase in leukocyte and eosinophil cationic protein levels, and 3) possible adaptation of the nasal mucosa in spite of constant high levels of ozone exposure in children during the summer season.

Adaptation, Physiological↗

PubMed1999

NO in exhaled air is correlated with markers of eosinophilic airway inflammation in corticosteroid-dependent childhood asthma.

The relationship between nitric oxide in exhaled air, levels of sputum eosinophils, sputum eosinophil cationic protein (ECP) and urinary eosinophil protein X (EPX) excretion has not yet been investigated in corticosteroid-dependent childhood asthma. Therefore, taking 25 children with stable asthma (mean age 11.2 yrs) treated with inhaled corticosteroids and nine nonatopic healthy control children (mean age 12.8 yrs) the level of exhaled NO was measured by means of a chemiluminescence analyser before and after sputum induction. This was conducted as a slow vital capacity manoeuvre under standardized conditions with a target flow of 70 mL x s(-1) against a resistance of 100 cm H2O x L(-1) x s. Sputum induction was performed by inhalation of hypertonic saline (3, 4, and 5%) in a standardized manner and a single sample of urine was collected. Exhaled NO (p = 0.01), absolute eosinophil cell counts in sputum (p = 0.02), sputum ECP (p = 0.09) and urinary EPX excretion (p = 0.02) were higher in asthmatics compared to control children. Exhaled NO was positively correlated with sputum ECP (r(s) = 0.59, p = 0.002), urinary EPX (r(s) = 0.42, p = 0.03), and sputum eosinophils (r(s) = 0.30, p = 0.15) in the asthmatic children. These correlations appeared to be pronounced after sputum induction, where NO values had decreased (p = 0.01). None of the correlations were observed in the group of nonatopic control subjects. Additionally there were significant correlations between sputum ECP and sputum eosinophils (r(s) = 0.69, p<0.001) as well as between sputum ECP and urinary EPX excretion (r(s) = 0.58, p = 0.003) in the asthmatics. Exhaled NO provides information about the degree of eosinophilic airway inflammation and thus appears to be a useful and easy-to-perform inflammatory marker in corticosteroid-dependent asthma.

Administration, Inhalation↗

PubMed1997

Effects of ambient ozone exposures during the spring and summer of 1994 on pulmonary function of schoolchildren.

To investigate the effect of natural exposure to ambient ozone over time, a follow-up study of school-aged children was performed in two small towns in southwestern Germany (Freudenstadt and Villingen) between March and October of 1994. Ozone half-hour mean concentrations were measured continuously and pulmonary function was tested in each child on four occasions (April, June, August, and September). To obtain an average short-term ozone effect, we first analyzed the data from the four time points separately and then constructed a model that included all information. During the study period the median (5th to 95th percentile) of all half-hour values of the ozone concentration was 101 micrograms/m3 or 50.6 ppb (45-179 micrograms/m3 or 22.5-89.8 ppb) in Freudenstadt and 64 micrograms/m3 or 32.1 ppb (1 to 140 micrograms/m3 or 0.5-70.1 ppb) in Villingen. To assess the effects of an individual ozone exposure we related the highest ozone concentration in the respective 24 hours before lung function testing to the results of the subconcentration in the respective 24 hours before lung function testing to the results of the subsequent pulmonary function tests. In the lung function test following the highest ozone exposure, the results of our cross-sectional linear regression analysis showed a significant negative correlation (P = 0.0181) between ozone exposure and forced vital capacity (FVC). In the longitudinal linear regression model we observed a negative statistical correlation between ozone exposure and lung function for the subpopulation living in the town with the high ozone levels (Freudenstadt). The association was more pronounced in boys than girls. For the children in Freudenstadt the decrement of FVC was -12.31 ml/10 micrograms/m3 ozone and the decrease in the forced expiratory volume in 1 second (FEV1) was -11.29 ml/10 micrograms/m3 ozone.

Air Pollutants↗

PubMedDate not supplied

[Characteristics of a target population for preventing house-dust mite allergy in toddlers].

AIM: To evaluate a recruitment strategy to identify high risk toddlers for a programme of prevention of allergy. For screening, parents were asked to participate in our study by information form and screening questionnaire on the occasion of routine check-up visits of toddlers scheduled between 20 and 48 months of age in four paediatric practices. As a next step, readiness of parents for implementation of preventive measures was confirmed. METHOD: Inclusion criteria were age between 20 and 48 months and a positive atopic family history (evaluated by 5 questions regarding asthma, allergic rhino-conjunctivitis and atopic dermatitis) of parents or siblings. This was confirmed by sensitization to an environmental allergen (skin prick test (SPT)) in at least one parent. If these inclusion criteria were fulfilled, the toddlers were randomly allocated to the intervention and control group of the prevention programme. RESULTS: 111 of 175 screening questionnaires (63.4 %) were returned. In 76.6 % (n = 85) of these 111 questionnaires a positive atopic family history (mother, father, sibling) was noted. All inclusion criteria were fulfilled by only 43 toddlers (age: median 33.6 months, 5-95 % quantile: 21.6-48 months). Based on the positive screening questionnaire, history of atopy was confirmed by positive SPT in 70.0 % of fathers and 77.8 % of mothers. Despite a negative screening questionnaire, history of atopy was detected by a positive SPT in 11.1 % of mothers and 47.4 % of fathers. Detection of specific IgE against house-dust mite in 9 of 18 serum samples revealed the risk for allergy of the toddlers. A re-evaluation after three months showed that all the elements of the prevention programme as well as the recommendations for the control group had been almost completely accepted by all the families concerned practically without any reservations. CONCLUSION: The recruitment of toddlers with high risk for developing allergy turned out well and could be validated. The prevention programme was readily accepted by the families and thus can be used for a larger study.

Antigens, Dermatophagoides↗