E. Dompeling

Increased bronchial hyperresponsiveness after inhaling salbutamol during 1 year is not caused by subsensitization to salbutamol

Recently, it was suggested that long-term administration of an inhaled beta 2-agonist might increase bronchial hyperresponsiveness (BHR) to histamine, possibly as a consequence of subsensitization to the inhaled beta 2-agonist. To test this hypothesis, we studied two groups of patients with asthma or with chronic obstructive pulmonary disease. An experimental group of 15 patients, inhaling 400 micrograms of salbutamol four times daily during 1 year and subsequently 40 micrograms of ipratropium bromide four times daily for 6 months, and a control group, consisting of 22 patients with the opposite treatment regimen. The BHR, the response in FEV1 to cumulative doses of salbutamol, and the number of beta 2-adrenoceptors and antagonist affinity of these receptors on circulating lymphocytes were assessed at the start of the study and at 6-month intervals for 1 1/2 years. The BHR increased significantly (p = 0.001) during the year salbutamol was inhaled and returned to about the value at the start of the study after inhaling ipratropium bromide for 6 months. No change occurred in the bronchodilating responses to cumulative doses of salbutamol, nor was any change observed in the number and the affinity of beta 2-adrenoceptors on lymphocytes. It was concluded that long-term use of salbutamol caused a small but significant increase in BHR. The increase in BHR was not caused by subsensitization of beta 2-adrenoceptors to salbutamol.

The PREVASC study: the clinical effect of a multifaceted educational intervention to prevent childhood asthma

As asthma is the most common chronic disease in childhood, much attention is directed towards primary prevention. Here, the clinical effectiveness of a multifaceted educational prevention was studied. A total of 476 high-risk children were recruited during the prenatal period by general practitioners and randomised to either: 1) a control group, receiving usual care; or 2) an intervention group in which families received instruction from nurses on how to reduce exposure of newborns to mite, pet and food allergens, and passive smoking. A total of 443 infants were followed-up for 2 yrs. At 2 yrs of age, the intervention group (n = 222) had less asthma-like symptoms, including wheezing, shortness of breath and night-time cough, than the control group (n = 221). No significant differences in total and specific immunoglobulin E were found between the groups. During the first 2 yrs of life, the incidence of asthma-like symptoms was similar in both groups; however, subanalysis revealed a significant reduction in the female, but not in the male, intervention group. In conclusion, the intervention used in this study was not effective in reducing asthma-like symptoms in high-risk children during the first 2 yrs of life, although it was modestly effective at 2 yrs. Follow-up is necessary to confirm whether the intervention can actually prevent the development of asthma.

Compliance of asthmatic families with a primary prevention programme of asthma and effectiveness of measures to reduce inhalant allergens – a randomized trial

Background Compliance to and the effect of pre‐ and post‐natal exposure reduction measures to prevent asthma in high‐risk children from asthmatic families were studied.

Prenatal exposure to mite and pet allergens and total serum IgE at birth in high‐risk children

To examine the relationship between prenatal exposure to mite, cat and dog allergens and total serum IgE at birth in newborns at high risk of asthma. In the homes of 221 newborns with at least one first‐degree relative with asthma, concentrations (ng/g dust) of allergens of house dust mite (mite), cat and dog were measured at the fourth to sixth month of pregnancy in dust samples from the maternal mattress and living room. At day 3–5 after birth, total IgE was measured in capillary heel blood. A total number of 174 blood samples were available (11 mothers refused newborns blood sampling, and in 36 cases the blood sample was too small for analysis). In 24% of the newborns, total IgE was elevated (cut‐off value 0.5 IU/ml). A significant dose response relationship was found between increasing mite allergen levels [divided in quartiles ng/g dust (qrt)] and the percentage of elevated IgE: first qrt (0–85 ng/g) 13%; second qrt (86–381) 19%; third qrt (382–2371) 26%; fourth qrt (≥2372) 42%, respectively, p = 0.01. This relationship remained significant after adjusting for passive smoking, maternal and paternal mite allergy, socio‐demographic factors, birth characteristics and (breast) feeding practice in the first week of life. In high‐risk newborns, prenatal exposure to mite allergens, but not to cat and dog allergens from dust of the living room and of the maternal mattress was associated with total serum IgE at birth.

Association between first‐degree familial predisposition of asthma and atopy (total IgE) in newborns

It is generally thought that infants with a first‐degree familial predisposition of asthma are at higher risk of developing asthma than infants without predisposition.

Het klinisch effect van een voorlichtingsprogramma om astma bij kinderen te voorkomen

SamenvattingSchönberger HJAM, Dompeling E, Knottnerus JA, Muris JWM, Van Weel C, Van Schayck CP. Het klinisch effect van een voorlichtingsprogramma om astma bij kinderen te voorkomen. Het Prevask-onderzoek. Huisarts Wet 2005;48(11):542-7.Achtergrond Aangezien astma de meest voorkomende chronische aandoening is bij kinderen, krijgt primaire preventie van astma veel aandacht. Wij onderzochten de klinische effectiviteit van een niet-medicamenteus preventieprogramma van astma bij kinderen. Methode Huisartsen en verloskundigen rekruteerden aanstaande moeders van babys met een hoog risico op astma door het vóórkomen van astma in het gezin. Zij werden door het lot toegewezen aan een controlegroep die gebruikelijke zorg ontving of aan een interventiegroep die het preventieprogramma kreeg. Verpleegsters instrueerden de ouders op welke wijze zij de blootstelling van hun pasgeborene aan allergenen van de huisstofmijt, huisdieren, voedselallergenen en passief roken het beste konden vermijden. Resultaten Van de 476 kinderen hebben wij 443 kinderen gedurende 2 jaar gevolgd. Aan het einde van het tweede levensjaar had de interventiegroep (n=222) minder astmatische symptomen – piepen en nachtelijk hoesten – dan de controlegroep (n=221) (OR 0,73; 95%-BI 0,56-0,96), kortademigheid (OR 0,76; 95%-BI 0,61-0,96) en nachtelijk hoesten (OR 0,72; 95%-BI 0,55-0,95). Het totale en specifieke IgE was niet verschillend tussen de groepen. De incidentie van astmatische symptomen in de eerst twee levensjaren was gelijk in beide groepen, maar bleek in subgroepanalyse significant verminderd in de meisjesinterventiegroep, maar niet in de jongensinterventiegroep. Conclusie Het preventieprogramma verminderde astmatische klachten in de eerste twee jaar niet, maar wel enigszins aan het einde van het tweede jaar. Follow-up is noodzakelijk om te bevestigen of met het preventieprogramma de ontwikkeling van astma kan worden voorkomen.

Die Behandlung chronisch-obstruktiver Lungenerkrankungen in der Allgemeinpraxis

Die chronische Bronchitis gehort ebenso wie das Asthma bronchiale zu den haufigsten chronischen Erkrankungen in der Bevolkerung [4,8,13]. Die meisten der betroffenen Patienten werden — jedenfalls in den Niederlanden und Grosbritannien — in der Allgemeinpraxis behandelt.