Are asymptomatic airway hyperresponsiveness and allergy risk factors for asthma? A longitudinal study

¹ Dept of General Practice, Radboud University Nijmegen Medical Centre, the Netherlands
² Dept of Pulmonary Diseases, Radboud University Nijmegen Medical Centre, the Netherlands
³ Dept of Pulmonology Dekkerswald, Radboud University Nijmegen Medical Centre, the Netherlands

^* To whom correspondence should be addressed. E-mail: L.vandennieuwenhof{at}hag.umcn.nl.

	Abstract

Airway hyperresponsiveness(AHR) is a characteristic feature of asthma, but it is yet unclear whether asymptomatic AHR is associated with a higher risk of asthma. The present study assessed whether there is an association between asymptomatic AHR in adolescence and asthma in adulthood. We also looked at the association between allergy and development of asthma.

14 years follow-up of a general population cohort of adolescents. Respiratory status was assessed at baseline in 1989 and at follow-up in 2004 by respiratory symptoms questionnaire, spirometry, and histamine challenge. Allergy status was also assessed.

The respiratory status of 199 subjects was assessed twice. Ninety-one subjects (46%) had the same AHR status in combination with respiratory symptoms at follow-up as at baseline. Adjusted for age, gender, allergy, family history of asthma and smoking history, having asymptomatic AHR was not statistically significant related with asthma 14 years later (OddsRatio 2.15, p=0.20, 95%CI: 0.67–6.83). For subjects with allergy at baseline, the OR for developing asthma was 4.45 (p=0.009, 95%CI 1.46–13.54).

Screening for asymptomatic AHR in adolescence does not identify subjects at risk for developing asthma. On the other hand, the presence of allergy in adolescence does seem to be a risk factor for asthma development.