Cross-sectional studies
have reported a lower prevalence of sensitization in older adults, but few longitudinal studies
have examined w
het
her t
his is an aging or a year-of-birt
h co
hort effect.<
h4 id="absSec_2">Objective
h4>
We sought to assess changes in sensitization and total IgE levels in a cohort of European adults as they aged over a 20-year period.
<
h4 id="absSec_3">Met
hods
h4>
Levels of serum specific IgE to common aeroallergens (house dust mite, cat, and grass) and total IgE levels were measured in 3206 adults from 25 centers in the European Community Respiratory Health Survey on 3 occasions over 20 years. Changes in sensitization and total IgE levels were analyzed by using regression analysis corrected for potential differences in laboratory equipment and by using inverse sampling probability weights to account for nonresponse.
<
h4 id="absSec_4">Results
h4>
Over the 20-year follow-up, the prevalence of sensitization to at least 1 of the 3 allergens decreased from 29.4% to 24.8% (−4.6%; 95% CI, −7.0% to −2.1%). The prevalence of sensitization to house dust mite (−4.3%; 95% CI, −6.0% to −2.6%) and cat (−2.1%; 95% CI, −3.6% to −0.7%) decreased more than sensitization to grass (−0.6%; 95% CI, −2.5% to 1.3%). Age-specific prevalence of sensitization to house dust mite and cat did not differ between year-of-birth cohorts, but sensitization to grass was most prevalent in the most recent ones. Overall, total IgE levels decreased significantly (geometric mean ratio, 0.63; 95% CI, 0.58-0.68) at all ages in all year-of-birth cohorts.
<
h4 id="absSec_5">Conclusion
h4>
Aging was associated with lower levels of sensitization, especially to house dust mite and cat, after the age of 20 years.