Findings before the diagnosis of asthma in young adults.
BACKGROUND
Asthma is a poorly understood disease. Risk factors are not established, and the natural history of the disease is unknown.


OBJECTIVE
Using subjects of a community-based study, we have prospectively compared young adults destined to develop asthma with control subjects to determine differences between them before diagnosis.


METHODS
Subjects were participants of the Tucson Epidemiologic Study of Airways Obstructive Disease. They were studied between the ages of 15 and 19 and subsequently every 1 to 2 years until they were at least 21 years old with questionnaire, spirometry, allergy skin testing, and serum IgE testing.


RESULTS
Logistic regression showed that "wheeze" and "attacks of shortness of breath with wheeze" were independently predictive of asthma. Positive allergy skin test results occurred more frequently among subjects who later received a diagnosis of asthma, and initially these subjects had higher serum IgE levels than control subjects (geometric mean IgE = 173.8 IU/ml vs 52.5 IU/ml for control subjects; p < 0.005). Although initial spirometric testing did not distinguish between future asthmatic subjects and control subjects, repeat testing after diagnosis did show significant differences in flows at low lung volumes.


CONCLUSIONS
These data suggest that symptoms and findings suggestive of asthma may be present for many years before diagnosis.
Dodge
R
R
Respiratory Sciences Center, University of Arizona College of Medicine, Tucson 85724.
Cline
M G
MG
Lebowitz
M D
MD
Burrows
B
B
D000328:Adult; D000375:Aging / Q000502:physiology; D000704:Analysis of Variance; D001249:Asthma / Q000175:diagnosis*; D005260:Female; D005544:Forecasting; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D012044:Regression Analysis; D012135:Respiratory Sounds; D013147:Spirometry
D007073:Immunoglobulin E